Chapter 13 CNS and 14 PNS

Question 1

PNS All neural structures outside the brain

Answer 1

Sensory receptors, peripheral nerves and associated ganglia, Motor endings

Question 2

Sensory Receptors

Answer 2

Specialized to respond to changes in their

environment (stimuli)

Question 3

Activation

Answer 3

results in graded potentials that trigger

nerve impulses

Question 4

Sensation

Answer 4

(awareness of stimulus) and perception (interpretation of the meaning of the stimulus) occur in the brain

Question 5

Classification of Receptors

Answer 5

Stimulus type, Location, Structural complexity

Question 6

Mechanoreceptors

Answer 6

respond to touch, pressure,

vibration, stretch, and itch

Question 7

Thermoreceptors

Answer 7

sensitive to changes in temperature

Question 8

Photoreceptors

Answer 8

respond to light energy (e.g.,

retina)

Question 9

Chemoreceptors

Answer 9

respond to chemicals (e.g., smell, taste, changes in blood chemistry)

Question 10

Nociceptors

Answer 10

sensitive to pain-causing stimuli
(e.g. extreme heat or cold, excessive pressure,
inflammatory chemicals)

Question 11

Adaptation

Answer 11

is a change in sensitivity in the

presence of a constant stimulus

Question 12

Receptor membranes

Answer 12

become less responsive

Question 13

Receptor potentials

Answer 13

decline in frequency or stop

Question 14

Structure of a Nerve

Answer 14

Cordlike organ of the PNS Bundle of myelinated and unmyelinated peripheral axons enclosed by connective tissue

Question 15

Classification of Nerves

Answer 15

Most nerves are mixtures of afferent and efferent

fibers and somatic and autonomic (visceral) fibers

Question 16

Pure sensory

Answer 16

(afferent) or motor (efferent) nerves

are rare

Question 17

Cranial Nerves

Answer 17

Twelve pairs of nerves associated with the brain

Question 18

Spinal somatic reflexe

Answer 18

Integration center is in the spinal cord effectors are skeletal muscle

Question 19

Testing of somatic reflexes

Answer 19

is important clinically to assess the condition of the nervous system

Question 20

The ANS consists of motor neurons that:

Answer 20

Innervate smooth and cardiac muscle and glands, Make adjustments to ensure optimal, support for body activities, operate via subconscious control

Question 21

Effects of age on ANS

Answer 21

Constipation
– Dry eyes
– Frequent eye infections
– Orthostatic hypotension

Question 22

Low blood pressure occurs

Answer 22

because aging pressure receptors
respond less to changes in blood
pressure with changes in body
position and because of slowed
responses by sympathetic
vasoconstrictor centers

Question 23

Spinal Nerves

Answer 23

31 pairs of mixed nerves named according to their

point of issue from the spinal cord

Question 24

Spinal Nerves: Roots

Answer 24

Dorsal and ventral roots unite to form spinal
nerves, which then emerge from the vertebral
column via the intervertebral foramina

Question 25

Dermatome:

Answer 25

the area of skin innervated by the
cutaneous branches of a single spinal nerve
All spinal nerves except C1 participate in

Question 26

Most dermatomes

Answer 26

overlap, so destruction of a
single spinal nerve will not cause complete
numbnes

Question 27

Hilton’s law:

Answer 27

Any nerve serving a muscle that
produces movement at a joint also innervates the
joint and the skin over the joint

Question 28

Motor Endings

Answer 28

PNS elements that activate effectors by releasing

neurotransmitters

Question 29

Inborn (intrinsic) reflex:

Answer 29

a rapid, involuntary, predictable motor response to a stimulus

Question 30

Learned (acquired)

Answer 30

reflexes result from practice or

repetition, Example: driving skills

Question 31

Components of a reflex arc (neural path)

Answer 31

Receptor—site of stimulus action
– Sensory neuron—transmits afferent
impulses to the CNS
– Integration center—either monosynaptic
or polysynaptic region within the CNS
– Motor neuron—conducts efferent
impulses from the integration center to an
effector organ
– Effector—muscle fiber or gland cell that
responds to the efferent impulses by
contracting or secreting

Question 32

Sympathetic nervous system

Answer 32

part of the nervous system that serves to accelerate the heart rate, constrict blood vessels, and raise blood pressure.

Question 33

Parasympathetic nervous system

Answer 33

The part of the involuntary nervous system that serves to slow the heart rate, increase intestinal and glandular activity, and relax the sphincter muscles.