Nervous System Flashcards

1
Q

What are the branches of the nervous system?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the different meninges?

A
  • dura mater: outermost layer
  • arachnoid: membrane attached to dura mater
  • pia mater: innermost layer, highly vascular, adherent to brain and spinal cord
  • leptomeninges - arachnoid + pia mater
  • subarachnoid space: contains CSF
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the embryonic brain divisions and their derived brain structures?

A
  • forebrain
    • telencephalon: cerebrum, basal nuclei, hippocampus, + amygdala
    • dincephalon: thalamus + hypothalamus
  • midbrain
    • mesencephalon: midbrain
  • hindbrain
    • metencephalon: pons + cerebellum
    • myelencephalon: medulla oblongata
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are some features of the surface of the brain?

A
  • gyrus/i + sulcus/i of main brain
  • folia + sulci of cerebellar cortex
    • arbor vitae “tree of life” cross-section
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the different kinds of nervous tissue and the system they are part of?

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is white matter? Grey matter?

A
  • white matter: formed by dense accumulations of myelinated axons. Myelin sheath is rich in lipids so has a white appearance
  • grey matter: rich neuronal cell bodies , glial cells, and neuropil. Neuropil represents the axons, dendrites and cytoplasmic projections of glial cells that form the background matrix to neuronal cell bodies within the grey matter.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

T/F: white matter is peripheral in the brain and central in the spinal cord

A
  • False; white mater is peripheral in the spinal cord and central in the brain
  • grey matter is peripheral in the brain and central in the spinal cord
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

T/F: the cells of the CNS that are sensitive to hypoxia are of mesodermal origin

A
  • False; ectodermal origin
  • ectodermal origin: neurons, astrocytes, oligodendrocytes
  • mesodermal origin: microglia, vascular endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What cells compose the CNS?

A
  • neurons
  • glial cells
  • ependymal cells
  • endothelial cells
  • pericytes of blood vessels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are neurons?

A
  • functional cells of the nervous system in which two protoplasmic properties are highly developed
    • irritability: generation of an impulse
    • conductivity: ability to transmit such a impulse from one locality to another
  • neurons are dispersed through the CNS and grouped in specific areas in the PNS
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are neurons distributed?

A
  • individually
  • layers (cortex)
  • groups
    • nuclei (CNS)
    • ganglia (PNS)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the structure of a neuron

A
  • parts:
    • perikaryon
    • nucleus
    • nucleolus
    • dendrites
    • axons
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Describe the structure of a soma

A
  • euchromatc nucleus w/ prominent nucleolus
  • basophilic cytoplasm: nissl substance, SER, and ribosomes
  • lipofuscin: “wear and tear” pigment
  • cell body = perikaryon/soma: contains nucleus + organelles, axons and dendrites branch off it
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the arrows pointing at?

A
  • yellow: lipofuscin
  • blue: nucleolus
  • green: nucleus
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is shown in this image?

A
  • neurons + glial cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are some features of synapses?

A
  • specialized junctions with other cells that are along the length or at end of an axon
  • act as transmission points for electrical impulses
  • can trigger the generation of an action potential in the postsynaptic cells, can be excitatory or inhibitory
  • synapses at end of an axon or axon branches are swollen into a club shape, called boutons terminaux
  • those along the length of the axon result in varicosities (swellings) called boutons en passant
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are structures of synaptic knobs?

A
  • 3 parts:
    • presynaptic part: termination of axon (bouton terminaux)
    • intersynaptic cleft
    • postsynaptic cleft (dendritic thorn)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

T/F: stimulatory synapse vesicles contain GABA, inhibitory synapse vesicles contain acetylcholine

A

-false; stimulatory = ACh, inhibitory = GABA

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Neurons can synapse with:

A
  • neurons
  • muscle
  • glands
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the sense organs of the skin?

A
  • thermoreceptor: sense heat or cold
  • meissner’s corpuscle: senses touch
  • nociceptor: sense pain
  • pacinian corpuscle: senses pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are functions of oligodendrocytes?

A
  • myelin sheath to axons
  • unlike Schwann cells (PNS), they form myelin sheaths for several axons at once (“octopus” shape)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is shown? What are some features?

A
  • oligodendrocyte
  • small dark nuclei (between myelin sheaths or sounds neurons)
  • can be destroyed by viruses/toxins resulting in primary demyelination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are some functions of microglia?

A
  • immunosurveillance
  • immunoregulation
  • reparative —> phagocytic
  • gitter cells (myeophages) —> activated during necrosis/inflammation —> globular and swollen after having phagocytized debris from injured cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is shown? What are some features?

A
  • microglia
  • derived from blood-borne monocyte
  • resident macrophage of CNS
  • Gitter cells: note cytoplasmic vacuolation due to ingestion of cellular debris
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is shown?

A
  • microglia
  • activated Gitter cells (macrophages) in a area of brain tissue necrosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is shown?

A
  • microglia
  • activated microglia cells in a myelin sheath (“myelophages” w/ a “digestion chamber”)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are some features of astrocytes?

A
  • CNS counterpart of the fibroblast
  • involved in cell communication and the functioning of blood brain barrier
  • 2 types:
    • protoplasmic (grey matter)
    • fibrillation (white matter)
  • glial fibrillary acidic protein (GFAP) staining
28
Q

What is shown?

A
  • astroytes
29
Q

What are functions of astrocytes?

A
  • transport of nutrients
  • part of bbb
  • antigen presentation
30
Q

What are features of ependymal cells?

A
  • form an epithelium that lines ventricular cavities within the brain and central canal of the spinal cord
  • typically cuboidal or columnar with numerous motile cilia on their apical surfaces
  • central canal ependymal cells have cilia to help the circulation of the CSF
  • limited regenerative capacity: do not typically undergo mitotic proliferation
31
Q

What is shown?

A
  • ependymal cells (in spinal cord central canal)
32
Q

What are functions of ependymal cells?

A
  • produce CSF
  • important barrier function that protects neural tissue from potential harmful substances (mechanism not really understood)
33
Q

What is shown? What kind of epithelium? What are the arrows indicating?

A
  • ependymal cells
  • simple columnar epithelium
  • motile cilia
34
Q

What are features of the ventricular system?

A
  • lined by ependymal cells
  • communicates with the subarachnoid space
  • circulates CSF
35
Q

What are features of cerebral spinal fluid?

A
  • produced in choroid plexus by specific modified ependymal cells
  • produced and MUST BE drained at a constant rate
  • the total volume of CSF is formed and renewed at least 3X a day
  • can be sampled for clinical evaluation
36
Q

What are functions of CSF?

A
  • medium for filtration system: facilitates removal of metabolic waste from the brain and exchange of biomolecules into and out of the brain
  • helps maintain the extracellular environment needed for the brain to function optimally (homeostasis)
  • cushions CNS
37
Q

Where and how is CSF produced?

A
  • formed as plasma: filtered from blood though the choroid plexus ependymal cells
  • produced by a mechanism that involves active secretion of Na+ into the ventricles —> water follows the resulting osmotic gradient

**plexus (Latin for brain) is a branching network of the vessels or nerves

38
Q

What is shown? What kind of epithelial cells? What kind of junctions and what is their purpose?

A
  • choroid plexus
  • a layer of cuboidal epithelial cells surrounding a core of capillaries and loose connective tissue
  • the epithelium: specific modified ependymal cells: have microvilli and are linked to adjacent cells by TIGHT junctions (unlike th ependymal)
  • these tight junctions prevent the majority of substances from crossing the cell layer into the CSF: blood-CSF barrier
39
Q

The choroid plexus folds into many villi around each capillary, creating frond-like processes that project into the ventricles. What does this do? What helps with this process?

A
  • increases the surface area of the choroid plexus
  • along with a brush border of microvilli
40
Q

T/F: There is only one choroid plexus

A
  • false; there is one choroid plexus in each of the 4 ventricles in the brain
  • it is present in all parts of the ventricular system (except the cerebral aqueduct, frontal horn and occipital horn of the lateral ventricles)
41
Q

Where is CSF resorbed?

A
  • in the subarachnoid space into venous circulation
42
Q

What are some features of the blood-cerebrospinal fluid barrier and brain-CSF boundary ?

A
  • pair of membranes separates blood from CSF and CSF from brain tissue
  • blood-CSF boundary at the choroid plexus is a membrane composed of ependymal cells and tight junctions that link them (choroid plexus capillaries are fenestrated and don’t have tight junctions)
  • brain-CSF boundary is the arachnoid membrane
43
Q

What are functions of the Blood-CSFB and Brain-CSFB?

A
  • prevent passage of most blood-borne substances into brain
  • facilitates transport of different substances into the brain due to distance structural characteristics between the two barriers (for a # of substances, BCSFB is primary site of entry into the brain)
  • facilitates removal of brain metabolites and metabolic waste into blood
  • modulates entry of leukocytes from the blood into the CNS
44
Q

The choroid plexus cells secrete ____________, which recruit ________________, among other cells, to the brain. What does this have implications in?

A
  • cytokines
  • monocyte-derived macrophages
  • normal brain homeostasis and neuroinflammatory responses
45
Q

What are the layers of the cerebellum (w/ arbor vitae)?

A
  • cortex cerebelli: grey matter (6 layers)

—> outermost to innermost
- molecular layer: basket cells
- ganglionic cell layer: purkinje cells
- granular cell layer: granule cells in stratum granulosum
- white matter core: myelinated nerve fibers

46
Q

What are the labels 1, 2, + 3 in this image of a cerebellum?

A
  • 1: molecular layer: basket cells
  • 2: ganglionic cell layer: purkinje cells
  • 3: granular cell layer
47
Q

What structure is shown in this image? Label the arrows

A
  • purkinje cell (blue)
  • green: molecular layer
  • red: dendrites of purkinje cell
  • yellow: neuron of purkinje cell
  • black: granular cell layer
48
Q

What is this image of? Label the arrow and numbers

A
  • cerebellum
  • arrow: purkinje cell
  • 1: molecular layer
  • 2: ganglionic cell layer
  • 3: granular cell layer
49
Q

What is this image of? (Be specific). Label the numbers and arrows. What is the importance of the yellow label?

A
  • cerebellum, fetal/newborn
  • 1/arrows: external granular layer
  • 2: molecular layer
  • 3: ganglionic cell layer
  • 4: granular cell layer
  • yellow: exterior cortical lamina - additional exterior layer tat populates the internal granular layer during early postnatal development - eventually disappears
50
Q

What are the cerebral cortical layers?

A
51
Q

What is shown in this image?

A
  • a nucleus in the CNS: a cluster of neurons, located deep within the cerebral hemispheres and brainstem that are performing a common function
52
Q

Describe the structure of the spinal cord

A
  • peripheral white matter, central grey matter
  • central canal: opening in the horizontal bar of the grey matter, remnant of the lumen of the embryonic neural tube
  • anterior horns: grey matter of the legs of the “H”, contains motor neurons whose axons make up the ventral roots of the spinal nerves
  • posterior horns: grey matter of the arms of the “H”, receives sensory fibers from neurons in the spinal ganglia (dorsal roots)
  • lined with ependymal cells
53
Q

T/F: Spinal cord neurons are large and pseudo-unipolar, especially in anterior horns where large motor neurons are found

A
  • false; large and multipolar
54
Q

What is this? Label some key features

A
55
Q

What are the functional divisions of the peripheral nervous system?

A
  • somatic nervous system: a one neuron system that innervates (voluntary) skeletal muscle or somatosensory receptors of the skin, muscle, and joints
  • autonomic nervous system: a two neuron visceral efferent system, that innervates cardiac and smooth muscle and glands. It is involuntary and has two major subdivisions:
    • sympathetic (thoracolumbar)
    • parasympathetic (craniosacral)
56
Q

What are features of nerves in the PNS?

A
  • collection of axons/dendrites outside the CNS
  • consists of axons, dendrites, blood vessels, glial cells, and connective tissue investments
  • endoneurium, perineurium, epineurium,
  • cells present: endothelial cells, fibroblasts, and Schwann cells
57
Q

What are features of ganglia in the PNS?

A
  • collections of neuronal cell bodies and processes found outside the CNS
  • cells of a ganglion: neurons, neuroglia cells (amphicytes), Schwann cells, endothelial cells. Axons also present
  • two types:
    • sensory (craniospinal)
    • autonomic
58
Q

What are the glial cells of the PNS and some features?

A
  • schwann cells:
    • envelope nerve fibers in the PNS
    • wind repeatedly around a nerve fiber
    • produces a myelin sheath similar to the ones produced by oligodendrocytes in the CN
    • assist in regeneration of damaged fibers
    • consists of plasma membrane of glial cells
    • 20% protein and 80% lipid
  • satellite glial cells (amphicytes):
    • surround the neurosomas in ganglia of the PNS
    • provide electrical insulation around the soma
    • regulate the chemical environment of the neurons
59
Q

Describe myelination

A
  • production of myelin sheath (by schwann cells/oligodendrocytes)
  • begins around the 14h week of fetal development (in humans)
  • proceeds rapidly during infancy
  • completed in late adolescence
  • dietary fat is important to nervous system development
60
Q

What is this structure? Label some important features

A
  • nerve fiber
61
Q

What is this structure? What are the black rings?

A
  • peripheral nerve
  • myelin sheaths
62
Q

What is shown in this image?

A
  • myelin sheath
63
Q

What is this structure? what are the purple stained structures?

A
  • peripheral nerve
  • schwann cells
64
Q

What can happen if the myelin sheath is damaged?

A
65
Q

Label the yellow and blue spaces

A
66
Q

What structure is shown? What are some features?

A
  • myenteric plexus
  • situated between the inner and outer longitudinal layers of the tunica muscularis
  • helps control peristaltic movement of the gastrointestinal tract