The process formation neural tube formation leaves open ends of the tube at each ends. These are called __1__. - The __2__ is located in what will become the lamina terminalis. - The __3__ is located in what will become the mid lumbar spinal cord.

1. neuropores 2. anterior neuropore 3. posterior neuropore

``` Peripheral Neural Crest Derivatives: Neural Elements: Dorsal root ganglia Paravertebral ganglia Prevertebral ganglia Enteric ganglia Parasympathetic ganglia of C.N. VII, IX &X Sensory ganglia of CN V, VII, IX, &X ``` ``` Non-Neural Elements: __1__ cells Melanocytes Odontoblasts Satellite cells of peripheral ganglia Cartilage of the pharyngeal arches __2__ and __3__ muscles __4__ cells of the adrenal medulla Pia and arachnoid of the meninges ```

1. Schwann cells 2. ciliary muscles 3. pupillary muscles 4. chromaffin cells

(Spring 2013) Unit II Neuro Flashcards by Dan Garner

Neural tissue appears at the end of the third week from an embryonic disc comprised of ectoderm, mesoderm and endoderm.
A specialized portion of ectoderm, the __1__, gives rise to the central and peripheral nervous systems.
Neuroectoderm is produced from ectoderm by induction from the __2__, a mesodermally derived structure that will eventually form the vertebral column.
The neuroectoderm forms the __3__which is formed by the end of the third week of gestation.

neuroectoderm
notochord
neural plate

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The neural plate is induced to form by the expression of the __1__ gene in the mesoderm and notochord that produces a protein (__1__ protein).
-The protein induces the differentiation of neuroectoderm and is responsible for the development of __2__ tube structures.

sonic hedgehog gene/protein

2. ventral neural tube

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__1__ refers to a process of the neural plate developing into a tubular structure, the __2__.
There are two primary process of neurulation that occur in the development of the nervous system.
__3__ occurs in the future rostral areas of of the neural plate.
-This process will give rise to the brain and spinal cord through lumbar levels.
__4__ occurs at the future caudal end of the neural plate and will give rise to sacral and coccygeal levels of the spinal cord.

neuralation
neural plate
primary neuralation
secondary neuralation

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__1__ occurs as a result of changes in neuroepithelial cells in the neural plate.
-The process of neurulation from neuroepithelial cells occurs as a result of both physical and chemical changes and is dependent upon the synthesis of microtubules (__2__ inhibited) and the contraction of microfilaments (__3__ inhibited).
This results in the physical arrangement of conical shaped neuroepithelial cells with apices toward the lumen of a tube.

neuralation
chochicine
cytochalasin

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__1__ begins by about 18 days.
The edges of the neural plate thicken to form folds (__2__).
The folds contact each other by about day 20-22 at what will be approximately spinal cervical levels and proceed in both rostral and caudal directions.

primary neuralation

2. neural folds

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__1__ involves the sacral and coccygeal segments of the spinal cord and their dorsal and ventral roots (caudal to the posterior __2__).
-The process begins on day 20 and is complete by day 42.
Secondary neurulation arises from a cell mass, the __3__.
-It joins the neural tube and becomes continuous with it.

secondary neuralation
posterior neuropore
caudal eminence

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The process formation neural tube formation leaves open ends of the tube at each ends. These are called __1__.

The __2__ is located in what will become the lamina terminalis.
The __3__ is located in what will become the mid lumbar spinal cord.

neuropores
anterior neuropore
posterior neuropore

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The closure of the neuropores to form a closed compartment is important for the normal development of the nervous system.
The ends of the tube (anterior and posterior neuropores) close at approximately __1__ and __2__ days respectively.

23 days

2. 26 days

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Neuroepithelial cells will form a __1__ epithelium of cells surrounding a lumen, that will be come the central canal of the spinal cord and the ventricles of the brain.
The neuroepithelial cells will thicken and begin to form a layer of cells on the outside of the tube that are committed to becoming neurons (__2__).
The neuroblasts will form an outer layer, the __3__ zone, while the neuroepithelial cells near the lumen (__4__ zone) will continue to divide.

pseudostratified epithelium
neuroblasts
mantle zone
ventricular zone

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The spinal cord is a good example of the first order development of the neural tube. Even in adults, it basically remains a tube with a lumen (__1__) lined by an epithelium (__2__).
The spinal cord arises from the caudal portion of the __3__and __4__.
The precursor cells that form the spinal cord are produced from the 4th to the 20th weeks of development.

central canal
ependyma
neural tube
caudal eminence

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With the continued development of neuroblasts in the __1__ zone, cell processes (axons) are sent out into an outer layer (the __2__ zone) that surrounds the mantle zone.
The high concentration of cell bodies in the mantle zone will form spinal cord __3__ matter, while the marginal zone will become __4__ matter.

mantle zone
marginal zone
gray matter
white matter

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In addition to the axons of neurons, the __1__ zone contains the developing supporting glial cells (astrocytes and oligodendrocytes) that will form the structure of the spinal funiculi.

marginal zone

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Cells in the mantle zone differentiate to form two columns of cells on each side of the spinal cord, including the
__1__- posterior to become the __2__ horns of gray matter (sensory related functions, GSA, GVA).
__3__-anterior to become the __4__ horns of gray matter motor related functions (GSE, GVE).
The __5__ and __6__ plates are areas of specialized glial cells in the midline that are induced by the same factors forming the alar and basal plates.

alar plate
posterior (dorsal) horns
basal plate
anterior (ventral) horns
roof plate
floor plate

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In addition to the alar and basal plates, the mantle zone also forms columns of cells that become the __1__ gray matter (__2__ cell column). This forms at the interface between the alar and basal plates.
The alar and basal plates are separated by the __3__on the ventricular surface. The remnant of this sulcus can be seen on the floor of the fourth ventricle.

intermediate
intermediolateral
sulcus limitans

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There are many molecular signals that are responsible for the development of the spinal cord, most of which are not understood. In the early part of neural development, the ventral portion of neural tube development is influenced by the same __1__ protein production as was responsible for neuroectoderm development in the neural plate.
__2__ protein expression appears important in the development of dorsal patterning. These two proteins are important in the dorsal-ventral patterning of the alar and basal plates.

2. bone morphogenic protein

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Peripheral nervous system neurons (dorsal root ganglia, autonomic ganglia), arise early in development of the neural tube from the __1__
These __2__ cells migrate away from the neural tube to form the dorsal root ganglia, sympathetic chain, parasympathetic ganglia and the enteric nervous system.

neural crest

2. neurralepithelial cells

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The __1__ neurons formed from the neural crest send out processes to contact the spinal cord, peripheral structures and other peripheral neurons, including the enteric nervous system.
The guidance of these growing processes to their targets appears to be regulated by pathways of extracellular matrix molecules (__2__, __3__) and receptors on neuronal processes (__4__).

peripheral neurons
fibronectin
laminin
integrins

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Peripheral Neural Crest Derivatives:
Neural Elements:
Dorsal root ganglia
Paravertebral ganglia
Prevertebral ganglia
Enteric ganglia
Parasympathetic ganglia of C.N. VII, IX &amp;X*
Sensory ganglia of CN V, VII, IX, &amp;X

Non-Neural Elements:
\_\_1\_\_ cells
Melanocytes
Odontoblasts
Satellite cells of peripheral ganglia
Cartilage of the pharyngeal arches
\_\_2\_\_ and \_\_3\_\_ muscles
\_\_4\_\_ cells of the adrenal medulla
Pia and arachnoid of the meninges

Schwann cells
ciliary muscles
pupillary muscles
chromaffin cells

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Although the brain develops from a portion the __1__l portion of the same neural tube as much of the spinal cord, the structural development of the alar and basal plates for the brain is much more elaborate.
This process begins with the formation of __2__ (__3__) of the neural tube.

rostral portion
outpocketings
vesicles

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After the anterior neuropore closes, (4th week) there is rapid growth of tissue in the cranial region, initially forming three primary brain vesicles:
__1__
__2__
__3__
The tube also bends in two regions, at the spinal cord rhombencephalon junction (__4__ flexure) and at the level of the mesencephalon (__5__ flexure).

Prosencephalon (forebrain)
Mesencephalon (midbrain)
Rhombencephalon (hindbrain)
cervical flexure
mesencephalic or cephalic flexure

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By week 5, the rhombencephalon and prosencephlaon are subdivided into two structures to form 5 secondary brain vesicles. The spinal cord is the 6th separate division.
The rhombencephalon divides at the __1__ flexure to form the __2__ caudally and the __3__ rostrally.
The prosencephalon is divided by the __4__ flexure to form the __5__ rostrally and the __6__ caudally. This is called __7__

pontine flexure
myelencephalon
metencephalon
telencephalic flexure
telencephalon
diencephalon
proencephalization

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Secondary Brain Vesicle Derivatives:
__1__- the 2 cerebral hemispheres, the preoptic area and most of the basal ganglia
__2__- thalamus, hypothalamus, epithalamus, subthalamus, optic nerves and optic cups, neurohypophysis (posterior lobe of the pituitary).
__3__– midbrain of the brainstem
__4__- pons and cerebellum
__5__- medulla
The spinal cord is considered a separate division, not technically derived from a secondary vesicle.

telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon

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The brainstem develops from the __1__ (medulla), __2__ (pons) and __3__ (midbrain).
The organization of the tissue begins similar to the spinal cord (alar and basal plates) except that in the upper medulla and pons, the dorsal regions are separated laterally by the __4__.
This process forms cell columns of functionally related neurons that will form the __5__ nuclei.

myelencephalon
metencephalon
mesencephalon
4th ventricle
cranial nerve nuclei

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Brainstem Development- Upper Medulla and Pons:
The opening and migration of the dorsal regions of the neural tube places the dorsal (sensory, GSA, SVA, GVA, SSA) cell columns into regions that are __1__ and __2__ in the brainstem, while motor related cell columns (GSE, GVE, SVE) are __3__ and __4__.

dorsal
lateral
ventral
medial

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Brainstem Development- Lower Medulla and Midbrain: The lower medulla and midbrain do not have a __1__, but have an organization that is similar to spinal cord. Some altered migration of cell groups does occur. In general, __2__ related nuclei are medial and ventral and __3__ related nuclei (and to some extent tracts) are dorsal and lateral.

1. ventricle 2. motor related nuclei 3. sensory related nuclei

Brainstem-Rostro-Caudal Development: With the anteromedial-posterolateral patterning of function in the brainstem, there is also a rostrocaudal division of the rhombencehphalon into segments (__1__). Neurons in a particular__2__form the equivalent of a spinal segment for cranial nerve functions. This separation appears to be controlled in part through the expression of __3__ (Hox) genes, some of which are expressed only in particular rhombomeres

1. rhombomeres 2. rhombomeres 3. homeobox

The cerebellum develops from the dorsolateral parts of the alar plates (sensory) that bend medially to form the __1__ lips. These join to form the __2__ plate. Further growth produces a midline vermis, cerebellar hemispheres, and later with a separation of the flocculonodular lobes.

1. rhombic lips | 2. cerebellar plate

Development of the Diencephalon and Cerebral Hemispheres: The development of the forebrain (__1__ induction) occurs primarily during the __2__ month of gestation. By week 5, the forebrain expands laterally to form the__3__(cerebral) vesicles, while the diencephalon expands essentially underneath them.

1. central induction 2. 2nd month of gestastion 3. telencephalic vesicles

The diencephalon will develop into the __1__ (4 things) and also the __2__that forms the __3__ nerve and retina. The hypothalamus and thalamus are separated by the __4__ sulcus, and the epithalamus by the __5__sulcus.

1. thalamus, hypothalamus, subthalamus, epithalamus 2. optic cup 3. optic nerve 4. hypothalamic sulcus 5. epipthalamic sulcus

``` The __1__ vesicle derivatives include the: Cerebral cortex Subcortical white matter Olfactory bulb and tract Basal Ganglia Amygdala Hippocampus ```

1. telencephalic vesicle

Development of the Telencephalon- Basal Ganglia: By about 6 weeks, the basal part of the anterior telecephalic vesicle begins to expand and form the __1__. As growth continues, axons from the developing cortex subdivides the corpus striatum into the __2__ nucleus and the __3__nuclei.

1. corpus striatum 2. caudate nucleus 3. lenticular nuclei

The ventricles arise from the lumen of the __1__ in cephalic regions. The cavities of the __2__ vesicles become the lateral ventricles. The __3__ cavity the third ventricle. The __4__ cavity the cerebral aqueduct. The __5__ cavity the fourth ventricle.

1. neural tube 2. telencephalic vesicles 3. diencephalic cavity 4. mesencephalic cavity 5. rhombencephalic cavity

The __1__arises from an outgrowth of the cells that line the lateral third and fourth ventricles (eventually ependyma) and blood vessels. The choroid plexus begins producing __2__ during prenatal development.

1. choroid plexus | 2. CSF

The major commissures develop with the __1__ initially in the area of the lamina terminalis. These include the: -__2__ commissure, -corpus __3__ -__4__ commissure. Commisures are also formed through the __5__ (optic chiasm, posterior commissure, habenular commissure).

1. telencephalon 2. anterior commisure 3. corpus callosum 4. hippocampal commisure 5. diencephalon

Cerebral cortex develops from the an area of the neural tube called the __1__. This has two regions the paleopallium (archipallium) and the neopallium. The __2__ will expand to form neocortex, The __3__ will form other regions of cortex considered to be phylogenetically older. This terminology persists in some adult structures.

1. pallium 2. neopallium 3. archpallium (paleopalium)

Cellular Migration in Nervous System Development: The organization of __1__ structures (cerebral and cerebellar cortex) and __2__ groups (thalamus, tectum) requires the highly structured migration of neuroblasts into particular sites usually layers) of the developing nervous system

1. laminar structures | 2. nuclear groups

Cellular Migration in Nervous System Development: The process begins with layers of __1__ growing in the ventricular zone of the neural tube. As the ventricular zone develops (this expansion isn’t called a mantle here) a __2__ zone develops. __3__ cells (radial glia) form processes that extend from the ventricular surface to the pia or outer limiting membrane (radial in the context of a tube).

1. neuroblasts 2. marginal zone 3. glial cells

As neuroblasts develop they will migrate along the radial glial process to varying levels of the expanding __1__ zone, depending upon the structure under development. At the point at which they stop, they may detach from the process and differentiate into mature neurons. In some instances, (thalamus) other radial processes such as __2__ are followed.

1. ventricular zone | 2. axons

Neuroblasts may also first form __1__ layers from which they have a secondary migration. This process may be used to form several different layers of neurons and cell processes as in cerebral __2__, or layers of nuclei as in the __3__.

1. germinal layers 2. cerebral cortex 3. thalamus

Cortical Development: The migration of neuroblasts and their expansion creates a massive growth and infolding of cortex, particularly __1__. This growth and folding creates the __2__i and __3__ of fully formed cerebral cortex

1. neocortex 2. gyri 3. sulci

Developmental Aspects Extending Postnatally: Considerable development of the nervous system occur over the perinatal period and into early childhood. Three important parameters are: -Neuronal __1__ -Neuronal process __2__(3 processes) -Establishment and remodeling of __3__contacts. These aspects begin to develop at about the 6th month of gestation

1. neuronal density 2. neuronal process outgrowth, branching, and myelination 3. synaptic contacts

The number of neurons produced during embryogenesis and up to 24 weeks gestation is 1 to 2 times more neurons than are present in the mature brain. Some neurons are genetically programmed to die through an active process, __1__. The process is called active because the death of neurons in these circumstances requires the synthesis of new __2__. What does this describe?

1. apoptosis 2. synthesis of new proteins 3. neuronal density

Whether or not neurons undergo apoptosis may be determined through the number of __1__ formed on them or by their connection with other neurons or target cells. The associated exposure of neurons to __2__ in their environment (NGF, BDNF, FGF) is one apparent mechanism that modulates apoptosis.

1. synapses | 2. growth factors

As with neurons in the developing nervous system, more axonal __1__ and __2__ occurs in the developing than is maintained in the adult. These branches are retracted as development proceeds. The growth of axons is believed to be guided by __3__molecules and __4__ factors in the axonal environment. Axonal connections may be maintained through trophic interactions between neurons and their targets. A loss of __5__ contacts by a neuron may result in apoptosis.

1. outgrowth 2. branching 3. EC matrix molecules 4. trophic factors 5. axonal contacts

Synaptic Contact and Plasticity: ___1__are formed and lost throughout life, but particularly in development. As with neurons themselves, more synapses are formed with a greater variety of circuits than will be maintained in adult stages. It is generally believed that __2__ that are actively used tend to be maintained or enhanced, while those not used will be lost.

1. synaptic contacts | 2. circuits

The maintenance of synapses related to activity is believed to be in part a result of a __1__ interaction between the pre and postsynaptic cells. When action potentials are generated and reach the postsynaptic cell, it responds by sending signals back to the presynaptic cell (__2__ transmission). This signal may act both locally to maintain the synapse and in the presynaptic cell to maintain viability.

1. trophic factors | 2. retrograde transmission

The complexity of __1__ formation is modulated throughout life and is important as part of postnatal development. The proper development and maintenance of dendrites and synaptic connections is dependent to some extent on __2__ stimulation apparently due to the __3__effects of synaptic contact. A lack of appropriate stimulation may result in a diminished development of neuronal and dendritic complexity.

1. dendrite 2. environmental stimulation 3. trophic effects

The maturation of axons and their __1__ is an important part of postnatal development. The myelination of CNS axons begins at about the __2__ month of development and peaks between birth and the__3__ year of life, but continues into adulthood. Myelination is important to establish the axonal __4__ velocities necessary for normal motor and sensory function. The process of myelination is often affected by congenital errors in metabolism and malnutrition.

1. myelination 2. 6th month 3. 1st year 4. conduction velocities

Neuroembryology II

Fuck you.

Defects in neurulation (neural tube formation, neural pore closure) are known as __1__ defects (raphe- G. seam, suture). - These defects are often accompanied by malformations in the surrounding tissue. - The incidence dysraphic defects may be reduced up to 70% by supplementation with __2__ (400µg/day), suggesting that some neural tube defects are produced from maternal metabolic defects that can be corrected with__2__.

1. dysraphic defects | 2. folic acid

Failure of the neural tube to close occurs most often at the level of the anterior or posterior__1__. The final anterior neuropore closure is located at the level of the __2__, the anterior wall of the third ventricle just below the anterior commissure.

1. neuropores | 2. lamina terminalis

Failure of the __1__to close properly or the overlying tissue to develop may result in a variety of defects at any level from the lamina terminalis to the cervical levels of the spinal cord. This is related to the fact that once formed, the neural tube separates from the surface ectoderm, and the surface ectoderm grows over the midline.

1. antetrior neuropore

__1__ is one of the most severe of the anterior neuropore closure defects. - The brain does not form, and the surrounding meninges and skull may not develop properly. It may also result from a failure of the cranium to form (__2__) and subsequent necrosis of the brain tissue. - Associated causes are maternal __3__ (maternal infection, sauna baths) - Neonatal death is inevitable. - Occurs in 1 of 2,000 births.

1. anencephaly 2. exencephaly 3. hyperthermia

Defects in the formation of the cranium (crania bifidum) may be accompanied by a herniation of the cranial contents (__1__). __1__are most common in the occipital region, but may also occur in frontal or parietal regions.

1. encephalocele

If the herniation only contains meninges and CSF it is a __1__; With meninges and brain a __2__; With meninges, brain, and part of the ventricle a __3__

1. meningocele 2. meningoencephalocele 3. meningohydroencephalocele

Some cystic defects can result in the herniation of the cerebellar vermis through the foramen magnum (__1__), usually causing pressure on the medulla and cervical spinal cord. It may be accompanied by a a cavitation (syrinx) of the spinal cord (__2__) or medulla (__3__). -Blockage of CSF flow through the ventricles resulting in hydrocephalus is also associated with this condition

1. Arnold-Chiari 2. syringomyelia 3. syringobulbia

Dysraphic effects related to the closure of the__1__(upper lumbar segments) involve the area just above the region of secondary neurulation (sacral and coccygeal). The defects may affect both the spinal cord and surrounding tissues. These defects are known as __2__.

1. posterior neuropore | 2. myeloschisis

__1__ can result from defects in the closure of the caudal neuropore or a failure of the neural tube to induce mesoderm to form the neural arches of one or more lumbar or vertebral segments (__2__). __2__ is general term for neural tube defects in the spinal region, it may or may not involve neural tissue.

1. Myeloschisis | 2. spina bifida

If the defect is only a defect of vertebral arch fusion and the skin is closed over the defect, the condition is __1__. - Some extent of this defect affects about 10% of otherwise normal people. - This site is usually marked by a patch of coarse hairs. If the skin is not closed and a patent aperture exists, it is __2__.

1. spina bifida occulta | 2. spina bifida aperta

When a cystic mass accompanies spina bifida, the malformation is __1__. - The cyst may contain only meninges and CSF (__2__), meninges, CSF and spinal neural tissue (__3__). - Elevated levels of __4__ are usually present. - Almost all cases of spinal bifida cystica are accompanied by __5__ because of associated spinal cord adhesion to the vertebral column and __6__ malformation.

1. spina bifida cystica 2. meningocele 3. meningomyelocele 4. alpha-fetoprotein 5. hydrocephalus 6. Arnold Chiari

With __1__, infants may be unable to move their lower limbs or unable to perceive pain in affected areas. The incidence is 5 per 10,000 births.

1. meningomyelocele

__1__ occurs when the neural tube does not close and is exposed without a covering of skin, bone or meninges.

1. Rachischisis

Malformations of the neural tube as part of secondary neurulation are called __1__. - Malformations are usually covered with skin. - This may appear as a dimple or unusual pigmentation and hair growth, and telangiectasias (large superficial capillaries, spider veins).

1. myelodysplasias

Myelodysplasias can cause abnormal adhesion of the spinal cord to the vertebral column may also occur resulting in __1__syndrome. -The spinal cord is placed under continued __2__ as the vertebral column grows, the spinal cord itself may be damaged, resulting in anesthesia in the legs and problems with bladder control.

1. tethered cord | 2. traction

Tethered cord as a result of spina bifida with continued growth of the spinal column may also pull the brainstem and cerebellum caudally. - This may pull the cerebellum into the foramen magnum and compress the brainstem (__1__). - Cranial nerve palsies and progressive loss of long tract motor function may occur.

1. Arnold-Chiari malformation

The failure of neural crest cells to properly differentiate or migrate can produce congenital malformations associated with peripheral nervous system development (typically autonomic and enteric nervous system ganglia). -The most common include congenital __1__ and familial __2__

1. megacolon | 2. dysautonomia

__1__ disease (1 in 7000 births)-results from mutations of the__2__gene which codes for a receptor essential for cell migration. - Parsympathetic ganglia fail to form on portions of the colon resulting in tonic contraction of parts of the colon and expansion of others. Most diagnosis is now in newborns. - Symptoms include failure to pass meconium in 24-48 hours. - Treatment is to remove the affected area of bowel.

1. Hirschsprung disease (congenital megacolon) | 2. RET gene

__1__ disease also results from a failure of neural crest cells to develop in the formation of ganglia, particularly sympathetic ganglia. - Patients have impaired pain and temperature sensation and autonomic deficits (cardiovascular instability, gastrointestinal dysfunction). - All proven cases have been in patients of Ashkenazi Jewish extraction.

1. familial dysautonomia

__1__ is the developmental separation of the prosencephalon into the diencephalon and telencephalon. -If this division does not occur fully, the malformation is __2__. If no lobes develop, the condition is __2__ holoproencephaly. -If some lobes are discernable, it is __3__ holoprosencephaly. -In these conditions, many structures such as the thalamus, corpus callosum, olfactory structures and meningeal structures may be poorly developed or absent.

1. Prosencephalization 2. holoprosencephaly 3. alobular holoproencephaly 4. semilobar holoproencephaly

Because facial structures also develop at this time, facial malformations also occur. - This may include __1__ (unusually close set eyes) or __2__. - HPE occurs in 1:15,000 live births, but may be present in 1:250 pregnancies resulting in early miscarriage. - Defects in the SHH gene or cholesterol biosynthesis are some potential causes, along with maternal alcohol abuse.

1. hypotelorism | 2. cyclops

If the flow of CSF through the ventricles is blocked during prenatal development, __1__may develop. - Congenital atresia of the __3__is a common cause of prenatal hydrocephalus. - Stenosis or blockage of the cerebral aqueduct can also occur as a result of infection or intraventricular hemorrhage. - As indicated above, hydrocephalus may also result from physical compression of the cerebellum and brainstem at the foramen magnum

1. congenital hydrocephalus | 2. cerebral aqueduct

Blockage of the exit of CSF from the__1__ventricles produces, ventricular enlargement, and because the bones of the head have not completely formed, an expansion of the cranium. -The result can be a large ventricular space with a __2__ of brain tissue and an enlarged __3__.

1. lateral ventricles 2. rim of brain tissue 3. enlarged cranium

The __1__malformation (1 in 25,000 births) results from a cystic dilation of the fourth ventricle with aplasia of the cerebellar vermis. - There may also be obstruction of the foramina of the 4th ventricle and hydocephalus. - It is often accompanied by other malformations and mental disability. It can be treated surgically with the placement of a __2__. - It is usually diagnosed in the first year of life. In older children, cerebellar signs (lack of coordination in walking) are usually noted.

1. Dandy-Walker | 2. CSF shunt

Gross abnormalities of cortical development may result from disorders of cell migration. -Failure of gyri to form may result in __1__, a smooth cortical surface. Unusually large gyri (__2__) or small gyri (__3__) may also occur

1. lissencephaly 2. pachygyria 3. microgyria

__1__ is a condition where clefts appear in one or both cerebral hemispheres. -This is believed to occur as a result of defects in cell migration or defects in blood supply to the area in early development.

1. Schizencephaly

Defects in __1__ in the formation of dendrites, synapses or myelination can occur both pre and post natal. - In some instances such as Down Syndrome, a lack of dendritic complexity is results from a genetic defect. - The result may be moderate to severe mental disability.

1. neuronal maturation

__1__ is a cranial vault size that is smaller than normal, usually as a result of a defect in brain development. - Causes may be genetic, from prenatal exposure to infection (e.g. toxoplamosis), exposure to drugs or other teratogens. - Impaired mental development occurs in more than ½ of cases.

1. Microcephaly

Some common disease organisms can produce defects in neural development. These range from viruses (rubella, measles, cytomegalovirus), to bacteria such as syphilis or protozoans, __1__ (found in garden dirt or cat feces, but also raw meat). __2__ is currently related to a range of defects that occur in 0.3% of live births in the U.S.

1. toxoplasmas | 2. Toxoplasmosis

Roughly 90% of the cerebral cortex is __1__. -The remainder is composed of phylogenetically older forms of cortex, Allocortex. ``` Six Layers for neocortex (isocortex): I – __2__ (Plexiform) Layer II – Outer __3__ Layer III – Outer __4__ Layer IV – Inner __5__ Layer V – Inner __6__ Layer VI – __7__ Layer ```

1. Neocortex 2. Molecular 3. Granular 4. Pyramidal 5. Granular 6. Pyramidal 7. Multiform

The six layers of neocortex are __1__throughout. - Primary motor and sensory areas provide the greatest contrast and are referred to as __2__. - Primary motor cortex (__3__ cortex) is dominated by pyramidal projection neurons. - Primary sensory cortex (__4__ cortex) is dominated by smaller cells, most notably stellate cells.

1. not uniform 2. heterotypical 3. agranular cortex 4. granular cortex

Cortical Neurons: Pyramidal neurons: -In all layers except Layer I (molecular layer) -Prominent in Layers __1__ - Large apical __2__ – extends toward molecular layer - Basal __2__ - projecting horizontally Major output pathway of the cerebral cortex (__3__ fibers) Also, association and callosal fibers Giant pyramidal neurons of __4__ – only in motor cortex, found in layer V.

1. II, III, & V 2. dendrite, dendrites 3. projection 4. Betz

``` Cortical Neurons: Intrinsic Neurons: Stellate (aspiny & spiny) neurons -Most numerous in Layer__1__; -receive __2__ projections -Spiny Stellate cells only excitatory __3__ (Glu); ``` __4__ cells: Found in layer III; dendrites in Layer IV __5__ cells: Layer III and V; dendrites in all layers. Cells of __6__ (not pictured): - Found in deeper layers; - multipolar neurons with short branching dendrites and an axon that projects to more superficial layers

1. layer IV 2. thalamocortical 3. excitatory interneurons 4. Chandelier cells 5. Basket cells 6. Martinotti

Axons Intrahemispheric (__1__ fibers): __2__ association – Layer III and V connect lobes together (more distant regions) __3__ association – Layer II and III connect gyri together Interhemispheric (__4__ fibers) - Layer III - connect left and right hemispheres (corpus callosum) and temporal poles (anterior commissure)

1. Association fibers 2. Long association 3. short association 4. Callosal fibers

Axons: Local __1__ Neuron -Connect different layers together __2__: -Go to subcortical areas, brainstem, and spinal cord What types? __3__: - From the thalamus (thalamocortical) to layer __4__ (some to Layers III and VI) - Noradrenergic, seritonergic, dopaminergic, cholinergic from other subcortical nuclei – diffuse inputs

1. Local Intrinsic Neuron 2. Corticofugal 3. Corticopetal 4. layer IV

Cerebral Cortex- Functional Areas: The structure and function of the cerebral cortex are__1__, although it appears as a homogenous sheet of tissue. Structural (Cytoarchitecture) differences are based on cortical thickness, width of individual layers, type and number of cells per layer – helps to parcelate the cortex. Korbinian Brodmann described __2__ (how many of what?) areas in man. Brodmann’s areas in many cases are used to describe __3__ areas of cortex – stroke and functional imaging have tested the validity of these associations

1. HETEROGENEOUS 2. 47 cytoarchitectural 3. functional

Make a chart for Brodman Areas on slide 10

go fuck yourself

The primary lobes of the brain include the (6) lobes. What are they? -The demarcation of these lobes are based on both anatomical and functional criteria.

frontal, parietal, temporal, occipital, limbic, insular

Frontal lobes are the largest lobes of the brain. They have __1__and __2__ functions. Some of the major functional components are: - __3__ cortex. - __4__ motor areas - Frontal __5__ fields - __6__ cortex

1. motor 2. cognitive 3. Primary motor cortex 4. Supplemental motor areas 5. frontal eye fields 6. Prefrontal cortex

The frontal lobes are separated from the parietal lobes by the __1__and from the temporal lobe by proximal portion of the __2__.

1. central sulcus | 2. lateral fissure

The primary gyri of the frontal lobe include the__1__gyrus (primary motor cortex) and the __2__, __3__ and __4__ frontal gyri -These are separated by the precentral sulcus and superior and inferior frontal sulci.

1. precentral gyrus 2. superior 3. middle 4. inferior

On the medial surface, the precentral gyrus continues within the longitudinal fissure as the __1__ gyrus (anterior portion of the paracentral lobule). -The superior frontal gyrus extends on the medial surface down to the __2__ sulcus. (aka the medial frontal gyrus here).

1. anterior paracentral gyrus | 2. cingulate sulcus

The __1__ is the medial extension of both the pre and post-central gyri. -It contains both primary __2__ (anterior) and primary __3__ (posterior) functional areas.

1. paracentral lobule 2. motor 3. sensory

Frontal Lobes- Functional areas: The precentral gyrus (Broadmann area 4) is __1__cortex -major motor output register to the spinal cord and brainstem -It is somatotopically organized such that areas that represent the legs are located in __2__ gyrus.

1. primary motor cortex | 2. anterior paracentral gyrus

Precentral gyrus: The trunk, hand, head, and tongue are represented more _1__ and __2__ -With the __3__ represented near the lateral fissure

1. inferior 2. laterally 3. tongue

In front of the precentral gyrus, are __1__ motor and __2__ areas related to the planning of motor activities (area 6). These areas communicate with area __3__ and subcortical structures (basal ganglia, cerebellum, etc.) in the planning of movements.

1. supplementary motor 2. premotor 3. area 4

Frontal Lobes- Functional Areas: Anterior to premotor cortex are the __1__ fields (area 8). -These areas facilitate the __2__ through connections to eye movement centers in the brainstem.

1. frontal eye fields | 2. cortical (conscious) control eye movements

``` Frontal Lobes- Functional Areas: The inferior frontal gyrus contains three primary parts: -pars__1__ near the lateral fissure -pars __2__ -pars __3__ ```

1. pars opercularis 2. pars trangularis 3. pars orbitalis

Frontal Lobes: The pars trangularis and pars opercularis correspond to __1__ area (areas 45, 44), the motor area for speech in the dominant (usually left) hemisphere. -These areas connect to the brainstem nuclei for cranial nerves that control the motor output for speech.

1. Broca’s area

Much of the remainder of the frontal lobe (__1__ cortex) is classified as multimodal associational with diverse cognitive functions including__2__, __3__, a sense of __4__,__5__ and social __6__. -It contains about 25% of the entire cortex of the human brain- (Primarily Brodmann Areas 9,10,11,12.)

1. prefrontal cortex 2. judgment 3. foresight 4. sense of purpose 5. responsibility 6. social propriety

Frontal Lobe- Ventral Aspect: - Ventrally, the prefrontal areas extend into the __1__ gyri - The olfactory bulb and tract lie in the __2__ sulcus, forming a medial boundary of the orbitofrontal gyri - Most medially, next to the longitudinal fissure is gyrus __3__, essentially an extension of the medial aspect of the superior frontal gyrus

1. orbitofrontal 2. olfactory sulcus 3. gyrus rectus

__1__ lobes- sensory and multimodal associative function. Contain: - __2__ cortex (postcentral gyrus) - __3__ areas, with functions include understanding spoken and written language (usually left hemisphere).

1. Parietal lobes 2. Primary somatosensory cortex 3. Sensory association areas

Laterally, the parietal lobes lie posterior to the __1__ sulcus and anterior to the extension of the parieto-occipital sulcus to the preoccipital notch. From the temporal lobe, it is above the lateral fissure and a __2__ between approximately the middle of the lateral fissure and the extension of the parieto-occipital sulcus.

1. central sulcus | 2. line

Medially, the parietal lobes contain the __1__ part of the __2__ lobule. - The __3__sulcus separates the parietal lobe from the occipital lobe. - Between these boundaries is the __4__, bordered inferiorly by an indistinct boundary with the cingulate gyrus.

1. posterior part 2. paracentral lobule 3. parieto-occipital sulcus 4. precuneus

The primary components of the parietal lobe are: - the __1__cortex (postcentral gyrus) - the __2__ lobule - the inferior parietal lobule (__3__gyrus, and the __4__ gyrus) The superior and inferior parietal lobules are separated by an __5__ sulcus

1. primary somatosensory cortex 2. superior parietal lobule 3. supramarginal gyrus 4. angular gyrus 5. intraparietal sulcus

The __1__ gyrus lies behind the central sulcus and anterior to the postcentral sulcus. It contains: - __2__ cortex, (SI -Broadmann areas__3__) on the lateral surface of the hemisphere - Posterior paracentral lobule on the medial surface of the hemisphere

1. postcentral gyrus 2. Primary somatosensory cortex 3. Broadmann areas 3,1,2

The postcentral gyrus is somatotopically organized in a manner similar to motor cortex. - Sensory areas from the genitals, foot, and leg are on the medial hemisphere in the __1__gyrus - The tongue is located most __2__. - Neurons in the postcentral gyrus respond to modality specific stimuli of discriminative touch, vibration, position, pain and temperature.

1. posterior paracentral gyrus | 2. laterally

``` __1__ cortex (SII) is located on the medial surface of the parietal operculum. -This area contains an additional sensory somatotopic map, although somewhat more crude than SI. ```

1. Secondary somatosensory cortex

SII areas project to insular cortex, which distributes to limbic areas, presumably for the memory of __1__ stimuli. -__2__ input (including taste) also projects to adjacent areas in this region. The __3__ contains long and short insular gyri surrounded by the borders of the lateral fissure (circular sulcus). -The anterior insula (near motor cortex) may also help to coordinate articulatory movements necessary for speech.

1. tactile stimuli 2. Viscerosensory input 3. insula

Parietal Lobes: The superior and inferior parietal lobules are separated by the __1__ sulcus. The superior parietal lobule (Brodmann areas 5 and 7) integrates __2__input from multiple __3__ that are used in motor planning (kinesthetic sense, hand eye coordination). -They project to supplementary motor areas in the frontal lobe.

1. intraparietal sulcus 2. somatosensory 3. modalities

The __1__ lobule contains the angular gyrus (area 39) and supramarginal gyrus (area 40). The general functions of this area differ with the hemisphere involved. In the dominant hemisphere, the __2__ gyrus is a center for comprehension of written language. Areas of the __3__ gyrus and posterior superior temporal gyrus (Wernicke’s area (Brodmann area 22)) is the areas for comprehension of spoken language.

1. inferior parietal lobule 2. angular gyrus 3. supramarginal gyrus

In the nondominant hemisphere, the inferior parietal lobule modulates __1__(perceptual awareness). Lesions to this area are associated with __2__ syndrome (failure to recognize the left side of the body as self).

1. attention to stimuli both on the body and in the visual field 2. hemineglect syndrome

__1__ lobes: visual function Contains: __2__ cortex and visual association (extrastriate) cortex. The primary identified gyri are associated with the medial aspect of the hemisphere

1. Occipital lobes | 2. primary visual cortex

Occipital Lobes- Gyri: Medially, the usually well defined parieto-occipital sulcus separates the parietal and occipital lobes. The calcarine sulcus divides the medial occipital lobe into the__1__above and __2__ gyrus below. Remaining areas of the occipital lobe (__3__ cortex, areas 18 and 19) are involved in the processing of visual data leading to perception of motion, depth (binocular vision), color, and position of an object.

1. cuneus 2. lingual gyrus 3. extrastriate cotex

__1__ (area __2__) cortex is on the medial side of the occipital lobe on either side of the calcarine sulcus. The retinal surface (and therefore the visual field) is represented in a topographic (__3__) fashion in the area around the calcarine sulcus

1. primary visual cortex 2. area 17 3. retinotopic

__1__ lobes: integrative sensory, some memory, auditory and olfactory functions. - It contains primary __2__ cortex and nearby __3__ area that coordinates the understanding of spoken language. - It also contains limbic areas, including the hippocampus.

1. Temporal lobes 2. primary auditory cortex 3. Wernicke’s area

Temporal Lobes- Basic Anatomy: On the lateral surface, the temporal lobe is comprised of: __1__, __2__, and __3__ temporal gyri separated by the superior and inferior temporal sulci

1. superior 2. middle 3. inferior

Temporal Lobe- Inferior: Ventrally, the inferior temporal gyrus may fold over to the inferior surface and become the__1__ gyrus (aka fusiform gyrus) -The lateral occipitotemporal gyrus may also be separated. -A __2__ gyrus may also be present as a defined structure. Under these conditions it will be separated from the lateral by the __3__ sulcus. -These areas, along with adjacent areas of the occipital lobe are involved in the recognition of objects and faces.

1. lateral occipitotemporal gyrus 2. medial occipitotemporal gyrus 3. occipitotemporal sulcus

Within the lateral fissure, the superior surface of the temporal lobe contains the transverse temporal gyri (of Heschl, areas 41 and 42). - The primary __1__ cortex is responsible for audition, receiving information from __2__. - Together with the immediately surrounding association cortex, it is generally involved in the process the association and recognition of sounds.

1. primary auditory cortex | 2. both ears

The __1__ lobe- primary processor of memory -Also involved in emotional behavior, integration of homeostatic responses, motivation and sexual behavior The major divisions are the __2__ area, __3__ gyrus, __4__ gyrus and uncus. The limbic lobe also contains primary olfactory cortex, and multimodal association cortex linked to memory.

1. limbic lobe 2. subcallosal gyrus 3. cingulate gyrus 4. parahippocampal gyrus

Limbic Lobe- Defining Sulci: - The __1__ sulcus separates the limbic lobe from anterior and dorsal structures. - The __2__ sulcus separates the corpus callosum from the limbic lobe.

1. cingulate sulcus | 2. callosal sulcus

Ventrally, the cingulate gyrus continues as the __1__ gyrus, named for the hippocampus just deep to it. The __2__ sulcus separates the parahippocampal gyrus from the occipitotemporal gyri. The anterior regions of the parahippocampal gyrus contain primary __3__ cortex (aka entorhinal, piriform cortex).

1. parahippocampal gyrus 2. collateral sulcus 3. primary olfactory cortex

Hippocampus and Cingulate gyrus : The hippocampal formation and adjacent areas of the parahippocampal gyrus have extensive interconnections with the cingulate gyrus. These circuits are necessary for the incorporation of short term to __1__memory.

1. long term memory

Cerebral Vasculature

this is gonna suck

The blood supply to the brain arises from two sources, the __1__system and the __2__ system. - The two systems join through communicating arteries in the circle of __3__ (cerebral arterial circle) on the base of the brain. - In most individuals, this will allow collateral circulation to compensate for interruption of some of the major arteries within the circle.

1. internal carotid 2. vertebrobasilar 3. Willis

The internal carotid artery (ICA) ascends from the bifurcation of the common carotid in the midcervical region (cervical part) to enter the petrous portion of the __1__ bone via the __2__ canal (petrous part). -Upon entering the cranium, the ICA travels forward across the cartilage filled foramen __3__. It enters the __4__ sinus (cavernous part) and travels anteriorly along side the sphenoid bone. -The ICA then ascends medial to the anterior clinoid process piercing through the dural roof of the sinus to become the cerebral part. The ICA then arches back below the optic nerve and upon reaching the anterior perforated substance bifurcates to form the anterior and middle __5__ arteries.

1. temporal bone 2. carotid canal 3. foramen lacerum 4. cavernous sinus 4. cerebral

No major branches are given off from the petrous part of the ICA within the carotid canal. -The first branches associated with the brain are given off in the __1__ sinus to supply the hypophysis and meninges.

1. cavernous sinus

The pituitary gland and part of the infundibulum are supplied by the superior and inferior __1__ arteries. These are branches of the ICA. The inferior branch arises in the __2__ sinus, while the superior branch typically arises from the__3__ (supraclinoid) part of the ICA.

1. hypophyseal arteries 2. cavernous sinus 3. cerebral

In addition to the superior hypophyseal artery, the cerebral part of the ICA gives off the following: 1. __1__ artery 2. Posterior __2__ artery 3. Anterior __3__ artery These are considered to be branches of the internal carotid, but in some cases arise from the middle cerebral

1. Ophthalmic artery 2. Posterior communicating artery 3. Anterior choroidal artery

The __1__ artery enters the orbit via the optic canal and give off multiple branches that supply the eye and the extraocular structures of the orbit. One branch is critical for visual function, the __2__. -This artery enters the optic nerve as it approaches the eyeball and supplies the retina

1. ophthalmic artery | 2. central artery of the retina

Because the ophthalmic artery arises early from the ICA, it can carry small particles (__1__) from the carotid. -These __1__ can cause transient or permanent visual loss and the appearance of small ischemic areas that can be visualized on the retina.

1. microemboli

The posterior __1__ artery travels across the oculomotor nerve in a posteromedial direction to join with the posterior __2__ artery, thus connecting the carotid with the vertebrobasilar system. -The size of these arteries varies greatly, and in a small percentage of individuals it may be absent.

1. posterior communicating artery | 2. posterior cerebral artery

The anterior __1__ artery (AchA) follows the optic tract in a caudal and lateral direction around the crus cerebri. As it reaches the lateral geniculate body it branches extensively. Many of these branches enter the__2__of the__3__ ventricle via the choroidal fissure to supply the choroid plexus.

1. anterior choroidal artery 2. inferior horn 3. lateral ventricle

Along its course, the AChA gives off branches to the optic tract, crus cerebri, __1__ (5 things), lateral thalamus (including LGB), and the retrolenticular limb of internal capsule. Clinical presentation is most consistent with damage to the posterior __2__ of the __3__ capsule. Signs include: - Hemiplegia - Hemianesthesia - Hemianopsia – Note: visual field defects are a variable feature and if present, may be transient.

1. amygdala, anterior hippocampus, tail of the caudate, medial globus pallidus, the posterior limb of the internal capsule (ventral portion), 2. posterior limb 3. internal capsule

The cerebral part of the internal carotid artery ends with two terminal branches, the __1__ and __2__ arteries. The anterior cerebral cerebral artery runs medially over the optic chiasm to a near midline position and is joined to its contralateral counterpart by the anterior __3__ artery near the cistern of the lamina terminalis.

1. anterior cerebral artery 2. middle cerebral artery 3. anterior communicating artery

Beyond the anterior communicating artery, the anterior cerebral artery supplies the __1__ aspect of the __2__ lobes (2 lobes). The branches extend dorsolaterally onto the lateral surface of the hemisphere. The primary branches of the anterior cerebral arteries are the orbitofrontal, frontopolar, and the __3__ artery and __4__ artery.

1. medial 2. frontal and parietal lobes 3. callosomarginal artery 4. pericallosal artery

Anterior Cerebral Artery Supplies: __1__ Lobule -Contains cortical centers for movement and sensation of the lower limb __2__ Cortex -Important for executive functions including decision making and planning Clinical Picture: Depends on the branch that is occluded May include: -Paralysis of the opposite foot and leg – UMN lesion -Sensory deficits over toes, foot, and leg -Cognitive impairments including planning and decision making; loss of initiative; memory and emotional disturbances -Transcortical motor aphasia may also be present if in left (dominant) hemisphere

1. Paracentral lobule | 2. Ventromedial Prefrontal Cortex

The __1__ artery is usually (70% of the time) the larger of the terminal branches of the internal carotid. -It moves laterally through the Sylvian cistern, giving off the __2__ arteries to the basal ganglia and internal capsule. It splits into __3__ and __4__ trunks as it enters the area of the insula.

1. middle cerebral artery 2. lenticulostriate artery 3. superior 4. inferior

The two trunks of the middle cerebral supply the inner aspects of the opercula and the lateral surface of the cerebral hemisphere. The branches on the lateral hemisphere are somewhat variable, but usually include branches adjacent to the central sulcus (__1__, __2__ and __3__ (Rolandic) arteries).

1. Precentral 2. Central 3. Postcentral

On the lateral hemisphere, the middle cerebral artery supplies a central area that is surrounded by other arterial territories, those of the anterior and posterior cerebral arteries. -It does NOT supply the__1__ aspect of the hemisphere.

1. medial

Middle Cerebral Artery Supplies: Supplies: -Primary sensory and motor areas for __1__ and __2__ -Left Side – speech areas including __3__ area and __4__ area -__5__ radiation -__6__ association cortex -Frontal __7__ Field

1. face 2. arm 3. Broca's area 4. Wernicke's area 5. optic radiation 6. Parietal association cortex 7. frontal eye field

Medial Cerebral Artery Clinical Presentation will depend on which division or branch is occluded May include: -Paralysis of opposite face and arm -Sensory deficits over opposite face and arm -Aphasia if on the left side -Visual field defects -Inattention and neglect of contralateral side of body or space and denial of illness if on right side -Transient paralysis of conjugate gaze to the contralateral side.

make a chart for clinical presentations

Although it is part of the vertebrobasilar system (bifurcation of the basilar), the __1__ artery (PCA) supplies the posterior areas of the hemisphere and is best considered with cortical distributions. The basilar bifurcation occurs at the level of the interpeduncular cistern. The posterior cerebral artery travels laterally over the __2__ nerve and wraps around the midbrain in the ambient cistern, running along the ventral and medial surface of the temporal lobe

1. posterior cerebral artery | 2. oculomotor nerve

Posterior Cerebral Artery: The early branches of the posterior cerebral arteries include the __1__ (4 arteries) artery, which collectively supply the midbrain, thalamus and choroid plexus

1. quadrigeminal artery, thalamoperforating arteries, medial and lateral posterior choroidal arteries, and the thalamogeniculate

The PCA continues posteriorly to supply the ventral and medial surfaces of the occipital lobe. Notably, it includes the __1__ artery, which supplies primary visual cortex.

1. calcarine artery

The PCA supplies: - Visual cortex - Medial surface of occiptal lobe (primary and association cortices) - Temporal lobe, caudal parietal lobe, and splenium of corpus callosum - Part of thalamus: - thalamogeniculate branch –posterior thalamus; - thalamoperforating branches to anterior and medial thalamus; - posterior choroidal arteries – posterior thalamus, choroid plexus of 3rd and lateral ventricles

make a chart

Clinical Presentation: (PCA) - Homonymous Hemianopia (with macular sparing – MCA provides collateral supply to occipital pole- macular vision) - Pure Alexia (inability to read) with involvement of posterior corpus callosum and left visual cortex; color agnosia may also be present. - Sensory deficits with deep territory involvement

make a chart

The __1__ arteries enter the lateral cerebellomedullary cistern after penetrating through the atlanto-occipital membrane. -Branches of the __1__ artery supply part of the medulla oblongata, cerebellum and the dura of the posterior cranial fossa.

1. vertebral arteries

The first major branch of the vertebral artery is the __1__ artery (PICA). -PICA supplies the dorsolateral medulla as it wraps around the medulla and emerges in the cisterna magna where it supplies the choroid plexus of the fourth ventricle and then the posterior and medial parts of the __2__ surface.

1. posterior inferior cerebellar artery | 2. inferior cerebellar surface

The __1__ artery most often arises from PICA. However, in about 25% of cases, it arises from the vertebral artery. -In addition to the dorsal part of the spinal cord, the __1__ artery supplies the dorsolateral region of the medulla oblongata caudal to the area served by PICA.

1. posterior spinal artery

Prior to joining to form the basilar artery, each vertebral artery gives rise to an __1__ artery. -These arteries typically join to form the one vessel seen on the ventral surface of the spinal cord. The __1__ artery supplies the anterior and medial areas of the medulla and spinal cord.

1. anterior spinal artery

The basilar artery lies on the ventral surface of the pons in the prepontine cistern. Its first large branch is the __1__ artery (AICA). -AICA wraps around the caudal middle cerebellar peduncle and onto the inferior surface of the cerebellum. It supplies the __2__ and _3__surfaces of the __4__, a portion of the __5__, and a small part of the choroid plexus that extends out of the fourth ventricle

1. anterior inferior cerebellar artery 2. ventral 3. lateral 4. cerebellum 5. pons

A small branch of AICA, (sometimes off the basilar) the __1__ artery arises near the facial and vestibulocochlear nerves and enters the internal acoustic meatus with them to supply portions of the inner ear. The basilar artery also gives off __2__, __3__, and __4__ circumferential branches to supply the pons.

1. labyrinthine artery 2. paramedian 3. short 4. long

The __1__ artery (SCA) arises from the basilar artery below it distal bifurcation. The SCA artery travels caudal to the oculomotor nerve around the crus cerebri in the ambient cistern where it divides into medial and lateral branches. -The SCA supplies the __2__ portion of the cerebellum, most of the __3__ nuclei, and the lateral__4__ of the rostral pons. It also serves caudal portions of the midbrain.

1. superior cerebellar artery 2. superior 3. deep cerebellar nuclei 4. tegmentum

The arteries forming the circle of __1__ give rise to numerous small (__2__, central, ganglionic) branches that supply the ventromedial structures of the brain. Divisions include the: - anteriomedial group - anterolateral group - posteromedial group - posterolateral group

1. circle of Willis | 2. perforating

The __1__ groups supply areas include the optic chiasm, anterior hypothalamus, and the anterior perforated substance. The lateral striate (lenticulostriate) arteries are sometimes included.

1. anterior groups

The medial and lateral striate arteries arise from the anterior cerebral artery (A2) and the middle cerebral artery (M1), respectively. - The __1__ arteries (recurrent artery of Heubner) supply the rostral part of the head of the caudate & lenticular n.; and anterior limb of the internal capsule. - The__2__ arteries supply the head and body of the caudate, most of the lenticular n. They also supply the dorsal part of anterior limb, genu, and posterior limb of the internal capsule.

1. medial striate arteries | 2. lateral striate (lenticulostriate) arteries

The __1__ groups supply the crus cerebri , the middle and posterior parts of the hypothalamus and as they enter the interpeduncular fossa form the posterior __2__ substance. The thalamoperforating, tuberothalamic, thalamogeniculate, and medial and lateral posterior choroidal arteries may be included in the posterior group.

1. posterior groups | 2. posterior perforated substance

Blood Supply to the Dorsal Thalamus: The thalamus is supplied primarily by branches of the __1__ artery. -These arteries include the thalamoperforating, thalamogeniculate (P1 area), and the medial and lateral posterior choroidal arteries that arise from beyond the branch of the posterior communicating artery (P2 area) on the posterior cerebral artery.

1. posterior cerebral artery

Blood Supply to the Dorsal Thalamus: Rostral areas of dorsal thalamus are supplied by the __1__ arteries (and tuberothalamic artery). Posterior and lateral regions are supplied by the posterior choroidal arteries and __2__ artery.

1. thalamoperforating arteries | 2. thalamogeniculate artery

The cerebral venous system empties through one major pair of vessels, the __1__ veins. The dural sinuses are discussed elsewhere, so only the major surface and internal veins will be addressed. -All of the major surface vessels will enter one of the __2__ sinuses, and veins tend to be much more variable in their pattern than arteries. The cerebral and spinal veins lack __3__, consequently the flow through veins can be altered by pathologic processes

1. internal jugular veins 2. dural sinuses 3. valves

On the lateral surface of the cerebral hemispheres, one finds the __1__ vein (of Trolard) and the __2__ vein (of Labbe). - These vessels form connections with the superior sagittal and transverse sinuses and the __3__ cerebral vein. - This vessel courses medially around the temporal pole to end in the cavernous sinus.

1. superior anastomotic vein 2. inferior anastomotic vein 3. superficial middle cerebral vein

In the midsagittal surface, the vessels drain into the sagittal sinus. Others from the lower medial surface near the corpus callosum and medial temporal lobe (the basal vein of __1__) join with internal cerebral veins to form the great cerebral vein (of__2__ ) that joins the __3__ sinus

1. basal vein of Rosenthal 2. great cerebral vein of Galen 3. straight sinus

On the base of the brain, the superior and inferior __1__ sinuses link the cavernous sinus to the transverse sinus and the origin of the internal jugular vein, respectively. The internal carotid artery passes forward through the lumen of the cavernous sinus along with the abducens nerve (CN VI). The oculomotor n., trochlear n., and the ophthalmic and maxillary branches of the trigeminal n. lie in the lateral wall.

1. superior and inferior petrosal sinuses

The__1__ veins are the veins draining the internal structures of the cerebral hemispheres. The internal cerebral veins join at the __2__ vein and empty into the straight sinus. These include the choroidal veins traveling from the choroid plexus, and the __3__ (terminal vein) vein that runs adjacent to the caudate nucleus.

1. internal cerebral veins 2. great cerebral vein 3. thalamostriate vein

The PCA continues posteriorly to supply the ventral and medial surfaces of the occipital lobe. Notably, it includes the __1__ artery, which supplies primary visual cortex.

1. calcarine artery

The PCA continues posteriorly to supply the ventral and medial surfaces of the occipital lobe. Notably, it includes the __1__ artery, which supplies primary visual cortex.

1. calcarine artery

make a chart

1. vertebral arteries

1. posterior inferior cerebellar artery | 2. inferior cerebellar surface

1. posterior spinal artery

1. anterior spinal artery

The basilar artery lies on the ventral surface of the pons in the prepontine cistern. Its first large branch is the __1__ artery (AICA). -AICA wraps around the caudal middle cerebellar peduncle and onto the inferior surface of the cerebellum. It supplies the __2__ and lateral surfaces of the cerebellum, a portion of the pons, and a small part of the choroid plexus that extends out of the fourth ventricle

1. anterior inferior cerebellar artery | 2. ventral

1. anterior inferior cerebellar artery 2. ventral 3. lateral 4. cerebellum 5. pons

1. labyrinthine artery 2. paramedian 3. short 4. long

1. superior cerebellar artery 2. superior 3. deep cerebellar nuclei 4. tegmentum

1. circle of Willis | 2. perforating

The __1__ groups supply areas include the optic chiasm, anterior hypothalamus, and the anterior perforated substance. The lateral striate (lenticulostriate) arteries are sometimes included.

1. anterior groups

1. medial striate arteries | 2. lateral striate (lenticulostriate) arteries

1. posterior groups | 2. posterior perforated substance

1. posterior cerebral artery

1. thalamoperforating arteries | 2. thalamogeniculate artery

1. internal jugular veins 2. dural sinuses 3. valves

1. superior anastomotic vein 2. inferior anastomotic vein 3. superficial middle cerebral vein

1. basal vein of Rosenthal 2. great cerebral vein of Galen 3. straight sinus

1. superior and inferior petrosal sinuses

1. internal cerebral veins 2. great cerebral vein 3. thalamostriate vein

``` Long Tracts: There are 3 major long tracts that are of utmost importance for neuroanatomical diagnosis in clinical practice: Sensory Tracts: __1__ Column – __1__System __2__ System ``` Motor Tracts: __3___ Tract Understanding the organization of these pathways, the levels of decussation, relationships to surrounding structures, and associated functions is critical for localizing lesions within the central nervous system -Likened to Meridians of __4_

1. dorsal column, medial lemniscal system 2. Anterolateral system 3. Corticospinal tract 4. meridians of Longitude

Look at slides 6, 7, 8

neuro blows

In the immature spinal cord, the mantle layer (intermediate zone) is populated by primitive neuroblasts that originate in the __1__ zone. -The mantle layer (and initially the ventricular zone) forms a dorsally located __2__ plate, which gives rise to GSA and GVA cell groups, and a ventrally located __3__ plate, which give rise to GVE and GSE cell groups.

1. ventricular zone 2. alar plate 3. basal plate

look at slide 10

fuck

The __1__ separates the alar and basal plates. A remnant of this sulcus can be seen on the floor of the fourth ventricle

1. sulcus limitans

Due to the opening of the neural tube and formation of the fourth ventricle in the upper medulla and pons, alar plate derivatives shift __1__, and therefore basal plate derivatives become __2__ located. Also, the brainstem has 2 additional functional columns, __3__ and __4-_, relating to pharyngeal arch derivatives and special senses, which are unique to the head and neck region.

1. laterally 2. ventromedially 3. SVE 4. SSA

The cell columns of the brainstem segment during development forming discrete gray matter __1__. This process is mediated in part by __2__ (HOX) genes. Thus, in the fully developed brainstem, functionally related cranial nerve nuclei are organized in __3__, longitudinal columns

1. discrete gray matter islands 2. homeobox 3. discontinuous

Cranial Nerve Nuclei: Functional components: Cranial nerve nuclei can be classified broadly as __1__ or __2__. These nuclei are derived from __3__ and__4__ plates, respectively. Note: In the brainstem, motor nuclei tend to be located __5__ and sensory nuclei tend to be located more__6__

1. motor 2. sensory 3. basal 4. alar 5. medially 6. laterally

Cranial Nerve Nuclei: Within these categories, more specific functional divisions exist: Motor: -__1__ Efferent – motor to skeletal muscle -*__2__ Efferent – motor to muscles derived from pharyngeal arches -__3__ Efferent – motor to viscera (smooth m., cardiac m., glands) Sensory: - __1__ Afferent /and *__1__ Afferent – sensory from viscera / tastebuds - __5__ Afferent – sensory from somatic structures (skin, muscle, joint) - __6__ – sensory from inner ear (auditory, vestibular) *Not present in Spinal Cord

1. General Somatic efferent 2. Special Visceral efferent 3. General Visceral efferent 4. General Visceral afferent, Special Visceral afferent 5. General Somatic afferent 6. *Special Somatic Afferent

Keep in mind: brainstem cranial nerve nuclei that are similar in function (e.g., motor) and innervate the same type of structures (e.g., skeletal muscle) occupy a similar location throughout the long axis of the brainstem. In addition, CN nuclei are found at particular levels along this long axis and are likened to Parallels of __1__ Thus, evaluation of the __2__ tracts (meridians of longitude) and __3__(parallels of latitude) provides information to help pinpoint the location of a brainstem lesion.

1. parallels of latitude 2. long tracts 3. cranial nerves

Make a chart for slide 17

The brainstem receives its blood supply from the __1__ system. -Each part of the brainstem is supplied by the individual vessels that overlie it

1.. vertebrobasilar system

Medulla Oblongata

Medulla (L., marrow) Oblongata: - Most caudal division of the brainstem, conical in shape - Derived from the __1__. - Contains primary nuclei for autonomic control of respiration, heart rate, blood pressure.

1. rhombencephalon

Long Tracts: There are two distinct long tract features that relate to the medulla oblongata. -In the caudal medulla, both the __1__system and the __2__ tract __3__, (i.e., cross from one side to the other).

1. dorsal column-medial lemniscal 2. corticospinal 3. decussate

Lower Medulla: Closed portion of the medulla containing the central canal. -While the caudal ventral boundary is the __1__, no definitive rostral ventral boundary exists. -Dorsally, no definitive caudal boundary exists, but the rostral boundary is the __2__

1. pyramidal decussation | 2. obex

Pyramidal (Motor) Decussation: -On the ventral surface of the medulla, the pyramidal decussation appears as a minor disruption of the anterior median fissure. Internally, however, the decussation is quite expansive. It is estimated that 80-90 percent of __1__ tract fibers cross over in the ventral caudal medulla to descend in the lateral funiculus of the spinal cord. Roughly 8% of fibers descend ipsilaterally in the __2__ funiculus of the spinal cord to decussate segmentally (anterior corticospinal tract). A small proportion of fibers (~2%) descend ipsilaterally to contribute to the __3__ corticospinal tract (tract of Barnes).

1. corticopspinal tract 2. anterior funiculus 3. lateral corticospinal tract

Pyramidal (Motor) Decussation: There is a somatotopy for the corticospinal tract fibers that cross over the rostrocaudal extent of the pyramidal decussation. Fibers originating in the upper extremity portion of primary motor cortex cross more __1__. Fibers originating in the lower extremity portion of primary motor cortex cross more __2__. As a result, discrete lesions in the pyramidal decussation may produce different and somewhat unusual patterns of weakness.

1. rostrally | 2. caudally

Level of Pyramidal Decussation: | Fibers within the fasciculus gracilis and fasciculus cuneatus begin to synapse in the __1__and __2__, respectively

1. nucleus gracilis | 2. nucleus cuneatus

``` Level of Pyramidal Decussation: The__1__ nucleus (pars caudalis) and tract take the place of the gray matter of the dorsal horn and tract of Lissauer, respectively. ```

1. spinal trigeminal nucleus and tract

Spinal Trigeminal Nucleus and Tract: - The spinal trigeminal nucleus is found within the lateral medulla, extending from the caudal pons all the way down into the upper cervical spinal cord. - The spinal trigeminal nucleus receives GSA afferents conveying __1__ (3 things) from the face and external ear. - Trigeminal afferents enter the brainstem at the level of the trigeminal nerve and then descend in the __2__ tract, located laterally adjacent to the spinal nucleus, to synapse in the __3__ nucleus along its rostral caudal extent.

1. pain, temperature, and crude touch 2. spinal trigeminal tract 3. spinal

The spinal trigeminal nucleus and tract give rise to a surface marking called the __1__ (or trigeminal tubercle). -Located lateral to the cuneate tubercle and tract

1. tuberculum cinereum

The spinal nucleus is divided into 3 subnuclei: __1__ (level of rostral pole of hypoglossal n. to caudal end of principal sensory nucleus (Pons)) -Tactile input (crude touch) __2__ (level of obex to rostral pole of hypoglossal nucleus) -Dental pain __3__ (C3 to the level of the obex) -Pain and temperature input

1. Pars Oralis 2. Pars Interpolaris 3. Pars Caudalis

Spinal Trigeminal Nucleus and Tract: The pars caudalis has a somtatotopic organization with input from__1__synapses ventrally and fibers from __2__ and the__3__ synapsing progressively more dorsal. -Sensory fibers from the external ear travel in CN VII, IX, and X to synapse in the dorsal most part of the caudal subnucleus.

1. V1 2. V2 3. V3

Spinal Trigeminal Nucleus and Tract: - An additional “onion skin” pattern for trigeminal input along the rostocaudal extent of the pars caudalis of thespinal nucleus has been described. - Nociceptive afferents from the circumoral region synapse in the __1__ part of the pars caudalis, whereas neurons innervating progressively more posterior and lateral parts of the face terminate in progressively more__2__ parts of the caudal subnucleus

1. rostral | 2. caudal

Level of Pyramidal Decussation: __1__ neurons originate in the spinal accessory nucleus located in the lateral portion of the ventral horn found from the junction of the spinal cord and medulla down to C5 (or 6) -Rootlets exit to form a trunk that ascends through the foramen magnum -Innervates the __2__ and __3__. -Cortical input to neurons innervating trapezius is crossed; Input to neurons innervating the SCM is ipsilateral. However, not all sources are in agreement.

1. GSE 2. trapezius 3. SCM

Level of Pyramidal Decussation: Other Tracts: -__1__ Fasciculus- (descending limb - medial vestibulospinal tract) and __2__ Tract Here these tracts are pushed laterally by the decussating CST fibers. -Anterior and Posterior __3__ tracts – retain position similar to that of spinal cord. -__4__ system (spinal lemniscus) – found medial to the spinocerebellar tracts; located in an anterolateral position much like in the spinal cord -__5__ tract closely associated with ALS in caudal brainstem. Retains similar position in the spinal cord

1. Medial Longitudinal fasciculus 2. Tectospinal tract 3. Spinocerebellar 4. Anterolateral system 5. Rubrospinal tract

Sensory Decussation: Neurons within the dorsal columns ascend to the caudal medulla to synapse in the dorsal column nuclei, __1__ nucleus and __2__ nucleus. -These nuclei are deep to the gracile tubercle (clava) and cuneate tubercle, respectively, observed on the dorsal surface of the medulla.

1. gracile nucleus | 2. cuneate nucleus

Sensory Decussation: Neurons within the dorsal column nuclei send axonal projections that arc across the tegmentum to enter the __1__ on the contralateral side in which they ascend to the thalamus (VPL). -Where they decussate, these fibers are referred to as __2__ fibers. -The fibers ascending in the medial lemniscus are somatotopically organized

1. medial lemniscus | 2. internal arcuate fibers

Level of Sensory Decussation: The __1__ nucleus lies laterally adjacent to the cuneate nucleus in the medulla oblongata. -The accessory cuneate nucleus is the rostral equivalent of the nucleus__2__(dorsal n.), receiving proprioceptive information from the upper extremity that is destined for the cerebellum.

1. accessory cuneate nucleus | 2. nucleus thoracicus

Large diameter afferents conveying proprioceptive and exteroceptive information enter the cervical (and perhaps upper thoracic) spinal cord to ascend in the fasciculus cuneatus and synapse in the __1__ (lateral, external) __1__ nucleus (instead of the nucleus thoracicus). -Neurons from the accessory cuneate nucleus project to the cerebellum as the __2__ tract, which enters the cerebellum via the inferior cerebellar peduncle (restiform body).

1. accessory cuneate nucleus | 2. cuneocerebellar tract

Level of Sensory Decussation: A number of structures appear that will be discussed with the upper medulla: __1__ nucleus (CN XII): located dorsally toward the midline __2__ nucleus of the vagus __3__ nucleus and tract Nucleus __4__ Inferior __5__ complex (inferior olive)

1. Hypoglossal nucleus 2. Dorsal motor nucleus 3. Solitary 4. nucleus ambiguus 5. olivary

Level of Sensory Decussation: Tracts: The __1__ tract and __2__ fasciculus are now located in the midline behind the medial lemnisci. The uncrossed __3__ tracts are located ventromedially

1. tectospinal tract 2. medial longitudinal fasciculus 3. pyramidal tracts

Level of Sensory Decussation: Tracts: The __1__ tracts, __2__ system, and __3__ tract have moved to a slightly more posterior position

1. spinocerebellar 2. anterlateral system 3. rubrospinal tract

Blood Supply to Lower Medulla: Major vessels 1. __1__ spinal artery- off vertebrals 2. __2__ arteries 3. __3__ spinal artery- usually a branch of PICA, but may also branch from vertebrals

1. anterior spinal artery 2. vertebral arteries 3. posterior spinal artery

Blood SUpply to the Lower Medulla: Areas Supplied: 1. __1__spinal artery- anteromedial areas of lower medulla 2. __2__ spinal artery- dorsal areas. 3. __3__ arteries-lateral areas At more rostral areas, __4__ supplies lateral areas

1. anterior spinal artery 2. posterior spinal artery 3. vertebral arteries 4. PICA

Upper Medulla: - Open portion of the medulla containing the caudal half of the __1__ ventricle. - On the dorsal surface, its caudal boundary is the __2__, and the rostral boundary is the __3__ of the fourth ventricle. - On the ventral surface there is no definitive caudal boundary, but the rostral boundary is the __4__ sulcus

1. fourth ventricle 2. obex 3. striae medullares 4. inferior pontine sulcus

Upper Medulla: Notes on Development: -Recall that sensory CN nuclei are found in a __1__ position due to the development of the fourth ventricle. -Motor CN nuclei tend to be located __2_. -Also, consider that the SVE column and to some extent the GSA column will migrate __3__. The inferior olive is a __4__ plate derivative

1. dorsolateral 2. ventromedially 3. anterolaterally 4. alar plate

Upper Medulla: Level of the Obex -Associated with CN__1__ -Many of the characteristics of the level of the sensory decussation are retained. Unique characteristics: Area __2__: -Circumventrical organ containing sinusoid capillaries (no blood brain barrier) -Chemosensitive trigger zone for emesis stimulated by blood-borne chemicals

1. XII | 2. Area Postrema

Level of the Obex: The __1__ body (inferior cerebellar peduncle) becomes notable in size. -Provides a major afferent pathway into the cerebellum, largely from the spinal cord and medulla (inferior olive). -Relatedly, the posterior __2__ tract disappears. -Cuneocerebellar tract fibers will also contribute to the restiform body, here

1. restiform body | 2. posterior spinocerebellar tract

Level of the Obex: The __1__ tract (CTT) begins to form. The CTT is a local communication pathway within the brainstem. It is far more pronounced in the rostral medulla and above. The CTT contains a number of different types of fibers, e.g., fibers descending from the parvocellar red nucleus, ascending (taste) fibers originating in the gustatory nucleus (rostral solitary nucleus), etc.

1. central tegmental tract

Level of the Obex: The __1__ tract (VTT) begins to form lateral to the medial lemniscus. -The VTT originates in the spinal trigeminal nucleus and carries pain and temperature from the face.

1. ventral trigeminothalamic tract

``` Level of the Obex: Structures retained from level of sensory decussation: -__1__ nucleus and nerve -Nucleus __2__ -Dorsal __3__ nucleus of Vagus -__4__ nucleus and tract -Nucleus __5__ and cuneatus -Accessory __6__ nucleus -Inferior __7__ -Spinal __8__ nucleus and tract ```

1. Hypoglossal 2. nucleus ambiguus 3. motor 4. Solitary 5. gracilis 6. cuneate 7. inferior olive 8. trigeminal

Level of the Obex: | Pathways retained from level of sensory decussation: (7)

``` Pyramids Medial lemniscus Tectospinal tract Medial longitudinal fasciculus Anterior spinocerebellar tract Anterolateral system Rubrospinal tract ```

``` Midolivary Level: Prominent Features: -Inferior__1__ complex -__2__nerve exits the preolivary sulcus -__3__ nerve exits the postolivary sulcus ```

1. inferior olivary complex 2. Hypoglossal nerve 3. Vagus nerve

Midolivary Level: Inferior Olivary Complex Constituents: a. __1__ nucleus- involved in control of planned or skilled, voluntary movements; predominantly cortical (and subcortical) afferents b. __2__ and __3__ olive- both accessory olives receive predominantly spinal afferents -stereotyped movements. The output fibers from the inferior olive project to the cerebellum mostly through the contralateral inferior cerebellar peduncle (olivocerebellar tract). Reciprocally connected

1. Principal olivary nucleus 2. medial accessory 3. dorsal accessory

Midolivary Level: The __1__ is found deep to the hypoglossal trigone present on either side of the median sulcus in the medullarly portion of the rhomboid fossa. -It contains motor neurons (GSE) that innervate most of the tongue muscle (except palatoglossus; CN X).

1. hypoglossal nucleus

Midolivary Level: The axons of __1__ motor neurons travel ventrally along the lateral aspect of the medial lemniscus to emerge from the brainstem between the pyramid and the inferior olive in the preolivary sulcus. -Cortical innervation of the hypoglossal nucleus is bilateral with a __2__ preponderance. -Ipsilateral input allows for functional recovery in the case of a supranuclear lesion.

1. hypoglossal | 2. contralateral preponderance

Midolivary Level: __1__ (NA) primarily contains motor neurons (SVE) that innervate muscles derived from the pharyngeal arches (branchiomotor). However, in addition, there is some (GVE) output to the cardiac ganglia. NA is located deep within the medullary reticular formation between the spinal __2__ nucleus and inferior __3__. It receive bilateral cortical innervation.

1. Nucleus Ambiguus 2. spinal trigeminal nucleus 3. inferior olive

Midolivary Level: __1__ contributes SVE component to CN IX, X, and XI which emerge from the medulla in the postolivary sulcus. IX: -Stylopharyngeus X: -Soft palate (except tensor veli palatini; CN V); pharyngeal muscles (except stylopharngeus; CN IX), laryngeal muscles, striated muscles of upper esophagus XI: -The cranial root of XI joins with the Vagus nerve contributing fibers that innervate muscles of the pharynx and larynx

1. Nucleus Ambiguus

Midolivary Level: The __1__ nucleus of the vagus (DMN) lies deep to the vagal trigone found lateral to the hypoglossal trigone in the floor of the fourth ventricle. -The DMN contains preganglionic parasympathetic neurons constituting the visceromotor (GVE) component of the vagus nerve. -Axons course ventrally and laterally to exit the medulla in the postolivary suclus.

1. dorsal motor nucleus of the vagus

Dorsal Motor Nucleus of Vagus These GVE fibers will travel in the vagus nerve to synapse on postganglionic parasympathetic neurons in terminal ganglia associated with the __1__ structures of the__2__, ie., the heart, lungs, esophagus, and gastrointestinal tract. Notably, the DMN receives input from the __3__ nucleus and takes part in the efferent component of the __4__reflex. -It also plays a role in emesis

1. visceral 2. thorax and abdomen 3. solitary nucleus 4. baroreceptor reflex

``` Midolivary Level: Solitary nucleus (and tract): ``` The solitary nucleus is located lateral to the DMN in the medulla. It can be divided into two general zones: 1. a __1__ (and lateral) __1__ zone that receives __2__ afferents (SVA) from the oral cavity and pharynx via CN VII, IX, & X. - Neurons from the gustatory nucleus project to the thalamus (VPM) in the ipsilateral central tegmental tract. From the VPM, fibers project to the gustatory cortex for conscious appreciation of taste.

1. rostral gustatory zone | 2. taste afferents

Midolivary Level: Solitary nucleus (and tract): a more caudal __1__ zone composed of several subnuclei that receive (GVA) input via CN XI & X from: -lungs, trachea, larynx, gastrointestinal tract (X) -carotid sinus (IX: baroreceptors - pressure) and carotid body (IX, X: chemoreceptors - O2, CO2). Note: There are also baroreceptors in the aortic arch and chemoreceptors in aortic bodies that provide input to solitary nucleus via the vagus nerve Neurons from the cardiorespiratory zone project to the DMN, NA, the IML of the upper thoracic spinal cord, and medullary reticular centers for cardiovascular and respiratory control. Notably, the caudal solitary nucleus takes part in the baroreceptor reflex

1. caudal cardiorespiratory zone

``` Midolivary level: __1__ Nuclei (inferior and medial) -The__2__ and __2__ vestibular nuclei are present within the rostral, dorsolateral medulla. -These nuclei receive input from the labyrinth of the inner ear and are involved in body equilibrium and control of eye movements. -Damage to the vestibular nuclei result in __3__, __3__, and __3__ ```

1. Vestibular nuclei 2. inferior and medial 3. vertigo, nausea, and nystagmus.

Midolivary Level: Restiform body enlarges __1__ nucleus and tract are in a similar position; Pars interpolaris – dental pain and temp; some crude touch. __2__ tract, medial __3__, tectospinal tract and medial longitudinal fasciculus, and __4__ system are in similar positions. __5__ nuclei are found in the ventral aspect of the pyramid. These nuceli are continuous with the pontine nuclei and will send axons into the cerebellum, as ventral external arcuate fibers and the striae medullares.

1. Spinal 2. Pyramidal tract 3. medial lemniscus 4. anterolateral system 5. Arcuate nuclei

Midolivary level: Nucleus __1__ and __1__ are no longer present; The vestibular nuclei adopt their position. Lateral cuneate nucleus may still be present. Rubrospinal, reticulospinal and vestibulospinal tracts are in a lateral position. The anterior spinocerebellar tract is present. Ventral Trigeminothalamic tract is lateral to medial lemniscus still.

1. gracilis and cuneatus | 2.

Rostral Medulla: Anatomical Notes Level of CN IX & VIII Note Appearance of: a. dorsal and ventral __1__ nuclei (C.N. VIII) discussed with pons)) b. Inferior __2__ nucleus (of IX) c. Nucleus __3__ (i.e. participates in visual fixation on objects) __4__ body enlarges Reticular formation enlarges

1. dorsal and ventral cochlear nuclei 2. salivatory 3. prepositous 4. Restiform body

Rostral Medulla: Inferior __1__ nucleus (GVE) a. Origin of parasympathetic motor fibers to the parotid gland. b. Fibers synapse in __2__ ganglion; postganglionic fibers supply parotid gland. c. Receives influences from hypothalamus and olfactory system

1. inferior salivatory nucleus | 2. otic ganglion

Rostral Medulla: Spinal __1__ nucleus (and tract), __2__ system, __3__ tract and anterior __4__ tract lie between the restiform body and Inferior olive. (Posterior spinocerebellar tract and cuneocerebellar tract are now part of the restiform body).

1. trigeminal 2. anterolateral 3. rubrospinal 4. spinocerebellar tract

Rostral Medulla: - __1__ tract is on the ventral surface - Medial __2__ is in the midline (arm representation near the top). - Medial __3__ fasciculus and __4__ tract are dorsal to the medial leminiscus

1. Pyramidal tract 2. medial lemniscus 3. medial longitudinal fasciculus 4. tectospinal tract

The __1__ formation is located throughout the brainstem and has a wide variety of functions including consciousness and sleep. This will be covered in a separate lecture.

1. reticular formation

Blood Supply to the Upper Medulla: 1. __1__ Arteries 2. Anterior __2__ Artery 3. __3__

1. Vertebral arteries 2. anterior Spinal artery 3. PICA

Blood Supply to the Upper Medulla: A. Major vessels: 1. __1__ spinal artery 2. __2__ arteries 3. __3__ artery 4. __4__ artery

1. anterior spinal artery 2. vertebral arteries 3. posterior spinal arteries 4. posterior inferior cerebellar artery

Blood Supply to the Upper Medulla: Areas supplied: 1. __1__ Artery -supplies medial and ventral 2. __2__ supply intermediate-lateral areas 3. __3__ artery supplies dorsal (caudal regions 4.__4__ supplies dorsolateral

1. Anterior Spinal artery 2. Vertebral arteries 3. posterior spinal artery 4. PICA

The pons is derived from the __1__ (primary brain vesicle), and later as part of the __2__ along with the cerebellum. It forms in the pontine flexure between the mesencephalon and myelencephalon. The development of the cerebellum will be discussed in a later lecture.

1. rhombencephalon | 2. metencephalon

For the pons, the __1__ plate is the source of sensory-related nuclei that will become associated with cranial nerves. The __2__ plate forms the midline and dorsal motor components of pontine cranial nerve nuclei. Cranial nerve sensory nuclei develop and remain in a dorsal and lateral position in the pons. The pontine nuclei migrate from part of the alar plate ventrally and medially to form the basilar pons. The axons from these nuclei will form the middle cerebellar peduncle that wraps around the brainstem in a lateral position.

1. alar | 2. basal

Pons- Major Divisions: In the adult, the pons has two major regions: Dorsal (and medial) Portion- A.K.A. __1__- Rostral continuation of medullary reticular formation and associated tracts Pontine cranial nerve nuclei Ascending sensory tracts -Ventral (and lateral) portion- __2__ Cortically derived axons, corticobulbar, corticospinal Pontine nuclei Projections of pontine nuclei to cerebellum-middle cerebellar peduncle

1. Pontine tegmentum | 2. basilar pons

The nuclei of CN __1__ overlap between the pons and medulla and in some cases is classified as lying in both.

1. VIII

Cochlear Component Axons from the spiral ganglia of the cochlea carry auditory information to the brainstem. Brainstem neurons contacted by auditory axons are located in: __1__ Cochlear Nucleus __2__ Cochlear Nucleus

1. Dorsal | 2. Ventral

Axons from the dorsal and ventral cochlear nuclei will eventually form the primary ascending auditory pathway, the __1__ To form this pathway, axons leave the nuclei in the in the dorsal, intermediate and ventral acoustic stria The axons primarily cross (smaller ipsilateral component) at more rostral levels. The region of the brainstem where crossing axons seen in sections are called the __2__ body (F)

1. lateral lemniscus. | 2. trapezoid body

Axons from dorsal and ventral cochlear nuclei may synapse in brainstem sound processing nuclei (accessory nuclei) including: - Nucleus of the __1__ body- localization of sounds - Superior __2__ nucleus- sound localization- reflex sound dampening via C.N. VII (stapedius muscle) and CN V tensor tympani) - Nucleus of the__3__-sound localization, acoustic reflexes( not as well defined

1. trapezoid 2. olivary 3. lateral lemniscus

Axons from the dorsal and ventral cochlear nuclei and those containing processed information from accessory collect primarily in the __1__ to ascend to: Inferior Colliculus Medial geniculate body (thalamus) Cortex (temporal, transverse gyri of Heschel)- conscious perception

1. contralateral lateral lemniscus

Because the __1__ travels bilaterally (contralateral predominance) in the dorsolateral brainstem, an ipsilateral lesion in the brainstem will not typically cause a hearing loss unless the nerve or cochlear nuclei are involved.

1. lateral lemniscus

. The __1__ component of the vestibulocochlear nerve innervates four nuclei in the dorsal and lateral part of the of the pontomedullary junction.

1. vestibular

Vestibular Component 1. transmits afferent information from vestibular apparatus. 2. Axons of origin arise from the vestibular ganglion; these project to the vestibular nuclear complex (4 nuclei each side) consists of : a. ___1__ vestibular nucleus b. __2__ vestibular nucleus (Deiter's nucleus) c. __3__ vestibular nucleus d. __4__ vestibular nucleus

1. Medial 2. Lateral 3. superior 4. inferior

Central nuclear projections of the Vestibular nuclei : __1__ via juxtarestiform body (balance coordination). There are some direct connections of the nerve to the flocculonodular lobe and deep cerebellar nuclei.

1. Cerebellum

CN VIII -Vestibular Related Pathways: __1__ nuclei: via the medial longitudinal fasciculus (MLF)- __2__-via MLF: projects to cortex to give conscious perception of equilibrium and orientation.

1. Oculomotor nuclei | 2. Thalamus

CN VIII -Vestibular Related Pathways: __1__- via two primary tracts: __2__ tract -from lateral vestibular nucleus (Deiter’s nucleus), excitatory to extensor spinal alpha motoneurons

1. Spinal Cord | 2. Lateral vestibulospinal

Medial vestibulospinal tract (AKA__1__ (MLF-descending )- it descends into the spinal cord. Inhibitory to neck and upper trunk muscles. Contributes to head-righting reflexes in relation to vision, etc.

1. Medial longitudinal fasciculus

Just rostral to the nuclei of CN VIII at the pontomedullary junction, the caudal pons contains the nuclei for Cranial Nerves __1__ and __1__ The nerves themselves exit from their nuclei in a ventral and slightly caudal direction to exit at the pontomedullary junction.

1. VI and VII.

__1__ Nerve- C.N. VII, (Level of VI &VII)- Exits brainstem just anterior to VIII at pontomedullary junction.

1. Facial nerve

Pons: Facial Nerve- C.N. VII-Motor Branch: Nuclei and Functional components: __1__ nucleus- Facial Motor function (SVE)- Somatic motor to pharyngeal arch muscles: -muscles of facial expression stylohyoid posterior belly of digastric stapedius- sound dampening

1. Facial motor nucleus

PONS- Facial Nerve- Motor Branch: Internal nerve course-axons loop around (internal genu of facial nerve) the nucleus of C.N. VI and exit__1__. Note that the axons forming the ‘loop’ are primarily from the motor nucleus

1. ipsilaterally

The "bump" on the floor of the IVth ventricle showing the presence of the abducens nucleus and the axons of the VII nerve surrounding it is the__1__

1. facial colliculus

PONS- Facial Nerve- Motor Branch- Cortical Innervation: Cortical innervation is __1__ to portion of nucleus innervating muscles of the forehead, but __2__ to area of the nucleus for muscles of the lower face. -This means that after a cortical or corticonuclear lesion function the the forehead may remain, but not to the lower face.

1. bilateral | 2. contralateral

PONS- C.N. VII-Intermedius Branch Functions Parasympathetic functions (GVE): __1__ glands via pterygopalatine ganglion __2__ membranes of nose, hard and soft palates __2__ glands- submandibular, sublingual via submandibular ganglion

1. lachrymal glands 2. mucous membranes 3. salivary

PONS- CN VII-Intermedius Branch-Brainstem Parasympathetic Nuclei: Superior __1__ Nucleus- (GVE)- diffuse collection of neurons in dorsolateral reticular formation, dorsolateral to descending limb of the facial nerve. Axons transverse the geniculate ganglion to synapse in the pterygopalatine and submandibular ganglia (cholinergic) Stimulate secretion from lachrymal and salivary glands (sublingual, submandibular . Also mucosa of nasal and oral cavities.

1. Salivatory

PONS- CN __1__- __2__ Branch Parasympathetic Functions: Central autonomic connections- to GVE: Pathway -From limbic system and olfactory areas through hypothalamus to the brainstem via the dorsal longitudinal fasciculus. Functions - Emotional responses, weeping, mouth watering to odors etc. Brainstem reflex circuits- reflex lachrymation from V, gustatory stimulation of salivation.

1. VII | 2. Intermedius

PONS-CN VII- Intermedius Function- __1__ | __1__ -(SVA) from anterior 2/3 of tongue and hard and soft palates via geniculate ganglion.

1. Taste

PONS- CN VII-Intermedius Taste Function- Nuclei: __1__ Nucleus (rostral portion, gustatory nucleus, SVA) Begins with sensory fibers innervating taste buds on tongue and hard and soft palates that run in the chorda tympani from the geniculate ganglion. It projects into the brainstem as part of the nervus intermedius and enters the tractus solitarius to synapse in the rostral portion of the nucleus. The nucleus sends information via__2__ tract to thalamus(VP) which projects to cortex (conscious perception of taste).

1. Solitary nucleus | 2. central tegmental

Pons - C.N. VII- Intermedius Branch Function-Somatic Sensation.: __1__ (GSA)-skin of the ear wall of acoustic meatus and external tympanic membrane via geniculate ganglion.

1. General Sensory

``` PONS- C.N. VII-Intermedius Branch Functions: __1__ nucleus-GSA Axons innervating areas around ear Cell bodies in geniculate ganglion Enter brainstem in nervus intermedius Descend in spinal tract of V to synapse. ```

1. Spinal V nucleus

know slide 32

abducens

Caudal pons: __1-_ Nerve-C.N. VI -(GSE)-(Level of VI & VII). Exits in the inferior pontine sulcus. Exclusively motor -innervation to__2__muscle of the eye (abduction of eye)

1. abducens nerve | 2. ipsilateral lateral rectus

Neurons located in abducens nucleus, beneath the axons of the facial nerve in the facial colliculus. Has a long intracranial course and is one of the most frequently injured of cranial nerves. Has complex central connections with __1-_nuclei

1. oculomotor

Caudal Pons- Abducens: The principal interactions with the oculomotor nucleus via the medial longitudinal fasciculus. This is involved in __1__ eye movements

1. conjugate eye movements

The pontine__1__formation, in the pontine tegmentum contains many nuclei that contribute to the reticular formation located over the entire brainstem. The __1__ formation forms complex connections between cranial nerve nuclei for reflex and visceral functions It has rostral projections to the thalamus that regulate consciousness and caudal projections that regulate motor and sensory functions These will be covered in later lectures

1. reticular

``` The tract between cranial nerves III and VI that carries information to coordinate eye movements is: The corticospinal tract The vestibulospinal tract The medial lemniscus The medial longitudinal fasciculus The lateral lemniscus ??? ```

medial longitudinal fasciculus

Caudal Pons-Locations of Major Tracts: General Organization The __1-_and __2__ (bulbar) tracts run through the substance of the basilar pons. The other ascending and descending major tracts become displaced into the pontine tegmentum.

1. corticospinal | 2. corticonuclear

Caudal Pons-Locations of Major Tracts-__1__: | The __1__ is still in the midline, but begins to turn so that the somatotopy shifts so the leg areas are more lateral.

1. Medial Lemniscus

The __1__ system is still in a lateral position within the pontine tegmentum, usually at its anterolateral edge with the forming middle cerebellar peduncle. The __2__ tract is just dorsal to the anterolateral system. Reticulospinals and vestibulospinals are still being formed in this area, so they are not clear.

1. anterolateral system | 2. rubrospinal

Caudal Pons-Locations of Major Tracts- Spinal V Nucleus: The__1__nucleus and tract of CN__2__ are still present as the pars oralis in a position just dorsal to the exit of the facial nerve. AKA __3__ tract

1. spinal nucleus 2. CN V 3. spinal tegmental tract

The __1__ fasciculus and the tectospinal tracts (now sometimes called the tectobulbospinal tract) are in a dorsal position near the midline. These tracts will now carry motor information for eye movements.

1. medial longitudinal

Major tracts entering the cerebellum beginning at the pontomedullary junction, The __1-_ peduncle (restiform body) will begin to enter the cerebellum in a dorsal and lateral position. -The ICP includes vestibulocerebellar projections called the __2__ body. The middle cerebellar peduncle (between the pons and cerebellum will wrap laterally around the inferior peduncle.

1. inferior cerebellar peduncle | 2. juxtarestiform

The two __1__ peduncles are present in more rostral sections forming part of the roof of the fourth ventricle along with the superior medullary velum, a connective tissue membrane between them.

1. superior cerebellar

``` Blood Supply to the Caudal Pons: The blood supply to the pontomedullary junction and caudal pons is somewhat variable with contributions from the: __1__arteries __2_ artery __3__ artery __4__ arteries. ```

1. Verterbral arteries 2. Basilar artery 3. Posterior inferior cerebellar artery 4. , Anterior inferior cerebellar artery

Blood Supply to the Caudal Pons- pontomedullary junction: -Areas most commonly are supplied: __1__and__2__branches of the basilar supply ventral and medial -__3__ supplies dorsolateral

1. vertebral 2. medial 3. PICA

Blood Supply to the Caudal Pons: Basilar Branches branches of the __1-_ artery, often described as paramedian, short and long circumferential branches. -Dorsal and lateral areas of the caudal pons may also be supplied by__2__

1. basilar | 2. AICA