Spinal Cord Reflexes

Question 1

Reflex

Answer 1

Programmed, predictable response to stimuli

Question 2

Types of reflexes

Answer 2

1) innate

2) learned

Question 3

Innate reflex

Answer 3

Genetic, automatic reflex present at birth

Question 4

Learned reflex

Answer 4

developed reflex following repeated exposure to same stimulus

Question 5

Reflex complexity types:

Answer 5

1) monosynaptic ipsilateral
2) polysynaptic ipsilateral
3) polysynaptic contralateral
4) reciprocal
5) intersegmental pathway

Question 6

Monosynaptic ipsilateral reflex conditions:

Answer 6

1 sensory input and 1 motor output

Stimulus enters/exits on same side of cord

Question 7

Polysynaptic ipsilateral reflex conditions

Answer 7

Has at least two synapses between 1 sensory, 1 association, and 1 motor neuron

Stays on same side of cord

Question 8

Polysynaptic contralateral reflex

Answer 8

Impulse crosses over gray commissure

At least 2 synapses between sensory, association, and motor neuron

Question 9

Reciprocal reflex purpose

Answer 9

Activates one muscle while inhibiting another

Example: to withdraw from pain

Question 10

Reciprocal reflex conditions:

Answer 10

Can be ipsilateral or contralateral

Multiple synapses with at least two motor neurons

Question 11

Intersegmental pathway condition:

Answer 11

Impulse travels from 1 segment of cord to another through white column.

Associations neurons use white matter tracts

Question 12

Reflex location types:

Answer 12

Spinal reflex

Cranial reflex

Question 13

Spinal reflex

Answer 13

Response involves motor neurons in cord only

Question 14

Cranial reflexes

Answer 14

Response is generated by brain

Question 15

How do mixed spinal nerves exit the vertebral column?

Answer 15

Pass through holes between adjacent vertebra

Question 16

Dorsal ramus

Answer 16

Posterior branch lateral of mixed spinal nerve

Innervates skin and muscles of midline of back

Question 17

Ventral ramus

Answer 17

Larger anterior branch lateral of mixed spinal nerve

Innervates rest of body

Question 18

Plexus group

Answer 18

Formed by groups of ventral ramus

Question 19

Rami communicantes

Answer 19

2 small branches off anterior side of ventral ramus

Connects to ANS (motor only)

Question 20

Nerve

Answer 20

Layers of connective tissue wrapped axons

Question 21

Nerve organization

Answer 21

Endoneurium

Perineurium

Epineurium

Question 22

Endoneurium

Answer 22

CT that holds group of axons together

Question 23

Perineurium

Answer 23

CT that holds together groups of axons known as fascicles

Question 24

Epineurium

Answer 24

Connective tissue that holds together several fascicles