Chapter 7 Peripheral Nervous System

Question 1

What is a nerve is the PNS?

what is the difference between sensory, motor, and mixed nerves

Answer 1

Nerve - bundle of neurons fibres in the PNS

Sensory nerve - carry nerve impulses toward CNS

Motor nerve - carry motor fibers away from CNS

Mixed nerves - carry both sensory and motor fibres, all spinal nerves are mixed nerves

Question 2

Identify the cranial nerves by number and
by name, and describe the major functions of each

Answer 2

-12 pairs of cranial nerves in neck and head

I - olfactory - nose - sensory
II - optic - eye - vision - sensory
III - oculomotor - eye - pupils movement - motor
IV - trochlear - vision- motor
V - trigeminal - face mixed nerve - mixed
VI - abducens - vision - motor
VII - facial - facial expressions - mixed
VIII - vestibulococlear - balance and hearing - mixed
IX - glossopharyngeal - swallowing - mixed
X - vagus - pharynx and larynx- mixed
XI - accessory - traps and sterno- motor
XII - hypoglossal - tongue - motor

Oh oh oh to touch and feel very good vagina ah heaven

Some say marry money but my brother says big brains matter more

Question 3

3. Identify the number and location of the spinal nerves

Answer 3

31 pairs by joining the ventral and dorsal roots of the spinal cord

Question 4

What are spinal nerves

What are ventral and dorsal roots

Answer 4

-31 pairs
- formed by the joining of dorsal and ventral roots on each side of the spinal cord

• splits into dorsal and ventral ramus (mixed nerves)

Question 5

What are the divisions of the autonomic nervous system and explain their synapses

Answer 5

The preganglionic axons both release acetylcholine

The postganglionic axons release different neurotransmitters

Parasympathetic - two neuron chain, acetylcholine in pre and post ganglion

Sympathetic- two neuron chain, acetylcholine in preganglion, post ganglion releases acetylcholine and epinephrine and norepinephrine in adrenal medulla in blood stream

Question 6

Describe the effects of aging on the
anatomy and physiology of the nervous
system

Answer 6

• neurons decrease
• slow nerve impulses speed conduction
• slower reflexes

Question 7

Describe the homeostatic relationship
between the nervous system and other body systems.

Answer 7

Nervous system regulates all organs inside the body and all stimulus outside the body and sends signals to the control centre (brain)

Question 8

What are the 3 connective tissue wrappings of a nerve?

Answer 8

Epineurium (wraps entire nerve)
Perineurium (wraps fascicles)
Endoneurium (wraps fibre)

Question 9

Which cranial nerve is the only one to serve structures outside the head and neck

Answer 9

X Vagus nerve

Question 10

The PNS has_________ (a group of cell bodies) and _________ (a group of nerve fibres)

Answer 10

ganglia and nerve

Question 11

What is a nerve?

Answer 11

A bundle of nerve fibers in the PNS

Question 12

What are mixed nerves?

Answer 12

Nerves that carry both sensory (afferent) nerves and motor (efferent) nerves

Question 13

What is a plexus? What are the 4 nerve plexuses?

Answer 13

Complex nerve network that serve the needs of the limbs

Cervical - neck and head
Brachial - arm
Lumbar - thigh
Sacral - ass, below knee, back of thigh

Question 14

What are the dorsal ramus and ventral ramus?

Answer 14

Where nerves cross over and become mixed carrying both sensory and motor nerves

Question 15

Although all body systems contribute to homeostasis, the stability of our internal environment depends largely on _________________

Answer 15

Autonomic nervous system

Question 16

When it comes to synapses, the autonomic nervous system differs from the somatic nervous system in that __________________

Answer 16

The autonomic has a chain of two motor neurons

Somatic axons extend all the way to the muscles

Question 17

What is the preganglionic neuron and postganglionic axon?

In what part of the nervous system are they found?

Answer 17

Preganglionic neuron - in the CNS and forms a synapse with a motor neuron outside the CNS

Postganglionic axon - extends to the organ it serves

These are only in the autonomic nervous system going to organs (not muscles) AKA parasympathetic and sympathetic divisions

Question 18

True or false: The parasympathetic and sympathetic nervous system affect the same organs

Answer 18

True

Question 19

In the sympathetic nervous system the body will also release __________ and ___________ in the blood stream

Answer 19

Epinephrine and norepinephrine hormone

Question 20

What are the three different pathways a sympathetic impulse can go to their synapse ?

Answer 20

1. In the sympathetic trunk at the same level
2. In the sympathetic trunk at a different level
3. Pass by the trunk becoming a splanchnic nerve to synspse in an anterior collateral ganglion

Question 21

Sensory neurons in PNS ganglia are ____________

Answer 21

Unipolar

Question 22

What is the cervical and lumbar enlargement?

Answer 22

Where the nerves of the upper and lower limbs meet the spinal cord

Question 23

True or false: the vagus nerve extends to the abdominal and thoracic cavities

Answer 23

True

Question 24

How many spinal nerves are in cervical, thoracic, lumbar and sacral sections of the spine

Answer 24

Cervical 8
Thoracic 12
Lumbar 5
Sacral 5

Question 25

Where does the spinal cord start and where does it end?

Answer 25

Starts in foramen magnum

Ends first or second lumbar vertebrae