Neuro midterm Flashcards
(359 cards)
1
Q
Neurology
A
the anatomy, physiology, and pathology of the nervous system
2
Q
Anatomy
A
study of structure
3
Q
Neuroanatomy
A
the study of the nervous system’s structure
4
Q
Physiology
A
study of function
5
Q
Neurophysiology
A
the study of the nervous system’s function
6
Q
Pathology
A
study of diseases
7
Q
Neuropathology
A
the study of nervous system diseases
8
Q
Neurosurgery
A
the removal or repair of structures that impair normal nervous system functioning
9
Q
Neuroradiology
A
the use of radiation therapy for nervous system tumors
10
Q
Neuroembryology
A
normal and pathological development of the nervous system
11
Q
Parts of the CNS
A
brain and spinal cord
12
Q
Parts of the PNS
A
spinal & cranial nerves
13
Q
Medical model of disability
A
focus on person with disability:
impairment
disability
handicap
14
Q
Social model of disability
A
focus on a society that disables:
function barriers
activity barriers
participation barriers
15
Q
Theoretical perspectives (bits and pieces - as a whole)
A
radical localists
localists
connectionists
holists
16
Q
Structural imaging
A
viewing the anatomy of the brain
17
Q
Functional imaging
A
viewing the physiology of the brain
18
Q
CT
A
- structural imaging
- computerized tomography
- uses x-ray beams that reflect off body’s tissues
- more reflection with dense tissues, like bone
- image = 2D image that can be rendered into a 3D image
19
Q
Positives of a CT
A
- commonly used
- easily accessible
- inexpensive
- quick processing time
20
Q
Negatives of a CT
A
- use of x-rays/cancer risk
- shows structure only
- difficulty observing new damage
- clarity of images (difficulty seeing soft tissues)
21
Q
MRI
A
- structural imaging
- magnetic resonance imaging
- magnetic current is applied to body that flips protons in body’s water molecules
- image formed from three planes (3D image)
22
Q
Positives of an MRI
A
- better images
- images in multiple dimensions
- no x-rays
- no preparation needed (ex: injections)
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Q
Negatives of an MRI
A
- more expensive than CT
- patients with metal in body
- patients must be still
- patients with claustrophobia will struggle with exam
24
Q
Angiography
A
- structural imaging
- method of imaging the structure of the vascular system
- iodine injected into this system
- x-rays used to image the vascular system
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Positives of an angiography
- excellent images of the vascular system
- assessment and treatment can be completed in the same session
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Negatives of an angiography
- invasive
- risk of bleeding, bruising, clotting, and swelling
- uses x-rays/radiation
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Spatial resolution
- functional imaging technique
- the location of brain activity when a stimulus is introduced
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Temporal resolution
- functional imaging technique
- the time between a stimulus being presented and the brain's response to that stimulus
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PET
- functional imaging
- positron emission tomography
- underlying logic = active brain areas need more energy
- image based on glucose metabolism in brain
- uses radioisotope
- emitted radiation is detected and an image is formed from it
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Positives of PET
good image of location of brain activity
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Negatives of PET
- invasive procedure because of injection
- radioactive material used
- more expensive technique than CT and MRI
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EEG & MEG
- functional imaging
- electroencephalography & magnetoencephalography
- show electrical responses to a particular stimulus
- stimuli can be presented in any modality: visual, auditory, somatosensory, olfactory
33
Positives of EEG/MEG
- low cost
- readily available
- good information on brain function
34
Negatives of EEG/MEG
image quality (none)
35
fMRI
- both structural and functional imaging
- functional magnetic resonance imaging
- critical element = blood oxygenation in brain during introduction of a stimulus
- no contrast needed (compared to PET)
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Positives of fMRI
- can see structure and function at the same time
- safe (no contrast needed)
37
Negatives of fMRI
- expensive
- not widespread
38
Spatial resolution from best to worst
fMRI
PET
EEG/MEG
39
Temporal resolution from best to worst
EEG/MEG
fMRI
PET
40
Anatomical position
- body erect
- palms out
- arms forward
- face forward
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Coronal section
-aka frontal
-divides structure into front and back portions
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Sagittal section
- aka lateral
- divides structure into left and right portions
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Transverse section
-aka horizontal
-divides structure into upper and lower portions
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Superior
- aka cranial
- from a high position
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Inferior
- aka caudal
- from a low position
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Anterior
- aka ventral
- toward the stomach
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Posterior
- aka dorsal (dolphin fin)
- toward the back
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Lateral
away from body's midline
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Medial
towards the body's midline
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Proximal
point nearest limb's attachment (a medical proxy is someone close to you)
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Distal
point farthest from limb's attachment
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Peripheral
toward the outer surface
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Central
toward the center
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Ipsilateral
on the same side
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Contralateral
on the opposite side
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Abduct
moving structures apart
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Adduct
bringing structures together
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Flexion
bending a joint
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Extension
straightening out a joint
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Supine
- face/ventral surface is up
- helps with respiration and velar articulation
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Pronate
face/ventral surface is down
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Anatomical approach
- based on the gross anatomy of the nervous system
-CNS & PNS
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Functional approach
- based on the function of the nervous system
- examples: voluntary & involuntary functions
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Developmental approach
- based on the development of the nervous system and neurodevelopmental terms
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Where do genes reside?
in the chromosomes
66
Where do chromosomes reside?
in the nucleus of the cell
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Karotype
- a person's unique collection of chromosomes
- individualized to you
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How many pairs of chromosomes are there?
23 pairs
46 individual
69
Down syndrome
extra copy of chromosome 21
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Turner syndrome
person only has 1 sex chromosome
71
Prader-Willi syndrome
defect of chromosome 15
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Fragile X syndrome
change to gene on X, fails to produce protein needed for brain
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Mitosis
- cell duplicates all contents and splits
- forming two identical daughter cells
- critical, controlled genes
- breakdowns cause diseases - cancer
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Meiosis
- two step process
- goal - correct number of chromosomes
- reduces chromosomes from 46 to 23 - form sperm/egg cells
- cells unite at conception each contribute to 23 chromosomes resulting 46 total
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Gene shuffling
genetic variation during division
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Dorsal induction
- 3-7 weeks
- period when neural tube is formed
- 3rd week: neural plate is formed
- 4th week: neural plate wraps around to form the neural tube
- 6th week: ends of neural tube close
- brain and spinal cord will develop out of the neural tube
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Neurulation
neural plate wraps around to form the neural tube
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Neural tube defects
failure of neural tube ends to close
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Encephalocele
part of the brain protrudes from the skull
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Anencephaly
- brain development ceases at brainstem
- child without cerebral hemispheres
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Spinal bifida
cyst on back that may or may not involve the spinal cord
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Ventral induction
- 2-3 months
- neurodevelopmental period when face and brain develop out of superior end of the neural tube
83
Telencephalon
- "end of the brain"
- cerebral cortex, basal ganglia, olfactory bulbs
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Diencephalon
thalamus, hypothalamus, epithalamus, subthalamus
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Mesencephalon
midbrain; front of brain stem, important for sensory, motor, arousal, damage to brain stem is dangerous
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Metencephalon
- hindbrain
- pons, cerebellum
87
Myelencephalon
- medulla (oblongata)
- connects brain to spinal column
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Neurogenesis
birth of new neurons
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Neural proliferation
- 3-4 months
- new neurons will become the gray and white matter of the cerebral hemispheres
- born out of spinal cord and brainstem
- interruptions in neural proliferation may result in microcephaly where children have abnormally small heads/brains
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Neuronal migration
- 3-5 months
- new neurons move in wavelike fashion to their correct position in the cerebral hemispheres
- at about 20 weeks, process stops and 6 layers of cerebral cortex are established
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Reelin
- part of process of neuronal migration
- signals neurons where to stop
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Cortical organization and synapse formation
- 5 months-years
- once neurons arrive at intended spot, they sprout dendrites and axons
- failure in this stage can lead to polymicrogyria
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Synaptogenesis
synapses begin to form between neurons
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Synaptic pruning
- eliminates unneeded connections
- part of the use it or lose it theory
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Polymicrogyria
too many gyri in the cerebral hemispheres
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Myelination
- birth-years after birth
- children's brains are still forming myelin
- neuron axons are coated with myelin
- process reaches its peak about 1 year after birth
- infants gain greater controls of their bodies and begin to develop the ability to communicate verbally
- failure in this stage may result in hypomyelination
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Hypomyelination
a reduced ability to form myelin resulting in intellectual disability
98
When does adolescence begin?
- 10-11 years for girls
- 11-12 years for boys
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Adolescent brain
- period of profound brain development that is not complete until about age 25
- adolescent brain is very plastic
- profound brain changes help to explain adolescent behavior
- teens rely more on feelings and impulses than logic and planning
100
Synaptic pruning
- begins at back of the brain and moves to the front
- prefrontal cortex is the last area to be pruned
101
What happens in the brain during adolescence?
thinning of gray matter
102
Examples of changes to the brain as we age
- lose neural circuits
- lose plasticity
- cortex thins due to dendrite thinning and decrease in number
- neurotransmitter levels decrease
- neurotransmitter receptor sites decrease
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What does structure and chemical changes result in?
loss of memory, attention, learning, and language
104
Molecules
consist of two or more atoms held together by a chemical bond
105
What are the 4 families of molecules?
simple sugars
fatty acids (or lipids)
amino acids
nucleotides
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Neurons
responsible for sending & receiving neurotransmitters
107
How are neurons classified?
shapes/# of appendages
function (afferent/efferent)
direction of action potential
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Classification of neurons: number of appendages
multipolar
bipolar
unipolar
pseudounipolar
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Classification of neurons: motor/efferent
- from the CNS to PNS
- final neurons in action sequence
- cell bodies in the motor nuclei of cranial nerves in brain stem and in anterior horns of spinal cord
- 2 types: alpha & gamma
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Classification of neurons: afferent/sensory
- from sensory receptors in body towards CNS
- first neurons in sensory sequence
- cell bodies (except olfactory) lie outside CNS
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Classification of neurons: interneurons
- transmit impulses between other neurons
- integrate sensations
- organize muscular and glandular response
- determine place and time of response
112
Cell body
- aka soma
- contains genetic information
- maintains neuron integrity/structure
- regulates production of proteins & lipids needed for energy
- holds nucleus, rough endoplasmic recticulum (Nissl substance), smooth endoplasmic recticulum, golgi apparatus, mitochondria
113
Axon
- long, thin, and spindly
- diameter approximately 100x smaller than human hair
- structure makes it susceptable to damage
- where action potentials are generated
- action potential travel down axon to release neurotransmitters
- axon covered in myelin
- ends in axon terminals
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Axon region
- aka axon hillocks/initial segment
- "manager" summing total inhibitory/excitatory signals to determine if action potential releases
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Axon telodendria
end branches of an axon
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Dendrites
- receives the data from other neurons
- collects and stores incoming information from axon terminals
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Cytoplasm
- jelly-like fluid found within the cell body but outside the nucleolus
- function in transport, maintain cell shape, protect & hosts metabolic process
118
Neurons compared to other cells: similarities
- have a membrane
- have a nucleus
- have a cytoplasm, mitochondria, and other organelles
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Neurons compared to other cells: differences
- have specialized projections
- communicate with each other through an electrochemical process
- can be long, several feet at times
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Neuron function
primary purpose = communication
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Efferent communication
motor signals from CNS to PNS (descending)
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Afferent communication
sensory signals from PNS to CNS (ascending)
123
Two phases of communication in neuron function
electrical phase (dendrites and axons)
chemical phase (neurotransmitters and synaptic cleft)
124
Impulses of neurons
- electrical currents/action potentials
- 2 types: excitatory (go) and inhibitory (no go)
125
Synapses
tiny gap where specialized parts of two neurons allow for chemical communication
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Electrical signals
within the neuron
127
Chemical signals
between the neurons
128
Presynaptic neuron
sends the information
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Postsynaptic neuron
receives the information
130
Action potential
created electrical signal
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Neurotransmitter
the action potential triggers the release of a chemical
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Process of neuronal communication
- action potential triggers release of NT
- chemical moves into synaptic cleft
- the NT binds to a receptor on the postsynaptic neuron
- the chemical newly introduced into that neuron causes ion channels to open
- the opening of ion channels allows charged particles to cross membrane of that neuron causing electrical charge to form in postsynaptic neuron
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Polarization
there are different electrical charges inside versus outside of neurons
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Inside neuron at rest
negative charge about -65 mV known as resting membrane potential
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Outside of neuron
neutral - 0 mV
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Hyperpolarized
when resting membrane potential becomes more negative -80 or -90 mV, less likely to generate/send a signal
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Depolarized
when resting membrane potential becomes "better" heading toward positive although still negative numbers -60 to -50 mV, more likely to generate & send a signal
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Membrane status
- neuron needs a threshold of "better" before a cascade of events can be activated
- the threshold is generally -50 mV
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Membrane potential
creates two gradients: electrical and ion
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Electrical gradient
ions "want" to move down their concentration gradients...positives more towards negative to make the "area" more positive
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Ion concentration
also move down concentration gradient from high to low (want to decrease concentration)
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Ions to remember
sodium
potassium
calcium
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Ions: in CNS inside cell
potassium
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Ions: in CNS outside cell
sodium & calcium
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Ion channel (passive transport)
- occur in cell membrane
- when open, the ions move freely based on their tendency for concentration gradient
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Excitatory postsynaptic potential (EPSP)
- neuron that received signal
- a neurotransmitter opens sodium channel, so sodium moves into neuron
- potential to cause depolarization
147
Inhibitory Postsynaptic Potential (IPSP)
- a neurotransmitter opens potassium channel, so potassium starts to move out the neuron and begin to hyperpolarize
- also could open chloride channels with the same result as hyperpolarization
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Summation
if enough sodium channels are opened and threshold reached
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Active transport post threshold
- if results was subthreshold, sodium-potassium ion pump uses active transport to restore the cell to resting membrane
- active transport
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Active transport
- energy in form of adenosine triphosphate (ATP)
- everything wants to go back to their resting state
151
Exocytosis
- the release from presynaptic neuron axon terminals called exocytosis
- the neurotransmitter spills into the synaptic cleft and binds to receptors of postsynaptic neuron
- either inhibitory or excitatory response will be created
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Resting potential
electrical difference between inside and outside membrane when neuron not excited
153
Action potential
rapid rise (depolarization) in potential followed by return to resting state
154
Graded potential
localized, small depolarizations could AP if meet threshold
155
Saltatory conduction
- rapid method where nerve impulses move down myelinated axon
- excitation occurs only at Nodes of Ranvier
- jumping of current from node to node
- nodes contain Na & K channels
- myelin allows rapid movement of the signal
156
What happens at the synapse?
- AP reaches bouton terminal
- causes release of chemical transmitter substance from synaptic vesicles
- causes next neuron to change charge
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Types of transport
active and passive
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Active transport
energy used
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Passive transport
no energy used
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What is AP due to?
concentration gradient
charge (electrical) gradient
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Depolarization
the equaling of gradients (both electrical and concentration)
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Repolarization
the re-establishing of the gradients (both electrical and concentration) by the Na/K pump (active transport)
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Intellectual disability
- sub-average intelligence (<70 IQ)
- occurs before age 18
- substantial limitations in functioning (e.g., educational struggles)
- dendritic spine differences
164
Benign brain tumors
non cancerous
165
Malignant brain tumor
cancerous
166
Brain tumor examples
neuromas (neurons)
gliomas (glial cells): astrocytoma, oligodendroglioma, schwannoma
167
Amyotrophic lateral sclerosis (ALS)
- motor neuron disorder
- withering of upper and lower motor neurons
- onset 40-60 years of age
- most die within 3-5 years
- no cure
168
Multiple sclerosis
- "multiple scarring"
- autoimmune disorder of unknown cause
- myelin around axon is damaged
- no cure, but medications can suppress symptoms
169
Myasthenia gravis
- "grave muscle weakness"
- neurological disease of the neuromuscular junction
- ACh receptors blocked by body's antibodies
- affects women in their 30s and men in 50s
- weakness and fatigue
- no cure
170
Guillian-Barre syndrome
- rapid, progressive demyelinating PNS disease
- most common form is autoimmune in nature
- progressive paralysis over 1 month, but then patient begins to recover over weeks/months
- many patients experience complete recovery
- at most serious stage, patients usually need ventilator support
- no cure
171
Spinal cord
- information superhighway conveying motor (efferent) and sensory (afferent) information between brain and body
- spinal nerves emerge from the spinal cord and innervate parts of the neck and below the neck
172
Spinal cord means for communication
brain to body
body to brain
surrounded by vertebral column
173
3 layer of meninges
pia mater - inner
arachnoid - web like, filled with CSF
dura mater - tough, outside layer
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Sections of spinal cord
cervical - neck
thoracic - chest
lumbar - lower back
sacral - pelvis
coccygeal - tailbone
175
4 fiber types of the spinal cord
- general somatic efferent - to skeletal muscles
- general visceral efferent - to smooth muscle, heart, glands
- general somatic efferent - from skin
- general visceral afferent - from lungs and digestive tract
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Funiculi
each white matter region contains multiple tracts
carries information up and down spinal column
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Dorsal root ganglion
collection of neuronal cells
signals from CNS from PNS
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Dorsal ramus
part of spinal nerve after the nerve exits intervertebral foramen
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Upper motor neuron (UMN)
- originates in the brain (cerebral cortex & brainstem)
- sends signal down spinal cord
- "commands" the movement
- located in CNS
- damage to UMN - splasticity, hyperflexia
180
Lower motor neuron (LMN)
- originates in the spinal cord
- directly controls the muscles by sending signals on to the muscles & glands
- "carries out" the action
- located in PNS
- damage to LMN - flaccid paralysis, muscle atrophy, decreased reflexes
181
Lateral corticospinal motor track
- descending
- helps with body movement, starts in motor cortex
- decussates at lower medulla - spinal juncture
- contralateral body movement
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Anterior (ventral) corticospinal tract
- descending
- originates in motor and premotor areas of frontal lobe
- smaller lateral cortical spinal tract, 10% of cortical spinal tract
- ipsilateral control of trunk muscles
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Rubrospinal tract
- originates in midbrain
- decussates in ventral midbrain
- inputs into ventral horn
- modulates flexor tone in upper limbs and shoulder
- terminates cervical/thoracic regions so does not impact lower limbs
184
Vestibulospinal tract
- originates in medulla
- ipsilateral
- inputs into ventral horn
- controls extensor tone in limbs and neck
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Ascending sensory tracks
divided into 1st, 2nd, 3rd, and 4th order neuron
186
1st order neuron
directly receive information from periphery to spinal cord
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2nd order neurons
within spinal cord (may decussate) to thalamus or brainstem
188
3rd order neurons
in thalamus, carry to specific areas of cerebral cortex
189
4th order neuron
in cerebral cortex, interpret signal
190
Dorsal columns
- ascending
- sensory receptors --> spinal cord (decussates) --> thalamus --> somatosensory cortex (located in postcentral gyrus)
- fine touch, pressure, proprioception
191
Ventral (anterior) spinothalamic track
- ascending
- anterior part of spinal cord
- light touch, rough touch, and pressure
192
Lateral spinothalamic track
ascending
lateral spinal cord
pain & temp
from peripheral --> spinal cord --> thalamus --> somatosensory cortex
193
Ventral spinocerebellar tract
- ascending
- ventral portion to spinal cord, to dorsal horn, decussates to cerebellum
194
Dorsal spinocerebellar track
- ascending
- dorsal portion to spinal cord, to dorsal horn, ipsilaterally to cerebellum
195
Spinal cord function
- relaying efferent and afferent information between body and brain
- mediating reflexes through the reflex arc
196
Reflexes
- controlled at level of spinal nerves and spinal cord
- signal goes to spinal cord and returns via reflex arc:
muscle stimulated --> muscle spindles detect the stretch --> info is sent through sensory neurons to dorsal root (gray matter) --> info sent to special neurons "interneurons" --> motor message sent via ventral root for muscle to contract
197
Spinal cord injury
- damage to spinal cord, often through car accidents/falls
- vehicular accidents account for 40% of cases
- can result in either paresis or plegia
198
Paraplegia/paraparesis
involves the legs
199
Quadriplegia/quadriparesis
involves arms and legs
200
Myelitis
- inflammation of spinal cord
- caused by virus, bacteria
201
Poliomyelitis
affects gray matter (motor loss)
202
Leukomyelitis
affects white matter (sensory loss)
203
Transverse myelitis
affects both gray and white matter (motor and sensory loss)
204
Peripheral neuropathy
- inflammation of the PNS
- results in degeneration of the spinal nerves, typically in feet
- caused by untreated diabetes, toxins, infections
- leads to paresthesia (abnormal sensation, skin may feel tingling, burning) or anesthesia (insensitivity pain)
205
Midbrain
- most superior
- 3 main parts: colliculus/tectum, tegmentum, peduncles
206
Colliculus/tectum
contains inferior colliculus (auditory processing) and superior colliculus (visual processing)
207
Tegmentum
- dorsal part, spreads length of brainstem but portions form midbrain
- tracts and nuclei are important for motor control and sensory processing
- nuclei include substantia nigra, red nucleolus, recticulum formation, sleep-wake cycle, periaqueductal gray matter
208
Peduncles
- ventral part, leg of brain
- connects rest of brainstem to forebrain
- main highway of signals to be transported between cortex to parts of CNS
- important in coordination
209
Pons
- middle portion
- connected to cerebellum, middle cerebellar peduncle
- acts as "bridge" relaying tracts cerebral cortex, cerebellum, and lower structures medulla and spinal cord
210
Medulla
- lowest portion
- sits ventral (anterior) to cerebellum
- connects to cerebellum via inferior cerebellar peduncle
- anterior surface is pyramids, contain descending motor tracts & olivary cortex
211
Brainstem functions
- regulating major life functions (heart beat/respiration)
- mediating head and neck reflexes (gag) via cranial nerves
- regulating alertness and wakefulness
212
Inferior olivary nucleus
integrates signals from spinal cord to cerebellum, functions, coordination
213
Cranial nerves
- 12 pairs
- emerge directly from cerebrum and brainstem
- emerge above first level of first vertebrae
- 2 in cerebrum: olfactory and optic
- function: relay information between brain and parts of body; info to and from head and neck, sense of vision, smell, hearing
214
What are the cranial nerves?
I olfactory
II optic
III oculomotor
IV trochlear
V facial
VI abducens
VII facial
VIII vestibulocochlear
IX glossopharyngeal
X vagus
XI spinal accessory
XII hypoglossal
215
Muscles of the tongue
- hypoglossal
- palatoglossus
216
CN in speaking
V, VII, X, XI, XII
217
CN in hearing
V, VII, VIII
218
CN in voice
V, VII, X, XII
219
CN in swallowing
V, VII, IX, X, XI, XII
220
221
Cerebellum
- consists of two hemispheres connected by vermis
- 3 lobes: anterior, posterior, and flocculonodular
- contrains gray - tightly folded, forms cerebellar cortex
- white matter - beneath cerebellar cortex
222
Cerebrocerebellum
- largest, involved in planning movements and motor learning
- receives cerebral cortex --> thalamus/red nucleus
223
Spinocerebellum
- vermis and intermediate zone, error correction movement and proprioception
224
Vestibulocerebellum
- input from vestibular system --> vestibular nuclei, controlling balance, and ocular reflexes - fixation on target
225
Major cerebellar pathways
vestibulocerebellar
vermal spinocerebellar
paravermal spinocerebellar
pontocerebellar
226
Vestibulocerebellar
overall body posture and balance
coordination of eye movements
227
Vermal spinocerebellar
trunk and girdle muscle tone and posture
228
Paravermal spinocerebellar
distal muscle group tone and posture
229
Pontocerebellar
planning, initiating, and timing of volitional motor activity
230
Motor functions of cerebellum
- planning, monitoring, and correction of motor movement using sensory feedback
- coordinates fine motor activity
- monitors head and neck position
- participates in learning of new motor skills
231
Linguistic functions of cerebellum
- perception of speech/language
- verbal working memory
- verbal fluency
- grammar processing
- writing/reading
232
Ataxia
discoordinated, clumsy movements
233
Dysmetria
over- or undershooting touching a mark
234
Dysiadochokinesia
inability to perform rapid, alternating movements of hand or mouth
235
Nystagmus
fast, involuntary eye movements either side to side or up and down
236
Ataxic dysarthria
slurred or scanning (broken into syllables) speech
237
Hypotonia
reduced muscle tone and reflexes, muscle tire
238
Cerebellar hemispheric syndrome
damage in hemisphere of cerebellum
stroke, tumor, MS
239
Thalamus
two hemispheres
sits above brainstem
relay stations
gateway to cerebral cortex
240
Functions of thalamus
- relays senses
- perception of pain, temperature, and touch
- imparts sense of pleasantness and noxiousness
- maintains cortical arousal, attention, and sleep-wake cycle
241
Medial geniculate body lateral ventral group
relays auditory information from subcortical midbrain structures to auditory cortex - hearing
242
Lateral geniculate body lateral ventral group
information from optic nerve to primary visual cortex in occipital lobe - visual
243
Ventral posterior medial lateral ventral group
input (pain, temp, touch) form trigeminothalamic tract from CN associated with face (V, VII, IX, X)
244
Ventral lateral and ventral anterior
both receive input from basal ganglia and cerebellum and send information to motor cortex
VL - motor planning
VL & VA - involved in speech production
245
Posterior communicating artery (PCA)
important to the blood supply for the thalamus
246
Cushing disease
- pituitary problem
- endocrine disorder caused by tumor on pituitary
- results in high levels of cortisol
- symptoms: moon facies, emotional disturbances, osteoporosis
247
Acromelagy
- pituitary problem
- extreme largeness
- caused by pituitary tumor
- results in pituitary producing too much human growth hormone
- symptoms: large stature, large nose and jaw
248
Epithalamus
- lies superior and posterior to thalamus
- connects limbic system to forebrain and other parts of brain
249
Parts of the epithalamus
pineal gland
habenula
stria medullaris
250
Pineal gland
produces melatonin, sleep-wake cycle, circardian rhythms
251
Habenula
olfactory reflexes and stress
252
Stria medullaris
white matter tract connects habenula to limbic system
253
Epithalamus functions
- sleep-wake cycle
- olfactory reflexes
- reward and aversion
254
Subthalamus
- lies below thalamus
- connects basal ganglia to the motor cortex
- important for modulation of movement outside of basal ganglia
255
Subthalamus damage can result in
hemiballismus: involuntary flinging of limbs
tremors
OCD
impulsivity
256
Basal ganglia
3 nuclei make up basal ganglia:
caudate nucleus
globus pallidus
putamen
257
Major pathways of basal ganglia
direct - facilitates movement
indirect - inhibits movement
258
Dyskinesias
- involuntary, erratic movements, often fluid and dance like
259
Athetosis
type of dyskinesia
slow and writhing of limbs, trunk, neck, face, and tongue
260
Chorea
type of dyskinesia
involuntary, unpredictable, rapid movement/contractions of face, arms, legs
261
Akinesias
lose ability to move muscles on own, frozen
262
Rigidity
type of akinesia
muscle stiff and tighten involuntarily
263
Dystonia
type of akinesia
involuntary muscle contraction, repetitive movement or abnormal postures
264
Bradykinesia
type of akinesia
slowness of movement, difficulty initiating movement
265
Parkinson's disease
- progressive neurological disease
- caused by degeneration of midbrain's substantia nigra and loss of dopamine to BG
- symptoms: muscle rigidity, dyskinesias, tremors, poor posture, dysphagia
266
Huntington's disease
- progressive, hereditary neurological disease due to degeneration of the basal ganglia
- onset at 35
- autosomal dominant pattern of inheritance
- symptoms: chorea, emotional/personality changes, dysarthria, dysphagia, dementia
267
Ventricles
fluid-filled spaces in brain
268
4 ventricles
right lateral ventricle
left lateral ventricle
third ventricle
fourth ventricle
269
Right/left lateral ventricle
- located in each hemisphere
- paired
- c-shaped
270
Third ventricle
- from diencephalon
- single structure
- slit like structure between two thalami and part of hypothalamus
271
Fourth ventricle
most inferiorly located
lies within brainstem
272
Where do lateral ventricles drain to?
3rd ventricle via forman of monroe (interventricular foramen)
273
Where does the 3rd ventricle drain to?
4th ventricle
274
Where does the 4th ventricle drain to?
central spinal canal and then drains to subarachnoid cisterns
275
Function of CSF
- provides mechanical protection/cushioning
- facilitates homeostasis
- facilitates communication between CNS and PNS and immune system
276
CSF
clear/colorless fluid
found in ventricular system, cerebral, spinal, and arachnoid, spaces and perivascular spaces in CNS
277
Choroid plexus
located in each ventricle
278
CSF components
water
protein 9
neurotransmitters
glucose
279
CSF production changes with
aging
hypertension
atherosclerosis
sleep deprivation
280
CSF impact on dementia/alzheimer's
- aging process can lead to hyposecretions of CSF because increased connective tissue and changes in vascular system causes CSF to back up
- interferes with the brain waste clearance system
281
Hydrocephalus
hemorrhage caused an inflammation response in the brain that caused hypersecretion
excess CSF builds up in ventricles
diagnose through CT, MRI, spinal tap
282
What do holes in the meninges do?
decrease CSF pressure
postural headaches
relayed to bouyance of brain and difficulty keeping brain supported if not enough CSF
283
Brain
weighs 3 pounds
2% of body's weight
20% of body's energy
function not related to size but to number and organization of neurons
2 hemispheres
284
Cerebral cortex
made of neuronal cell bodies (gray)
below gray matter is neuronal axons (white)
285
Longitudinal fissure
separates cerebral hemispheres
286
Tentorium cerebelli
separates occipital lobe from cerebellum
287
Falx cerebelli
separates hemispheres of cerebellum
288
Function of meninges
protection of brain
shock absorber
anchor CNS to limit brain's movement
provide support system for blood vessels, nerves, lymphatics, and CSF
289
Epidural space
- between skull and dura mater
- anesthesia injected
290
Subdural space
- between dura mater and arachnoid mater
- in normal conditions, there is not a space --> brain bleed/trauma (subdural hematoma)
291
Subarachnoid space
between arachnoid & pia mater
filled with CSF, cushions & protects brain
292
Blood brain barrier
- highly selective/permeable membrane
- lines blood vessels in brain
- acts as filter to protect CNS
- regulates substances that pass through bloodstream into brain
- formed tightly packed specialized cells that form barrier around the brain capillaries
293
Functions of BBB
- protects against foreign invaders
- protects against hormones/neurotransmitters in rest of body
- maintains constant environment for brain
294
What can violate the BBB
hypertension
developmental problems
hyperosmolality
microwaves
radiation
infection
trauma
295
Circumventricular organs
- series of structures located around ventricular system
- highly vascular, lack BBB
- link CNS, vascular system, and endocrine systems, creating alternative route for hormones ad neuropeptides
296
Toxins that can cross BBB
lead/mercury/iron
alcohol/nicotine/caffeine
anesthetics
bacteria (meningitis)
highly lipid soluble molecules
diseases (cancer)
crossover of some drugs (dopamine)
297
Blood enters brain through
carotid and vertebral arteries
- feed circle of Willis
298
Aorta
begins in lower left chamber of the heart
extends upward toward head
299
3 branches that come off aortic arc
brachiocephalic
left common carotid
left subclavian artery
300
Arteries leading into circle of willis
bilateral internal carotids
basilar
301
Arteries leading out of circle of willis to the brain bilaterally
PCA
MCA
ACA
302
Anterior cerebral artery
medial and superior parts of frontal lobe
divided into central and cortical
303
Middle cerebral artery
substantial portions of cerebrum
bulk of lateral surface cerebrum and parts of frontal, temporal, and parietal lobes
304
Superior branch of MCA
portions of motor strip, premotor area, left hemisphere, Broca's area
305
Inferior branch of MCA
postcentral gyrus, Wernicke's area
306
Posterior cerebral artery
occipital lobe, posteriormedial temporal lobes, midbrain, thalamus, choroid plexus, parts of lateral and third ventricles
branches: central & cortical
307
Vertebral basilar system
blood supply to thalamus, cerebellum, occipital lobes, brainstem, and cervical spinal cord
308
Posterior inferior cerebellar artery (PICA)
largest branch
supplies critical regions of medulla, 4th ventricle and cerebellum
309
Basilar artery
- main artery that supplies blood to posterior brain including brainstem, cerebellum, and occipital lobes
- divides into AICA, superior cerebellar, and posterior cerebellar
310
Waste removal: the venous system
- moves deoxygenated blood away from the brain
- removed through 4 sinuses in meninges: superior sagittal, transverse, occipital, sigmoid
- superficial and deep cerebral veins then remove
311
Cerebrum
- two cerebral hemispheres
- layers from superficial to deep:
surface gray matter
white matter
deep gray matter
ventricles
312
Cerebral cortex features
gyri
sulci
fissures: longitudinal, central, lateral
313
Central fissure/sulcus
divides frontal lobe from parietal lobe
314
Lateral fissure
separates frontal and parietal lobes from temporal lobe
315
Precentral gyrus
- in front of central sulcus, location of primary motor cortex
- voluntary movement on opposite side of body
316
Postcentral gyrus
- parietal lobe, contains primary somatosensory cortex
- sensation from opposite side of body is processed
317
Superior temporal gyrus
- located in top most part of temporal lobe
- involved in speech/lang processing, contains primary auditory cortex
318
Lobes of the brain
frontal
parietal
occipital
temporal
319
Frontal lobe
reasoning, planning, motor movement
320
Parietal lobe
sensory perception and interpretation
321
Occipital lobe
vision
322
Temporal lobe
memory, receptive lang
323
Hemispheric specialization: lang dominance
most people are left hemisphere language dominant
324
Interhemispheric connections
- corpus callosum is a band of fibers that connects the right and left hemispheres together
- numerous connections with cerebral hemispheres; superior longitudinal fasciculus and arcuate fasciculus
325
Ischemia
blood flow to a part of the body is reduced/blocked
326
Causes of ischemia
- thrombus: local blockage, breaking off of plaque
- embolus: develops in another area of the body, breaks off and travels to brain, stuck in narrow vessel; air, fat, blood clot
327
Arteriovenous malformation (AVM)
- aberrant tangle of arteries and veins
- occurs in brain and spine
- present from birth
- enlarge/cause disruptions
- can rupture
- can be treated surgically depending on location
328
What can ischemia lead to?
hypoxia: inadequate oxygenation
anoxia: no oxygenation
infarct: brain tissue died
329
Causes of ischemia
vasospasm: blood vessel spasms and restricts blood flow
edema: swelling, compression of tissue
penumbra: swelling in tissue around site of damage
330
Aneurysm
wall of blood vessel weakness and breaks causing blood to leak into brain
331
3 types of an aneurysm
saccular/berry
fusiform
mycotic
332
Saccular/berry aneurysm
pouching of one side of artery
333
Fusiform aneurysm
ballooning of all sides of artery
334
Mycotic aneurysm
infection weakens the artery
335
TBI problems
attention
orientation
memory
reasoning
problem solving
executive functions
336
Neuroplasticity
the adaptive capacity of the CNS
337
Functional reactivation
recovery of function after period of latency
338
Functional reorganization
another brain area regions take over the function of the damaged area using surrounding tissue or regions in the opposite hemisphere
339
Impacts on neuroplasticity
excessive drinking, drug, caffeine use - decreases neuroplasticity
vitamin b, omega 3s, magnesium - increases neuroplasticity
340
Prefrontal cortex
functionally involved with cognition (executive control), personality, decision making, and social behavior
341
Frontal eye fields
- controls eye movements
- damage results in eyes deviating towards the side of injury
- involved in uncertainty and hope
342
Broca's area
- area 45
- involved in interpretation of language and planning/programming of verbal responses
343
Pars opercularis
- area 44
- coordination of speech organs for language production
344
Premotor cortex
- BA 6
- selecting and planning of motor movements
- supplementary motor area involved in sequencing and turning on motor plans
345
Primary motor cortex
- BA 4
- sends motor plans developed to the muscle for them to act
346
Primary sensory cortex
- BA 1, 2, and 3
processes somatosensory information such as vibration, proprioception, touch, stereognosis
347
Somatosensory association cortex
- BA 5 and 7
- interprets sensory experience during motor movements
- refine motor action
- fine movement associated with speech
348
Angular gyrus
- BA 39
- reading, math abilities
- understanding metaphors/sense of embodiment
- damage can lead to alexia and acalculia
349
Supramarginal gyrus
- closely related to angular gyrus
- involved in phonological system, stores auditory representations of phoneme (auditory images)
- helps sound out words
- damage can result in phonological dyslexia, difficulty reading new and nonwords
350
Visual cortex
- information from eyes is received and processed
- damage causes cortical blindness
351
2 streams of vision in visual cortex
dorsal stream: where of vision, analyzes motion and spatial relationships
ventral stream: what of vision, analyzes form, colors, and faces
352
Inferior temporal area
- processing of auditory and language information as well as reading facial emotions
- hallucinations
353
Parahippocampal hyrus
- hippocampus: associated with declarative memory
- entorhinal cortex: major input/output relay between cerebral cortex and hippocampus
354
Fusiform gyrus
- remembering and naming seen objects
- functions as a visual lexicon
- lesions can cause anomia and lexical agraphia
355
Temporal pole
left: semantic processing, speech comp, narrative comp
right: integration of emotion into narratives, identifying familiar voices
both: theory of mind and empathy
356
Primary auditory cortex
- initial cortical region that receives auditory information from the ears via CN VIII and auditory pathway
- processes sound intensity/frequency
- organize by tones
357
Wernicke's area
- attaching meaning to auditory information
- damage can result in aphasia
358
Cingulate cortex
- anterior parts: cognitive control, detecting errors, detecting conflicts, problem-solving
- posterior parts: autobiographical memory, managing risky behavior, emotional processing
- ACC filters out irrelevant info
- PCC detects important info
359
Insular cortex
- posterior-dorsal area: raw sensory perception of bodily states (pain, intensity, location)
- dorsal-caudal area: connections to BA 5 and 7, so involved in emotional and cognitive aspects of body integrating sensory feedback into motor behavior
