Paper 2- biopsychology Flashcards
What are all the divisions of the nervous system?
DRAW
What makes up the CNS?
- Brain
- Spinal cord
Functions of the Spinal Cord
Relays information between the brain and the rest of the body.
Helps the brain monitor & regulate body proceseses e.g. digestion
Function of the Brain
The brain is responsible for core information processing and conscious awareness.
The brains outer layer is called the cerebral cortex and this is highly developed in humans.
The brain is divided into two ‘hemispheres’ (left and right) which can have unique and shared function.
The parts of the brain
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The peripheral nervous system (PNS)
Consists of all of the nerves, that are external to the central nervous system.
Helps to relay impulses from the CNS to parts of the body, and from parts of the body back to the CNS.
Has two systems: Somatic Nervous System and Autonomic Nervous system.
The somatic nervous system
The Somatic nervous system controls the body’s voluntary muscle movements.
The autonomic nervous system
The Autonomic nervous system controls the body’s automatic processes.
The ANS is sub-divided further into the ‘Sympathetic’ nervous system and the ‘Parasympathetic’ nervous system.
What is the difference between the sympathetic and parasympathetic nervous systems?
Sympathetic:
“Fight or Flight”
Noradrenaline
Prepares the body (e.g. increases heartrate, dilate pupils)
Decreases use of non-vital organs (e.g. digestive system)
Parasympathetic: “Rest and Digest” Acetylcholine Relaxes the body Restores organs to ordinary processing
What is a neurone?
A neurone is a specialised cell which carries neural information around the body.
What are the 3 types of neurone?
- Sensory neurone
- Motor neurone
- Relay neurone
Sensory neurone
Carry messages from sensory receptors (vision, touch etc.) to the spinal cord and the brain.
Relay neurone
Connect the CNS to ‘effectors’ like muscles and glands.
Motor neurone
Connect the sensory neurones to the motor neurones and other neurones.
Structure of a neurone
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Difference in structure of neurones
Motor neurones have long axons and short dendrites
Sensory neurones have short axons and long dendrites
Relay neurones have short axons and dendrites.
Synaptic transmission
Synaptic transmission is how neurones communicate with other neurones and parts of the body.
A synapse is the ‘gap’ which is formed between neurones and impulses are carried across these gaps in order to continue to the destination.
Transmission of the impulse occurs through release of ‘neurotransmitters’ into the synapse.
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What are neurotransmitters?
Neurotransmitters are chemicals which diffuse across the synapses to relay impulses to the next neurone.
They are released from ‘synaptic vesicles’ into the synapse and absorbed on the other side by ‘post-synaptic receptor sites’.
Excitatory and inhibitory neurotransmitters
Neurotransmitters have one of two effects on the neighbouring neurons.
For example;
1) Serotonin inhibits neurons which are receiving the impulses, making the neuron ‘negatively charged’ and less likely to fire.
2) Adrenaline does the opposite. Adrenaline excites receiving neurons making them more likely to fire.
3) SUMMATION
Eary theories of the brain
The holistic view:
Before the 19th century scientists held a holistic view of the brain.
That all parts are involved in thoughts and action.
Phrenology:
Around in 19th century.
Scientists believed that you could measure the skull and feel lumps and bumps in the skull to predict personality traits.
Case study: Phineas Gage
Working on the railway lines with explosives- set off accidentally.
A metal rod went through his left cheek, behind his left eye and through the top of his skull.
Damaged his frontal lobe.
Changed his personality. Became quick-tempered and rude.
‘no longer Gage’.
