biopsychology Flashcards
(NS) what is the nervous system?
- specialised network of cells in the human body & is the primary communication system
- uses electrical signals –> fast moving
- has 2 main functions:
- to collect + process + respond to info in the environment
- to co-ordinate the working of different organs + cells
- has 2 sub-systems = CNS + PNS
what are all the functions + divisions of the nervous system
(A1)
[specialised network of cell in human body & is primary communication system] -> uses electrical signals
NS:
- functions: to collect + process + responsd to enviro info & to co-ordiante how diff organs + cells work
- 2 sub-systems: CNS + PNS
CNS: (central nervous system) {from NS}
- made up of brain + spinal cord:{processes info}
– (B) centre of consciou sawareness
– (B) cerebal cortex = highly developed in humans -> disinguishes our mental functions from animals
– (B) made up of 4 areas = frontal, parietal, temporal and occipital
– (SC) [extension of brain & responsible for reflexes + passes messages from brain]
– (SC) connects erves to PNS
PNS: (peripheral nervous system) {from NS}
- main role = transmits messgaes via neurons to + from CNS
- made up of ANS + SNS
SNS: (somatic NS) {from PNS}
- [controls muscle movement + recieves info from sesnory receptors]
- made up of 12 crainial nerves + 31 spinal nerves {which contains motor + sensor neurons}
– sensory neurons = to CNS
– motor neurons = from CNS
ANS: (autonomic NS) {from PNS}
- [governs vital fucntions in body]
– ege -> breathing // heart rate / digestion // sexual arousal
- control some functions that we aren’t consiously aware of
- made up of SNS + PSN
SyNS (sympathetic NS) {from ANS}
- [involved in responses that help deal w emergencies {fight ot flight response}]
- dialtaed pupils // weak salivary flow // acc heart // relaxed bladder
PaNS:
- [involved w regulating bodily functions after fight or flight]
- contricts pupils // inhibits heart
the structure + function on neurons
(A1) A01
neurones [cells that comm via synapses]
- action potential travels within neuron = electrical impulse
- action potential travels between synapses = chemical impulse
structure:
- dendrites [receptors @ end -> recieved signals]
- nucleus [contains genetic material]
- axon (the long part)
– made up on mylein sheaths [insulation layers that helps ection potential travel faster]
– gaps inbetween MS = ‘nodes of ranvier’
- axon terminal [at end of neuron -> connects w dendtires of neighbouring neuron]
-> cell body has dendrites that recieve info from other neurons -> this info passes along axon, as an electrical impulse & and this uses mleine sheaths
types of neurons:
- motor neurons: [connects CNS to effectors (muscles + glands)] -> short dendrites + long axon
- sensory neurons: [carries info from PNS to CNS] -> long dendrites + short axons
- relay neurons: [connect sensory neurons to motor neurons] -> short dendrites + short axons
synaptic transmission
(A1)
[the comm of neurons via sending chemical messenges from 1 neuron to another]
- pre-synaptic terminal [axon terminal] -> covered by pre-synaptic membrane & post-synpatic terminal [dendrites of new neurone]
- gap between this = synaptic cleft
= presynaptic terminal = has synaptic vesicles {tiny sacs which release neurotransmitters(chemicals)}
process:
nerve impulse @ pre-synaptic terminal
=> synaptic vesicles travel down PS membrane
=> neurotransmitters = released in to synaptic cleft
=> which diffuse to post synaptic terminal
=> neurotransmitters bind to PS reeptors on PS membrane
=> chem message = converted back to electrical impulse … electrical transmission
excitatory + inhibtory neurotransmitters
(A1)
- neurons = activated inside cell & is briefly positively charged -> travels to denrites / post-synpatic receptors => causes small + chnage in dendrites
- when neurons = not sending signals -> it’s @ rest {neg charged}
excitatory potential = more likely that neurons fire
- eg -> dopamine (can be both) // adrenaline
ihibitory potential = less likely to fire -> messages = likely to be stopped@ post-synaptic neuron
- eg-> serotonin // GABA
the endocrine system -> the G+Hs
(A1)
[works w NS to control vital functions in body using the (para)/sympathetic nervous system]
- uses chemcial signals (slower + longer-lasting) & hormones + glands = used
glands + hormones:
- hormones = chem messenger -> intstructs body to peforms certain psychical + mental functions (thru the bloodstream)
– most Hs effect cells in organs
– they regulate bodily functions
– they only influence behaviour (not cause)
- hypothalamus -> [brain reigon that controlls pituitary gland] -> body temp // water intake
- pituitary -> [regulates fuctions of other endocrine glands]
- thyroid / parathyroid -? [involved in metabolism + growth + maturation] @ throat
- adrenals -> [helps trigger FoF response] & [produces Hs that control blood sugar + reacts to stressors + regulates blood pressure] @ top of kidneys -> imp hormones = cortisol + aldosterone
- pancreas -> [produces insulin + glucagon + somatostatin (regulates blood sugar levels)]
- ovaries -> [secretes female sex H (estrogen)]
- testes -> [secretes male sex H (testosterone) + sperm]
communication:
stimulus => gland releases hormones into bloodstream until it reaches target cell (binds to cell’s receptor)
fight or flight reponse: [when the endocrine system + ANS work toegther]
stressor = percieved
=> hypothalamus triggers activity in sympathetic branch of ANS
=> ANS causes change from normal resting state (parasympathetic) -> physiologically aroused (sympathetic state)
=> adrenaline = released (from adrenal medulla) to bloodstream
=> adrenaline triggers physiological change (high heart rate / sweat…) - creates energy for FoF
=> in safety -> body returns to parasympathetic state
sympathetic state - bodily changes:
- inc-ed heart rate
- inc-ed breathing rate
- dialted pupils
- inhibits digestion
- inhibits saliva production
-> paraS = opp
fight or flight
(A1) A01+A03
aniety + fear = important for survival -> acts as mechanisms to protect body
SNS controls FoF -> has control the necessary bodily changes
amygdala: [recognises threat / ‘stressor’
- almond-shaped structure in brain
- responsible for emotional responses & links to memory
- body responds in diff ways to acute ST stressors & chronic LT stressors
- communicates w hypothalamus [arouses activity in SNS]
– hypothalamus alerts adrenal medulla [sympathetic branch triggered] to relaease adrenaline + noradrenaline => causes phsyiological changes
adrenaline: [neurotransmitter + hormone]
- released from adrenal medulla
- makes FoF quick + long-lasting
when in safety -> Para-SNS returns NS to norm state -> takes longer than SympNS
long term stressors:
- eg -> stressful jobs // presistent financial problems
- body cannot survive in FoF indefinitely {no saliviation + no digestion …}
so -> body goes into Hypothalamic-Pituitary-Adrenocotrical axis (HPA)
- (hypothalamic) -> if stressor continues -> hypothalamus releases chemical messenger (CRH) -> released into bloodstream
- (pituitary) -> @ pituitary gland, CRH caused PG to produce + release ACTH (adrenocortical hormone)
- (ACTH) = stimulates adrenal cortex to release cortisol -> gives bursts of energy + lower sensitivity to pain {has neg effects - like inhibiting immune system}
HPA axis:
hypothalamus –{releases CRH}–> to pituitary gland –{releases ACTH}–> to adrenal cortex –{releases cortisol into bloodstream}–> stored glugoce => glucagon (provides more energy) —-> negative feedback to hypothalamus or PG
evaluation:
(D) lacks population validity
- most research = only uses male ptts
- when generalsing reults to women -> overlooks gender diffs & assume we behave the same {beta bias}
-> limits reliability
(D) other explanations
- freeze response -> no reaction - oppses FoF {IDs}
(D) lacks temporal valdiity
- ancestors = FoF is helpful -> currently (financial // educatonal) stressor -> can’t fight or rin - have to conorotn -> this was of ‘coping’ isn’t applicable in everyday life
- FoF can be overaacitve => hyperactive anxiety {dramatices anxiious events}
brain localisation
(A2)
[different functions = localised to diff parts of the brain]
laterisation = on one heisphere only
– hemisphereic lateralisation [diff hemipspheres have diff functions]
left hemisphere = language here & controls activity on right side
right hemispherse = spatial skills & controls activity on left side of the body
-> cross-lateralisation (for vision + movement + touch)
both hemispheres = involved in: vision + hearing + smelling + movement + touch + taste
4 lobes:
- frontal -> (left) motor cortex & Broca’s area
- parietal -> (both)somatosensory cortex
- temporal -> (both) auditory + language cortex & (left) Wernicke’s cortex
- occipital -> visual cortex
corpus callosum:
- L + R hemipsheres comm thru sending nerve impulses using CC
- CC + [bundle of axon that connect the hemipsheres]
