Spinal Nerves and Nerve Plexuses

Question 1

How many nerves are in the cervical region?

Answer 1

8

Question 2

How many nerves are in the thoracic region?

Answer 2

12

Question 3

How many nerves are in the lumbar region?

Answer 3

5

Question 4

How many nerves are in the sacral region?

Answer 4

5

Question 5

Which is smaller, the dorsal ramus or the ventral ramus?

Answer 5

dorsal

Question 6

What does apaxial mean?

Answer 6

Innervation of back muscles with dorsal rami; they allow the spine to be erect.

Question 7

What does hypaxial mean?

Answer 7

innervation of upper and lower limbs; they receive info from ventral rami of spinal nerve.

Question 8

Which rami carries visceral motor components?

Answer 8

ventral

Question 9

What kind of nerve system forms the sympathetic trunk?

Answer 9

spinal nerve ganglion

Question 10

The sympathetic trunk is connected to spinal nerves in which regions?

Answer 10

thoracic and upper lumbar.

Question 11

Where types of nerves are associated with the sympathetic trunk?

Answer 11

visceral motor (autonomic), sympathetic, and grey & white rami communicantes.

Question 12

what is exteroception?

Answer 12

instant awareness of something painful happening, e.g. snakebite.

Question 13

What is interoception?

Answer 13

visceral (e.g. nausea) or referred pain.

Question 14

What is proprioception?

Answer 14

A sense of the surroundings/space around a body, as well as balance.

Question 15

What is a dermatome?

Answer 15

A area of skin innverated by the sensory fibers of a single nerve root.

Question 16

What is a myotome?

Answer 16

A group of muscles that is primarily innervated by the motor fibers of a single nerve root.

Question 17

What are the three ways that spinal nerves are distributed in the body?

Answer 17

intercostal nerves, dorsal rami, and spinal nerve plexuses.

Question 18

intercostal nerves always extend from whcih rami?

Answer 18

ventral rami (they are hypaxial); they can also extend from dorsal

Question 19

nerve plexuses extend from which rami?

Answer 19

ventral rami (hypaxial)

Question 20

What is the intercostalbrachial nerve?

Answer 20

Nerve found around T2; it is responsible for referred pain

Question 21

What is the subcostal nerve?

Answer 21

A pair of nerves at T12; it innervates the lateral abdominal region. The first lumbar vertebrae are below it.

Question 22

Where does the dorsal rami innervate?

Answer 22

Back of head to the butt. It also extends laterally (but not very much) along the back.

Question 23

What are the nerve plexuses?

Answer 23

A network of interweaving ANTERIOR rami of spinal nerves. They are on the right and left sides of the body.

Question 24

What vertebrae make up the cervial plexus?

Answer 24

C1 - C4

Question 25

What is the ansa cervicalis?

Answer 25

C2; LOOP of nerves that innervate neck muscles.

Question 26

What is the phrenic nerve?

Answer 26

C3; nerve that runs from the hyoid to clavicle and scapula.

Question 27

What spinal nerves innervate the diaphragm?

Answer 27

C3, C4, C5

Question 28

What vertebrae make up the brachial plexus?

Answer 28

C5 - T1

Question 29

What are the divisions of the brachial nerves (proximal to distal?)

Answer 29

roots, trunks, divisions, cords, branches

Question 30

What does the brachial plexus innervate?

Answer 30

clavicle, arm, hand

Question 31

What vertebrae make up the lumbar plexus?

Answer 31

L1 - L4

Question 32

What does the lumbar plexus innervate?

Answer 32

femur, hip, lower abdomen, leg

Question 33

What vertebrae make up the sacral plexus?

Answer 33

L5 - S4

Question 34

What adoes the sacral plexus innervate?

Answer 34

the gluteal region, shin, calf and foot.

Question 35

What are reflexes?

Answer 35

Rapid, involuntary reactions of muscles to glands to a stimulus.

Question 36

What are the three properties of reflexes?

Answer 36

stimulus, rapid response with few neurons and an identical and automatic response every time.

Question 37

What are ipsliateral reflex arcs?

Answer 37

the receptor and effector organs of the reflex are on the same side of the spinal cord. (e.g. muscles in left arm contract to pull left hand away from a hot object).

Question 38

What are contralateral reflex arcs?

Answer 38

the sensory impulses from a receptor organ cross over through the spinal cord to activate effector organs in the opposite side limb.

Question 39

What are monosynaptic reflexes?

Answer 39

reflexes that do not involve neurons. Example is tapping the patellar ligament.

Question 40

What are polysynaptic reflexes?

Answer 40

reflexes that involve interneurons and more complex pathways. There is a more prolonged delay between stimulus and response. Example is withdrawl reflexes (e.g. hot stove)

Question 41

What are stretch reflexes?

Answer 41

monosynaptic reflexes that monitor and regulate skeletal muscle length. When a stimulus results in stretching of muscle, the muscle contracts.

Question 42

What does the golgi tendon reflex do?

Answer 42

prevents skeletal muscle from tensing excessively. It signals interneurons to inhibit the actions of motor neurons. It is a mechanism to prevent excessive tension damage.

Question 43

Where are Golgi tendon organs?

Answer 43

nerve endings located within tendons near a muscle-tendon junction.