Pdbio Exam 2 Lecture 12

Front 1

How many pairs of spinal nerves are there?

Back 1

31

Front 2

What is a dermatome?

Back 2

A specific segment of skin supplied by a single pair of spinal nerves

Front 3

Shingles

Back 3

During initial infection, the chickenpox virus sometimes leaves the skin and invades the posterior root ganglion

Virus remains latent until adulthood

Rash of scaly, painful blisters (usually confined to one or a few adjacent dermatomes)

Front 4

Nerve plexuses

Back 4

A network of interweaving spinal nerves

Split into multiple "named" nerves that innervate various body structures

Principle plexuses (cervical, brachial, lumbar, and sacral)

Front 5

Which spinal nerves make up the cervical plexus?

Back 5

C1-C4

Front 6

What does the cervical plexus innervated

Back 6

Anterior neck and parts of the head and shoulders

Front 7

What innervates the diaphragm?

Back 7

Phrenic nerve

Front 8

Which spinal nerves keep the diaphragm alive?

Back 8

C3-C5

Front 9

Which spinal nerves make up the brachial plexus?

Back 9

C5-T1

Front 10

What does the brachial plexus innervate?

Back 10

Pectoral girdle and upper limbs

Front 11

Which spinal nerves make up the lumbar plexus?

Back 11

L1-L5

Front 12

What does the lumbar plexus innervate?

Back 12

Lower limb

Front 13

Which spinal nerve innervated the anterior thigh muscles?

Back 13

Femoral nerve

Front 14

Which spinal nerves make up the sacral plexus?

Back 14

L4-S4

Front 15

What does the sacral plexus innervate?

Back 15

Lower limb

Front 16

Sciatic nerve

Back 16

Innervates all of the lower limb except anterior/medial thigh

Divides into the tibial and common fibular (peroneal) nerve

Front 17

What are the five steps of the reflex arc?

Back 17

1. Receptor

2. Sensory (afferent) neuron

3. Interneuron

4. Motor (efferent) neuron

5. Effector

Front 18

Monosynaptic reflexes

Back 18

The simplest of all reflexes

No interneurons (faster)

Example: stretch reflex (knee-jerk)

Front 19

Polysynaptic reflexes

Back 19

More complex neural pathway

More than one synapse involving interneurons within the reflex arc

Example: withdrawal reflex

Front 20

Differences between somatic nervous system and autonomic nervous system

Back 20

Somatic:

1 somatic sensory neuron

1 somatic motor neuron

Autonomic:

1 visceral sensory neuron

2 autonomic motor neurons (preganglionic an postganglionic -- adds another level of control)

Front 21

What is the autonomic nervous system divided into?

Back 21

Sympathetic and parasympathetic divisions

Front 22

What is the origin of the sympathetic division?

Back 22

T1-L2

Front 23

What are the functions of the sympathetic division?

Back 23

"Fight or flight"

Activated in emergency situations and when excited or stressed

Front 24

What is the origin of the parasympathetic nervous system?

Back 24

Brainstem (CN III, VII, IX, and X)

Sacral spinal cord

Front 25

What are the functions of the parasympathetic nervous system?

Back 25

"Rest and digest"

Conserves energy and replenishes energy stores

Front 26

________ are innervated by both sympathetic and parasympathetic divisions?

Back 26

Most organs -- this is called dual innervation

Front 27

Opposite effects on an organ can be achieved by...

Back 27

increasing or decreasing activity in one division (sympathetic or parasympathetic)