Lesson 10

Question 1

where does the spinal cord extend from?

Answer 1

the foramen magnum

Question 2

where and what does the spinal cord terminate as?

Answer 2

conus medullaris, L1 or L2

Question 3

what does the spinal cord become after L1/L2?

Answer 3

cauda equina

Question 4

what does cauda equina literally mean?

Answer 4

horse tail

Question 5

the spinal cord is covered by all three meninges down to the _____ vertebra.

Answer 5

S2

Question 6

only the _____ mater extends to the posterior coccyx as the _____ _____

Answer 6

pia, filum terminale

Question 7

the spinal cord is secured to the vertebrae by the _____ _____ of the pia mater

Answer 7

denticulate ligaments

Question 8

conus medullaris

Answer 8

where the spinal cord tapers off around L1/L2

Question 9

the “cone” part of conus comes from….

Answer 9

the structure is the three dimensional shape of a cone

Question 10

what does the filum terminale do?

Answer 10

holds the spinal cord in place at the end of your spine

Question 11

gray matter

Answer 11

location of neuronal cell bodies

Question 12

dorsal (posterior) horns

Answer 12

interneurons and sensory fibers from the dorsal root ganglion

Question 13

ventral (anterior) horns

Answer 13

motor neurons of somatic nervous system that projects fibers through the ventral root

Question 14

lateral horns

Answer 14

motor neurons of autonomic nervous system (sympathetic) which leaves the cord through the ventral root

Question 15

gray commissure

Answer 15

connects the left and right horns; surrounds the central canal

Question 16

white matter

Answer 16

myelinated nerve fibers, bisected by fissures (anterior median fissure and posterior median sulcus)

Question 17

three primary regions of groupings of axons with the same origin, terminus, and function

Answer 17

1. posterior funiculus
2. lateral funiculus
3. anterior funiculus

Question 18

posterior funiculus

Answer 18

carries info on joint and muscle position and fine touch

Question 19

proprioception

Answer 19

the body’s awareness of the limbs even if they aren’t in view

Question 20

lateral funiculus (2)

Answer 20

• carries info on proprioception, pain, temp, pressure, coarse touch
• used in relaying motor info to control skeletal muscles, posture, visceral muscle functions, muscle tone, and balance

Question 21

anterior funiculus (2)

Answer 21

• carries info on pain, temp, pressure, and coarse touch
• used in relaying motor info to control skeletal muscle, posture, visceral muscle functions, muscle tone, and balance

Question 22

how to identify dorsal vs ventral funiculus (2)

Answer 22

1. the dorsal median sulcus is more shallow than the central median fissure
2. dorsal root is attached to the dorsal root ganglion and the dorsal spinal cord

Question 23

there are _____ pairs of spinal nerves

Answer 23

31

Question 24

where do the ventral and dorsal rami branch from?

Answer 24

they branch from the spinal nerve shortly after exiting the spinal column

Question 25

there are four major plexuses

Answer 25

cervical, brachial, lumbar, and sacral

Question 26

cervical plexus (4)

Answer 26

- formed from ventral rami of C1-C5 - serves the neck and shoulder - major motor branch: phrenic nerve in C3/4 and some of 5 - innervates the diaphragm

Question 27

C1 through C7 spinal nerves emerge above or below the vertebrae they are named after?

Answer 27

above; all other spinal nerves emerge BELOW

Question 28

where does the C8 spinal nerve emerge from?

Answer 28

between C7 and T1; there is no C8

Question 29

brachial plexus (2)

Answer 29

- formed from ventral rami of C5 through C8 and T1 - serves the shoulder, arms, and hand

Question 30

the brachial plexus is arranged into what? (4)

Answer 30

trunks, divisions, cords, and major peripheral nerves

Question 31

the brachial plexus cords are divided into 5 major peripheral nerves

Answer 31

1. axillary 2. radial 3. median 4. musculocutaneous 5. ulnar

Question 32

brachial plexus: peripheral nerves - axillary (2)

Answer 32

- C5 and C6 - serves the shoulder muscles, and the skin of the shoulder area

Question 33

brachial plexus: peripheral nerves - radial (2)

Answer 33

- C5 through C8 and T1 - serves extensor muscles of the arm, forearm, and hand (on the posterolateral surface of the arm/forearm) thumb side

Question 34

brachial plexus: peripheral nerves - median (2)

Answer 34

- C8, T1, and C5 through C7 - serves flexor muscles of the forearm, hand (some), and the skin on the lateral surface of the palm in the middle

Question 35

brachial plexus: peripheral nerves - musculocutaneous (2)

Answer 35

- serves flexor muscle for the forearm and flexion - serves the skin of the lateral surface of the forearm in the elbow/axillary area

Question 36

brachial plexus: peripheral nerves - ulnar (2)

Answer 36

- serves the flexor carpi ulnaris, flexor digitorum, and other hand muscles - skin of the medial third of the anterior/posterior hand (at the pinkie side)

Question 37

lumbar plexus (3)

Answer 37

- from ventral rami of L1 through L4 (sometimes T12) - serves lower abdominopelvic region and anterior thigh - femoral nerve (innervates anterior thigh), branches into the saphenous nerve

Question 38

sacral plexus (3)

Answer 38

- from the ventral rami of L4 through S4 - serves butt, posterior surface of the thigh, leg, and foot - major nerve is the sciatic nerve, the largest in the body, which divides into common fibular and tibial nerves

Question 39

ulnar nerve

Answer 39

on the pinkie finger side of your arm, aka ulnar side

Question 40

musculocutaneous nerve

Answer 40

usually near the elbow armpit area

Question 41

median nerve

Answer 41

in the middle of the arm

Question 42

axillary nerve

Answer 42

in the shoulder ish area

Question 43

radial nerve

Answer 43

runs along the same side as the radius, aka thumb side/lateral side of your arm

Question 44

femoral nerve

Answer 44

major nerve at the top of the leg on the front side

Question 45

saphenous nerve

Answer 45

the big nerve going down your leg after the femoral nerve splits/branches

Question 46

sciatic nerve

Answer 46

the "starting big nerve" at the top of the back of the leg

Question 47

tibial nerve

Answer 47

on the medial/big toe side of the leg, on the same side as the tibia

Question 48

common fibular nerve

Answer 48

on the lateral/pinkie toe side of the leg, same side as the fibula

Question 49

ANS

Answer 49

autonomic nervous system

Question 50

what is the ANS?

Answer 50

a subdivision of the peripheral nervous system (PNS) that controls functions not under conscious control

Question 51

what does the ANS serve? (3)

Answer 51

cardiac muscles, smooth muscle in the viscera and blood vessels, and internal organs

Question 52

what two motor neurons primarily control the ANS?

Answer 52

1. preganglionic neuron 2. ganglionic neuron

Question 53

the preganglionic neuron is where?

Answer 53

in the brain and spinal cord

Question 54

the ganglionic neuron is where?

Answer 54

in the ganglion outside the CNS

Question 55

two major divisions of the ANS

Answer 55

sympathetic and parasympathetic

Question 56

sympathetic division of the ANS (3)

Answer 56

- fight or flight response - postganglionic axons release norepinephrine - preganglionic neurons located in the lateral horn of grey matter synapses with ganglionic neurons in the paravertebral ganglion alongside the vertebral column

Question 57

parasympathetic division of the ANS

Answer 57

- resting, digestion - postganglionic axons release acetylcholine - preganglionic neurons located in the brain of cranial nerves III, VII, IX, X, and S2-S4 synapses with ganglionic neurons in the terminal/intramural ganglion close to target

Question 58

sympathetic trunk

Answer 58

the "chain of nerves" down the back