biopsychology lessons 1-5 Flashcards
THE NERVOUS SYSTEM DIAGRAM
nervous system
central nervous system. peripheral nervous system
brain. spinal cord. somatic nervous system. autonomic nervous system
sympathetic nervous system parasympathetic NS
what is CNS
made up of brain and spinal cord. brain split into two hemispheres. spinal cord is extension of brain responsible for reflex actions also connects nerves to PNS
what is PNS
transmits messages to and from the CNS. divided into autonomic and somatic.
ANS - vital unconscious functions such as breathing and heart rate
SNS - controls conscious functions such as muscle movement
what are the brain components
cerebrum - split into 4 lobes - frontal, temporal, parietal, occipital. two hemispheres which communicate via corpus callosum
cerebellum - back of cerebrum which controls skills and balance
diencephalon - sits above brain stem and split into 4 - thalamus, hypothalamus, epithalamus, subthalamus. coordinates endocrine system.
brain stem - regulates automatic functions such as breathing and heart rate
what is the somatic nervous system
facilitates communication between the CNS and the outside world through muscle movement
what is the autonomic nervous system
regulates involuntary actions such as heart beats and digesting food. ANS control centre is in the brain stem
what is the sympathetic nervous system
involved in responses that help us deal with fight and flight such as increasing heart rate etc.
what is the parasympathetic nervous system
relaxes body after an emergency has passed by slowing the heart beat and is involved in energy conservation
what are structure of neurone components
cell body: contains nucleus and has dendrites attached
axon: has myelin sheath to speed electrical transmission which are segmented by nodes of ranvier
axon terminal: at end of axon which communicates with next neurone
what are the 3 types of neurones
sensory: carry messages from PNS to CNS. has nucleus on axon
relay: connect sensory to motor. has short dendrites and no myelin sheath
motor: connects CNS to effectors has short dendrites and myelin sheath
what is synaptic transmission
process by which neighbouring neurones communicate with each other by sending chemical messages
describe the process of synaptic transmission
when a neurone is activated by a stimulus the inside becomes positively charged causing an action potential to occur which creates an electrical impulse which travels down axon. once action potential reaches axon terminal it crosses gap between pre-synaptic neurone and post synaptic neurone which is the synapse. axon terminal has synaptic vessels which contain neurotransmitters.
what are inhibitory neurotransmitters
responsible for calming the mind and body. eg. serotonin and GABA. inhibitory neurotransmitter binding to post synaptic cell results in an inhibitory post synaptic potential making neurone less likely to fire.
what are excitatory neurotransmitters
likely to increase your chances to activate or carry out a behaviour. eg. adrenaline and dopamine. when excitatory neurotransmitter binds to post synaptic receptor it causes electrical charge on membrane of post synaptic neurone resulting in excitatory post synaptic potential meaning post synaptic cell is more likely to fire
what is summation
the net result of adding up the excitatory and inhibitory synaptic input
how can the strength of EPSP’s be increased
by spatial summation whereby a large number of EPSP’s are generated at many different synapses. by temporal summation whereby a large number of EPSP’s are generated at the same synapse by a series of high frequency action potentials.
what is the role of the endocrine system
network of glands and hormones which control vital functions. slower but more long lasting changes than the nervous system.
pituitary gland function
master gland which controls the release of hormones from other glands
hypothalamus role
stimulates and controls release of hormones from pituitary gland.
thyroid role
releases thyroxine which regulates metabolic rate
adrenal medulla role
releases adrenaline which induces a fight or flight response
adrenal cortex role
releases glucocorticoids such as cortisol which release stored glucose and suppressed immune system and mineralocorticoids which regulate water balance
testes role
releases androgens mainly testosterone which develops male sexual characteristics and promotes muscle mass.
ovaries role
releases oestrogens mainly oestradiol which regulates female reproductive system and menstrual cycle.
pineal gland role
releases melatonin which regulates arousal and the sleep cycle
anterior pituitary gland hormones
Adrenocortical trophic hormone which targets adrenal cortex
thyroid stimulating hormone which targets thyroid
prolactin which targets mammary glands to release milk
FSH which targets ovaries and testes
growth hormone which targets cell growth
melanocyte stimulating hormone which targets melanin production
posterior pituitary gland hormones
vasopressin or anti diuretic hormones which regulate water balance
oxytocin which promotes uterine contractions
what happens in our brain during fight or flight
area in the brain called the amygdala is activated and sends signal to hypothalamus which communicates with rest of body via sympathetic nervous system. the amygdala associates sensory signals with emotions such as fear and anger.
response to acute (sudden) stressors
the sympathetic nervous system is triggered and prepares body for fight or flight by sending signal to adrenal medulla to release adrenaline which circulates body to increase heart rate and breathing rate.
parasympathetic nervous system role in FoF response to stress
It dampens down stress response. the PNS slows down heartbeat and blood pressure. body goes into rest and digest
evaluation of fight or flight
advantages: makes sense from evolutionary psychology pov as it helps an individual to survive by fighting or fleeing.
disadvantages: when faces with dangerous system it is not only limited to fight or flight and psychologists suggest there is freeze. gray suggests the first response to danger is to avoid confrontation by freezing. FoF is more a male response as females adopt a tend and befriend response. von dawans found it is w both male and female as in 9/11 both genders contacted love ones and helped each other.
