Chapter 13: Spinal Reflexes

Question 1

functions of white matter tracts & gray matter tracts

Answer 1

white matter tracts are highways for nerve impulse conduction to and from the brain

gray matter nuclei recieve and integrate incoming and outgoing info

Question 2

reflex arc

Answer 2

the interrelationship btwn an afferent and an efferent neuron that occurs in the brain and spinal cord

Question 3

5 functional components of a reflex arc

Answer 3

1. sensory receptor
2. sensory neuron
3. interneuron or association neuron in the integrating center
4. motor neuron
5. effector

Question 4

sensory receptors conducts impulse from _______ to ______

Answer 4

axon conducts impulses from receptor to integrating center

Question 5

interneuron or association neuron in the integrating center conducts impulses from ______ to ______

Answer 5

relays impulses from sensory to motor neuron

Question 6

motor neuron conducts impulse from ______ to ______

Answer 6

axon conducts impulses from integrating center to effector

Question 7

effector responds to

Answer 7

motor nerve impulses

• any muscle or gland

Question 8

reflex

Answer 8

rapid, predictable, automatic response to external changes to help maintain homeostasis

Question 9

monosynaptic reflex arc

Answer 9

simplest reflex arc

• contains 1 sensory neuron
• 1 motor neuron
• 1 synapse

Question 10

stretch or extensor reflex is imortant for

Answer 10

maintaining muscle tone and muscle coordination during exercise

Question 11

patellar reflex is an example of _______ that controls _________ by causing __________

Answer 11

extensor reflex that controls muscle length by causing muscle contraction

Question 12

reflex arc for patellar reflex

stimulant

sensory receptors

spindles

sensory neuron

integrating center

motor neuron

effectors

response

Answer 12

stimulant: neurological hammer

sensory receptors: muscle

spindles/proprioceptors: respond to stress

sensory neuron: enters posterior root and goes through horn

integrating center: gray matter of horn

motor neuron: impulse along anterior root

effectors: thigh entensor muscles (quad)
response: extends knee (hammies)

Question 13

4 branches (rami) or spinal nerves

Answer 13

meningeal ramus, posterior ramus, anterior ramus, rami communicantes

Question 14

meningeal ramus

Answer 14

• smallest
• reenters through IVF
• innervates: bertebral, meninges, blood vessels

Question 15

posterior ramus

Answer 15

motor and sensory fibers

• innervates skin and posterior muscles of trunk

Question 16

anterior ramus

Answer 16

• largest
• motor and sensory fibers
• innervates to extremities + lateral anterior trunk

Question 17

nerve plexus

Answer 17

networks (interbranching) of anterior rami from several adjacent spinal nerves

• move directly to body areas
• peripheral nerves arise from plexi and then travel to body regions

Question 18

intercostal/thoracic nerves

locate

innervations

Answer 18

anterior rami of spinal nerves T2-T12

• dont enter into formation of plexuses
• innervate at the intercostal muscles, skin of trunk, ab muscles

Question 19

cervical plexus

location

innervations

nerve

injury

Answer 19

anterior rami of C1-C4

• innervates: muscles/skin of neck + posterior scalp
• phrenic nerve: carries fibers from C3, C4, C5
• Spinal injusry above C3=paralysis of diaphram

Question 20

brachial plexus

ocation

innervations

injury (6)

Answer 20

anterior rami of C5-T1

• innervate: skin, muscles of arms, upper back, shoulder, chest
• injury to brachial plex=Erm Duchenne palsy (waiters tip), Klumpkes palsy, wrist drop, carpal tunnel, claw hand, winged scalpula

Question 21

lumbar plexus

location

innervations

nerves (2) injury

Answer 21

anterior rami of L1-L4

• innervates low. ab wall, external genetalia
• largest nerves=femoral, obturator
• injury to femoral nerve=inability to extend leg, loss of sensation in skin over front thigh

Question 22

injury to the sciatic nerve results in?

Answer 22

sciatic pain, burning, numbness, tingling, loss of sensation, muscle weakness that extends from butt down the post/ant leg

• occurs due to: herniated disc, dislocated hip, osteoarthritis, lumbosacral spin, pressure from gravid uterus

Question 23

coccygeal plexus

location

innervations

nerve

Answer 23

anterior rami of S2-S4

• innervates at genetalia and butt
• pudendal nerve comes off coccygeal plexus

Question 24

what is the skin over the entire body supplied by?

Answer 24

spinal nerves that carry somatic sensory nerves into the spinal cord

Question 25

all spinal cords except _____ innervate specific, constant segments of the skin called \_\_\_\_\_\_

Answer 25

C1, dermatomes

Question 26

how does knowledge of dermatones help doctor?

Answer 26

they can determine which segments of the spinal cord or which spinal nerve is malfuctioning