Biopsychology Flashcards
What is the structure of most Neurones?
Dendrites -> Cell body -> axon with nylon sheath -> Axon terminals
CNS - Spinal cord
- It is a bundle of nerve fibres
- Main function- relay info between brain and body
- Also enables us to preform simple reflex
CNS function
- control of behaviour
- regulation of the bodies physiological processes
The brain main areas
Cerebrum, cerebellum, diencephalon, and brain stem
What does the Cerebrum do?
Decided into 4 lobes -
- Frontal - involved in speech thought & working memory
- Parietal - processes sensory info e.g touch
- Occipital - processes visual info
- Temporal - involves hearing and language comprehension
What does the cerebellum do?
Involved in controlling motor skills, balance & coordinating muscles
What does the Brain stem do?
- Responsible for regulating automatic functions essential for life
- Allows impulses to pass between brain and spine
What does the Diencephalon do?
-Two parts : Thalamus (acts as relay station and involved in sleep/wakefulness), hypothalamus (regulates body temp, hunger, &thirst. Acts as a link between endocrine system and nervous system)
PNS function
Connects CNS with the body and outside world
Two sections of PNS
Somatic
- Controls voluntary movement of skeletal muscles
- involved in reflex actions
Autonomic
- Governs involuntary activities of non-skeletal muscles and internal body systems
- is Autonomous
- divided into sympathetic and parasympathetic
What is the Sympathetic NS?
- Produces Arousal and energy
- preparing the body for rapid action enabling us to respond quickly and effectively
- E.g increased hr, reduced stomach activity
- Fight or flight
What is the Parasympathetic NS?
- Invloved in reducing arousal and conserving energy, relaxes body again once threat passed
- Returns the body to a state of normality
- E.g Decreases heart rate, Increases stomach activity
- Rest and digest
Sensory Neurone
- Unipolar
- Cell body with two stems either side
- carry info from body to CNS
Motor Neurone
- Multipolar
- Single axon, many dendrites
- Carry motor commands from CNS to Skeletal muscles or glands
Relay Neurone
- Mostly Multipolar
- have cell body surrounded entirely by dendrites
- in between sensory and motor neurones
- Within the CNS
- Allow sensory and motor neurones to communicate
What does the info in neurones travel in?
Travels in the form of an electrical signal known as a Action potential
What does the process of synaptic transmission refer to?
Process by which a action potential passes across the synaptic cleft from presynaptic neurone to postsynaptic neurone
What is the synapse?
- Small gap between neurones in which neurotransmitters are released, permitting nerve impulses to be transmitted between neurones
- includes membranes of post and presynaptic neurone and the synaptic cleft
What is a neurotransmitter?
- chemical messenger or substance that transmits nerve impulses across synapse
- can cause excitatory, inhibitory effect, or both.
- E.g Serotonin, Dopamine
The process of synaptic transmission
- Vesicles containing neurotransmitters at end of axon and axon potential stimulates vesicles to release them by merging to the membrane and releasing them into the synapse
- neurotransmitters diffuse across gap and bind to specialised receptors on postsynaptic membrane
- depending on receptor it will either produce a excitatory or inhibitory effect
What happens after synaptic transmission?
- Neurotransmitters released back into the cleft and either:
- Diffuse and drift away
- Are broken down by enzymes
- are-uptaken into the presynaptic neurone and repackaged/ stored for later
Excitatory neurotransmitter
- Make postsynaptic neuron more likely to fire
- increase neural activity
- E.g Noradrenaline
Inhibitory neurotransmitter
- make postsynaptic neurone less likely to fire
- decrease neural activation - Calming effect on mind and body
- E.g. GABA
What’s the result of an Excitatory neurotransmitter?
Excitatory postsynaptic potential (EPSP) - making it more likely for the postsynaptic cell to fire
What’s the result of a inhibitory neurotransmitter?
Inhibitory postsynaptic potential (IPSP) - making it less likely for the postsynaptic cell to fire
What is the Process of Semation?
- takes account of all connections
- determines by the sun of all the excitatory and inhibitory synaptic input
- depending on overall/net effect of these means
- Inhibitory-reduces likelihood of a action potential being generated
- Excitatory- increases likelihood of action potential being generated
What’s a neurotransmitter that can either be excitatory or inhibitory?
Acetylcholine
What is Localisation of function?
Refers to the belief that specific areas of the brain are associated with specific functions (E.g. language, memory, hearing ect)
What is Hemispheric lateralisation
Refers to the fact that 2 halfs of brain are not entirely alike
- each hemisphere has functional specialisations
- some mental processes in the brain are mainly specialised to either the left or right hemisphere E.g. left hemisphere is dominant for language & speech, Right hemisphere is for visual/motor tasks
The Motor cortex
- Responsible for voluntary motor movement
- Located frontal lobe
- on both hemispheres however left hemi controls right side of body and vice versa
The somatosensory Cortex
- processes input from sensory receptors in body that are sensitive to touch.
- Located in parietal lobe
- in both hemispheres
- again one side of hemi receiving info from opposite side of body
Auditory centres/ cortex
- Concerned with hearing
- Located in temporal lobes in both sides
Visual centres/cortex
- deals with visual info
- located in occipital lobes and is on both sides
- left hemi deals with input from right hand side visual field and vice versa
Language centre - Wernickes Area
- Deals with Comprehension of language
- Located in left temporal lobe
Language centre - Broca’s area
- Critical for speech production
- located in frontal lobe of the left hemisphere
+What evidence of localisation is there from brain scans?
-Brain scans have been used to demonstrate the Wernickes area was active during listening tasks whilst the brocas was active during a reading task, suggesting that theses areas of the brain have different functions
+There is also case study evidence of Phineas Gagein support for localisation which states…
- Damage occurred to his left frontal lobe via a metal rod being forced through his head
- this damage has left a mark on his personality - turned form someone calm to someone rude
- This change in temperament suggests that the frontal lobe may be responsible for regulating mood.
- HOWEVER it is difficult to draw general conclusions from the case of gage as it may not be down to the physical damage but more the mental trauma of the incident that caused his personality change
-What does plasticity suggest about localisation of function?
- argues against it because when the brain is damaged, and a particular function has been compromised or lost, the rest of the brain appears to be able to reorganise itself in an attempt to recover the lost function.
- HOWEVER this does not happen every time like with stroke victims never being able to recover the abilities they have lost.
What is Hemispheric lateralisation
Refers to the idea that some functions might be going in only one hemisphere rather then both E.g lateralised to the hemisphere like the language centres being on the left and the visual on the right
How are hemispheres connected?
Via bundles of nerve fibres called the Corpus Callosum
-allows two hemispheres to communicate
What is split brain research mean?
Refers to those studies of individuals who have been subjected to the surgical separation of the corpus callosum to treat severe epilepsy
