The Brain Flashcards
What does the CNS consist of?
- Brain
- Spinal Chord
What are creatures with a CNS called?
Verebrates, i.e. humans, all mammals, reptiles, birds and fish (not insects or octopodes).
What is the other nervous system which exists in the body?
Peripheral Nervous System - stretches out from the brain and spinal chord into every other parts of the body.
What does the Peripheral Nervous System include?
- Sensory neurones
- Motor neurones
What do Sensory neurones do?
Carry information back to brain as sensations (“5 senses”).
What do Motor neurones do?
Carry messages from brain, telling muscles to move glands to release their hormones.
What links the two hemispheres of the brain together?
“Bridge” of nerve fibres (corpus callosum) allow the left and right hemispheres to communicate with each other.
What is brain lateralisation?
The way the left and right sides of the brain have different functions.
What does the left hemisphere control?
- The right side of the body.
- Language centre (damage takes away power to speak or write).
- Tasks to do with logic, i.e. reasoning and numbers.
- Abstract thought.
What does the right hemisphere control?
- Left side of the body.
- Spatial awareness, i.e. reading maps or judging distances.
- Performs tasks to do with creativity and the arts.
What is the Cortex?
Complex out layer of the brain.
What does the cortex do?
Handles a lot of “higher” brain functions, i.e. conscious thought and interacting with the world around us.
What lobes are the cortex divided into?
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Occipital lobe
- Brain stem
- Cerebellum
What does the Frontal lobe do?
Handles most of our conscious planning.
Contains pre-frontal cortex.
What does the Pre-fronal cortex do?
Handles self-control and decision making (important for aggression).
What does the Parietal lobe do?
Controls language but specialises in touch and direct bodily movements.
What happens if you damage the parietal lobe?
Failure to store new info and problems in understanding what others are saying to us.
What does the Temporal lobe do?
Handles most memory functions.
What does the Occipital lobe do?
Processes sight and our sense of our environment (makes sense of visual info so we’re able to understand it) - located at the back of the brain.
What happens if you damage the occipital lobe?
Cross-eyeing and partial/entrie blindness.
What is the Limbic System?
Sub-cortical structures beneath the cortex, which handle memory and raw appetites, i.e. sleep, hunger, agression and sex (thought to be the source of all our basic emotions).
What are the Sub-cortical structures?
- Thalamus
- Amygdala
- Hypothalamus
- Hippocampus
- Olfactory bulb
What does the Thalamus do?
Sorts and relays info to the different parts of the forebrain (“the brains switchboard”).
What does the Amygdala do?
Brains “emotion centre” - handles instinctive emotional responses to things, especially anger and fear (If it’s working properly, we should only fear things that are dangerous).
What happens if there is damage to the amygdala?
Damage, through stroke, tumour or developmental issues, may lead to over-reactive amygdala (overly fearful or agg in situations).
- Raine et al. (1997) noticed amygdala’s in murderers pleading NGRI functioned erratically; suggested they mat not have felt fear or agg at appropriate times.
- Animal studies show when amygdala is damaged, animla stops showing fear of threatening stimuli.
What does the Hypothalamus do?
Regulates hunger, thirst, sexual arousal and sleep. Also part of endocrine system which regulates hormone production in the body.
What happens if there is damage to the hypothalamus?
Animals have been known to lose all interest in food or start eating compulsively.
How does the hypothalamus lead to aggression?
- Regulates testosterone which is implicated in aggression.
- Has been shown to cause agg behaviour when electrically stimulated.
- Has receptors that help determine aggression levels based on interactions with serotonin and vaspressin.
What does the Hippocampus do?
Important for forming new memories.
What happens if there is damage to the hippocampus?
Destroys the ability to form new memories, i.e. H.M. (Henry Molaison), whose hippocampus was removed during brain surgery. Clive Wearing had viral infection which damaged his hippocampus which had the same result.
