Peripheral Nervous System

Question 1

What are the two functional divisions of the peripheral nervous system?

Answer 1

Afferent (sensory)
Efferent (motor)

Question 2

What are the divisions of the efferent division?

Answer 2

Somatic (motor) nervous system (SNS)

Autonomic nervous system (ANS)

Question 3

Voluntary control of skeletal muscles

Answer 3

Somatic (motor) SNS

Question 4

Involuntary control of smooth muscle, cardiac muscle and glands

Answer 4

Autonomic (ANS)

Question 5

Fight or flight

Answer 5

Sympathetic

Question 6

Rest and digest

Answer 6

Parasympathetic

Question 7

Controls all voluntary motor actions outside the CNS

Answer 7

Somatic nervous system

Question 8

Skeletal muscles

Answer 8

Somatic effectors

Question 9

T/F
The autonomic nervous system contains both afferent (sensory) and efferent (motor) components

Answer 9

True
*the efferent components are emphasized here

Question 10

T/F
Autonomic nervous system carries fibers to and from the autonomic effectors

Answer 10

True

Question 11

What is the major function of the autonomic nervous system?

Answer 11

To regulate heart rate, smooth muscle contraction, and glandular secretions to maintain homeostasis

Question 12

What are the two efferent divisions of the autonomic nervous system?

Answer 12

Sympathetic

Parasympathetic

*both do opposite things to maintain homeostasis

Question 13

T/F
Many autonomic effectors are dialog innervated, which allows remarkably precise control of effector

Answer 13

True

Question 14

Functions to regulate visceral effectors (smooth, cardiac muscle and glands) in ways that tend to maintain or quickly restore homeostasis

Answer 14

Function of the autonomic nervous system ANS

*keeps important variables (temperature, HR, BP, digestion, respiration) within an ideal healthy range

Question 15

How many pairs of spinal nerves are connected to the spinal cord?

Answer 15

31
*8 C
*12 T
*5 L
*5 S
*1 Co

Question 16

T/F
Cervical nerves come out mostly above their matching vertebrae

Answer 16

True
*all others the opposite

Question 17

T/F
Thoracic, lumbar, sacral, and coccygeal nerves exit below their matching vertebrae

Answer 17

True
*opposite from cervical

Question 18

What is the lower end if the spinal cord called, past L1?

Answer 18

Cauda equina (horses tail)

Question 19

How do the spinal nerves attach to the spinal cord?

Answer 19

2 roots:

Ventral (anterior) root

Dorsal (posterior) root

Question 20

Root that included motor neurons that carry information from the CNS to effectors (muscles/glands)
*away from spinal cord

Answer 20

Ventral root

Question 21

Root that includes sensory fibers that carry info from receptors in peripheral nerves to CNS
*towards spinal cord

Answer 21

Dorsal root

Question 22

T/F
All spinal nerves are mixed nerves; contain both motor and sensory fibers

Answer 22

True

Question 23

T/F
Ventral and dorsal nerve roots combine to form the spinal nerve

Answer 23

True

Question 24

Where does the spinal nerve exit the spinal column?

Answer 24

Through the intervertebral foramina

Question 25

When the spinal nerve exits the intervertebral foramina, what does it split into?

Answer 25

Dorsal and ventral rami *ventral is the larger branch

Question 26

Supplies skin and muscles of the posterior surface of the head, neck and trunk

Answer 26

Dorsal ramus

Question 27

Supplies muscles and glands in the extremities and the lateral and anterior portions of the neck and trunk *also connected to sympathetic chains (ANS)

Answer 27

Ventral ramus

Question 28

T/F Ventral rami of most spinal nerves ( except nerves T2-12) subdivide to form complex networks called plexuses

Answer 28

True

Question 29

What are the 4 major plexuses ?

Answer 29

Cervical Brachial Lumbar Sacral

Question 30

“Braid” Nerves mix and reorganize to form new individual nerves

Answer 30

Plexus *each new nerve from a plexus contains fibers that serve a specific body region

Question 31

T/F Plexuses make the system more efficient and provide backup - damage to one spinal nerve usually doesn’t cause total loss of function in the region

Answer 31

True

Question 32

Plexus -located deep in the neck -innervated muscles and skin of the neck, upper shoulder and part of the head -include phrenic nerve - innervates diaphragm -includes 2 cranial nerves: accessory nerve (Xl) and hypoglossal nerve (Xll)

Answer 32

Cervical plexus (C1-5)

Question 33

Plexus -located deep within the shoulder -innervates lower part of shoulder and entire arm

Answer 33

Brachial plexus (C5-T1)

Question 34

Plexus -located in the lumbar region of the back near the psoas muscle -innervates the thigh and legs

Answer 34

Lumbar plexus (L1-4)

Question 35

Plexus -located in the pelvic cavity on the anterior surface of the piriformis muscle -innervates most of the leg below the knee and feet -major nerve is sciatic nerve (largest nerve in body)

Answer 35

Sacral plexus (L4-S4)

Question 36

-S5 joins with coccygeal nerve -supplies skin that lies over coccyx bone

Answer 36

Coccygeal plexus

Question 37

T/F There is no plexus from T2-12

Answer 37

True