Human Physiology Chapter 13: The Peripheral Nervous System

Front 1

What are the two main types of reflexes?

Back 1

Learned (acquired) reflexes and inborn (intrinsic) reflexes

Front 2

What are acquired reflexes?

Back 2

They are complex reflexes that result from practice or repetition

Front 3

What are intrinsic reflexes?

Back 3

They are simple reflexes that are rapid, predictable motor responses to a stimulus

Front 4

Are intrinsic reflexes involuntary or voluntary?

Back 4

Involuntary (even if reflex involves voluntary skeletal muscles)

Front 5

What are the five steps to the reflex arc?

Back 5

1. Sensory receptor
2. Sensory neuron caries afferent input to the CNS
3. Integration center
4. motor neuron carries efferent output from CNS to effectors
5. Effector

Front 6

Most sensory neurons are unipolar or multipolar?

Back 6

unipolar!

Front 7

Motor and association neurons are unipolar or multipolar?

Back 7

Multipolar!

Front 8

What are the two types of reflexes, scientifically?

Back 8

Autonomic reflexes and Somatic reflexes

Front 9

What are autonomic reflexes?

Back 9

Autonomic reflexes are involuntary that involve smooth muscle, cardiac muscle and glands

Front 10

What are some examples of autonomic reflexes?

Back 10

Pupils dilating, salivate when hungry, etc

Front 11

What are somatic reflexes?

Back 11

Somatic reflexes are involuntary reflexes that involve skeletal muscle

Front 12

What are 3 important facts about spinal somatic reflexes?

Back 12

1. Integration occurs in the spinal cord
2. Do not require input from the brain, occur even when the brain is damaged
3. brain usually dampens the reflex

Front 13

TRUE OR FALSE: Somatic reflexes are involuntary even though they involve voluntary skeletal muscles.

Back 13

True

Front 14

What are stretch reflexes?

Back 14

Stretch reflexes are the simplest somatic spinal reflex

Front 15

What is the stimulus for stretch reflexes?

Back 15

A stretch in a skeletal muscle

Front 16

What are the responses to stretch reflexes?

Back 16

1. Reflex contraction of stretched muscle
2. Reflex relaxation of opposing muscle

Front 17

Skeletal muscles often work in what kind of pairs?

Back 17

Opposing!

Front 18

If both opposing muscles contract at the same time, what occurs?

Back 18

No movement

Front 19

During the stretch reflex, one muscle ______ while the opposing muscle ______.

Back 19

Contracts. Relaxes

Front 20

What is the purpose of the stretch reflex?

Back 20

To maintain muscle tone in large postural muscles

Front 21

What are the sensory receptors in muscles?

Back 21

muscle spindles

Front 22

What are muscle spindles?

Back 22

Muscle spindles are proprioceptors which give you your "body sense"

Front 23

What do muscle spindles detect?

Back 23

They detect changes in muscle length

Front 24

When a muscle is unstretched, APs are generated at what kind of rate?

Back 24

Constant rate

Front 25

When a muscle is stretched, APs are generated at what kind of rate?

Back 25

Increasing rate

Front 26

A muscle responds to stretch by doing what?

Back 26

Contracting

Front 27

When only motor neurons are activated and extrafusal muscle fibers contract, the muscle spindle becomes what? What happens to APs?

Back 27

Slack and no APs are fired

Front 28

When both extrafusal and intrafusal muscle fibers contract, muscle spindle tension is what?

Back 28

maintained!

Front 29

What activates the muscle spindle?

Back 29

A stretch

Front 30

A stretch excites sensory neurons that synapse directly with what?

Back 30

Motor neurons in the spinal cord

Front 31

What are the sensory receptors in muscles?

Back 31

muscle spindles

Front 32

What are muscle spindles?

Back 32

Muscle spindles are proprioceptors which give you your "body sense"

Front 33

What do muscle spindles detect?

Back 33

They detect changes in muscle length

Front 34

When a muscle is unstretched, APs are generated at what kind of rate?

Back 34

Constant rate

Front 35

When a muscle is stretched, APs are generated at what kind of rate?

Back 35

Increasing rate

Front 36

A muscle responds to stretch by doing what?

Back 36

Contracting

Front 37

When only motor neurons are activated and extrafusal muscle fibers contract, the muscle spindle becomes what? What happens to APs?

Back 37

Slack and no APs are fired

Front 38

When both extrafusal and intrafusal muscle fibers contract, muscle spindle tension is what?

Back 38

maintained!

Front 39

What activates the muscle spindle?

Back 39

A stretch

Front 40

A stretch excites sensory neurons that synapse directly with what?

Back 40

Motor neurons in the spinal cord

Front 41

Motor neurons cause stretched muscles to what?

Back 41

contract

Front 42

Which reflexes are the only reflexes that are monosynaptic?

Back 42

Stretch reflexes!

Front 43

What is an example of a monosynaptic stretch reflex?

Back 43

Patellar (knee-jerk) reflex

Front 44

During the patellar reflex, which muscle is stretching and contracting?

Back 44

Quadriceps!

Front 45

What is reciprocal inhibition?

Back 45

Sensory neurons excite interneurons that then inhibit motor neurons to opposing muscles

Front 46

Is reciprocal inhibition monosynaptic or polysynaptic?

Back 46

Polysynaptic

Front 47

If motor neurons are firing, muscles are always what?

Back 47

Contracting

Front 48

Which neurons fire APs while the patellar reflex is activated?

Back 48

Sensory neuron, motor neuron to quadriceps, and interneurons

Front 49

Sensory neuron causes EPSPs or IPSPs in the motor neuron to quadriceps and in the interneuron?

Back 49

EPSPs!

Front 50

Interneuron causes EPSPs or IPSPs in motor neuron to the hamstrings?

Back 50

IPSPs!