Lesson 11

Question 1

reflex arc

Answer 1

mediated by neural paths (connections of neurons) to yield rapid involuntary muscle response to stimuli

Question 2

two main groups of reflexes

Answer 2

1. autonomic
2. somatic

Question 3

autonomic reflexes

Answer 3

mediated through autonomic nervous system; smooth muscles in digestion, glands in sweating

Question 4

somatic reflexes

Answer 4

involve sensory stimulation that causes skeletal muscle to react; withdraw reflex from pain

Question 5

components of a reflex arc (5)

Answer 5

1. receptor
2. sensory neuron
3. integration sensor
4. motor neuron
5. effector

Question 6

spinal reflexes

Answer 6

initiated and completed at the spinal cord level without the involvement of higher brain centers (somatic)

Question 7

knee-jerk reflex

Answer 7

utilizes a two neuron, monosynaptic reflex arc

Question 8

flexor reflex

Answer 8

utilizes sensory and motor neurons connected by interneurons, polysynaptic reflex arc

Question 9

spinal reflex: stretch reflex (2)

Answer 9

• maintains posture/balance and locomotion
• tendon stretch causes agonist muscle contraction and antagonistic relaxation

Question 10

spinal reflex: crossed extensor reflex

Answer 10

flexion of one limb followed by extension of the opposite limb

Question 11

spinal reflex: superficial cord reflex (2)

Answer 11

• results from pain and temperature changes
• ex. plantar reflex, Babinski’s sign

Question 12

patellar (jerk) reflex (4)

Answer 12

1. tapping the patellar ligament excites muscles
2. afferent impulse travels to spinal cord where info is relayed to motor/interneurons
   3a. motor neuron send activating impulse to quadriceps, extending the knee
   3b. interneurons make inhibitory synpases with ventral horn that prevent antagonist muscle contraction

Question 13

cranial nerve reflex: corneal reflex (2)

Answer 13

• a function of cranial nerve V (trigeminal)
• touching of the cornea causes blinking

Question 14

cranial nerve reflex: gag reflex (2)

Answer 14

• a function of cranial nerves IX (glossopharyngeal) and X (vagus)
• touching of uvula causes gag

Question 15

pupillary reflexes

Answer 15

reflex caused by light stimulation of cranial nerve II (optic) causing iris constriction by cranial nerve III (oculomotor)

Question 16

pupillary light reflex

Answer 16

pupil constricts due to light stimulus

Question 17

consensual reflex

Answer 17

light stimulation of one eye causes constriction in contralateral (opposite) eye

Question 18

ciliospinal refelx

Answer 18

stimulation of the back of the neck causes ipsilateral pupil dilation (same side)

Question 19

salivary reflex

Answer 19

food order detection causes salivation

Question 20

exteroceptors

Answer 20

react to external stimuli

Question 21

interoceptor/visceroreceptors

Answer 21

react to internal stimuli

Question 22

proprioceptor

Answer 22

detects body/limb position

Question 23

hair follicle receptor (3)

Answer 23

• free/naked nerve ending
• non-encapsulated
• detects light touch

Question 24

free nerve endings detect (2)

Answer 24

pain and temperature

Question 25

encapsulated nerve endings: tactile Meissner’s corpuscle

Answer 25

detects light touch and light pressure

Question 26

encapsulated nerve endings: bulbous Ruffini’s corpuscle

Answer 26

detects deep pressure and stretching

Question 27

encapsulated nerve endings: lamellar Pacinian corpsucle

Answer 27

detects deep pressure and high frequency vibrations

Question 28

four qualities of cutaneous sensation

Answer 28

1. touch
2. heat
3. cold
4. pain

Question 29

are cutaneous sensations distributed evenly throughout the body?

Answer 29

no, it’s distributed non-uniformly; distribution is based on importance of the area and need for the receptors

Question 30

two-point threshold

Answer 30

smallest distance two points of contact can be perceived; use a vernier caliper for this activity

Question 31

tactile localization

Answer 31

determining which point on skin has been stimulated

Question 32

adaptation

Answer 32

sensory receptor discharge from stimulus slows causing the perception of stimulus to decrease

Question 33

referred pain

Answer 33

perception of pain from one area of the body when another area is actually receiving the noxious stimulus