AN120: Nerves

Question 1

What does the nervous system do?

Answer 1

Together with the endocrine system, controls and integrates the activites of the body.

Question 2

What are the divisions of the nervous system?

Answer 2

Functionally:
- somatic NS
- autonomic NS

Anatomically:
- central NS: brain (controls voluntary activities) & spinal cord (controls involuntary activity: sympathetic & parasympathetic)
- peripheral NS: cranial nerves (12 pairs) & spinal nerves (31 pairs: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal)

Question 3

What is the Central NS?

Answer 3

it is composed of neurons that are supported by neuroglia.

Question 4

Define neuron

Answer 4

nerve cells and their processes (dendrites and axons)
dendrites: short processes of cell body while axons are the longest processes,

Question 5

What is the CNS organized into?

Answer 5

1. Gray matter: nerve cells embedded in neuroglia
2. White matter: nerve fibres (axons) embedded in neuroglia

Question 6

What is the PNS divided into?

Answer 6

1. Cranial nerves
2. Spinal nerves

Question 7

What are cranial nerves?

Answer 7

they are 12 pairs of nerves arising mostly from the brain stem and distributed (through skull foramina) into the head & neck (except vagus “Xth” 10 which also supply thorax and abdomen)

Question 8

which cranial nerve supplies the abdomen and thorax?

Answer 8

Vagus nerve

Question 9

what are the 12 cranial nerves?

Answer 9

l. olfactory nerve (sensory)
ll. optic nerve (sensory)
lll. occulamotor (motor)
lV. trochlear (motor)
V. trigeminal (both)
Vl. abducens nerve (motor)
Vll. facial nerve (both)
Vlll. vestibulocochlear (sensory)
IX. glosspharyngeal (both)
X. vagus (both)
Xl. accessory nerve (motor)
Xll. hypoglossal (motor)

Question 10

CNS

what is the brain composed of ?

Answer 10

1. cerebrum
2. cerebellum
3. brain stem

Question 11

What cerebral hemispheres?

Answer 11

they consists of outer grey matter (cell bodies) and inner white matter (axons).
- contain spaces called ventricles filled with fluid (CSF)

Question 12

what is the cerebellum?

Answer 12

it consists of two cerebrellar hemispheres and midline portion.

Question 13

What does the diencephalon consist of?

Answer 13

• thalamus
• subthalamus
• epithalamus
• hypothalamus
• metathalamus

Question 14

What is the diecephalon a part of?

Answer 14

The brain stem.

Question 15

what does the brain stem consist of?

Answer 15

• dicephalon
• midbrain
• pons
• medulla

Question 16

What is continuous with the medulla oblangata?

Answer 16

The spinal cord.