Biopsychology Flashcards
CNS vs PNS
CNS is brain and spinal cord
PNS is everything else and divided into somatic and autonomic nervous system
Somatic nervous system
sensory and motor neurons for info to and from CNS - used in reflex actions
carries commands from motor context and under conscious control
controls skeletal muscles
Autonomic nervous system
involuntary actions, mainly controls smooth glands and muscles, only motor pathways controlled by brain stem
made up of sympathetic and parasympathetic - fight and flight, rest and digest
Neurons
specialised nerve cells moving electrical impulses to and from CNS
cell body, nucleus, dendrites receiving impulses from sensory receptors, axon carries impulse from cell body to axon terminal, myelin sheath insulates and speeds axon impulse made of schwann cells, nodes of ranvier and gals in myelin sheath further speeding up
Sensory neurons
found in sensory receptors carrying electric impulses from sensory receptors to CNS via PNS- convert sensory info to impulses then brain converts to sensation to respond appropriately, some sensory impulses terminate at spinal cord so reflexes occur quickly without brain response delay.
Have cell body and nucleus midway through neuron
Motor neuron
In CNS but project axons outside CNS - sends impulses to glands and muscles effectors to take response by releasing neurotransmitters to bind to muscles leading to movement
have cell body and nucleus at end of neuron
Relay neuron
in CNS - connect motor to sensory neurons so can communicate with each other - in a reflex arc they analyse the sensation and decide a response without waiting for brain to process pain
Most circular of all - looks like a spike
Synaptic transmission + direction
neurons transmit action potentials between pre and post synaptic neuron - only in this direction as vesicles with neurotrasmitters only present in pre synaptic membrane, and receptors only present in post synaptic membrane
diffusion from high to low concentration gradient
synaptic transmission sequence
action potential reaches presynaptic terminal
neurotransmitters escape vesicles in exocytosis
then diffuse across synaptic cleft
if net PSP is excitatory then impulse fired
then reuptake when neurotransmitters taken back for future processes
PSP
either excitatory neurotrasmittors leading to EPSP causing charge in post synaptic membrane or inhibitory neurotransmitters IPSP makes it less likely to fire impulse
net EPSP and IPSP sum and determines if impulse fired
Medication
some mimic inhibitory neurotransmitters like SSRI and GABA which bind to post synaptic receptor, so less likely to fire, inhibiting action potential
hence decreases overall and brain activity so less pain
some may also work to reduce/ increase time between reuptake
Endocrine system
Chemical system of comms via blood stream
Glands Produce and secrete different hormones to regulate bodily functions at different areas
Only affect target cells with specific receptor sites, when enough sites are stimulated it causes a physiological reaction
Pituitary gland
aka master gland
in brain controlled by hypothalamus
controls release of hormones from all other glands
anterior pg releases ACTH to regulate cortisol levels (stress response)
Posterior pg releases oxytocin used for infant mother bonding
Adrenal glands
two situated on top of each kidney made of 2 parts
adrenal cortex - outer section - produces cortisol (as regulated by ACTH by apg) - when chronic long term stress - affects cardiovascular system e.g increase blood pressure and vessel constriction
adrenal medulla - inner section - produces adrenaline for fight or flight in times of acute stress with many effects
Sympathomedullary pathway
fight or flight response generated by sympathetic branch of autonomic nervous system
hypothalamus triggers SNS stimulates adrenal medulla to release adrenaline into bloodstream
Direct effects of adrenaline
Increased heart rate, constriction, blood focused to brain, muscles and not skin or kidneys, no digestion, more respiration/sweating, pupil dilation, glucose released and muscle tensed
General effects of adrenaline
Preparing for physical action as more blood and oxygen to skeletal muscles, prepare for rapid response planning by increasing oxygen and blood to brain
After fight or flight
Parasympathetic nervous system dampens down stress response starting rest and digest process, adrenaline and heart rate return to normal etc
Fight or flight eval
+ Makes sense from evolutionary psychology as individuals allowed to survive by fighting or fleeing a threat
+ Those with malfunctioning adrenal glands lack normal fight or flight response
- Gray (1988) suggests freeze is first where you stay still and observe for danger
- Taylor (2000) found women tend and befriend - protect offspring and seek mutual groups for protection - amplified by oxytocin
- Von dawans (2012) reported tend and befriend in both genders during 911 as they called loved ones and gave comfort to each other
