Biopsychology Flashcards
What is the nervous system?
A specialised network of cells in the human body and is our primary communication system
What does the nervous system use?
Electrical signals via nerves
Is the nervous system fast or slow?
Fast
What are the two main functions of the nervous system?
- To collect, process and respond to information in the environment
- To co-ordinate thw working of different organs and cells in the body
What two sub sections does the nervous system consist of?
- The peripheral nervous system
- The central nervous system
What does the central nervous system consist of?
Brain and spinal cord
What does the peripheral nervous system consist of?
The autonomic nervous system and somatic nervous system
What is the autonomic nervous system responsible for?
The fight/flight response
What is the endocrine system?
Works alongside the nervous system to control vital physiological processes
What does the endocrine system use to deliver hormones to target sites in the body?
Blood vessels
Is the endocrine system fast or slow?
It is slower and longer-lasting than the nervous system
What are hormones?
Chemical messages that circulate the bloodstream, influencing different bodily processes
What do hormones do?
Alter the probability of a behaviour occurring- so they influence behaviour
What hormones does the pituitary gland release?
Anterior: ACTH
Posterior: Oxytocin
What effect does the pituitary gland have on the body?
- Stimulates the adrenal cortex and the release of cortisol during the stress response
- Responsible for uterus contractions during childbirth
What hormones does the adrenal gland release?
Cortisol, adrenaline, noradrenaline
What effect on the body does the adrenal gland have?
-Located at the top of each kidney, produce hormones that help the body control blood sugar, burn protein and fat, react to stressors like a major illness or injury, and regulate blood pressure
What hormones do the reproductive organs release?
Oestrogen and testosterone
What effect on the body do the reproductive organs have?
- Responsible for the development and regulation of the female reproductive system and secondary sex characteristics
- Responsible for the sex drive, sperm production, muscle strength and secondary sex characteristics
What is the pituitary gland regulated by?
The hypothalamus
What is the pituitary gland divided into?
- Anterior lobe
- Posterior lobe
What is the fight or flight response?
A sequence of internal processes that prepares the body for struggle or escape
What two branches is the autonomic nervous system divided into?
The parasympathetic branch and the sympathetic branch
What is the sympathetic branch responsible for?
The SAM respose to stress- physical arousal of the body
What is the parasympathetic branch responsible for?
Counteracting the SAM response to stress- relaxation and energy conservation
Are the sympathetic and parasympathetic branches fast or slow acting?
Sympathetic is fast and parasympathetic is slow
What physiological changes are occurring when the sympathetic branch is activated?
- Dilates pupils
- Inhibit salivation
- Accelerates heartbeat
- Dilate bronchi
- Inhibits digestion
- Stimulates glucose release
- Relaxes bladder
What physiological changes are occurring when the parasympathetic branch is activated?
- Constricts pupils
- Stimuates salivation
- Slows heartbeat
- Constrict bronchi
- Stimulates digestion
- Contracts bladder
What are the body’s two stress responses responsible for?
- Acute stress (short term)
- Chronic stress (long term)
What is responsible for the acute stress reponse?
Sympathetic Adrenal Medullary Axis (SAM)
What is responsible for the chronic stress reponse?
Hypothalamic Pituitary Adrenal Axis (HPA)
Outline the SAM response to acute stress e.g. falling down
- Activates the sympathetic branch of the ANS
- Neuronal messages are sent to the inner core of the adrenal gland called the adrenal medulla
- This results in the secretion of adrenaline and noradrenaline
- This leads to the fight or flight reponse and the physiological changes
Outline the HPA reponse to chronic stress e.g. multiple deadlines
- Releases Corticotrophin Releasing Hormone
- Activates the pituitary gland
- Causes the release of the ACTH stress hormone
- This stimulates the outer edge of the adrenal gland called the adrenal cortex
- Allows the production of glucocortoids (Glucose and Cortisol)
- Glucocortoids are released into the liver to release stored glucose
- Leads to the suppression of the immune system
Evaluate the fight/flight response
- Taylor et al found that females respond to stress differently- tend (protecting their young) and befriend (protecting alliances with other women) as fleeing too readily can endanger their offspring
- Response to chronic stress can be counterproductive in today’s society- in modern life the stress response can be repeatedly activated which can lead to physical damage in blood vessels and eventually heart disease
- The freeze reponse challenges fight or flight- Gray argues that before fighting or fleeing most animals freeze to stop, look and listen in order to make the best response
What are neurons?
Cells that are specialised to carry neural information throughout the body
What are the three types of neuron?
- Sensory
- Motor
- Relay
What is the general structure of a neuron?
- Cell body- control centre of the neuron
- Dendrites- receive signals from other neurons or from sensory receptors
- Axon- carries the electrical impulse away from the cell body down the length of the neuron
- Myelin sheath- insulates/ protects the axon and allows the nerve impulse to be transmitted more rapidly along the axon
- Terminal buttons- these are at the end of the axon and communicate with the next neuron across the synapse
What are sensory neurons?
- Carry nerve impulses from sensory receptors to the spinal cord and brain
- Convert information from senses into neural impulses
- When these impulses reach the brain they are translated into sensations
- Some neurons terminate in spinal cord to allow reflex actions
- They have long dendrites and short axons
What are relay neurons?
- Most neurons lie somewhere between the sensory input and motor output
- Allow sensory and motor neurons to communicate with each other
- Relay neurons lie wholly within the spinal cord and brain
- They have short dendrites and short axons
What are motor neurons?
- These neurons connext the central nervous system to muscles
- They form synapses with muscles and control their contraction
- When stimulated, motor neurons release neurotransmitters that bind to the muscle receptors to trigger a response
- This leads to muscle movement
- They have short dendrites and long axons
What is synaptic transmission?
When a nerve impulse passes across the synaptic cleft from one neuron to another
Outline the process of synaptic transmission
- Electrical impulse arrives at the pre-synaptic terminal
- This stimulates vesicles (sacs holding neurotransmitters)
- This releases neurotransmitters which diffuse across the gap between the two neurons, known as a synapse
- The neurotransmitters arrive at te postsynaptic receptors
- Postsynaptic effects are either excitatory or inhibitory
What are excitatory neurotransmitters?
- Neurotransmitters such as adrenaline are the system’s on switches
- These cause excitation of the post-synaptic neuron by increasing its positive charge
- This makes it more likely to fire
What are inhibitory neurotransmitters?
- Neurotransmitters such as serotonin are the system’s off switches
- These cause inhibition of the post-synaptic neuron by increasing its negative charge
- This makes it less likely to fire
- Inhibitory neurotransmitters are responsible for calming the mind and body
What is the likelihood of a cell firing determined by?
- Adding up the excitatory and inhibitory neurotransmitters binding to the post-synaptic neuron
- The net result of this calculation (summation) determines whether or not the cell fires
What is the localisation of cortical function?
The theory that specific areas of the brain are associated with different functions
What functions are associated with the brain stem?
Basic life functions such as breathing and heart rate
What functions are associated with the cerebellum?
Basic motor control, balance and some simple learning