Chapter 13 - Continued

Question 1

Dorsal ramus

Answer 1

supplies posterior body trunk (back); (sensory & motor nerves); supplies skin, muscles in back; does NOT form nerve plexuses

Question 2

Ventral ramus of T2 - T12

Answer 2

do NOT form nerve plexus; supplies the intercostal muscles (which assist in breathing); always mixed nerves (sensory & motor)

Question 3

Ventral ramus of all other spinal nerves

Answer 3

C1 - C8; T1; L1 - L5; S1 - S5; C0; form nerve plexuses

Question 4

nerve plexuses

Answer 4

formed by the intermixing of ventral rami from different spinal nerves; supplies majority of the body; mixed–relays info from both directions

Question 5

4 Major Nerve Plexuses (ventral ramus)

Answer 5

1. Cervical plexus
2. Brachial plexus
3. Lumbar plexus
4. Sacral plexus

Question 6

Cervical plexus - function & ex.

Answer 6

intermixing of ventral rami of C1 -C4; supplies neck muscles; 4 nerves form plexus;
ex. phrenic nerve - supplies the diaphragm

Question 7

Brachial plexus - function & ex.

Answer 7

intermixing of ventral rami of C5 - C8 & T1; supplies the entire arm; 2 plexuses-one on each side; most complicated plexus;
ex. radial nerve - supplies the extensor muscles of the arm

Question 8

T2 - T12

Answer 8

do not form nerve plexuses; wherever they branch is where it supplies

Question 9

Lumbar plexus - function & ex.

Answer 9

ventral rami of L1 - L4; supplies the thigh & parts of abdominal wall;
ex. femoral nerve - supplies anterior thigh & medial parts of leg

Question 10

Sacral plexus - function & ex.

Answer 10

ventral rami of L4 - S4 (a little overlap w/lumbar plexus); supplies most of the leg, pelvic, buttocks muscles;
ex. Sciatic nerve - longest nerve in the body; supplies part of thigh & rest of leg

Question 11

Reflex

Answer 11

rapid, involuntary motor response to a stimulus; stimulus - harmful to body;

Question 12

reflex arc

Answer 12

pathway followed by nerve impulses that produce a reflex

Question 13

Spinal reflexes

Answer 13

reflexes mediated by the spinal cord; most reflexes are initiated & completed @ the spinal cord

Question 14

Reflex arc (5 phases)

Answer 14

1. sensory receptor - detects something potentially harmful
2. sensory neuron - carries info to CNS
3. integration center - always inside CNS; interprets info
4. motor neuron - carries info away from CNS to effector
5. effector - responding organ/muscle/gland that responds

Question 15

1st 4 phases of reflex arc involves the NS & the last phase responds to the NS but in not part of the NS

Answer 15

1. sensory receptor
2. sensory neuron
3. integration center
4. motor neuron
   - -5. EFFECTOR - not part of NS

Question 16

Ex of Spinal reflexes

Answer 16

Stretch reflexes - prevents overstretching of muscles;

ex of stretch reflexes - patellar reflex - quick way to check that NS is working properly