BIOPSYCHOLOGY Flashcards
what is a nervous system
network of cells which acts as primary communication and is based on electrical and chemical signals
whats the role of the central nervous system
the CNS is made up of the brain and spinal cord. the CNS controls behaviour by regulating the bodies physiological processes
what does the brain do?
the brain is the centre of conscious awareness and receives info from the sensory receptors
the ……… is highly developed and gives us higher mental functions than animals
cerebral cortex
whats the spinal cord
responsible for reflex actions. it passes messages from the brain and connects nerves to the peripheral nervous system
what does the peripheral nervous system do
transmits messages from the environment to the central nervous system via millions of neurones
what does the somatic nervous system do
controls voluntary muscle movement and receives info from the sensory receptors eg: speaking
what does the autonomic nervous system do
controls involuntary, unconscious movement of the body eg: blinking, this is controlled by the hypothalamus
what does the sympathetic nervous system
fight or flight response, helps the body prepare for dangerous situations
name 3 things the sympathetic nervous system increases
heart rate
sweat
breathing
name 3 things the sympathetic nervous system decreases
digestion
urination
salivation
what does the parasympathetic nervous system do
rest and digest response, relaxes the body and returns us to our normal state
what are neurones
transmits signals electrically and chemically to provide the nervous system with the means to communicate
role of synapses
send electrical impulses to neighbouring neurones
role of myelin sheath
cover axon and acts as insulation to help keep electrical signals inside cell and allows them to move quicker
role of axon
transfers electrical impulse signals from the cell body to synapse
what does the soma do
the cell body, this contains most of the cells organelles
what does the nucleus do
contains the cells DNA
what do the dendrites do
receives electrical impulses from the neighbouring neurones
3 characteristics of sensory neuron
carry messages from peripheral nervous system to CNS
have myelin sheath
cell body is off axon
3 characteristics of relay neuron
no myelin sheath
only in CNS
connects sensory neurones to motor neurones and other relay neurones
3 characteristics of motor neurones
has myelin sheath
cell body within dendrites
connects CNS to muscles and glands to trigger response
whats synaptic transmission
neurones are seperated from eachother by tiny gap called synapse.
they pass messages to each other using synaptic transmission
first stage of synaptic transmission
electrical impulses pass down axon of the first neuron
second stage of synaptic transmission
vesicles containing neurotransmitters move towards pre synaptic membrane
third stage of synaptic transmission
vesicles fuse with pre synaptic membrane and release neurotransmitters into synaptic cleft ( the gap )
fourth stage of synaptic transmission
neurotransmitters diffuse across synapse and attach to receptors on post-synaptic membrane
fifth stage of synaptic transmission
activity in the receptors cause neurones to have an excitatory effect or inhibitory
whats an excitatory effect?
increases chance of neuron firing
whats an inhibitory effect
decreases chance of neuron firing
last stage of synaptic transmission
neurotransmitter are recycled back to pre synaptic neuron
whats summation?
excitatory and inhibitory influences are summed and must reach a certain threshold for an action potential to be triggered
whats the first way drugs can do to neurotransmitters
inhibit the re uptake of neurotransmitters ( increases neurotransmitters reaching post synaptic neuron )
whats the second thing drugs can do the neurotransmitters
block receptors, this decreases the amount of neurotransmitters reaching post synaptic neuron
whats the endocrine system
works alongside nervous system to control functions through use of hormones
whats a gland
organs that produce hormones
whats a hormone
whats secreted into the blood, which affects target cells that have receptors
what does the hypothalamus do
responsible for secretion of hormones
detects incorrect levels of hormones in blood
what hormone does the pituitary gland secrete
controls release of hormone from gland.
anterior- ACTH ( causes adrenal to secrete cortisol )
posterior- oxytocin , contractions and breastfeeding
pineal gland hormone secrete and effect
melatonin
sleep/ wake cycle
high melatonin = sleepy feeling
thyroid hormone secretion and effect
thyroxine, responsible for growth, metabolism and appetite
pancreas hormone secrete and effect
insulin and glucagon
insulin lowers blood sugar
glucagon- raises
adrenal gland hormone secretion and effect
cortisol and noradrenaline
c- stress hormone, releases glucose for energy
a: fight or flight response
ovaries hormone secretion and effect
oestrogen, regulates menstrual cycle
testes hormone secretion and effect
secretes testosterone, responsible for male characteristics eg: sperm production
define stress
biological and psychological response when encountering threat we dont feel able to deal with
how does the pituitary gland detect stress?
the hypothalamus is activated if a situation is stressful and then signals the pituitary gland
what do we do in times of short term stress
flight or fight ( SAM pathway )
what do we do in times of long term stress
HPA axis
list the fight or flight steps
( AHSSC )
amygdala sends signal to hypothala
hypothalamus activates SAM
SAM stimulates sympathetic ns
sympathetic ns stimulates adrenal medulla, releasing adrenaline and noradrenaline into blood
cause physiological changes
name 5 physiological changes during stress
inc heart rate
inc breathing rate
pupil dilation
sweat production
reduction of non essential functions eg: urination and salivation
what does the parasympathetic action do
returns body back to normal state, working in the opposite direction to the sympathetic
THIS IS THE REST AND DIGEST
define localisation of function
the theory that different areas of the brain are responsible for specific behaviours, processes and activities
context ( 3 points ) of LOF
before 19th century, view of brain was hollistic. this means all parts of brain are involved
scientists disproved this in 19C
this suggests that if certain parts of brain are damaged, the function of area will be too
front lobe responsibilities and what cortex is located
responsible for: movement, problem solving, concentration, behaviour and mood, stm
MOTOR CORTEX
parietal lobe responsibilities and cortex
- sensory info
- perception
- body awareness
- attention
SOMATOSENSORY CORTEX
temporal lobe responsibilities and cortex
- hearing
- language
- memory
- smell and taste
AUDITORY CORTEX
occipital lobe responsibilities and cortex
- vision
- perception
VISUAL CORTEX
role of motor cortex
controls voluntary movement in opposite site of body
found in frontal lobe
role of somatosensory cortex
where sensory info from skin is processed
located in parietal lobe
role of visual cortex and where located
info from eyes processed
occipital lobe
role of auditory cortex and location
speech based info is analysed
found in temporal
where are the language centres in brain located
left hemisphere
broca and wernickes
brocas area
located in left frontal lobe
responsible for speech production
damaged= brocas aphasia
characterised by slow speech, lacking fluency
wernickes area
located in left temporal lobe
responsible for language understanding
damaged= wernickes aphasia
define hemispheric lateralisation
the idea that the two halves of the brain are different and that certain behaviours and mental processes are controlled by one hemisphere
left and right hemisphere responsibilities
left: language, music, analytical tasks, viewing objects
right: drawing, spatial awareness, recognising emotions in others
define contralateral
right hemisphere controls left and left hemisphere controls right
what connects the two hemispheres
the two hemispheres are connected through nerve fibres called the corpus callosum
allows communication
epilepsy surgery
cutting the corpus callosum, stopping hemispheres communicating
we use this research to identify which behaviours are lateralised
KEY STUDY
sperry and gazzaniga
AIM
aim: examine extent that two hemispheres had function roles
KEY STUDY
sperry and gazzaniga
procedure
studied 11 split brain patients
showed word or imagine in right visual ( controlled by left ) and other.
patients couldnt complete picture
sperry findings
objects shown in right visual field- pp could describe
objects in left: pp couldnt describe
LANGUAGE CENTRES IN LEFT
sperry right hemisphere findings
shown in right- pp couldnt draw
shown in left- pp could draw
VISUAL CENTRE IN RIGHT
define plasticity
brains ability to change and adapt as a result of experience
how does plasticity work ( 3 points )
the functions change as a result of experience and injury
as a baby, the brain experiences growth of synaptic connections
as we get older, the used ones get strengthened- synaptic pruning
key study- maguire
aim
to examine whether structural changes could be detected in the brains of people with extensive experience of spatial navigation
key study- maguire
method
16 male london taxi drivers with more than 1.5 years experience
control group of 50 males non taxi
took mri scans of brain
key study- maguire
findings and conclusion
increased ‘grey matter’ in taxi driver
positive correlation between amounts of time driving and volume of hippocampus
supports idea of brain plasticity
define functional recovery
a form of plasticity following damage to brain. the brain is able to transfer functions from damaged area to non damaged
define axonal sprouting
new nerve endings grow to make connections with undamaged nerves to form new pathways
define recruitment of homologus area
the opposite side of brain takes over the task
define stem cells within functional recovery
unspecialised cells that become different cells to cary out functions
why do we look at the brain
to diagnose illness and investigate localisation
define spatial resolution
this refers to the smallest feature that a scanner can detect. The greater the spatial resolution, the clearer the image
temporal resolution definition
the accuracy of the scanner in relation to time. refers to how quickly the scanner can detect change
whats a post mortem examination
analysing brain after death
often used in rare disorder cases
to identify area brain responsible for rare disorder
may be compared to normal
whats FMRI
detects changes in blood oxygen levels and blood flow in specific areas of brain
uses big magnets to detect oxygenated and deoxygenated blood
produces 3D images
EEG
measure electrical acitvity using skull cap
scan records brainwave patterns that are generated when neurons fire
used in abnormalities eg: epilepsy
ERP
use electrodes attached to scalp
more specific measurements
remove any unwanted EEG data
define a biological rhythm
distinct patterns of change in bodies activity that conform to time periods. influenced by internal clocks
define an endogenous pacemaker
the internal body clock that regulates many biological rhythms eg: sleep and wake cycle
define exogenous zeitgebers
external factors that affect biological rhythms, eg: the influence of light on our sleep/ wake cycle
whats the difference between circadian and ultradian rhythms
circadian last for 24 hours
ultradian occur more then once in 24 hours
infrarian occur less than once in 24 hours
example of circadian rhythm
sleep wake cycle
body temperature
sleep wake cycle
- light is detected by eye
- sends a signal about light detected to the SCN ( biological clock )
- if theres little light, SCN causes pineal gland to secrete melatonin
- if theres lots of light, SCN causes pineal gland to stop secretion
STUDY
siffre’s cave
spent a long period of time without any light to study his biological rhythm
bio rhythm became 25 hours instead of 24
suggests that endogenous pacemakers influence rhythms
STUDY
aschoff and wever
sent pps into ww2 bunker no light
all but one pp ( 29 hours ) had a cycle of 24-25
suggests ez dictate 24 hours used to
cycle may be slightly longer
STUDY
folkard
studied 12 people in dark cave for 3 weeks
slept 11.45pm woke 7.45am
researchers changed clock
only 1 pp adjusted to 22 hour day
SUGGESTS CIRCADIAN RHYTHM CAN BE EASILY OVERRIDEN
example of infradian rhythms
menstrual cycle
monthly changes in hormone levels which regulate ovulation
3 steps of menstrual cycle
- oestrogen causes ovary to develop egg and release through ovulation
- after o, progesterone helps womb lining to thicken
- egg absorbed into body and womb lining leaves through flow ( if pregnancy doesnt occur )
STUDY
mcClintock 1998
29 irregular period women studied
samples of pheromones gathered from 9 via cotton pad on armpit
pads treated w alchol, frozen, rubbed on upper lip of all
pads from day were applied on that correct day
68% experiences changed to cycle
define SAD
seasonal affective disorder
low mood, lack of interest in life
type of infradian rhythm, called circannual rhythm
linked with melatonin production
knock on effect of seratonin
example of ultradian rhythm
sleep cycles
5 stages, lasting 90 mins each
characterised by different brainwave using EEG
LIGHT SLEEP STAGE
stage1- muscle slows, twitching, brain waves h frquency s amplitude
stage2- breathing and heart slows, decrease in body temp
sleep spindles in alpha waves
HEAVY SLEEP
stage3
- deep sleep
- difficult to wake
- brain begins to generate slow delta waves
stage 4
- very deep sleep
- rhythmic breathing
- limited muscle activity, delta wave
REM SLEEP
stage 5
- rapid eye movements
- brainwaves speed up, dreaming
- muscles relax, heart rate inc
- breathing rapid and shallow
what is the superchiasmatic nucleus
tiny bundle of nerve cells in the hypothalamus, in both hemispheres of the brain
one of main endogenous pacemakers and crucial for circadian rhythms
SCN and the optic chasm
the optic chasm is the nerve fibres connected in the eye on the way yo the left and right visual cortex of the cerebral cortex
SCN above optic chasm and receives info on light
continues when eyes are shut, allowing us to adjust
SCN and the optic chasm
the optic chasm is the nerve fibres connected in the eye on the way yo the left and right visual cortex of the cerebral cortex
SCN above optic chasm and receives info on light
continues when eyes are shut, allowing us to adjust
where does SCN pass into to?
passes info of day length and light levels to pineal gland
pineal gland inc melatonin at night and decrease in day
STUDY
deCoursey et al 2000
destroyed SCN in 30 chipmunks
sleep cycle dissapeared
killed by predators as they shouldve been asleep
STUDY
Ralph et Al
bred mutant hamsters with 20 hour sleep cycle
when the scn cells from foetal tissue of mutant hamsters were transplanted into brains of normal, they had the same sleep/ wake
suggests endogenous pacemakers is mostly responsible for sleep/ wake
whats an exogenous zeitberg
external factors that reset the internal body clock through ‘entrainment’
without these, the body clock continues
study
campbell and murphy
light may be detected by skin instead of eyes
15 pps were woken and a light pad was shone on the back of knees
light may not rely on eyes to influence brain
social cues in babies, regarding to sleep
6 weeks circadian rhythms begin
16 weeks trained by parents schedules
social cues in babies, regarding to sleep
6 weeks circadian rhythms begin
16 weeks trained by parents schedules
