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