Biopsychology Flashcards
What is the biological approach?
Suggests that everything psychological is first biological, so to fully understand human behaviour we must look at biological structures and processes within the body.
What is the nervous system?
Highly specialised set of cells and the primary internal communication system. Made up of billions of neurons.
What are the two main functions of the brain?
To collect, process and respond to information in the environment.
To co-ordinate and direct the working of different organs and cells within the body.
What is the central nervous system made up of?
The brain and spinal cord
What is the peripheral nervous system made up of?
The semantic nervous system and the autonomic nervous system
What is the autonomic nervous system made up of?
The sympathetic branch and para sympathetic branch
What does the brain do?
Centre of all consciousness that controls all behaviours. Involved in all psychological processes. Primitive parts involved in breathing and heartbeat. Higher order thinking such as planning and problem solving.
What is the spinal cord?
Contains a series of neurons and nerve circuitry. Carries messages from the brain to the peripheral nervous system. Allows the brain to monitor bodily processes like breathing and digestion.
What is meant by an arc reflex?
Do not involve conscious part of the brain. The stimulus is picked up by the receptor. An impulse is then transmitted down the sensory neuron to the CNS. The relay neuron takes it through the CNS. The impulse then moves from the CNS to the effector through the motor neuron. The effector then causes a proactive response against the stimulus. The effector can be a muscle or gland.
What is the peripheral nervous system?
All the nerves outside the brain and spinal cord. Main function is to relay nerve impulses from the CNS to the rest of the body and back.
What is the somatic nervous system?
Contains both motor and sensory neurons so transmit info to and from the senses and the CNS. Sensory neuron to CNS
Motor neurons from CNS.
Controls voluntary movements, skeletal muscles and bones. The control centre is the motor cortex. Also involved in arc reflex actions.
What is the autonomic nervous system?
Only contains motor neurons. Contains internal organs and glands that we do not need to be consciously aware of. Transmits to and from internal organs to sustain life processes. The control centre is the brain stem. The two parts of the ANS are responsible for functions that keep the body in a stable state (homeostasis)
What does the somatic nervous system do?
Transmit and receive information about the senses such as visual or auditory - sensory pathways
Motor pathways - direct voluntary movement of skeletal muscles and orchestrates all of our movements from the brain
What is the parasympathetic nervous system?
Maintains and conserves body energy and functions. Returns the body to a state of relaxation and decreases bodily activities after activation from the sympathetic branch.
What is the sympathetic nervous system?
It prepares the body to expend energy for fight or flight. This involves physiological changes which prepare the body for activity and slows down other non-essential activities.
What dies the parasympathetic nervous system do?
Increases digestion
Increases saliva production
Decreases heart rate
Stimulates bile production
Contracts the bladder
Constricts pupil dilation
Constricts bronchi
What does the sympathetic nervous system do?
Slows digestion
Inhibits saliva production
Increases heart rate
Stimulates glucose production
Relaxes the bladder
Dilate pupils
Dilates bronchi
Neuron - cell body
Contains nucleus, which contains all genetic material of the cell
Neuron - dendrites
Branch like structures that project from the cell body. Carry impulses from other neurons towards the cell body.
Neuron - axons
Carry impulses away from the cell body down the length of the neuron
Neuron - myelin sheath
A layer that covers the axon and speeds up the electrical impulse
Neuron - Nodes of Ranvier
Segments the myelin sheath. They speed up transmission of the impulse by forcing it to ‘jump’ across gaps along the axon
Neuron - terminal buttons
At the end of the axon and communicate with the next neuron in the chain across the synaptic gap by using neurotransmitters
What is a sensory neuron?
Found in receptors and carry nerve impulses to the spinal cord and brain. When the impulses reach the brain, they are translated into sensations such as vision, hearing, taste or touch to give information about the environment. Some neurons stop at the spinal cord, allowing for quick research actions.
What is the structure of the sensory neuron?
Long dendrites and short axons
What is a relay neuron?
Found in the brain and spinal cord, and allow sensory and motor neurons to communicate. They are found between sensory input and motor output.
What is the structure of a relay neuron?
Short dendrites, and long or short axons
What is a motor neuron?
Found in the CNS and control muscle movement. When they are stimulated, they release neurotransmitters that bind to the receptors on the muscles to trigger a response.
What is the structure of a motor neuron?
Short dendrites and long axons
What is the first stage of synaptic transmission?
Dendrite picks up NTs and sends an action potential through the cell body and along the axon to the terminal button.
What is the second stage of synaptic transmission?
Once the action potential has reached the terminal button, it needs to be transferred to another neuron. To achieve this it must cross the synaptic gap between pre and post synaptic neuron.
What is the third stage of synaptic transmission?
Synaptic vesicles store NTs - chemical messengers that convert the impulse to a chemical message
What is the fourth stage of synaptic transmission?
As the impulse reaches the synaptic vesicle, they release the NTs that cross the synaptic gap
What is the fifth stage of synaptic transmission?
The NT diffuses across the synaptic gap then binds to the specialist receptors on the surface of the next cell that recognise it and match that particular cell - eg dopamine receptors recognise dopamine
What is the sixth stage of synaptic transmission?
Once the next cell is activated the receptor molecules produce either an excitatory effect or an inhibitory effect depending on the summation of activity at a post synaptic level.
What is the seventh stage of synaptic transmission?
It is completed by a process called reuptake. This is where the NT is taken back up/recycled by the pre-synaptic neuron
What are the key areas of synaptic transmission?
Synaptic vesicle
Terminal button
Synaptic gap
Receptor
Neurotransmitters
Post synaptic neuron
What is a neurotransmitter?
Chemicals that are released from the end of brain cells that allow them to communicate with each other and relay messages to different areas of the brain. As one neuron releases an NT, receptors on other neurons pick up this message and relay it to the next neuron. Neurotransmitters affect the transfer of an impulse to another neuron or muscle.
What is an excitatory effect?
They create a positive charge, making the neuron more likely to fire. This rise in action potential will increase activity.
What is an inhibitory effect?
They create a negative charge, making the neuron less likely to fire. This fall in action potential will decrease activity.
What is the first function of the endocrine system?
Functions to secrete hormones into the bloodstream to regulate many of our bodily functions. Together with the nervous system, they work closely together to regulate and coordinate physiological processes in the body.
What is the second function of the endocrine system?
To provide a chemical system of communication via the bloodstream. It’s a network of glands throughout the body that secrete chemical messengers and deliver them to target sites throughout the body.
What are hormones?
Chemicals released from glands that circulate in the bloodstream and are carried to target structures around the body.
What hormones are released by the pituitary gland?
ACTH, growth hormone and prolactin
What does ATCH do?
It targets the adrenal cortex and stimulates the release of glucocorticoids, which is a key component in the stress response.
What does the growth hormone do?
Produced by the anterior pituitary for the general promotion of cell growth and multiplication.
What does prolactin do?
Produced in the anterior pituitary gland, and it is involved in the production of milk for infants. It regulates the immune system and behaviour.
What does the adrenal gland do?
Produces adrenaline which prepares the body for emergencies, increases heart rate and breathing, raises blood sugar level and diverts blood from the gut to the limbs.
What does the pineal gland do?
It produces melatonin, which affects reproductive development and daily physiologic cycles. More melatonin increases sleep.
What does the pancreas do?
Secretes insulin which converts excess glucose into glycogen in the liver. It then produces glucagon which converts glycogen back into glucose in the liver.
What does the thyroid do?
It secretes thyroxine which controls the rate of metabolism and rate that glucose is used up in respiration and promotes growth.
What is the appraisal of the stressor?
The body appraises the situation using its sensory systems and stored memories. The hippocampus and amygdala to recognise emotional reactions to stimuli and access stored memories for potential danger. The hypothalamus is then alerted which controls the systems that have central roles in the stress response.
What is the sympathomedullary pathway?
Situation is perceived as stressful due to memories, emotions or instincts. The hypothalamus is alerted. This recognises the stress as acute so the SAM pathway is activated. This stimulates the adrenal gland which is situated just above the kidneys. The adrenal medulla secretes the hormones adrenaline and corticosteroids.. These hormones prepare the body for fight or flight.
How does adrenaline affect the body?
Increases perspiration because it regulates body temperature
Dilates pupils because it improves vision
Increases rate of respiration because it increases oxygen intake
Increases heart rate and raises blood pressure because it increases blood flow to organs and spreads adrenaline around the body.
Increases blood flow to muscles for muscular tension because it reduces reaction time.
What happens when we experience a stressor?
Our body activates the autonomic nervous system, specifically the sympathetic branch. This arouses the body and activates the SAM pathway. After a few minutes the parasympathetic branch will be activated, which will reduce the fight or flight response.
What is spatial resolution?
The capacity a technique has to tell you exactly which area of the brain is active
What is temporal resolution?
The ability to tell you exactly when the activation happened
What are post mortem examinations?
When a person’s physical brain is examined who displayed a particular behaviour that suggested possible brain damage. They try to correlate structural abnormalities with behavioural changes. In modern examinations, the brain can be sliced into sections and studied on a microscope.
What are the strengths of post mortem examinations?
Allows detailed observation of anatomical structure and neurochemical aspects of the brain that is not possible with non-invasive techniques.
Provides insight into deeper regions of the brain like the hypothalamus and hippocampus which other techniques cannot access.
What are the weaknesses of post mortem examinations?
Retrospective method so it may be hard to make comparisons with functioning before death.
Need for special permission leads to small sample size
Ethical issues as there are debates on whether patient would need to give consent before death, though patients with severe psychological deficits would be unable to give consent.
What is functional Magnetic Resonance Imaging?
An fMRI uses a strong magnetic field and radio waves to detect changes in blood oxygenation and flow in the brain as a result of neural activity. It takes repeated scans to form a dynamic image of concentration of blood in the brain at one time. Areas of high activity will have a high amount of blood concentration. This allows active sections of the brain to be identified.
What is a strength of fMRIs?
Provides moving picture of brain activity which is highly valuable when trying to link brain activity to key behaviours.
It is considered to be more ethical due to it being a non invasive scanning method.
It has a good spatial resolution of 1-2 mm, which allows scientists to discriminate between different areas of the brain.
What are the weaknesses of fMRIs?
Scans simply measure blood flow, so scientists are unable to conclude whether the brain region is associated with a particular function - we cannot establish cause and effect.
Poor temporal resolution of 1-4 seconds, meaning scientists are unable to predict with a high degree of accuracy the onset of brain activity.
