Histology (01/21) Nervous Tissue

Question 1

what are the three functions of the nervous system?

Answer 1

• gathers info (sensory input)
• interprets sensory info (integration) and decides aciton
• produces motor output which activate effector organs

Question 2

cranial nerves, ganglia, and plexuses are all found in the ________ nervous system

Answer 2

peripheral

Question 3

collection of axons found in the PERIPHERAL nervous system

Answer 3

nerve

Question 4

main functional units of the nervous system, produce and transmit action potentials, cannot multiply or divide

Answer 4

neurons (nerve cells)

Question 5

significantly outnumber neurons, provide structural support and insulation, do NOT general action potentials, CAN multiply and divide

Answer 5

neuroglia (supporting cells)

Question 6

what are the three special characteristics of neurons?

Answer 6

• extreme longevity
• amitotic (most of them)
• high metabolic rate (need large supply of oxygen and glucose)

Question 7

the main function is the biosynthetic center of a neuron, always UNMYELINATED and no action potentials (makes stuff for the rest of the cell)

Answer 7

perikaryon (neuron cell body)

Question 8

transport from cell body to axon terminal

Answer 8

anterograde

Question 9

transport from axon terminal to cell body

Answer 9

retrograde

Question 10

clumps of RER and ribosomes in cell body

Answer 10

nissl bodies

Question 11

where action potentials are generated

Answer 11

axon hillock

Question 12

main function is being the receptive or main input region of neuron (looks like little branches/spines)

Answer 12

dendrites

Question 13

T/F a neuron can only have one dendrite?

Answer 13

false

Question 14

main function is conducting region of neuron, as it generates action potentials (nerve impulses) and transmits them

Answer 14

axon

Question 15

T/F a neuron can only have one axon

Answer 15

True

Question 16

where are the two places that neurotransmitters can go after leaving the axon terminals

Answer 16

• another neuron

- effector cell (muscle or gland)

Question 17

place located in between myelin sheaths on an axon

Answer 17

node of ranvier

Question 18

plasma membrane around the axon associates with ____ and _____ channels

Answer 18

• Na+

- K+

Question 19

plasma membrane around the axon terminals associates with _____ channels

Answer 19

Ca+

Question 20

neurons with 3 or more processes

Answer 20

multipolar

Question 21

neurons found between motor and sensory neurons

Answer 21

interneurons (associate neurons)

Question 22

still have both a dendritic side and an axon terminal side but the cell body is only connected to the axon by a single process

Answer 22

unipolar neurons

Question 23

what are the most common types of neurons?

Answer 23

multipolar

Question 24

what are the most rare types of neurons?

Answer 24

bipolar

Question 25

neuron type that is most abundant in the body and is the major type in the CNS MOTOR NEURON

Answer 25

multipolar

Question 26

neuron type that is rare and are found in some special sensory organs (olfactory mucosa, eye) SPECIAL SENSORY

Answer 26

bipolar

Question 27

neuron type found mainly in the PNS. common only in dorsal root ganglia of the spinal cord and sensory ganglia of cranial nerves GENERAL SENSORY

Answer 27

unipolar

Question 28

synapse between axon terminal and dendrite

Answer 28

axodendritic

Question 29

synapse between axon terminal and cell body

Answer 29

axosomatic

Question 30

synapse between two axons

Answer 30

axoaxonic

Question 31

synapse between two dendrites

Answer 31

dendrodendritic

Question 32

synapse between dendrite and cell body

Answer 32

dendrosomatic

Question 33

what are the two most common types of synapses?

Answer 33

- axodendritic | - axosomatic

Question 34

neuron carrying impulse/signal towards synapse

Answer 34

presynaptic neuron

Question 35

neuron carrying impulse/signal away from synapse

Answer 35

postsynaptic neuron (this can also be effector cell)

Question 36

in electrical synapses, axon potentials are transmitted between adjacent cells via ____ _____. this is seen often in the heart and is used to _____ cells

Answer 36

- gap junctions | - synchronize

Question 37

slower than electrical synapses due to the transfer of electric signal to chemical and back to electric

Answer 37

chemical synapse

Question 38

what are the three ways in which a neurotransmitter can be removed from the postsynaptic receptor?

Answer 38

- degradation by enzymes - reuptake by astrocytes or presynaptic terminal - diffusion away from synapse

Question 39

type of neuroglia that is most common in white matter (bc they are associated with myelin) they wrap around MULTIPLE axons

Answer 39

oligodendrocytes

Question 40

neuroglia that is most common in gray matter and is involved in controlling the ionic environment of the neurons

Answer 40

astrocytes

Question 41

type of neuroglia that line the ventricles in the brain (anywhere that there is space) and are part of the choroid plexus

Answer 41

ependymal cells

Question 42

type of neuroglia that is evenly distributed btw gray and white matter and is in charge of analyzing tissue for invading cells (immune defense)

Answer 42

microglia

Question 43

cells that produce the myelin sheath in the CNS (one to one ratio)

Answer 43

schwann cells

Question 44

matter composed primarily of myelinated axons and some neuroglia

Answer 44

white matter

Question 45

matter composed of neuronal cell bodies, dendrites, unmyelinated axons, axon terminals, and neuroglia (color is due to nissl bodies)

Answer 45

gray matter

Question 46

cluster of neuronal bodies in the PNS

Answer 46

ganglion

Question 47

cluster of neuronal bodies in the CNS

Answer 47

nucleus

Question 48

bundle of neuronal axons in the PNS

Answer 48

nerve

Question 49

bundle of neuronal axons in the CNS

Answer 49

tract

Question 50

outter most tissue covering of nerves

Answer 50

epineurium

Question 51

innermost tissue covering of nerves

Answer 51

endoneurium

Question 52

tissue covering that surrounds each nerve fascicle

Answer 52

perineurium

Question 53

how many pairs of spinal nerves are there?

Answer 53

31

Question 54

what are the two functions of the myelin sheath?

Answer 54

- protect and electrically insulate axons from other axons | - increases speed of nerve impulse transmission

Question 55

what are the two things that rate of impulse depends on with reference to axons?

Answer 55

- axon diameter (thicker goes quicker) | - myelination

Question 56

conduction via unmyelinated axons

Answer 56

continuous conduction

Question 57

conduction via myelinated axons

Answer 57

saltatory conduction