Nervous System

Question 1

What are the 3 main functions of the Nervous System?

Answer 1

Sensory function (perception), Information transfer and processing, and Motor function

Question 2

What makes up the CNS?

Answer 2

Central Nervous System: Brain and Spinal Cord

Question 3

What are the divisions of the PNS?

Answer 3

Peripheral Nervous System: Sensory (afferent) division and the Motor (efferent) division

Question 4

What is the function of Sensory nerves?

Answer 4

Sensory (afferent) nerves transmit impulses towards the CNS from the body

Question 5

What is the function of Motor nerves?

Answer 5

Motor (efferent) nerves transmit impulses from the CNS to the body

Question 6

What do most Neurons consist of (include how many)?

Answer 6

1 Cell body, many Dendrites and 1 Axon

Question 7

Describe the cell body

Answer 7

Where the nucleus & other cellular organelles are found

Question 8

Describe dendrites

Answer 8

The receiving or input portions of a neuron that carry impulses towards the cell body

Question 9

Describe Axon

Answer 9

Long, thin portion of the neuron which transmits electrical signals from the cell body to the axon terminals. Neurons communicate with each other via chemicals called synaptic bulb ends

Question 10

How do myelin sheaths affect neurons?

Answer 10

Neurons with axons covered with myelin sheaths can conduct electrical impulses much faster than those that do not.
They also protect nerve cells

Question 11

How do Nodes of Ranvier affect Neurons?

Answer 11

Nodes of Ranvier assist in the rapid transmission of nerve impulses
i.e. The greater the number of Nodes of Ranvier, the faster the transmission.

Question 12

How does a Myelinated neurone differ from a non-Myelinated neurone?

Answer 12

A non-Myelinated neurone has a continuous Myelin sheath, there are no Nodes of Ranvier and only one Schwann cell.
A Myelinated neurone will have at least one Node of Ranvier, and is made up of multiple Schwann cells

Question 13

What is a Schwann cell?

Answer 13

Schwann cells have multiple functions within the PNS.

Importantly, concentric Schwann cells form Myelin sheath

Question 14

What are Neuroglia?

Answer 14

Non-impulse generating/conducting cells in the nervous system

Question 15

What are some of the roles of the Neuroglia?

Answer 15

Providing structural support for neurons.
Creating a blood-brain barrier.
Restricting movement of substances between the blood & tissue fluids within the CNS.
There are neuroglia that take on the role of phagocyte, removing debris & damaged tissue.

Question 16

What makes up the cranial Vault?

Answer 16

Brain - 80%,
Cerebral blood - 12%,
Cerebral spinal fluid - 8%

Question 17

What are the 4 major sections of the brain?

Answer 17

Brain stem,
Cerebellum,
Diencephalon, and
Cerebrum

Question 18

What makes up the brain stem?

Answer 18

Mid Brain,
Pons Varolli, and
Medulla Oblongata.
Together they control level of consciousness

Question 19

What is the function of the Medulla Oblongata?

Answer 19

Relays sensory & motor input between other parts of the brain & spinal cord.
Contains centres to manage heart rate, BP & breathing.
Contains origins of a number of cranial nerves

Question 20

What is the function of the Pons Varolla?

Answer 20

Relays nervous impulses from one side of the cerebellum to the other & between medulla & midbrain.
Contains origins of a number of cranial nerves.
Contains centres to regulate breathing

Question 21

What is the function of the Mid Brain?

Answer 21

Relays motor output from the cerebral cortex & sensory input from the spinal cord to the thalamus.
Controls & co-ordinates movement.
Contains origins of two cranial nerves

Question 22

What is the structure and function of the Cerebellum?

Answer 22

Made up of two hemispheres.
It is responsible for coordinating complex & skilled movements (i.e. muscle memory).
Regulates posture & balance

Question 23

What is the structure and function of the Diencephalon?

Answer 23

Connects the cerebrum with the brain stem.
It is comprised of the thalamus & hypothalamus, and is the link between the nervous system & the endocrine system (hormones)

Question 24

What is the function of the Thalamus?

Answer 24

Relays sensory input to the cerebral cortex.

Provides perception of touch, pressure, pain, and temperature

Question 25

What is the function of the Hypothalamus?

Answer 25

Controls & integrates autonomic nervous system activity. Regulates behavioural patterns & circadian rhythms. Controls body temperature. Regulates eating & drinking

Question 26

Describe the anatomy of the Cerebrum

Answer 26

The largest part of the brain which is split into two hemispheres. Has an outer rim of grey matter & an internal region of white matter. The outer rim of grey matter contains the cerebral cortex, which, although thin contains billions of neurons.

Question 27

What are the 4 lobes of each hemisphere of the Cerebrum?

Answer 27

Frontal, Parietal, Temporal, & Occipital

Question 28

What are the 3 Meninges?

Answer 28

Dura Mater Arachnoid Mater Pia Mater

Question 29

Describe the Dura Mater

Answer 29

Tough outer layer consisting of connective tissue

Question 30

Describe the Arachnoid Mater

Answer 30

Middle layer. The sub-arachnoid space is filled with CSF

Question 31

Describe the Pia Mater

Answer 31

Delicate inner layer containing small blood vessels that supply O2 and nutrients to the brain

Question 32

What does CSF stand for?

Answer 32

Cerebrospinal fluid

Question 33

What is Cerebrospinal Fluid (CSF)?

Answer 33

A clear, colourless liquid Protects the brain and spinal cord from physical and chemical injury Carries O2, glucose and other nutrients essential for normal brain function Removes waste products

Question 34

How many and what are the vertebrae in the vertebral column?

Answer 34

``` 33 total 7 Cervical 12 Thoracic 5 Lumbar 5 Sacral 4 Coccygeal ```

Question 35

Where does the spinal cord extend between and what is the cone-like structure formed?

Answer 35

Medulla oblongata to the superior border of 2nd lumbar vertebrae The cone-like structure is the conus medullaris

Question 36

What do the nerves that originate distal to the conus medullaris form?

Answer 36

Cauda equine (horses-tail)

Question 37

How many pairs of spinal nerves are there? (Break it down!)

Answer 37

``` 31 total 8 Cervical 12 Thoracic 5 Lumbar 5 Sacral 1 Coccygeal ```

Question 38

What does the Somatic Nervous System allow you to do and how?

Answer 38

Also known as Voluntary Nervous System Allows a person to consciously control their skeletal muscles due to somatic nerve fibres that conduct impulses from the CNS to the skeletal muscles

Question 39

What are the 3 parts of the Autonomic Nervous System?

Answer 39

Sympathetic nervous system Parasympathetic nervous system Enteric nervous system

Question 40

What is the Enteric Division?

Answer 40

Part of the ANS, its an expansive network of neurons within the walls of the gastrointestinal (GI) tract, pancreas and gall bladder

Question 41

How does the Enteric Division work?

Answer 41

Part of the ANS, sensory nervous function enables monitoring of the mechanical state of the alimentary canal and the chemical status of the stomach and intestines It outputs motor signals to modify the motility and secretions of the gut Controls diameter of local blood vessels

Question 42

What does the Sympathetic Division do?

Answer 42

``` Part of the ANS, it prepartes the body to respond to stress Stimulates cardiac activity Opens the airways Dilates skeletal blood vessels Reduces gastric activity ```

Question 43

What does the Parasympathetic Division do?

Answer 43

Part of the ANS, known as the 'rest-and-digest division' Has a general peacemaker effect Stimulates digestion and absorption of food Slows down cardiac and respiratory activities

Question 44

What does S.A.M.E stand for?

Answer 44

Sensory Afferent Motor Efferent