Nervous System

Question 1

What is the CNS protected by?

Answer 1

1. bones of the cranium and vertebral canal
2. The meninges
3. Cerebrospinal fluid

Question 2

cerebrospinal fluid

Answer 2

1. protection (shock absorber)
2. support (buoyancy)
3. transport/nutrition (providing oxygen and glucose and eliminating CO2

Question 3

Cerebrum

Answer 3

cerebral cortex is 2-4mm grey outer layer of cerebrum.
white matter deep inside cerebrum
Basal Ganglia is internal grey matter

Question 4

Tracts

Answer 4

tracts are between grey cerebral cortex and grey basal ganglia.
bundles of myelinated white fibres
inside CNS, called tracts and outside CNS they are called nerves.

Question 5

Types of Tracts

Answer 5

1. connect cortex areas within the same hemisphere
2. connect left and right hemispheres
3. connect cortex to other parts of brain or to the spinal cord

Question 6

what are the cerebral cortex functions?

Answer 6

1. thinking, reasoning, learning
2. memory
3. intelligence
4. sense of responsibility
5. perception of senses
6. initiation and control of voluntary muscle contraction

Question 7

what are the functional areas of cortex?

Answer 7

1. sensory areas- interpret impulses from receptors
2. motor areas- control muscular movements
3. association areas- concerned with intellectual and emotional processes

Question 8

Corpus Callosum

Answer 8

wide band of nerve fibres that lies under cerebrum at base of longitudinal fissure.
connect left and right hemispheres

Question 9

Cerebellum

Answer 9

1. exercises control over posture and balance
2. co-ordination of voluntary (smooth) muscle movement
   receives sensory information from inner ear for posture and balance
   receives sensory information from stretch receptors in skeletal muscles
   all processes are sub-conscious

Question 10

What happens when the cerebellum is damaged?

Answer 10

Movements still occur but are spasmodic, jerky and uncontrolled.

Question 11

Hypothalamus

Answer 11

Middle of the brain

Concerned with homeostasis

Question 12

What does the hypothalamus regulate?

Answer 12

1. autonomic nervous system (HR, BP, digestive juices, movement of alimentary canal, pupil diameter)
2. body temperature
3. food and water intake
4. patterns of waking and sleeping
5. contractions of urinary bladder
6. emotional responses
7. secretion of hormones

Question 13

Medulla Oblongata

Answer 13

Continuation of spinal cord below base of brain

Automatically adjusts many body functions

Question 14

What does the medulla oblongata contain?

Answer 14

1. cardiac centre (rate and force of heartbeat)
2. respiratory centre ( rate and depth of breathing)
3. vasomotor centre (diameter of blood vessels)
4. expulsion centre (sneezing, vomiting)

Question 15

Spinal Cord

Answer 15

cylindrical tube from the foramen magnum (hole in skull where spinal cord starts) to L2
approx. 44cm long
same protection as brain EXCEPT dura mater (out meninges) is NOT attached to bone. Instead, layer of fat, vessels and connective tissue cushions.

Question 16

How is the grey and white matter arranged in spinal cord?

Answer 16

Reverse to the brain.

White matter surrounds grey central region.

Question 17

what does the central canal of spinal cord contain?

Answer 17

Contains cerebrospinal fluid

Question 18

Tracts in the Spinal Cord

Answer 18

Myelinated nerve fibres arranged in bundles (tracts)
Ascending tracts carry impulses towards the brain
Descending tracts carry impulses away from the brain.

Question 19

What is the function of the spinal cord

Answer 19

provides a pathway for communication between muscles and glands and the brain. Integration of automatic, protective reflexes.

Question 20

What are the 3 layers of meninges?

Answer 20

dura mater, arachnoid and pia mater