nervous tissue

Question 1

3 fxns of nervous system

Answer 1

1. collect info in pns, send to cns
2. process and evaluate info
3. cns responds, pns carries commands to effectors

Question 2

somatic sensory

Answer 2

sensory inout that is consciously perceived from receptors
ex: eyes ears skin

Question 3

visceral sensory

Answer 3

sensory input that is not consciously perceived from receptors of blood vessels and internal organs
ex: heart

Question 4

somatic motor

Answer 4

motor output that is consciously or voluntarily controlled
effector is skeletal muscle

Question 5

autonomic motor

Answer 5

motor output that is not consciously or is involuntarily controlled; effectors are cardiac muscle, smooth muscle, and glands

Question 6

neurons

Answer 6

excitable cells that initiate and transmit nerve impulses

Question 7

glial cells

Answer 7

nonexcitable cells that support and protect neurons

Question 8

fxns of glial cells

Answer 8

protect and nourish neurons, provide an organized supporting framework for all nervous tissue

Question 9

astrocytes

Answer 9

most abundant glial cells
versatile
regulate tissue fluid composition, structural framework, replacing damaged neurons, neuronal development, anchor neurons, exchange bw neurons and vasculature

Question 10

astrocytosis

Answer 10

replacing damaged neurons

Question 11

synaptic transmission

Answer 11

important in synapse maintenance, number of synapses, and may play a role in signaling
loss observed in neurological disorders/neurogenerative diseases

Question 12

ependymal cells

Answer 12

epithelial, line cavities of brain and spinal cord, slender processes that branch out for communication, choroid plexus in association with nearby capillaries for CSF production

Question 13

microglia

Answer 13

small cells with thorny processes that monitor health of nearby cells, transform into macrophage to protect CNS from invading microbes and dead neural tissue

Question 14

oligodendrocytes

Answer 14

large cells with bulbous body and slender cytoplasmic processes that ensheathe axons (myelin sheath)

Question 15

satellite cells

Answer 15

flattened cells arranged around neuron cell bodies in ganglia, separate cell bodies from interstitial fluid, control chemical environment, regulate exchange of nutrients and wastes between neuron and environment

Question 16

ganglion

Answer 16

group if nerve cell bodies in the PNS

Question 17

schwann cell

Answer 17

neurolemmocyte
form myelin sheath around axon in PNS, act as phagocyte to remove debris, peripheral nerve fiber regeneration

Question 18

neuron special characteristics

Answer 18

high metabolic rates, extreme longevity, amitotic, PM site of electrical signaling

Question 19

neuron cell body

Answer 19

soma
activity occurs here
has nissl bodies, golgi, neurotubules, neurofibrils, pigment inclusions

Question 20

neurotubules

Answer 20

movement of substances

Question 21

neurofibrils

Answer 21

intermediate filaments, help form myofibrils

Question 22

dendrites

Answer 22

short branches that receive signals

Question 23

axon

Answer 23

arises from axon hillock, send signals to other cells

Question 24

anterograde movement

Answer 24

from soma to synaptic knobs (away)

Question 25

retrograde movement

Answer 25

from synaptic knobs to soma (toward)

Question 26

structural classifications of neurons

Answer 26

number of neuron processes unipolar, bipolar, multipolar

Question 27

most common neuron type

Answer 27

multipolar

Question 28

functional classifications of neurons

Answer 28

direction of nerve impulse sensory, motor, interneuron

Question 29

sensory neuron impulses move

Answer 29

toward CNS

Question 30

motor neuron impulses

Answer 30

from CNS to PNS

Question 31

interneuron

Answer 31

intermediate, typically multipolar, in CNS

Question 32

afferent transmission

Answer 32

info goes from PNS to CNS

Question 33

efferent transmission

Answer 33

info goes from CNS TO PNS

Question 34

unipolar neurons are generally involved in

Answer 34

sensation

Question 35

bipolar neurons are generally involved in

Answer 35

sensation in special senses

Question 36

myelination fxn

Answer 36

produces faster nerve impulse conduction

Question 37

myelin

Answer 37

lipid-protein composite, support protect and insulate axon formed by schwann cells and oligodendrocytes

Question 38

saltatory conduction

Answer 38

node jumping

Question 39

why is myelination only on axon and not on dendrites or soma?

Answer 39

dendrites and soma need the surface area for better communication

Question 40

unmyelinated axons observe

Answer 40

continuous conduction, but are slower

Question 41

synapse

Answer 41

specialized jxn where nerve impulse is transmitted

Question 42

no synapses are found where … is present

Answer 42

myelination

Question 43

electrical synapses

Answer 43

gap jxns formed by connexons, no delay

Question 44

chemical synapses

Answer 44

most numerous, use neurotransmitter, synaptic delay

Question 45

functional syncytium

Answer 45

group of cells working as a single unit

Question 46

rate of nerve impulse conduction can only be influenced by 2 factors

Answer 46

1. axon’s diameter 2. presence/absence of myelin sheath

Question 47

nervous system coordinates and integrates nervous activity because neurons are organized into complex patterns called…

Answer 47

neuronal circuits

Question 48

4 types of circuits

Answer 48

converging, diverging, reverberating, parallel-after discharge

Question 49

pns regeneration of axons

Answer 49

1. amount of damage 2. secretion of nerve growth factors 3. distance between site of damage and effector organ

Question 50

cns regeneration of axons

Answer 50

very limited due to 1. no release of nerve growth factors 2. high cellular density tends to complicate regrowth 3. both astrocytes and CT coverings may form scar tissue, obstructs axon regrowth

Question 51

nerve

Answer 51

cablelike bundle of parallel axons in the pns

Question 52

tract

Answer 52

term for nerve in the cns

Question 53

nerves are surrounded by 3 consecutive ct wrappings

Answer 53

endoneurium, perineurium, and epineurium

Question 54

classification of nerves

Answer 54

direction of transmission sensory, motor, and mixed