biopsychology Flashcards
define the nervous system
specialised network of cells and is our primary internal communication system
2 major functions of the nervous system
- to collect process and respond to information in the environment
- to coordinate the workings of different organs and cells in the body
what are the 2 subsystems the nervous system is divided into
- central nervous system
- peripheral nervous system
what is the central nervous system
consists of the brain and spinal cord
the brain is the centre of all conscious awareness
the spinal cord is an extension of the brain, responsible for reflex arc
define the peripheral nervous system
transmits messages via neurones to and from the central nervous system
subdivided into:
autnomic nervous system
somatic nervous system
define the autonomic nervous system
transits info to and from organs
the system acts involuntarily
subdivided into sympathetic and parasympathetic
define somatic nervous system
transmits info from sense organs to central nervous system,
receives info from CNS for muscles to act
define the endocrine system
works alongside the nervous system to control the vital functions of the body. Acts more slowly compared to the nervous system but has widespread effects
Instructs glands to release hormones. the hormones are then secreted into the bloodstream and are carried towards target organs in the body
the main endocrine gland is the pituitary gland located in the brain as it controls the release of all other endocrine glands in the body
biological changes in the sympathetic state 6
- increase heart rate
- increase breathing rate
- dilates pupils
- inhibits digestion
- inhibits saliva production
- contracts rectum
biological changes in the parasympathetic state 6
- decrease heart rate
- decrease breathing rate
- constricts pupils
- stimulate digestion
- stimulate saliva production
- relaxes rectum
define adrenaline
a hormone produce by adrenal glands which is part of the body immediate stress response system.
adrenaline has a strong effect on the cells in the cardiovascular system stimulating heart rate, contracting blood vessels and dilating air passages
what do the endocrine and ANS work together for
the flight or flight response
the endocrine and ANS working together
- when a stressor is perceived:
- hypothalamus triggers the activity in the sympathetic branch of the autonomic nervous system
- ANS changes from resting parasympathetic state to sympathetic state
- stress hormone adrenaline is released from the adrenal medulla into the bloodstream
- adrenaline triggers physiological change arousal for fight or flight e.g. increased heart rate
- once the stressor has passed the parasympathetic branch returns the body to resting state e.g. decrease heart rate
what are the 3 types of neurone
motor sensory and relay
define neuron
process and transmit messages through electrical and chemical signals
define sensory neurones
carry messages from the PNS to the CNS
they have long dendrites and short axons
define relay neurones
connect sensory to other relay or motor neurones
short dendrites and short axons
define motor neurones
connect CNS to the effectors
short dendrites and long axons
define the cell body of a neurone
includes a nucleus which contains genetic information of the cell.
branch-like structures dendrites protrude from the cell body
define the axon
carries an impulse away from the cell body down the length of the neurone
axon covers in a fatty layer called myelin sheath that protects the axon and speeds up electrical transmission of the impulse
define nodes of ranvier
if the myelin sheath was continuous, this would slow down the speed of transmission
so the myelin sheath is segmented by gaps, the Nodes of Ranvier which speeds up transmission by forcing them to ‘jump’
define terminal buttons
are at the end of the axon
communicate with the next neurone across a chain across a synapse
define electric transmission
when a neurone is at resting state, inside the cell is negatively charged compared to outside
when a neuron is activated by the stimulus the charge becomes positive causing an action potential
this creates an electrical impulse that travels down the axon towards the end of the neurone
define neural networks
groups of neurones where they communicate with eachother
what is each neurone separated by
a synapse
how are signals between neurone communicated
synaptic transmission
how are signals within neurone communicated
transmitted electrically
what happens when the electrical impulse reaches the end of the terminal
triggers the release of neurotransmitter from the synaptic vesicles
define neurotransmitters
chemicals that diffuse across the synapse to the next neuron in the chain, released from the synaptic vesicles
can be divided into into excitatory and inhibitory
what do neurotransmitters do
-once the neurotransmitter crosses the synapse, it Is taken up by the postsynaptic receptor sites, the dendrites of another axon
-here it is converted back into an electrical impulse
each neurotransmitter has a complementary specific shape to that of the post synaptic vesicles
-all have specific functions such as acetylcholine is found at each point where a motor neurone meets a muscle, upon its release the muscle will contract.