The Brain, Behaviour and Disease

Question 1

What 2 halves is the cerebrum split into?

Answer 1

Cerebral hemispheres

Question 2

Where is the cerebral cortex found?

Answer 2

• A thin outer layer on the cerebrum
• The back of the cortex is involved in vision and the front is involved in thinking

Question 3

What is the function of the cerebrum?

Answer 3

Involved in vision, learning, thinking, emotions and movement

Question 4

What is the function of the hypothalamus?

Answer 4

• Maintains body temperature (thermoregulation)
• Produces hormones that controls the pituitary gland

Question 5

What is the function of the medulla oblongata?

Answer 5

Automatically controls breathing rate and heart rate

Question 6

What is the function of the occipital lobe?

Answer 6

Visual processing area of the brain

Question 7

What’s the function of the cerebellum?

Answer 7

Coordinating movement and balance

Question 8

What do CT scanners use to visualise the brain?

Answer 8

• Use radiation to produce cross-section images of the brain
• Dense structures absorb more radiation than less dense structures so show up lighter on the screen

Question 9

How can CT scans be used to investigate brain structure and function?

Answer 9

• Shows major structures of the brain but not its functions so can show diseased or damaged parts of the brain
  E.g, if an area of the brain is damaged and the patient can’t see then that area is involved in vision

Question 10

What do MRI scanners use to visualise the brain?

Answer 10

Use a really strong magnetic field and radio waves to produce cross-section images of the brain

Question 11

How can MRI scans be used to investigate brain structure and function?

Answer 11

• Gives higher quality images than CT for soft tissue types and better resolution
• Clearly see difference between normal and abnormal brain tissue

Question 12

How can CT scans be used in medical diagnosis?

Answer 12

• Can be used to diagnose medical problems
• Blood has a different density from brain tissue so shows up lighter, identify extent of bleeding and its location

Question 13

How can MRI scans be used in medical diagnosis?

Answer 13

• Can be used to diagnose medical problems
• Tumour cells show up lighter and the scan will show its exact size and location and you can also work out the effected brain functions

Question 14

What are fMRI scans used for and how do they work?

Answer 14

• Show brain activity
• More oxygenated blood flows to active parts of the brain, the signal returned to the scanner is stronger from the oxygenated blood
• Allow active parts of the brain to be identified

Question 15

How can fMRI scans be used to investigate brain structure and function?

Answer 15

• Gives a detailed, high resolution picture of brain structure and can be used to study brain functions
• If a function is carried out whilst in the scan it will be highlighted in the fMRI scan

Question 16

How can fMRI scans be used in medical diagnosis?

Answer 16

• Show damaged or diseased areas of the brain and allows you to study conditions caused by abnormal activity

Question 17

What are PET scans used for and how do they work?

Answer 17

• Show how active different areas of the brain are
• A radioactive tracer is introduced into the body and is absorbed by tissues, it builds up a map of radioactivity in the body

Question 18

How can PET scans be used to investigate brain structure and function?

Answer 18

• Very detailed and can be used to investigate structures and functions

Question 19

How can PET scans be used in medical diagnosis?

Answer 19

• Can show if parts of the brain is unusually inactive or active so are useful in studying disorders

Question 20

What is habituation?

Answer 20

• Animals increase their chance of survival by responding to stimuli but if that stimulus is unimportant there’s no point in responding to it
• If an unimportant stimulus is repeated over a period of time an animals learns to ignore it this is habituation

Question 21

How can habituation affect effectors?

Answer 21

• Repeated exposure decreases Ca2+ entering the pre-synaptic neurone
• This decrease means less neurotransmitters released from vesicles that can bind to receptors on the post-synaptic membrane
• Fewer Na+ channels open so a reduced chance of threshold for an action potential being reached so fewer signals sent to effector

Question 22

What is the visual cortex made up of?

Answer 22

Ocular dominance columns, which is groups of neurones that receive information from the visual cortex

Question 23

How does the visual cortex develop?

Answer 23

Soon after birth, the neurones in the visual cortex of baby mammals begin to form connections allowing the transfer of visual information

Question 24

What is the critical period?

Answer 24

• After birth both eyes need to be visually stimulated in order for the neurones in the visual cortex to be organised correctly
• Synapses that pass on nerve impulses during this critical period are strengthened and become permanent