Nervous System

Question 1

Roughly, how many neurons are there in an individuals body

Answer 1

100 billion

Question 2

What nervous tissue:

1. Receives information
2. Communicates information
3. Transmits information

Answer 2

1. Dendrites
2. Synapses
3. Axons

Question 3

What nerves enter into the spinal cord

Answer 3

Peripheral nerves

Question 4

What is a nerve cell called

Answer 4

A ganglion

Question 5

What nerves travel away (towards) the CNS

Answer 5

Efferent (afferent)

Question 6

Where does information from the face travel directly to

Answer 6

The brain stem (not through the spinal cord)

Question 7

How many pairs of cranial nerves exist and where do they input directly into

Answer 7

12 pairs; directly into the brain/brain stem

Question 8

How many pairs of spinal nerves exist and where do they input directly into

Answer 8

31 pairs; directly into the spinal cord

Question 9

What do the cranial and spinal nerves collectively make up

Answer 9

The peripheral nervous system

Question 10

What are the 2 functional sections of the nervous system and are they voluntary/involuntary

Answer 10

1. Somatic (information from the outside world); voluntary

2. Autonomic (information we don’t think about); involuntary

Question 11

What are the lumps and bumps in the brain called

Answer 11

Gyrus/gyri

Question 12

What are the indentations through the brain called

Answer 12

Sulcus/sulci

Question 13

What is the most important function of the cerebellum (little brain)

Answer 13

Controls movement and balance

Question 14

Name the 3 components that make up the brain stem (start with the most superior)

Answer 14

1. Midbrain
2. Pons
3. Medulla oblongata

Question 15

What does the brain stem connect

Answer 15

Connects the spinal cord with the cerebral hemispheres

Question 16

Name the 4 lobes of the brain

Answer 16

1. Frontal
2. Temporal
3. Parietal
4. Occipital

Question 17

What does the longitudinal fissure separate

Answer 17

The left and right cerebral hemispheres

Question 18

What 2 cranial nerves enter directly into the brain

Answer 18

1 & 2

Question 19

What does grey matter contain

Answer 19

Neurons; nerve cells/bodies

Question 20

What does white matter contain

Answer 20

Axons (communication cables) used to talk to separate nerves

Question 21

What is the region called deep in the brain that contains grey matter

Answer 21

Internal capsule

Question 22

Where is the grey matter located in the spinal cord

Answer 22

Contained within the centre of the spinal cord; white matter is on the outside

Question 23

Name the 2 swollen regions of the spinal cord, and why do we need them

Answer 23

1. Cervical enlargement
2. Lumbar enlargement
   Due to the presence of limbs; need lots of neurons to carry out the motor functions

Question 24

What do the posterior and anterior roots of the spinal cord contain

Answer 24

Posterior = 100% sensory
Anterior = 100% motor

Question 25

What do peripheral nerves consist of

Answer 25

Axons and their supporting cells

Question 26

What benefit does a myelin sheath bring to an axon

Answer 26

Speed up the electrical signals neurons use to talk to each other (electrical insulator)

Question 27

What cells produce myelin sheaths

Answer 27

Schwann cells

Question 28

What does a plexus of nerves exit towards

Answer 28

Towards the limbs

Question 29

What is a dermatome

Answer 29

Area of skin supplied by the sensory fibres in a given segmental somatic nerve

Question 30

What is an individual peripheral nerve composed of

Answer 30

Fascicles, which are made up of 100s-1000s of axons

Question 31

What are the 2 parts of the autonomic nervous system

Answer 31

Sympathetic (“fight or flight”); parasympathetic (opposes everything the sympathetic system does)

Question 32

Where do the sympathetic nerves enter and exit the spinal cord

Answer 32

Between T1 and L2; restricted to the thoraco-lumbar outflow

Question 33

What are the sympathetic chains and where do they run

Answer 33

Series of connected ganglia; go from the top to the bottom, and sit either side, of the vertebral column

Question 34

What nerves emerge from the sympathetic chains

Answer 34

Splanchnic nerves

Question 35

Where are the parasympathetic nerves restricted to

Answer 35

The cranio-sacral outflow

Question 36

Where do the vertebral arteries emerge from and what do they form

Answer 36

Subclavian arteries and form the basilar artery

Question 37

Describe the pathway of the vertebral arteries

Answer 37

Follow the cervical bones and enter through the foramen magnum (where they form the basilar artery)

Question 38

What areas of the nervous system do the vertebral arteries supply

Answer 38

Much of the:

1. Cerebellum
2. Brain stem
3. Posterior part of the cerebral hemispheres
4. Upper spinal cord

Question 39

What vessels supply the majority (2/3) of the cerebral hemispheres

Answer 39

Internal carotid arteries

Question 40

What circle of blood vessels connects the vertebral and internal carotid systems

Answer 40

Circle of Willis

Question 41

Name the 3 layers of connective tissue membrane that cover the CNS (start with deepest)

Answer 41

1. Pia mater
2. Arachnoid mater
3. Dura mater

Question 42

What gives the brain its shine

Answer 42

Pia mater (few cells thick); follows the lumps and bumps of the brain

Question 43

What minor vessels drain deoxygenated blood from the brain

Answer 43

Dural venous sinuses

Question 44

What do the dural venous sinuses drain into

Answer 44

Internal jugular veins

Question 45

What does the choroid plexus secrete, and how much does it secrete a day

Answer 45

Cerebro-spinal fluid; 400-500ml/day

Question 46

What is the purpose of cerebro-spinal fluid

Answer 46

Cushions the brain both internally (ventricles) and externally (subarachnoid space)

Question 47

What allows the CSF to be reabsorbed into the dural venous sinuses

Answer 47

Specialised structures called arachnoid granulations