Brain Structure Flashcards
What are the main three parts of the brain?
Forebrain, midbrain and hindbrain
What does the forebrain do?
Receiving and processing sensory information and higher order thinking processes (emotions, memory, language)
What does the midbrain do?
Coordinated movement, sleep and arousal (reticular formation) and connects hind and forebrain
What does the hindbrain do?
Important for movement and balance - connects spinal cord to brain
What is Adrenaline/ Epinephrine?
Fight or Flight response/ excitatory:
Produced in stressful situations. Increases heart rate and blood flow, leading to physical boost and heightened awareness.
(Sympathetic NS)
What is Noradrenaline?
Concentration/ mostly excitatory:
Affects attention and responding actions in the brain. Contracts blood vessels, increasing blood flow.
What is Dopamine?
Pleasure/ excitatory:
Feelings of pleasure, also addiction, movement and motivation. People repeat behaviors that lead to dopamine release.
What is Serotonin?
Mood/ inhibitory:
Contributes to well-being and happiness. Helps sleep cycle and digestive system regulation. Affected by exercise and light exposure.
GABA
Calming/ main inhibitory:
Calms firing nerves in the central nervous system. High levels improve focus, low levels cause anxiety. Also contributes to motor control and vision
Acetylcholine
Learning/ excitatory:
Involved in thought, learning and memory. Activates muscle action in the body. Also associated with attention and awakening.
Glutamate
Memory/ main excitatory:
Most common neurotransmitter. Involved in learning and memory, regulates development and creation of nerves contacts.
Endorphins
Euphoria/ excitatory:
Released during exercise, excitement and sex, producing well-being and euphoria, reducing pain.
What does the Medulla do?
Controls breathing, heart rate and digestion
Pons
- Receives visual information
- Controls eye/body actions
- Regulates sleep, arousal and some muscle movement
Cerebellum
- Receives information from pons
- Coordinates body movement (especially fast movement)
- Regulates posture and balance
- Learning, memory, other cognitive processes
What is in the brain stem?
- Midbrain
- Pons
- Medulla oblongata
What parts are in the forebrain?
- Cerebrum
- Corpus Callosum
- Thalamus
- Hypothalamus
What is the cerebrum?
- Outer layer = cerebral cortex
- split into left and right hemispheres (separated by longitudinal fissure)
- Two hemispheres connected by corpus callosum
What is the cerebral cortex?
- Very thin (3m)
- Billions of neurons
- Lots of grooves (bulges = gyru/gyri, valleys = sulci)
- Has 4 lobes
What is the Thalamus?
- Beneath cerebral cortex
- Left/right half
- ‘communication center’ - receives, processes, and prioritises information
- Receives stimuli from sensory organs (except nose)
- Helps regulate cortex activity
Hypothalamus
- Below thalamus
- Maintains survival functions: sleep, temperature, emotions ect.
- Regulates: Feeding, Fighting, Fleeing, Fornication (4Fs)
What does the left brain do? (name at least 3)
- Sensory stimulus from the right side of body
- Motor control of right side of body
- Speech, language and comprehension
- Analysis and calculations
- Time and sequencing
- Recognition of words, letter and numbers
What does the right brain do? (name at least 3)
- Sensory stimulus from the left side of body
- Motor control of left side of body
- Creativity
- Spatial ability
- Context/ perception
- Recognition of faces, places and objects
What are the four major area of the cerebral cortex?
- Frontal lobe
- Occipital lobe
- Parietal lobe
- Temporal lobe
What is the fontal lobe?
Largest lobe. Located at the front of the brain.
Functions:
- Initiating body movement
- Language
- Planning
- Judgement
- Problem solving
- Personality/ emotion
What happens if the left hemisphere of the frontal lobe is damaged?
Loss of motor control on right side of body.
What happens if the right hemisphere of the frontal lobe is damaged?
Loss of motor control on left side of body.
What is the parietal lobe?
Made up of somatosensory cortex mostly.
Functions:
- Receiving information on sensation (touch, pressure, pain, temperature)
- Body and spatial awareness (i.e. ability to perceive your own body and where things are located around you)
What does damage of parietal lobe do?
Leads to an inability to process sensation or that part of body feels numb.
What is the temporal lobe?
Contains primary auditory cortex.
Parts of lobe are sensitive to specific sounds.
Functions:
- Auditory analysis eg. understanding sounds, music, speech, sound location ect.
What happens if the temporal lobe is damaged?
Leads to forms of deafness (depends on which side of the brain is damaged).
What are the 4 primary cortexes?
- Primary Visual cortex
- Primary auditory cortex
- Primary motor cortex
- Primary somatosensory cortex
What are the four associative areas?
- Pre-frontal cortex (frontal lobe)
- Broca’s area (production of speech)
- Wernicke’s area (understanding speech)
- Gerschwind’s area
What is the pre-frontal cortex/ what does it do?
Part of the frontal lobe.
Located behind the forehead (above the eyes).
Is responsible for the non-motor functions of the frontal lobe.
Functions:
- Planning
- Complex cognitive behaviour
- Personality
- Aspects of social behaviour
PS. most neurologists agree that the prefrontal cortex is not fully developed until around the age of 25.
Define sprouting
Sprouting is the growth of extra dendrites on neurons so more connections between neurons can be made.
Define Pruning
Pruning is the dying of neurons that are no longer needed.
What is grey matter and white matter?
Grey matter is all the cell bodies of neurons.
White matter is the axons of neurons that are surrounded by the fatty, white myelin sheath.
What is Phrenology?
A theory that analyses a person’s strengths/ weaknesses based on size and shape of regions on the skull.
- 26-40 regions or ‘organs’ in the skull associated with mental abilities and character traits
- The bigger the region, the more it is used
Why was Phrenology discredited?
- Difficult to locate ‘mental organs’ and how many there were
- Experiments showed loss of parts of the brain resulted in no change in function or a different function than what Gall predicted
What was the importance of Phrenology?
Established the idea that certain functions are controlled by certain regions of the brain.
What was the split brain study?
The purpose was to be a treatment for sever epilepsy cases in the 1940 (goal was to limit electrical storm on one side of the brain)
Procedure:
Sever corpus callosum (connects two hemispheres of brain)
Results:
Reduction in epileptic seizures - most people led normal lives
What did the split-brain study reveal?
Demonstrated that the left and right brain are specialized in different tasks.
What was the procedure of the split-brain studies like?
Under laboratory conditions, patients had images flashed to either their right of left visual fields while they looked at a dot in the middle of the screen.
Their response differed depending on if the image flashed on the left or right side of brain.
Left side is specialized in analytical and verbal tasks.
Right side is dominant in non-verbal tasks, visual-spatial processing and facial recognition.
