Nervous System Unit Lesson 4: Peripheral Nervous System

Question 1

what is the peripheral nervous system composed of

Answer 1

all the other nerves when you exclude the brain and spinal cord

Question 2

what is the purpose of the peripheral nervous system

Answer 2

its purpose is to send signals from outlying(far from a center/main body) neurons to the central nervous system for processing

Question 3

what are sensory pathways

Answer 3

chains of neurons that travel from a receptor to the cerebral cortex

Question 4

what are motor pathways

Answer 4

chains of neurons that travel from the brain to motor neurons

Question 5

what are the two components of the PNS

Answer 5

nerves and ganglia

Question 6

what are nerves

Answer 6

assemblages of axons that are referred to as “nerve fibres”

Question 7

what are ganglia

Answer 7

swollen regions in the nerves that contain collections of cell bodies

Question 8

what are cranial nerves(how many pairs, what do they do)

Answer 8

12 pairs of nerves that link regions of the brain to regions in the face, neck, and torso

Question 9

what are spinal nerves(how many pairs, where are they located)

Answer 9

31 pairs of nerves that emerge from between openings in the vertebral column

Question 10

the spinal nerves are arranged in a manner where two short branches(dorsal root and ventral root) attach to the spinal cord and join together moving away from it. what does the dorsal root contain and what is it composed of?

Answer 10

the dorsal root contains cell bodies termed dorsal root ganglion and it is composed of sensory fibres conducting impulses toward the spinal cord

Question 11

the spinal nerves are arranged in a manner where two short branches(dorsal root and ventral root) attach to the spinal cord and join together moving away from it. what does the ventral root contain and what does it do?

Answer 11

it contains motor fibres that conduct impulses away from the spinal cord to the effectors

Question 12

what is the somatic nervous system(what is it responsible for?)

Answer 12

it is a part of the peripheral nervous system that takes sensory information from receptors to the central nervous system and takes motor commands from the CNS to the skeletal muscles

Question 13

what nervous system contains reflex arcs

Answer 13

the somatic nervous system

Question 14

what are reflexes

Answer 14

automatic, involuntary responses to a stimulus

Question 15

what are reflex arcs

Answer 15

nerve pathways that initially circumvent(go around) sending the signal to the brain

Question 16

how do reflex arcs work

Answer 16

the stimulus is sent to the spinal cord where it travels through short interneurons and motor neurons that elicit an immediate response from an effector

Question 17

divide the autonomic nervous system into parts

Answer 17

it can be divided into sympathetic and parasympathetic divisions

Question 18

what is the sympathetic nervous system(what is it responsible for)

Answer 18

it is a collection of nerves that are concerned with stressful situation

Question 19

what happens when your sympathetic nervous system is active(also talk about one of its functions)

Answer 19

portions of your body are stimulated to the state best suited for the situation. one of the functions is to activate the adrenal medulla to secrete hormones epinephrine and norepinephrine into the blood

Question 20

what is the parasympathetic nervous system responsible for

Answer 20

functions that are opposite to the sympathetic nervous system(“rest and digest”, housekeeper)

Question 21

what is the main neurotransmitter associated with the parasympathetic nervous system and what are its effects like

Answer 21

acetylcholine(ACh). in its interactions with cells, it promotes effects that are opposite to the sympathetic nervous system