13.7 Structure and function of the brain

Question 1

what are the 5 main areas of the brain and their main functions

Answer 1

1. cerebrum (voluntary actions such as learning/memory/personality/conscious thought)
2. cerebellum (unconscious functions such as posture/balance/non-voluntary movement
3. medulla oblongata (autonomic control such as heart and breathing rate)
4. hypothalamus (regulatory centre fro temperature and water balance)
5. pituitary gland (stores and releases hormones)

Question 2

what type of images can be used to observe the brain

Answer 2

• photo (during autopsies and can help see positions of lesions which can be linked to observed changes in behaviour/capabilities before death)
• MRI
• fMRI (brain can be studied during activities as active areas have increased blood flow)
• CT (series of x-rays to create 3D images)

Question 3

describe the cerebrum

Answer 3

• receives sensory info, interprets it and sends impulses to effectors to produce desired response
• coordinates all voluntary and some involuntary
• highly convoluted = increased SA = more capacity for complex activity
• 2 hemispheres which control opposite halves of the body
• outer layer = cerebral cortex = 2-4mm
• sophisticated processes happen in frontal and prefrontal lobe
• size of sensory area allocated is proportionate to receptor cells present in that body part
• info passed to other areas called association areas to be analysed
• size of motor area located is proportionate to motor endings in it
• motor movement mostly controlled by motor cortex at the back of the frontal lobe
• visual info goes to occipital lobe

Question 4

describe the cerebellum

Answer 4

• control of muscular movement, body posture and balance
• if damaged, person has jerky, uncoordinated movement
• gets info from organs of balance in the ears and tone of muscles and tendons
• relays info to cerebral cortex

Question 5

describe the medulla oblongata

Answer 5

• regulatory centres of the autonomic nervous system
• control reflex activities
• e.g. breathing and heart rate
• controls swallowing, peristalsis and coughing

Question 6

describe the hypothalamus

Answer 6

• main control region for autonomic nervous system
• 2 centres for parasympathetic and sympathetic systems
• controls complex behaviour patterns (feeding, sleeping, aggression)
• monitors composition of blood plasma (conc of water and blood glucose so has rich blood supply)
• produces hormones

Question 7

describe the pituitary gland

Answer 7

• at the base of the hypothalamus
• anterior = produces 6 hormones including FSH (reproduction and growth hormone)
• posterior = stores and releases hormones produced by hypothalamus including ADH (urine production)