Chapter 13: Spinal Cord, Nerves, & Somatic Reflexes

Question 1

conduction

Answer 1

nerve fibers that conduct info up and down the spinal cord (CNS)

Question 2

neural integration

Answer 2

input from multiple sources, integrated & executed output

Question 3

locomotion

Answer 3

repetitive, coordinated contractions of several muscle groups

Question 4

reflexes

Answer 4

STAY AT THE SPINAL CORD LEVEL

involuntary stereotyped responses

Question 5

spinal cord

Answer 5

cylinder of nervous tissue that arises from the brainstem at the foramen magnum of the skull

Question 6

spinal cord passes through_____ and gives rise to ___ pairs of spinal nerves.

Answer 6

vertebral canal; 31

Question 7

Where do the 31 spinal nerves pass?

Answer 7

1st pair: between the skull & C1

rest through intervertebral foramina

Question 8

What 2 parts of the spinal cord are thicker than elsewhere?

Answer 8

• cervical enlargement (upper limbs)

- lumber enlargement (lower limbs)

Question 9

medullary cone

Answer 9

cord tapers to a point inferior to lumbar enlargement

Question 10

cauda equina

Answer 10

bundle of nerve roots that occupy the vertebral canal from L2 to S5

Question 11

meninges

Answer 11

three fibrous connective tissue membranes that enclose the brain & spinal cord

Question 12

What are the 3 meninges (superficial to deep)?

Answer 12

-dura mater, arachnoid mater, & pia mater

Question 13

What is special about the pia mater?

Answer 13

it is continuous with the brain & spinal cord

Question 14

What space surrounds the meninges?

Answer 14

epidural space

Question 15

spina bifida? How is it prevented?

Answer 15

• congenital defect in which one or more vertebrae fail to form a complete vertebral arch for enclosure of the spinal cord
• prevented via folic acid(B vitamin)

Question 16

The ____ is shaped like a butterfly and is surround by the ___ in 3 columns.

Answer 16

gray matter; white matter

Question 17

gray matter (2)

Answer 17

• little myelin

- site of info processing, synaptic integration

Question 18

white matter (2)

Answer 18

• abundantly myelinated

- carry signals from one part of the CNS to another

Question 19

columns of funiculi

Answer 19

3 pairs of these white matter bundles (posterior, later, ventral columns)

Question 20

ascending tracts

Answer 20

carry sensory info up the spinal cord (afferent)

BODY->SPINAL CORD->BRAIN

Question 21

descending tracts

Answer 21

carry motor info down the spinal cord (efferent)

Question 22

decussation

Answer 22

the fibers pass up or down the brainstem & spinal cord they CROSS OVER from left to right (CROSS OVER EVENT)

Question 23

contralateral

Answer 23

when the origin & destination of a tract are on opposite sides of the body

Question 24

ipsilateral

Answer 24

when the origin & destination of a tract are on the same side of the body

Question 25

What are the 3 sensory neurons of the ascending tract?

Answer 25

first order, second order, third order neurons

Question 26

first order neuron (ASCENDING)

Answer 26

detect the stimulus & transmit signal to spinal cord/brain | presynaptic

Question 27

second order neuron (ASCENDING)

Answer 27

continues to the thalamus at the upper end of brainstem | -interneurons

Question 28

third order neuron (ASCENDING)

Answer 28

carries the signal the rest of the way to the cerebral cortex -interneurons

Question 29

ascending tracts (5)

Answer 29

- gracile fasciculus - cuneate fasciculus - spinothalamic tract - spinoreticular tract - spinocerebellar tract

Question 30

gracile fasciculus Location? Decussate? Function?

Answer 30

posterior medulla oblongata sensations of the limbs and trunk (lower level)

Question 31

proprioception

Answer 31

nonvisual sense of the position and movements of the body

Question 32

cuneate fasciculus Location? Decussate? Function?

Answer 32

posterior medulla oblongata same as gracile fasciculus from T6 and up

Question 33

medial lemniscus

Answer 33

formed from the second order neurons of gracile & cuneate systems that decussate in the medulla

Question 34

Carry signals for pain, pressure, temp, light touch, tickle. and itch

Answer 34

spinothalamic tract

Question 35

Carry signals for vibration, visceral pain, deep & discriminative touch, and proprioception

Answer 35

gracile & cuneate fasciculus

Question 36

spinothalamic tract Location? Decussate? Function?

Answer 36

anterior and lateral in the spinal cord pain, pressure, temp, touch, etc

Question 37

spinoreticular tract Location? Decussate? Function?

Answer 37

anterior and lateral in the spinal cord sensation of pain from tissue injury

Question 38

spinocerebellar tract Location? Decussate? Function?

Answer 38

lateral no decussation feedback from muscles (proprioception)

Question 39

How many neurons involved in descending tracts?

Answer 39

2 (upper and lower motor neurons)

Question 40

Upper motor neurons (DESCENDING TRACT)

Answer 40

originate in the cerebral cortex and terminate on a lower motor neuron

Question 41

Lower motor neuron (DESCENDING TRACT)

Answer 41

originate in brainstem or spinal cord (leads the rest of the way)

Question 42

corticospinal tract Location? Decussate? Function?

Answer 42

cerebral cortex medulla oblongata precise fine coordinated movements

Question 43

tectospinal tract Location? Decussate? Function?

Answer 43

midbrain midbrain reflex turning of head to sound and sights

Question 44

lateral & medial reticulospinal tract Location? Decussate? Function?

Answer 44

reticular formation of brainstem no decussation awareness of pain

Question 45

lateral & medial vestibulospinal tract Location? Decussate? Function?

Answer 45

brainstem no decussation control balance & posture

Question 46

Polio & ALS

Answer 46

both cause destruction of motor neurons & production of skeletal muscles from lack of innervation (mixing of afferent & efferent)

Question 47

Each spinal nerve has 2 points of attachment, where are they?

Answer 47

posterior dorsal root & anterior ventral root

Question 48

posterior dorsal root

Answer 48

INPUT to spinal cord

Question 49

anterior ventral root

Answer 49

OUTPUT out of the spinal cord

Question 50

What are the 3 divisions of nerves in the distal branches?

Answer 50

anterior ramus posterior ramus meningeal branch

Question 51

Nerve plexus are found where

Answer 51

in the anterior rami branch

Question 52

what are the 5 nerve plexuses?

Answer 52

``` cervical brachial lumbar sacral coccygeal ```

Question 53

Shingles remains for life in the ____ _____

Answer 53

posterior root ganglion

Question 54

radial nerve injury

Answer 54

crutch paralysis

Question 55

sciatic nerve injury

Answer 55

sharp pain from "ass to toes"

Question 56

dermatome

Answer 56

specific area of the skin that receives sensory input from spinal nerves

Question 57

reflexes

Answer 57

quick involuntary stereotyped responses of muscle

Question 58

properties of reflexes (4)

Answer 58

requires stimulation quick involuntary stereotyped

Question 59

conditioned reflexes

Answer 59

learned reponses

Question 60

pathway of reflex arc (5 steps)

Answer 60

1. somatic receptors 2. afferent nerve fibers 3. integrating center 4. efferent nerve fibers 5. effectors

Question 61

muscle spindle

Answer 61

stretch receptors embedded in skeletal muscles

Question 62

stretch reflex

Answer 62

when a muscle is stretched, it "fights back" and contracts maintain tone

Question 63

tendon reflex

Answer 63

knee jerk | contraction of muscle when tendon is tapped

Question 64

flexor reflex

Answer 64

quick contraction of flexor muscles resulting in withdrawal of a limb from an injurious stimuli

Question 65

paraplegia

Answer 65

paralysis of both lower limbs

Question 66

quadriplegia

Answer 66

paralysis of all four limbs

Question 67

hemiplegia

Answer 67

paralysis on one side of the body

Question 68

paresis

Answer 68

partial paralysis or weakness of the limbs