Chapter 4.1 Central Nervous System✓

Question 1

Define the role of the nervous system

Answer 1

The role of the nervous system is to receive and process information from sense organs and bring about responses to the information received.

Question 2

What are the two divisions of the nervous system?

Answer 2

The Central Nervous System (CNS) and the Peripheral Nervous System (PNS)

Question 3

What is the central nervous system made up of and what is its role?

Answer 3

It is made up of the brain and the spinal cord and its role is to receive information from all over the body and process it.

Question 4

What is the peripheral nervous system made up of and what is its role?

Answer 4

It is made up of nerves that carry messages to and from the CNS and receptors, to muscles and glands in your body

Question 5

How do the central nervous system and the peripheral nervous system link?

Answer 5

They link by transmitting signals between the brain, spinal cord (CNS) and the body’s receptors, muscles and gland (PNS)

Question 6

What are the three structures that protect the CNS?

Answer 6

-bone (cranium and vertebrae)
-membrane called meninges
-cerebrospinal fluid

Question 7

What bone is the brain protected by?

Answer 7

The cranium

Question 8

What bone protects the spinal cord?

Answer 8

The vertebral canal

Question 9

What do the bone provide for the brain and spinal cord?

Answer 9

A strong and ridged structure to protect the structures underneath

Question 10

What are the three layers of menings?

Answer 10

-Dura mater
-Arachnoids mater
-Pia mater

Question 11

What is a meninge?

Answer 11

Meninges are membranes/connective tissue that cover the brain and the spinal cord

Question 12

Describe the dura mater layer.

Answer 12

-The outermost layer
-Tough and fibrous
- Provides a layer of protection for the brain

Question 13

Describe the arachnoid mater layer.

Answer 13

-The middle layer
-Loose mesh of fibres

Question 14

Describe the pia mater layer.

Answer 14

-The inner layer
-Delicate layer
-Contains blood vessels and sticks closely to the surface of the brain and spinal cord

Question 15

Define cerebrospinal fluid (CSF)

Answer 15

Cerebrospinal fluid is a protective structure that occupies a space between the middle and inner layer of the meninges (between the arachnoid and pia layer)

Question 16

Where does CSF circulate through in the brain and spinal cord?

Answer 16

Cerebrospinal fluid ciruclates through cavities in the brain and through a canal in the centre of the spinal cord

Question 17

What does CSF contain.

Answer 17

Cerebrospinal fluid is a clear, watery fluid containing a few cells and some urea, glucose, protein and salts.

Question 18

What are the three functions of the CSF?

Answer 18

-Protection: Acts as a shock absorber, cushioning any blows or shocks the CNS may sustain

-Support: The brain is suspended inside the cranium and floats in the fluid that surrounds it.

-Transport: The CSF is formed from the blood, and circulates around through the CNS before eventually re-entering the blood capillaries. During this circulation it takes nutrients to the cells of the brain and spinal cord and carries away their waste

Question 19

Define the cerebrum

Answer 19

The cerebrum is the largest part of the brain

Question 20

What does the cerebrum consist of?

Answer 20

It consists of a thin layer (2-4 mm) of grey matter known as the cerebral cortex.

Question 21

What does grey matter consist of?

Answer 21

It consists of neuron cell bodies, dendrites and unmyelinated axons.

Question 22

What is white matter made out of?

Answer 22

Myelinated axons.

Question 23

What gives white matter its colour?

Answer 23

The fatty natures of the myelin sheath gives its colour and texture.

Question 24

What is the grey matter called that is deep inside the cerebrum?

Answer 24

basal ganglia

Question 25

What is the function of the basal ganglia?

Answer 25

The basal ganglia, are associated with the control of skeletal muscles, play a role in initiating desired movements and inhibiting unwanted movements.

Question 26

What is the purpose of the folding of the cerebral cortex?

Answer 26

To increase its surface area for a large number of neurons

Question 27

What does folding produce in the cerebral cortex?

Answer 27

It produces round ridges called convolutions

Question 28

What are the two terms called when convolutions are separated?

Answer 28

They are separated by either shallow downfolds called sulci (sulcus) or deep downfolds called fissures.

Question 29

What is the deepest fissure called and what does it almost separate?

Answer 29

Its called the longitudinal fissure and it almost separates the cerebrum into two halves - the left and right cerebral hemispheres

Question 30

What are the four lobes of the cerebral cortex?

Answer 30

-Frontal lobe -Parietal lobe -Temporal lobe -Occipital lobe

Question 31

What is regarded as the fifth lobe?

Answer 31

The insula

Question 32

What are the functions of the frontal lobe?

Answer 32

-Thinking -Problem solving -Emotions -Personality -Language -Control of movement

Question 33

What are the functions of the parietal lobe?

Answer 33

-Processing temperature -Touch -Taste -Pain -Movement

Question 34

What are the functions of the temporal lobe?

Answer 34

-Processing memories and linking them with senses -Receives auditory information

Question 35

What is the function of the occipital lobe?

Answer 35

-Vision

Question 36

What are the functions of the insula?

Answer 36

-Recognition of different senses and emotions -Addiction and psychiatric disorders

Question 37

What are the three functional areas of the cerebral cortex and define them.

Answer 37

-Sensory areas: Interpret impulses from receptors -Motor areas: Control muscular movements -Association areas: Concerned with intellectual and emotional processes

Question 38

Define corpus callosum

Answer 38

The corpus callosum is a wide bundle of white matter that links the two cerebral hemispheres

Question 39

What joins the two hemispheres?

Answer 39

The corpus callosum

Question 40

Where is the corpus callosum located?

Answer 40

It is located underneath the cerebrum at the base of the longitudinal fissure

Question 41

Where is the cerebellum located?

Answer 41

It is located underneath the rear part of the cerebrum

Question 42

Describe the structure of the cerebellum?

Answer 42

The outer folded part of the cerebellum is grey matter and inside is white matter that branches to all parts of the cerebellum.

Question 43

What is the cerebellum responsible for?

Answer 43

It is responsible for posture, balance and the coordination of voluntary muscle movement.

Question 44

Where is the hypothalamus located?

Answer 44

It lies in the middle of the brain and cannot be seen from the outside the brain

Question 45

What is the main role of the hypothalamus?

Answer 45

To maintain homeostasis

Question 46

What are the functions of the hypothalamus?

Answer 46

Functions include: -The autonomic nervous system (involuntary processes), including heart rate and blood pressure -Body temperature -Food and water intake -Patterns of walking and sleeping -Contractions of the urinary bladder -Emotional responses e.g. fear, anger, pleasure -The secretion of hormones and coordination of parts of the endocrine system. -(Acting through the pituitary gland, hypothalamus regulates metabolism, growth, reproduction and responses to stress)

Question 47

Define the medulla oblongata

Answer 47

The medulla oblongata is a continuation of the spinal cord.

Question 48

What centres does the medulla oblongata contain and define them.

Answer 48

It contains: -The cardiac centre: regulates the rate and force of the heart beat -Respiratory centres: Controls rate and depth of breathing -The vasomotor centre: Regulates the diameter of blood vessels -In addition, other centres regulate: -reflexes of swallowing, sneezing, coughing and vomiting

Question 49

How long is the spinal cord?

Answer 49

roughly 44cm long in an adult

Question 50

What are the two main functions of the spinal cord?

Answer 50

-Carrying sensory impulses to the brain and motor responses from the brain. -Integrating fast automatic responses called reflexes

Question 51

What are ascending tracts in the spinal cord?

Answer 51

Bundles of sensory axons that carry impulses upwards towards the brain

Question 52

What are descending tracts in the spinal cord?

Answer 52

Bundles of motor axons that conduct impulses downwards away from the brain.

Question 53

What structure allows for the bending of the spine?

Answer 53

The space surrounding the spinal cord filled with fat, connective tissue and blood vessels which cushions and allows for flexibility for spinal movements.

Question 54

How is the outermost meningeal layer of the spinal cord different from that of the cerebrum?

Answer 54

In the cerebrum, the outermost meningeal layer is fused to the bone where as in the spinal cord it is attached to the bone.

Question 55

How are the grey matter and white matter arranges in the spinal cord?

Answer 55

The grey matter is centrally located and shaped like an "H" while the white matter surrounds it.