2.2 - Biopsycholgy (set A - Nervous System) Flashcards
Explain the role of the central nervous system?
The CNS comprises of the brain and spinal cord
- 2 main functions - to control behaviour and regulate the body’s physiological processes
Explain the role of the spinal cord?
- relays information between the brain and rest of the body - allows the brain to monitor and regulate bodily processes (eg digestion/breathing)
Spinal cord involved in performing simple reflexes
Explain the basic structure of the brain?
Divided into 4 main areas cerebrum, cerebellum, diencephalon and brain stem
Cerebrum is largest part and is further divided into 4 different lobes
- cerebrum is split into 2 halves (cerebral hemispheres)
Cerebellum sits beneath the back of cerebrum
The diencephalon lies beneath the cerebrum and on top of the brain stem
Explain the structure and role of the cerebrum?
- largest part of the brain
- divided into 4 different lobes - which each have a different primary function (eg frontal lobe involved in thought and production of speech)
- cerebrum split down middle into 2 halves (cerebral hemispheres) which communicate with each other via the corpus callosum
Each hemisphere is specialised for particular behaviours
Explain the structure and role of the cerebellum?
- sits beneath the back of the cerebrum
- involved in controlling a persons motor skills and balance (controls muscles allowing movement)
Explain the importance of the diencephalon?
Lies beneath the cerebrum and on top of the brain stem - contains 2 important structures thalamus and hypothalamus
Thalamus - acts as a relay station for nerve impulses, routing them to the appropriate part of the brain
Hypothalamus - regulatinon of body temperatures and links the endocrine system and nervous system
Outline the division of the nervous system?
Nervous system divided into central nervous system and peripheral nervous system
central nervous system divided into spinal cord and brain
peripheral nervous system divided into somatic nervous system and autonomic nervous system
autonomic nervous system divided into sympathetic nervous system and parasympathetic nervous system
Outline the components of the peripheral nervous system?
Divided into 2 main divisions somatic nervous system and autonomic nervous system (ANS)
- function of the peripheral nervous system is to really nerve impulses from the CNS to the rest of the body
autonomic nervous system further divided into sympathetic and parasympathetic nervous systems
Explain the function of the somatic nervous system?
part of the peripheral nervous system and contains both sensory receptors and motor pathways
- sensory neurones carry sensory information to the CNS, where as motor pathways take information from the CNS to glands and muscles
Explain the function of the autonomic nervous system?
regulates involuntary actions (eg heartbeat and breathing) which are important for maintaining homeostasis, regulating internal body conditions
- Contains motor pathways, does not contain sensory neurones
divided into sympathetic and parasympathetic nervous systems
Explain the function of the sympathetic nervous system (SNS)?
Primarily involved in fight or flight response - increases heart rate and blood pressure to help deal with emergencies
Neuron’s from SNS travel to every organ and gland to prepare the body (eg triggering the release of stored energy, dilation of pupils, hair to stand on end ext)
Explain the function of the parasympathetic nervous system (PNS)?
Returns the body to normal conditons after the emergency response - causes the heartbeat to slow down and reduces blood pressure
- digestion which is inhibited during fight or flight is resumed
**also called ‘rest and digest”
Outline the key features of the somatic nervous system?
- connects external sensors organs though the brain to the muscles
- includes both sensory and motor neurones
- under voluntary control - involves us processing the information
Carries impulses from CNS to muscles
Outline the key features of the autonomic nervous system?
- regulates involuntarily actions likes heartbeat and breathing
- involved in regulating internal processes (homeostasis)
motor neurones only
What are the 3 types of neurons - outline brief structure?
- sensory neurons
- relay neurons
- motor neurons
neurons are specialised cells which carry neural information throughout the body
Structure typically consists of a cell body, dendrites and an axon
Outline the structure of neurons?
Dendrites at one end of neurone receives signals from other neuron’s - they are connected to the cell body (the control centre of the neurone)
Impulse carried along axon - before terminating at axon terminal (myelin sheath, is an insulating layer around axon)
Explain the role of the myelin sheath regarding the function of neuron’s?
Insulating layer which forms around axon
Function is to allow nerve impulses to transit more rapidly along the axon - damage to it can slow impulses down
Outline the role of sensory neuron’s?
- carry nerve impulses from sensory receptors (receptors for vision,taste)
- found in eyes, ears, tongue and skin
- convert sensory information into neural impulses which are translated into sensations in the brain
not all sensory information travels to brain, some neuron’s terminate in the spinal cord - allowing for reflex actions
Outline the role of relay neuron’s?
Allow sensory and motor neuron’s to communicate with each other
relay neurones are only found within the brain and spinal cord
Outline the role of motor neuron’s?
- conduct signals from CNS to effector organs (eg muscles)
- have long axons which form part of PNS
Form synapses with muscles, when stimulated the neuron releases neurotransmitters that bind to receptors on the muscle and triggers a response, leading to movement
What is a synapse?
Conjunction of the end of the axon of one neurone and the dendrite of another
gap between presynaptic neurone and post synaptic neurone is synaptic gap
Outline synaptic transmission?
Synaptic vesicles, small sacs at the end of the axon of a nerve cell contain chemical messengers (neurotransmitters) that assist in the transfer of the impulses - they are released as the action potential reaches them
Neurotransmitters diffuse across the gap and bind to specialised receptors on the surface of their complementary cell where they are activated and produce either excitatory or inhibitory effect on the post synaptic neuron
Explain the process of ‘re-uptake’?
Synaptic transmission ends when the neurotransmitter is taken up again by the presynaptic neurone, where its stored and made available for later
- how quickly the presynaptic neuron takes back the neurotransmitter determines how long its effects will be
antidepressant drugs prolong action of neurotransmitter by inhibiting re-uptake - increases levels of neurotransmitters
Explain the role of excitatory neurotransmitters - give 2 examples?
Increase the likelihood that an excitatory signal is sent to the postsynaptic cell which is then more likely to fire
- acetylcholine
- noradrenaline
Explain the role of inhibitory neurotransmitters - give 2 examples?
They decrease the likelihood of that neurone firing - generally responsible for calming the mind and body
- GABA
- serotonin
Explain what determines whether a nerve cell will fire?
Nerve cell receives both excitatory and inhibitory neurotransmitters at the same time but the likelihood of firing is determined by by adding up the excitatory and inhibitory synaptic input (summation)
