[2] Lecture 18: Nervous Tissue

Question 1

Specialized to receive stimuli

Answer 1

Irritability

Question 2

Specialized to transmit impulses

Answer 2

Conductibility

Question 3

Cellular conponents of nervous tissue:

Answer 3

Neurons

Neuroglial cells

Question 4

Conduct impulses fundamental structural and functional unit of NS

Answer 4

Neuron

Question 5

Nonconductive cells support and protect the neurons

Answer 5

Neurglial cells

Question 6

3 parts of neuron

Answer 6

Cell body-soma

Dendrites

Axon

Question 7

Contains nucleus
Nissl bodies consists of RER and fire ribocomes
Extensive rER visible w/ light microscopy and elaborate golgi
Abundant mito.
Abundant microtubules and IFs
Lipofucsin granules are formed from lysosomes and accumulate w/ age of the neuron.
Asso. W/ ligand gated channels and local potentials.

Answer 7

Cell body

Question 8

Conduct impulses (local potentials) towards cell body;
Contain nissl substance, mito, and other cytoplasmic components as cell body EXCEPT golgi;
May be studded w. Spines;
Tend to taper distally;
Asso. W/ ligand gated channels and local potentials

Answer 8

Dendrites

Question 9

Site for the origin of the axon;

Devoid of nissl substance; asso. W./ AP generation

Answer 9

Axon hillock

Question 10

Asso. W/ voltage gated cation channels and APs;
Contain mito. And microtubules;
Lacks RER, ribosomes, and golgi apparatus;
Constant diameter its entire length;
Terminates in branching telodendrites- which contain synaptic vesicles and r/t proteins;
Telodendrites form presynaptic membranes.
May be enclosed in myelin sheath.

Answer 10

Axon

Question 11

[ ]’s of RER free ribosomes in axon cell body

Answer 11

Nissan bodies found

Question 12

Transmit sensory impulses from sensory receptors to CNS

Answer 12

Sensory (afferent) neuron

Question 13

Transmit impulses from CNS to a muscle or gland

-somatic and autonomic motor neurons

Answer 13

Motor [efferent] neurons

Question 14

Transmit impulses w/in CNS and btw sensory and motor neurons

Majority of neurons

Answer 14

Interneurons

Question 15

Innervate skeletal muscles

Answer 15

Somatic

Question 16

Innervate glands, cardiac, smooth muscle

Divided into parasympathetic/sympathetic neurons

Answer 16

Autonomic motor neurons

Question 17

Most common morphilogical type

Have single axon and multiple dendrites

Answer 17

Multipolar neurons

Question 18

Have 2 processes one at each end of the spindle-shaped neuron

Found in asso. Of special senses such as olfactory and visual

Answer 18

Bipolar neuron

Question 19

Have a single process from cell body that bifurcated into a central and peripheral process

Found in ganglia spinal cord [dorsal root ganglia]

Answer 19

Pseudounipolar neuron

Question 20

Neurons w/ long axons which leave the grey matter of which theyre a part

Answer 20

Golgi I neuron

Question 21

Neurons w/ short axons which ramify through the gray matter

Answer 21

Golgi II neuron

Question 22

Bundle of axons [fibers] in the PNS

Answer 22

Nerve

Question 23

Bundle of axons [fibers] in the CNS

Answer 23

Tract

Question 24

Aggregation of cell bodies and dendrites in the PNS

Answer 24

Ganglion

Question 25

Aggregation of cell bodies and dendrites in the CNS

Answer 25

Nucleus

Question 26

Thick fibrous coat Covers entire nerve Supplied by blood and lymphatic vessels Type I collagen and fibroblasts

Answer 26

Epineurium

Question 27

Dense CT Covers bundles of axons [fascicles] w/in one nerve; Epithelial-like fibroblasts on inner surface are joined by tight junctions: Zonulae occludens, provide permeability barrier, this layer has to rejoined in microsurgery for limb reattachment. -blood nerve barrier-endothelial cells of vessels are linked by tight junctions

Answer 27

Perineurium

Question 28

Thin layer of reticular CT Surrounds individual fibers and schwann cells Type III collagen

Answer 28

Endoneurium

Question 29

Receptors; | Ion channels

Answer 29

Membrane specializations

Question 30

Ion channels on membrane of neuron [4]

Answer 30

Ligand gated on dendrite/cell bodies K+ channels on axon Voltage-gated Na+ channels on axon Voltage-gated Ca++ channels on axon

Question 31

``` Synaptic vesicles Vesicular docking proteins and synapsin filaments; Dense bodies Mito. Voltage-gated Ca+ channels ```

Answer 31

Presynaptic membrane

Question 32

Receptors | Ligand-gated ion channels

Answer 32

Postsynaptic membrane

Question 33

Cell body toward distal end of axon -transport

Answer 33

Anterograde

Question 34

Axon towards cell body-transport

Answer 34

Retrograde

Question 35

Kinesin direction transport

Answer 35

Towards distal end of axon- anterograde

Question 36

Dyenein transport direction

Answer 36

Towards cell body- retrograde

Question 37

CArries endocytosis materials and recycled proteins Rate of transport-100-300 mm/day:

Answer 37

Dyenein- retrograde

Question 38

``` Slow rate of transport. Only in anterograde transport; Two systems: -Slow component A (SCa)- microtubuels and neurofilaments -SCb- enzymes actin, clathrin ```

Answer 38

Kinesin anterograde

Question 39

Describe axonal transport

Answer 39

Anterograde transport of a vesicle that has came from axon golgi along a miscrotubule is mediated by kinesin. Retrograde transport of a vesicle along microtubule is mediated by dynein