Biopsychology Flashcards
what is the nervous system?
a specialised network of cells in the body as our primary communication system, based on electrical & chemical signals
what are the 2 main functions of the nervous system?
- collect process & respond to info in the environment
- co-ordinate different organs & cells in the body
what are the two subsystems of the nervous system?
central nervous system & peripheral nervous system
what is the CNS made up of?
brain & spinal cord
what is the role of the spinal cord?
passes messages to & from the brain & connects nerves to the PNS - also responsible for reflex actions
what are the subsystems of the PNS?
autonomic nervous system & somatic nervous system
what does the brain do in the nervous system?
receives & process sensory info, initiates responses, stores memories, generates thoughts & emotions, site of conscious awareness
what’s the role of the somatic system?
controls voluntary movement & the skeletal muscles, also allows for reflex actions
what’s the role of the autonomic system?
controls involuntary responses & smooth muscles - examples = breathing, heart rate, digestion
what is the autonomic system divided into?
sympathetic & parasympathetic division
what is the sympathetic division’s role?
initiates fight or flight
what is the parasympathetic division’s role?
rest & digest state
name the main endocrine glands in the human body
hypothalamus, pituitary, thyroid, parathyroid, adrenal, pancreas, ovaries (female), testes (male)
what is the endocrine system?
one of the body’s major information systems that instructs glands to secrete hormones into the bloodstream which are carried towards target organs
what hormone does the thyroid gland release and what does it do?
thyroxine increases heart rate increases metabolic rates, which affects growth rates
what is the pituitary gland known as & what does it do?
the ‘master gland’ - controls the release of hormones from all the other glands in the body
what happens to the endocrine & ANS systems during fight or flight
hypothalamus activates pituitary gland, ANS switches from parasympathetic to sympathetic, adrenaline released from adrenal medulla
what happens in the sympathetic state?
heart rate increased, breathing rate increased, pupils dilate, digestion inhibited, saliva production inhibited
what happens in the parasympathetic state?
heart rate decreases, breathing rate decreases, pupils constricted, digestion stimulated, saliva production stimulated
what lobes are the pituitary gland made up of & what do they do?
- anterior lobe = releases ACTH, stimulating the adrenal cortex & release of cortisol
- posterior lobe = releases oxytocin, responsible for uterus contractions during childbirth
what main hormone does the pineal gland release?
melatonin, responsible for biological rhythms like the sleep-wake cycle
2 parts of the adrenal gland & their roles
- adrenal medulla = releases adrenaline & nonadrenaline (fight or flight)
- adrenal cortex = releases cortisol, stimulating glucose release whilst suppressing the immune system
role of testes
release androgens, including the main hormone testosterone responsible for male sex characteristics
role of ovaries
release oestrogen, controlling the regulation of the female reproductive system
what are neurons?
nerve cells which process & transmit messages through electrical & chemical signals
role of sensory neurons & their structure
carry messages from the PNS to the CNS, they have long dendrites & short axons
role of relay neurons & their structure
connect the sensory neurons to the motor/other relay neurons, with short dendrites & axons
role of motor neurons & their structure
connect the CNS to effectors (muscles & glands), with short dendrites & long axons
label a neuron & the roles of each part
- cell body includes the nucleus containing the genetic material of the cell
- dendrites protrude from the cell body which carry nerve impulses from neighbouring neurons toward the cell body
- axon carries impulses away from the cell body down the length of the neuron
- a fatty layer of myelin sheath protects the axon & speeds up electrical transmission - segmented by gaps called nodes of ranvier which force the impulse to jump across the gaps
- terminal buttons communicate with the next neuron in the chain across the synapse
when are neurotransmitters released from synaptic vesicles?
when the electrical impulse reaches the presynaptic terminal
what are neurotransmitters?
chemicals which diffuse across the synapse to the next neuron
what happens once a neurotransmitter crosses a gap?
it’s taken up by a postsynaptic receptor site on the dendrites of the next neuron where the chemical message is converted back into an electrical impulse
what happens if the impulse is excitatory?
the key fits & ‘opens’ the receiving neuron, activation of the receptor causes depolarisation of the membrane & promotes an action potential in the receiving neuron
what happens if the impulse is inhibitory?
the key fits but stops any other keys, activation of the receptor causes hyperpolarisation & depresses action potential generation
example of an excitatory neurotransmitter
adrenaline (also a hormone) causes excitation of the postsynaptic neuron by increasing its positive charge & making it more likely to fire
example of an inhibitory neurotransmitter
serotonin causes inhibition in the receiving neuron, making it more negatively charged so less likely to fire
what is summation?
whether a postsynaptic neuron fires or not
what does adrenaline do during fight or flight & why?
- increased heart rate = increase blood flow to organs & adrenaline around body
- increased breathing rate = increase oxygen intake
- pupil dilation = increase light intake & vision
- sweat production = regulate temp
- inhibit digestion salivation etc = increase energy for other essential functions
