Central nervous system

Question 1

Central nervous system

Answer 1

Made up of the brain and spinal cord, protected by the bones of the cranium and vertebral canal, the meninges and cerebrospinal fluid

Question 2

Peripheral nervous system

Answer 2

made up of nerves that send impulses to and from the CNS

Question 3

Layers of the cerebrum

Answer 3

Grey, white, grey, Lobes are named according to the cranial bones that cover them, Cerebral cortex (grey)- 2-4mm outer layer of cerebrum, White matter deep inside cerebrum, Basal ganglia- internal grey matter

Question 4

Tracts

Answer 4

Bundles of myelinated white fibres between the cerebral cortex and basal ganglia WITHIN THE CNS called tracts, OUTSIDE THE CNS called nerves

Question 5

Types of tracts

Answer 5

Connect cortex areas within the same hemisphere, Connect left and right hemispheres, Connect cortex to other parts of brain or spinal cord

Question 6

Functions of the cerebral cortex (8)

Answer 6

Thinking, reasoning, learning, Memory, Intelligence, Sense of responsibility, Perception of the senses, Initiation and control of voluntary muscle contraction

Question 7

Functional areas of the cerebral cortex

Answer 7

Sensory tract- interprets impulses from receptors, Motor tract- controls voluntary muscular movements, Association areas- concerned with intellectual and emotional processes

Question 8

Cerebellum (little brain)

Answer 8

Grey, white (no internal grey matter), Exercises control over posture and balance, Co-ordination of voluntary muscle movement so that the movement is smooth, Receives sensory information from a variety of sense receptors, All processes are sub-conscious (involuntary)

Question 9

Damage to the cerebellum

Answer 9

movements still occur but are spasmodic, jerky and uncontrolled

Question 10

Hypothalamus

Answer 10

Lies in the middle of the brain, Mostly concerned with homeostasis (regulation of internal environment)

Question 11

What does the hypothalamus regulate (7)

Answer 11

Autonomic nervous system (Heart rate, blood pressure, digestive juices, movement of alimentary canal, pupil diameter), Body temperature, Food and water intake, Patterns of waking and sleeping, Contractions of urinary bladder, Emotional responses, Secretion of hormones

Question 12

Medulla oblongata

Answer 12

Continuation of spinal cord just below base of brain, Automatically adjusts many body functions, Contains cardiac, respiratory, vasomotor and expulsion centres

Question 13

Cardiac centre

Answer 13

controls heart rate and depth (how hard and fast the heart pumps)

Question 14

Respiratory centre

Answer 14

controls breathing rate and depth

Question 15

Vasomotor centre

Answer 15

controls dilation and constriction of blood vessels

Question 16

Expulsion centre

Answer 16

controls involuntary reflexes like coughing, sneezing and vomiting

Question 17

Spinal cord

Answer 17

Cylindrical tube from the foramen magnum (where the spin enters the skull) to L2, Approximately 44cm long, Has same protection as brain except dura mater (outer meninges) which isn’t attached to bone, Protected by a layer of fat, vessels and connective tissue cushions, Grey and white matter reverse of that in the brain

Question 18

Ascending tract

Answer 18

Carries impulses towards the brain

Question 19

Descending tract

Answer 19

Carry impulses away from the brain

Question 20

Corpus callosum

Answer 20

Wide band of WHITE nerve fibres that lie underneath the cerebrum at the base of the longitudinal fissure, Nerve fibres connect to the left and right hemispheres of the brain

Question 21

How does the cranium and vertebral canal protect the CNS

Answer 21

provides physical protection against blows

Question 22

How does the meninges protect the CNS

Answer 22

A tough and fibrous protective matter, Has 3 layers of tissue: Dura mater, arachnoid and pia mater (PAD backwards)

Question 23

How does the cerebrospinal fluid protect the CNS

Answer 23

Sits on the inside and outside of the brain and spinal cord, Provides nutrients to the brain and spinal cord and removes waste (works similarly to the blood), Creates buoyancy and absorbs shocks