Nervous Tissue

Question 1

neuron

Answer 1

basic structural and functional unit of nervous system

w/ cell body, dendrites, axon

Question 2

cell bodies

aka soma aka perikaryon

Answer 2

trophic/nutritional and metabolic center of the cell

where protein synthesis occurs

membrane specialized for nerve impulse generation

Question 3

cell body appearance

Answer 3

clear, euchromatic nucleus
dense nucleolus
has organelles and cytoplasm

nucleus is always active/synthesizing proteins

Question 4

multipolar neuron

organelles

Answer 4

most common type

-Nissl bodies (RER) for neurotransmitter syn
-Golgi apparatus to package NTs into vesicles
-Mitochondria
-lysosomes

Question 5

multipolar structural components

Answer 5

microfilaments/actin
neurofilaments-changes in formation characteristic of alzheimers

microtubules: form neuronal cytoskeleton for framework to support axons/axonal transport

Question 6

multipolar appearance

Answer 6

Nissl bodies = basophilic clumps of RER

axons = pale since no RER or golgi

Question 7

inclusions

Answer 7

neuromelanin: in substantia nigra, @ midbrain
lipofuscin: in ganglion cells sympathetic

Question 8

multipolar dendrites

Answer 8

radiate from soma to inc receptive area of neuron like antennas that branch and taper

transmit impulses to cell body or other dendrites

never myelinated, have organelles

Question 9

bipolar neurons

Answer 9

special senses aka smell/vision/hearing/balance

Question 10

pseudounipolar/unipolar

Answer 10

cell bodies enclosed in cranila nerve sensory ganglia OR dorsal root ganglia

impulse bypasses cell body (peripheral dendrites > axon terminals to CNS

Question 11

somatic sensory neurons

Answer 11

innervate skin, muscle, tendons, ligaments, joints

transmit touch, pressure, pain, temp, position

Question 12

visceral sensory neurons

Answer 12

mucous membranes, glands, blood vessels, organs

pain or pressure sensations

Question 13

skeletal motor neurons

Answer 13

skeletal muscle

Question 14

visceral motor neurons

Answer 14

smooth muscle, cardiac muscle or glands

Question 15

neuroglial cells

Answer 15

physical and physiological support to neurons

types:
astrocytes
microglia
oligodendrocytes

Question 16

astrocytes

Answer 16

largest glial cell

cover capillaries w/ vascular feet

assist in blood brain barrier w/ sealant deep to pia mater, scar tissue, monitor ECS

Question 17

oligodendrocytes

Answer 17

myelinate axons in CNS in segments of 3

Question 18

microglia

Answer 18

phagocytic, clean up debris in CNS

Question 19

ependymal cells

Answer 19

line CNS cavities aka ventricles and central canal of spinal cord,

cover choroid plexus

simple cuboidal-columnar shape

Question 20

unmyelinated axons

Answer 20

in CNS: not covered by glia
in PNS: occupy groove of Schwann cell

Question 21

Schwann cells

Answer 21

myelinate axons in PNS
via membrane circles around axon until sheath is formed

Question 22

nodes of ranvier

Answer 22

bare segments of axon b/t internodes
larger in CNS than PNS

Question 23

PNS axon layers

Answer 23

indiv axon= myelin sheath > basal lamina> endoneurium

bundle of axons = perineurium

gross nerve = epineurium

Question 24

gray matter

arrangement

Answer 24

cerebral cortex & cerebellar cortex: sheet of cell bodies + neuroglia

nuclei: collections/clusters of cell bodies + neuroglia in CNS

Question 25

white matter

Answer 25

myelinated axons and neuroglia in CNS contain tracts, fasiculi, commissure, funiculi

Question 26

PNS | consists of

Answer 26

nerves (bundles of axons + neuroglia) plexuses: (network of nerves) ganglia: (collections of cell bodies + ganglia in PNS)

Question 27

voluntary/somatic system

Answer 27

control skeletal muscle and movement

Question 28

involuntary/autonomic system

Answer 28

divisions: sympathetic parasympathetic enteric

Question 29

sympathetic

Answer 29

thoracolumbar flight/fight/fright ganglia: sympathetic trunk/chain, visceral

Question 30

parasympathetic

Answer 30

craniosacral smooth and cardiac muscle, glands of head/thoracic/abdominal/pelvic viscera maintain homestasis ganglia: ciliary, pterygopalatine, submandibular, otic

Question 31

enteric

Answer 31

peristalsis, gland secretions, blood flow thru GI tract cells embedded w/i wall of GI

Question 32

chemical synapses | have

Answer 32

presynaptic membrane, synaptic vesicles presynaptic density (active site)> synaptic cleft > postsynaptic membrane w/ neurotransmitter receptors, postsynaptic density, ligand gated sodium channel | associated with neurotransmitters

Question 33

choroid plexus | consists of

Answer 33

in folds of pia mater and brain vetricles fenestrated capillaries aka leaky covered by ependymal cells w/ ZO's

Question 34

choroid plexus | forms

Answer 34

makes CSF transported from subarachnoid space to SSS via arachnoid villi>granulations | superior sagittal sinus

Question 35

axoplasmic transport

Answer 35

anterograde: away from cell body via kinesin OR retrograde: toward cell body via dynein

Question 36

anterograde systems

Answer 36

1. slow transport: uses tubulin, actin, neurofilament proteins, enzymes 2. fast transport: uses ATP, organelles, vesicles, neurotransmitters, calcium

Question 37

retrograde transport system

Answer 37

fast only- uses ATP, SER, vesicles, mitochondria, amino acid sugards, nucleotides, neurotransmitters, Ca2+ | viruses and toxins too

Question 38

astrocytoma

Answer 38

fibrous make up 80% primary brain tumors in adults

Question 39

ependymoma

Answer 39

tumor growing into fourth ventricle that compreses surrounding structures 5% of primary brain tumors

Question 40

myelin

Answer 40

has lipoprotein formed by concentric layers of cell membranes w/ high lipid content inc impulse conduction and insulate neuron

Question 41

synapse | definition

Answer 41

junction b/t presynaptic AKA neuron postsynaptic AKA another neuron, muscle cell, gland cell

Question 42

types of synapses

Answer 42

axodendritic: most common, axon >dendrite axosomatic: axon>soma axoaxonic: axon>axon

Question 43

electrical synapses

Answer 43

not common in mammals impulse transmission is rapid @cerebral cortex, brainstem, retina

Question 44

fusion methods | vesicle and presynaptic membrane

Answer 44

kiss and run collapse: empty entire contents

Question 45

nerve regeneration | PNS-anterograde changes

Answer 45

-distal to injury -axonal degradation and elimination of debris by phagocytic cells -schwann cells proliferate w/ external lamina =empty guiding tubes/tunnels

Question 46

nerve regeneration | PNS, retrograde changes

Answer 46

-proximal to injury -chromatolysis: cell body hypertrophies/swells, nissl bodies disperse, nucleus moves periphery -axon grows sprouts that are guided by schwann cells thru tube -sprouts become endoneurium except first one to reach target cell = synapse