Types And Subdivisions And Communication In Nervous Tissue

Question 1

How is nervous system divided

Answer 1

Central

Peripheral

Question 2

what does PNS consist of

Answer 2

Cranial nerves from brain (12)

Spinal nerves from spinal cord (31 pairs)

Question 3

What is PNS sub divided in to

Answer 3

Somatic

Autonomic

Question 4

What does the somatic nervous system do

Answer 4

Controls voluntary movement of body by acting on skeletal muscles

Question 5

What does the autonomic nervous system do

Answer 5

Regulation of:
Heart rate
Blood pressure
Digestion 
Temp regulation
Reproductive function 
Involuntary response

Question 6

Two divisions of autonomic

Answer 6

Sympathetic

Parasympathetic

Question 7

Contains both sensory and motor neurons

Answer 7

Somatic ns

Question 8

Function of sensory neurons

Answer 8

Convey input from receptors for somatic senses and from receptors for the special senses

Question 9

Function of somatic motor neurons

Answer 9

Innervate skeletal muscles

effectors of somatic nervous system and produce both reflexive and voluntary movements

Question 10

Main input to ANS..

Answer 10

Visceral sensory neurons

Question 11

Compare between the somatic and autonomic motor neurons

Answer 11

Somatic: axon is long myelinated and extends from cns to skeletal ms fibers in its motor unit
Autonomic: 2 motor neurons
Preganglionic=cell body in CNS, myelinated and axon extends from CNS to an autonomic ganglion
Postganglionic= un myelinated axon extends directly from ganglion to effector

Question 12

What neurotransmitter do somatic motor neurons release vs autonomic

Answer 12

Somatic: ach
Autonomic: ach and NE

Question 13

How are nerve fibers classified

Answer 13

1)distribution
Somatic= supply skeletal ms of body
Autonomic= various internal organs 
2) function
Motor/efferent: from cns to diff parts of body
Sensory/afferent: from receptor to cns
3)structure 
Myelinated and non
4) diameter and conduction

Question 14

What causes depolarization in presynaptic terminal

Answer 14

Action potential

Question 15

What occurs as a result of depolarization

Answer 15

CA2+ enters pre synaptic terminal causing release of neurotransmitter in to synaptic cleft

Question 16

What hyperpolarizes post synaptic membrane and what depolarizes post synaptic membrane

Answer 16

Inhibitory neurotransmitters

Excitatory neurotransmitters

Question 17

Summarize the steps of ap in a neuromuscular junction

Answer 17

1-depolarization of presynaptic terminal and Ca2+ uptake
2-ca2+ uptake causes release of ach in to synaptic cleft
3- diffusion of ach to post synaptic membrane and binding of ach to cholinergic receptor
4-end plate potential in post synaptic membrane
5-depolarization of adj muscle membrane to threshold

Question 18

What stimulates ca2+ channels to open

Answer 18

Depolarization of presynaptic terminal

Question 19

What degrades ach

Answer 19

Aceytlcholinestrase

Question 20

What does the reflex arc consist of

Answer 20

Sense organ (receptor)
Afferent neuron
Efferent neuron
One or more synapses within a central integrating station(center) 
Effector

Question 21

How do the afferent neurons enter the brain or spinal cord

Answer 21

Via dorsal roots or cranial nerves

Question 22

How does efferent neuron leave brain or spinal cord

Answer 22

Ventral roots

Corresponding motor cranial nerves

Question 23

What are monosynaptic arcs

Answer 23

Reflex arc with a single synapse between afferent and efferent neuron

Question 24

Give an ex for a mono synaptic arc

Answer 24

Knee jerk reflex/stretch reflex

Question 25

Response of withdrawal reflex

Answer 25

Flexor muscle contraction and inhibition of extensor muscles

Question 26

What are examples of autonomic reflex action

Answer 26

Stretch receptor in bladder wall initiate a reflex contraction
Peristalsis initiated when gut wall is stretched by contents of the lumen