Nervous System Flashcards
1
Q
- Aka “Vegetative/ Involuntary/Visceral Nervous System”
- Functional division of the Nervous System
- Innervates viscera, smooth and cardiac muscles and glands which are all involuntary
- Divided into Sympathetic & Parasympathetic
A
Autonomic Nervous System (ANS)
2
Q
The space between ganglion and capsular cells
A
Perilymphatic space
3
Q
Three parts of the brainstem
A
- Midbrain
- Pons
- Medulla oblongata
4
Q
The cell membrane of axon
A
Axolemma
5
Q
- Aka Fusiform (Pleomorphic/Polymorphic)
Cell layer - Deepest layer
- Adjacent to white matter
- Consists of intermixed cells of raging shapes (spindle- shaped) and sizes (fusiform, granules, stellate, cells of
Martinotti)
A
Multiform layer
6
Q
- Highly vascular innermost layer
- Made up of mesenchymal cell
- Gives rise to choroid plexus
A
Pia mater
7
Q
▪ clusters of neurons in the CNS
▪ Islands of gray matter/ clusters of nerve cell bodies in the CNS sharing a common function
▪ Edinger-Westphal nucleus, red nucleus, etc.
A
Nuclei
8
Q
- large sponge-like cavity that surrounds the trabeculae, filled with CSF, forms a hydraulic cushion
which protects the CNS fromtrauma - Connective tissue of the arachnoid is said to be Avascular
- Arachnoid Villi/Arachnoid Granulation
A
Subarachnoid space
9
Q
− Synthesize myelin in the CNS
− Correspond to the Schwann cells of the PNS
− Myelin in CNS is rich in glycolipids
− Myelin in PNS is rich in phospholipids
− Classification
1. Interfascicular
▪ In between the fascicles
▪ Located along andin between axons which they myelinate
- Satellite
▪ Found in the cerebrum and cerebellum
− Myelinate several axons (Schwann cells myelinate one nerve fiber)
A
Oligodendrocytes
10
Q
The primary
type of cell that most anyone associates with the nervous system. They are responsible for the
computation and communication that the nervous system provides. They are electrically active and release chemical signals to target cells.
A
Neurons
11
Q
Small, unmyelinated fibers conducting at 0.5 to 2 m/sec (autonomic and
some sensory fibers)
A
Group C fibers
12
Q
- ependymal cells + underlying blood vessels of the pia mater
- CSF production
A
Choroid plexus
13
Q
- Phagocytes
- Macrophages of the CNS
- Member of the MPS (Mononuclear Phagocytic system)
- Numerous lysosomes indicative of their phagocytic activity
- May be involved in AIDS, producing AIDS dementia
A
Microglia
14
Q
Large fibers that conduct at 15 to 100 meters/seconds (motor and sensory
fibers)
A
Group A fibers
15
Q
Part of the cerebral peduncle that contain certain nuclei, tracts and decussations
A
Tegmentum
16
Q
- Lower most part of brainstem
- Between pons and spinal cord at foramen magnum
- Connected to cerebellum by inferior cerebellar peduncle
A
Medulla oblongata
17
Q
- CENTER or MIDDLE cerebellum layer
- Purkinje cells
- pyriform or pyramidal in shape with ramified dendrites that extend into the molecular
layer
A
Purkinje layer
18
Q
Receptor for deep pressure
A
Golgi Mazzoni
19
Q
Connects pons and cerebellum to diencephalon
Shortest and uppermost part of brainstem
4th ventricle continues with Sylvius aqueduct at midbrain
Divided by imaginary line passing through aqueduct into ventral (cerebral peduncle) and dorsal (tectum)
A
Midbrain
20
Q
Expanded part of pons ventrally connecting cerebrum and cerebellum via middle cerebellar
peduncle-3 parts
A
Basis pontis
21
Q
It includes:
▪ Diencephalon
▪ Midbrain
▪ Pons
▪ Medulla oblongata
A
Brainstem
22
Q
A brain disorder that happens when certain nerve cells in your brain misfire. it
causes seizures, which can affect your behavior or the way you see things around you for a short time. it is treated with antiepileptic drugs or surgery may be an option for people whose seizures are not controlled by medication, or who cannot tolerate the side
effects of seizure medications.
A
Epilepsy
23
Q
Surface of the cerebrum that has folded appearance
A
Sulci and gyri
24
Q
It is responsible for reabsorbing CSF back to venous blood sinus circulation
A
Pacchionian granulations
25
− Short axons
− Terminates within the same vicinity
− E.g. Purkinje cells of cerebellum
Golgi Type II
26
27
- Made up several fasciculi as bundles of nerve fibers covered by dense CT (epineurium) then
gives off septa
- Perineurium surrounds the bigger bundles of nerve fibers, then sends finer septa
- Endoneurium that surrounds individual nerve fibers
- Vasa Nervorum blood supply to the nerve; Nervi Nervorum innervates the nerve
Nerve Trunk
28
* Made up of small stellate granular cells
* Aka small stellate granular cell layer
Internal granular layer
29
Sensory organs found in the conjunctiva and external genitalia
End bulb of Krause
30
The association of the nerve cell bodies with the glial cell
Neurothil
31
Located at the Dorsum of the brainstem at
the pons and is connected via cerebellar
peduncles
Coordinates muscular activity
Maintains posture and equilibrium
Consists of convoluted folds called the Cerebellar Folium and this is separated by Sulci.
Cerebellum
32
A cellular sheath made up of squamous cells that
forms a semi-permeable barrier, characterized by
the abundance of myofilaments & supported by basal lamina
Perineurium
33
* Soma + Cytoplasm
* Contains the organelles in the fish- eyed nucleus (pale, poorly- stained with darkly staining nucleolus)
Perikaryon
34
* Efferent Pyramidal neurons- most conspicuous
* 1 or more cell type predominate per layer
* Horizontal and radial axons of the neuronal cells gives it Laminated Appearance
* Has 6 layers
Cerebral cortex
35
It conducts impulses AWAY from the CNS to the effector organ
Efferent/Motor neurons
36
* Structural and functional units of the NS
* Number of neurons in the body: 10^10 - 10^11 PARTS
Neurons
37
* Tissue that makes up the nervous system
* Basic property: Conductivity (Conduction of nerve impulses)
* Made up of cells and fibers
Nervous Tissue
38
* Largest part of the brain and is composed of right and left hemispheres
* Performs higher functions (Touch, vision, hearing, speech, reasoning, emotions, learning, and fine
control movement)
Cerebrum
39
Arachnoid + Pia mater
Leptomeninx
40
* Also called Plexiform Layer
* Overlying it is a delicate connective tissue in the brain called pia mater
* Basket cells, capsular substance cells
* Peripheral portion: neuroglial cells and
Horizontal Cells of Cajal (small fusiform cell)
Molecular layer
41
* Outermost layer of the meninges
* Thick External layer
* Consisting of dense, fibroelastic connective tissue which is
continuous with the periosteum of the skull
* Around the spinal cord, the dura mater is separated from the periosteum of the vertebrae by the Epidural Space (contains a plexus of thin-walled veins and areolar connective tissue)
Dura mater
42
Receptor organ for touch found in finger tips, lips, palms, soles, nipple and
conjunctiva
Meissner’s corpuscle
43
Its grey mater is located peripherally, white mater
is located centrally
Cerebrum and Cerebellum
44
* Made up of loose CT
* Highly avascular
* Give rise to Arachnoid Villi
Arachnoid
45
− Synthesize CSF
− Cuboidal/columnar cells lining the ventricles of the brain and central spina canal that synthesize CSF
− Beneath ependymal cell layer are numerous BV that form the choroid plexus
Ependymal cells
46
Nerve fibers that are formed in granular layer
Mossy fibers
47
▪ Numerous/ branched dendrites; one axon
▪ Motor neurons of the spinal cord
▪ Internuncial neurons
▪ Most of the cells in NS are multipolar
Multipolar
48
▪ Betz cells in motor cortex
▪ Paired Mauthner neurons in the medulla oblongata
Giant neurons
49
* Innermost Layer of the meninges (rests directly on the surface of brain and spinal cord)
* Delicate layer
* Lined internally by Flattened, mesenchymally derived cells
* Pia mater + Glial Layer = Physical Barrier (separates the CNS tissue from CSF)
Pia mater
50
* OUTER cerebellum layer
* relatively fewer and smaller neuronal cell bodies
* many fibers that extend parallel to the length of the folium
Molecular layer
51
* Upwards continuation of medulla posteriorly of pons
* Along the mid line lies the Raphae nuclei
Pontine tegmentum
52
Part of the cerebral peduncle that contain corticobulbar, corticospinal, corticopontine
Basis pedunculi (crus cerebri)
53
* aka small pyramidal cell layer
* made up of small pyramidal cell
External granular layer
54
The tunnels covered by the Pia matter
where blood vessels penetrate the CNS
Perivascular spaces
55
* Abundant number of neuronal cell bodies, dendrites, initial unmyelinated portions of axons, astrocytes, and
neuroglial cells
* Where most synapses occur
* Occupies the thick surface of cortex of both cerebrum and cerebellum
Gray mater
56
It contains polyribosomes attached to endoplasmic reticulum that indicates high metabolic activity.
Nissl bodies
57
Impinges on the effector organ
Axon terminal
58
* Region of the spinal cord that is arranged roughly in letter “H”
* Consists of dendrites, axons, supporting cells and their processes and nerve cell bodies
* As compared to cerebral and cerebellar arteries, the spinal cord doesn’t have cortex and is not layered
* Its primary significance is the site of synapse
* Consists of long slender posterior horns and short thick ventral horns joined by
horizontal gray commissure
* Ventral horns have large multipolar neurons (motor) while dorsal horns (sensory)
* The central spinal cord is lined by ependymal cells
Inner (Central) gray mater
59
Layer of the cerebrum that contains numerous neuroglial cells and
largest pyramidal cells (especially in the motor area- Betz cells are found)
Internal Pyramidal layer
60
* Basal ganglia structure
* Black substance: neuromelanin in dopaminergic neurons
Substantia nigra
61
Receptor organ for heat sensation found in subcutaneous tissue finger tips and joint capsule
Ruffini’s end organ
62
− Long axons
− Originate in the CNS and terminates distant from its origin to the periphery
− e.g. Cranial nerves
Golgi Type I
63
It conduct impulses TOWARDS CNS
Afferent/Sensory neurons
64
− Largest neuroglial cell
− Take part in the formation of tight junctions that make up the BBB (fluid and electrolyte balance)
− “End-feet” impinge on BV and neuron to form the BBB
− 3 Types:
1. Protoplasmic - Forms BBB in the gray matter
2. Fibrous - Forms BBB in the white matter
3. Specialized Astrocytes
▪ Bergman Glial cells in the cerebellum with protoplasmic processes that extend up to the pia mater
▪ Muller cells intermediate between astrocytes and ependymal cells
▪ Pituicytes in neurohypophysis
Astrocytes
65
It is located between sensory and motor
neurons
Internuncial/ Interneurons/ Central/ Intercalated neurons
66
Part of the cerebral peduncle that contain pigmented masses of grey matter belong to extrapyramidal system
Substantia nigra
67
▪ In spinal and cerebral ganglia
▪ Only one process; usually the axon; no dendrites
▪ Amacrine cells of retina: no axons; have one
dendrite
▪ Ganglion cells
Unipolar/ Pseudounipolar
68
The cytoplasm of axon
Axoplasm
69
* Synthesize by ependymal cells
* CSF in Central Spinal Canal
* Central spinal canal is equivalent to ventricles of the brain
Cerebrospinal fluid
70
▪ 1 axon, 1 dendrite
▪ Neurons of the special senses
▪ In retinal, gustatory, vestibulocochlear, olfactory epithelium
Bipolar
71
* aka medium- sized pyramidal cell layer
* made up of medium- sized pyramidal cell
External pyramidal layer
72
* Found in midbrain
* Involved in motor coordination
* Pale pink/ red due to iron which may be present in two forms, hemoglobin and ferritin
Red nucleus
73
* Region of the spinal cord that contains no nerve cell bodies
* Arranged in ascending and
descending nerve fiber tracts, supporting cells and their processes.
Outer (Peripheral) white mater
74
Cells in the 3rd ventricle that interdigitate with the ependymal cells
Tanycytes
75
Consists of organs and structures located within the cranial cavity and vertebral canal. Includes brain and spinal cord
Central Nervous System (CNS)
76
* a.k.a “Pachymeninx”
* Avascular
* Reflection/folds give rise to venous sinuses (transverse/ sagittal/ cavernous)
Dura mater
77
It is made up of ependymal cells + BV that synthesize CSF
Choroid plexus
78
Surround the ganglion cells in the spinal cord
Capsular/ Satellite Cells
79
* Where large pyramidal cells are seen (Betz cell)
* Aka Ganglion cell layer
Internal pyramidal layer
80
Fibers that conduct impulses at 3 to 14m/sec (mainly visceral sensory fibers)
Group B fibers
81
Receptor organ that mediate deep pressure and found hand, foot, palms, soles, peritoneum, pleura, mesenteries, penis, clitoris, urethra, nipple, breast and pancreas
Pacinian corpuscle
82
Three layers of the cerebellum
1. Molecular layer
2. Purkinje layer
3. Granular layer
83
− Slender cells that synthesize myelin in the PNS
− Form a sheathe called the Sheath of Schwann/ Neurilemmal sheath
− Myelin
− lipid cover rich in phospholipids in the PNS and rich in glycolipid in the CNS
− Oblique discontinuities in the Schwann sheath are called “Schmidt-Lanterman clefts”
Schwann cells
84
It includes organs and structures located outside the cranial cavity and vertebral canal
* Includes:
- 12 pairs of Cranial nerves
- 31 pairs of Spinal nerves
- Sympathetic, Peripheral (i.e. Auerbach’s plexus) and Spinal ganglia
- Sensory receptors (pain receptors, Meissner’s corpuscles)
Peripheral Nervous System (PNS)
85
* INNER cerebellum layer
* with numerous small neurons that exhibit intensely stained nuclei
Granular layer
86
Conducts between neurons appearing as end feet/ terminal buttons
Synapses
87
▪ clusters of neurons in the PNS
▪ Auerbach’s plexus, Meissner plexus, Dorsal root ganglia
Ganglia
88
Branches of axons
Axon Collaterals
89
They are known to play a supporting role for nervous
tissue. Ongoing research pursues an expanded role that they might play in signaling, but neurons
are still considered the basis of this function.
Glial cells
90
* Middle part of brainstem (between medulla and midbrain)
* Connected to cerebellum by middle cerebellar peduncle.
* Consists of 2 parts: Basis Pontis (ventrally) and Pontine Tegmentum (dorsally)
Pons
91
The six layers of the cerebrum
1. Molecular layer
2. External granular layer
3. External pyramidal layer
4. Internal granular layer
5. Internal pyramidal layer
6. Multiform layer
92
Nerve fibers that make synapses in all the layers
Climbing fibers
93
They are < 4 microns in diameter
Dwarf neurons
