The Biological Approach Flashcards
What are the assumptions?
psychology is a science and should be studied scientifically
brain and mind are same, we can study the mind by studying the brain
behaviours have an evolutionary basis; genes have adapted over many years
no genes for behaviours, genes synthesise proteins which affect behaviour
behaviours are influenced by heredity, genetics, biological structures, chemical processes and evolution
what is a genotype?
- actual genetic makeup.
- shown by 23 pairs of chromosomes.
- 50% is identical to our siblings and parents, but identical twins share 100%.
- dictates characteristics such as hair colour and eye colour
- someone is born with this
what is a phenotype?
- product of what happens when someone interacts with the environment
- e.g. height is a genotype, but nutrition and diet affects the likelihood of someone reaching that potential height
- can be physical, behavioural or psychological
what is a dominant gene?
controls expression of characteristics of both pairs are dominant or if one is recessive
what is a recessive gene?
only influences expression of a characteristic if both pairs of genes are recessive
what is monozygotic (MZ)?
identical twins.
share 100% of genetic makeup
develop from one fertilised egg
what is dizygotic (DZ)?
non identical twins
develop from 2 fertilised eggs
share 50% of genetic makeup
what does concordant mean?
the presence of the same trait in both members of a pair of twins
what does discordant mean?
when one twin shows a trait the other doesn’t
strengths of biological approach?
uses scientific methods (EEG etc); technological advancements means it’s not open to bias
quantitative data
real life applications such as development of psychoactive drugs
twin studies have lots of data
explanations in terms of neurotransmitters
limitations of biological approach?
only discovers association between 2 factors, can’t be sure one causes the other
quantitative data
deterministic- sees behaviour as out of our control: implications for legal system
reasons for behaviour can’t be explained
cannot separate nature and nurture in twin/family studies
cannot account for why DZ twins show higher concordance than normal siblings
what is the central nervous system (CNS)?
made up of the brain and spinal cord
the brain ensures life is maintained and is responsible for planning, problem solving, thinking etc
the spinal cord facilitates messages to and from the brain and PNS and is involved in reflex actions
what is a motor neuron?
part of CNS
carry’s information about movement out from the brain
have long axons
carries nerve impulses to muscles
what is a sensory neuron?
part of CNS
carries sensory information inward to the CNS
carries nerve impulses from receptors in the PNS to the CNS
what are the stages of a reflex behaviour?
- sensory information about the heat is detected and passed to the CNS by sensory neurons
- they pass the message on to a relay/interneuron in the spinal cord
- this sends a message down a motor neuron to the muscles, which contract, causing you to move your arm
what is the peripheral nervous system (PNS)?
the nerves that are outside the brain and spinal cord
transmits messages via the millions of neurons to the whole body from the brain and vise versa
broken down into the somatic and autonomic systems
what does the somatic system do?
transmits and recieves messages from the senses
e.g. visual from the eyes
also controls muscle movements and receives information from sensory receptors
what does the autonomic system do?
transmits and receives messages from the organs
governs vital functions like breathing, digestion, heart rate and stress responses (automatic processes)
broken down into the parasympathetic and the sympathetic systems
what is the parasympathetic system?
Constricts pupils Stimulates tear glands Strong stimulation of salivary flow inhibits heart, dilates arterioles Constricts bronchi Stimulates stomach motility and secretion stimulates pancreas Stimulates intestinal motility Contracts bladder Stimulates erection
what is the sympathetic system?
prepares the body for action
Dilates pupils No effect on tear glands Weak stimulation of salivary flow Accelerates heart, constricts arterioles Dilates bronchi Inbibits stomach motility and secretion inhibits pancreas and adrenals. Inhibits intestinal motility Relaxes bladder Stimulates ejaculation
what is the axon?
takes information away from the cell body
what is the axon terminals?
hair like ends of the axon
what is the cell body (soma)?
contains the nucleus
what are the dendrites?
extensions from the cell body that take information to the cell body
what is the myelin sheath?
fatty substance that surrounds and protects some nerve fibres
what are the nodes of ranvier?
one of the many gaps in the myelin sheath
what is the nucleus?
contains chromosomes
what are schwann’s cells?
cells that produce myelin - located within the myelin sheath
what is synaptic transmission?
neurons communicate through synapses which are small gaps between neurones where neurotransmitters are realeased and passed from the axon terminal or one neuron, to the dendrite of the recovering neuron
when there are enough activated receptors, another nerve impulse is created and the message is passed on
what is excitatory potential?
acetylcholine is an example of an excitatory NT
if enough of this NT binds to the post synaptic receptors, the chance of nerve firing increases
what is inhibitory potential?
GABA is an example of an inhibitory NT
it binds with the post synaptic neuron, stabilising the membrane, making an action potential less likely (calming effect on neural activity)
what are examples of neurotransmitters?
dopamine
serotonin
melatonin
what is dopamine?
plays a role in movement, memory, and pleasurable reward and motivation
what is serotonin?
plays a role in mood, sleep, digestion, nausea, wound healing, bone health, blood clotting etc
what is melatonin?
helps with timing of circadian rhythms and sleep
is the endocrine system part of the nevvous system?
no
what does the endocrine system consist of?
all glands in the body and the hormones they produce
what is the endocrine system controlled by?
the CNS and chemical messages in the blood
are hormones the same as neurotransmitters?
no!
what does the endocrine system maintain?
maintains stable biological functions, known as homeostasis
how are hormones released?
realeased by glands and are usually transported in the bloodstream, whereas neurotransmitters involve communication between neurons.
only a few substances count as both hormones and neurotransmitters eg oxytocin
what do hormones in the endocrine system do?
regulate growth and development, reproduction, sleep, mood, tissue function etc
what does the endocrine system consist of?
pituitary gland thyroid gland parathyroid gland adrenal glands pancreas ovaries/testes thymus
difference between hormones travelling in the bloodstream compared to electrical messages?
hormones travelling through the bloodstream reach their target organ at a much slower pace than electrical messages
are hormones broken down as quickly as NTs?
No, so the effects of the hormones can last for a longer period of time
how are hormones picked up by their target organ?
hormones travel all over the body, but are only picked up by receptor sites on cells that are directly affected by the hormone (target cells) in target organs
when are hormones secreted?
when a gland is stimulated
this might be due to a chemical message or by a change in the concentration of another substance
what does the hypothalamus do?
it is located in the brain
regulates hunger, thirst, sleep and wakefulness, plus most involuntary mechanisms including body temperature
what does the pituitary gland do?
it is located in the brain
controls all other endocrine glands. influences growth, metabolism and regeneration
what do the thyroid glands do?
regulates your energy and metabolism
what does the parathyroid do?
secretes hormones necessary for calcium absorption
what does the thymus do?
helps build resistance to disease
what does the pancreas do?
aids in the digestion of protein, fats and carbohydrates. produces insulin which controls blood sugar levels
what do the adrenal glands do?
secretes hundreds of compounds including cortisone and adrenaline which help you to react to emergencies.
regulates metabolic processes in the cells, water balance, blood pressure etc
what do the ovaries do?
influences how your blood circulates and determines your mental rigour and your sex drive (testes in males)
what coordinates fight or flight?
the hypothalamus
what systems does fight or flight involve?
both the endocrine system and the nervous system
what is the process of a fight or flight response?
- in the initial shock response, the hypothalamus triggers activity in the sympathetic branch of the ANS
- this stimulates the adrenal medulla within the adrenal glands which releases adrenaline and noradrenaline in the blood stream
- the hormones affect the body
- these changes in the body preserve energy and ensure the body is ready for action. this means that we are prepared in a stressful situation
