The Brain, Behaviour and Disease Flashcards
What 2 halves is the cerebrum split into?
Cerebral hemispheres
Where is the cerebral cortex found?
- A thin outer layer on the cerebrum
- The back of the cortex is involved in vision and the front is involved in thinking
What is the function of the cerebrum?
Involved in vision, learning, thinking, emotions and movement
What is the function of the hypothalamus?
- Maintains body temperature (thermoregulation)
- Produces hormones that controls the pituitary gland
What is the function of the medulla oblongata?
Automatically controls breathing rate and heart rate
What is the function of the occipital lobe?
Visual processing area of the brain
What’s the function of the cerebellum?
Coordinating movement and balance
What do CT scanners use to visualise the brain?
- 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
How can CT scans be used to investigate brain structure and function?
- 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
What do MRI scanners use to visualise the brain?
Use a really strong magnetic field and radio waves to produce cross-section images of the brain
How can MRI scans be used to investigate brain structure and function?
- Gives higher quality images than CT for soft tissue types and better resolution
- Clearly see difference between normal and abnormal brain tissue
How can CT scans be used in medical diagnosis?
- 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
How can MRI scans be used in medical diagnosis?
- 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
What are fMRI scans used for and how do they work?
- 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
How can fMRI scans be used to investigate brain structure and function?
- 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
How can fMRI scans be used in medical diagnosis?
- Show damaged or diseased areas of the brain and allows you to study conditions caused by abnormal activity
What are PET scans used for and how do they work?
- 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
How can PET scans be used to investigate brain structure and function?
- Very detailed and can be used to investigate structures and functions
How can PET scans be used in medical diagnosis?
- Can show if parts of the brain is unusually inactive or active so are useful in studying disorders
What is habituation?
- 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
How can habituation affect effectors?
- 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
What is the visual cortex made up of?
Ocular dominance columns, which is groups of neurones that receive information from the visual cortex
How does the visual cortex develop?
Soon after birth, the neurones in the visual cortex of baby mammals begin to form connections allowing the transfer of visual information
What is the critical period?
- 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
