biopsychology

• what are the 4 divisions of the nervous system

  central

  peripheral

  autonomic

  somatic
• outline the central nervous system

  - made up of the brain and spinal cord
• outline the peripheral nervous system

  - transmits information from the environment to the CNS via sensory neurones

  - transmits information from the CNS to effectors via motor neurones to produce an action
• what are the 2 divisions of the peripheral nervous system

  - autonomic

  - somatic
• outline the somatic nervous system

  - receives information from the sensory organs via sensory neurones and transmits this to the CNS

  - transmits information from the brain to the muscles / effectors in order to produce voluntary movements
• outline the autonomic nervous system

  - regulates involuntary internal body processes such as heart rate, digestion and breathing
• what are the 2 branches of the autonomic nervous system

  - sympathetic

  - parasympathetic
• outline the sympathetic branch of the autonomic nervous system

  - responds to perceived threats by producing physiological changes that prepare the body for a fight or flight reaction

  - may include heart rate increasing, digesting slowing and respiration rate increasing
• outline the parasympathetic branch of the autonomic nervous system

  - restores regular physiological functioning when the perceived threat has passed and the body does not need to be prepared for a fight or flight reaction

  - may include heart rate decreasing, digestion resuming and respiration rate decreasing
• what is a neurone

  - type of cell specialised to transmit information in the form of electrical impulses
• what are the 3 types of neurone

  - sensory

  - relay

  - motor
• draw a sensory neurone and describe the structure

  - connected to a receptor cell

  - axon surrounded by myelin sheath

  - cell body attached to axon

  - dendrites at opposite end to receptor cell

  
• draw a relay neurone and describe its structure

  - very short unmyelinated axon and long dendrites

  - cell body found at the end of the neurone, near the dendrites

  - pre-synaptic terminal at opposite end to dendrites

  
• draw a motor neurone and describe its structure

  - long myelinated axon and short dendrites

  - cell body found at the end of the neurone near the dendrites

  - connected to an effector (either a muscle or gland)

  
• what is the direction that neurones transmit information (which way round are they)

  SENSORY

  receptor cell ---> dendrites

  
  

  RELAY

  dendrites ---> pre-synaptic terminal

  
  

  MOTOR

  dendrites ---> effector
• describe how the 3 neurones transmit information

  - sensory neurone receives information from the environment through sensory organs and transmits this via the PNS to the brain

  - relay neurones are found in the brain and spinal cord, they receive information from sensory neurones and coordinate an appropriate response - relay information between sensory and motor neurones

  - motor neurones transmit information from the brain to an effector (muscle or gland) which produces and appropriate response
• what is a synapse/ synaptic terminal

  - a gap between two neurones
• describe the process of synaptic transmission

  - electrical impulse arrives at pre-synaptic neurone

  - causes vesicles containing neurotransmitter to fuse with the presynaptic neurone membrane

  - neurotransmitter is released into the synaptic cleft

  - neurotransmitter binds to receptor sites on the post-synaptic neurone

  - neurotransmitter either produces and inhibitory or excitatory effect on the post-synaptic neurone which determines whether an action potential will be produced in the post-synaptic neurone
• what happens to excess neurotransmitter in the synaptic cleft?

  - reuptake back to the pre-synaptic neurones may occur

  - neurotransmitter will be stored in vesicles
• why are synapses unidirectional?

  - vesicles with neurotransmitter are only found in the pre-synaptic neurones

  - receptors are only found on the post-synaptic neurones

  - neurotransmitter diffuses from a high concentration (in vesicles) to a low concentration (in synaptic cleft)
• what is meant by excitatory neurotransmitters

  - makes the inside of the post-synaptic neurone more positively charged, increasing the likelihood that an electrical impulse will be transmitted
• what is meant by inhibitory neurotransmitters

  - makes the inside of the post-synaptic neurone more negatively charged, decreasing the likelihood that an electrical impulse will be transmitted
• how does summation affect synaptic transmission

  - each neurone has multiple dendrites, so has multiple synapses

  - summation is the combined effect of excitatory and inhibitory neurotransmitters, which determines whether an electrical impulse will be transmitted

  - if more excitatory neurotransmitters than inhibitory neurotransmitters are released, the net effect will be excitatory and an electrical impulse will be transmitted
• how do SSRI'S function

  - prevent the reuptake of serotonin from the synapse by blocking reuptake channels on the pre-synaptic neurone

  - more serotonin remains in the synapse, which allows for more stimulation of the post-synaptic neurone

  - treats depression and OCD/anxiety
• outline the endocrine system

  - a system in the body that works alongside the nervous system, transmitting information through hormones to control functions within the body
• what are hormones?

  - chemical messengers released by glands in the endocrine system that travel through the bloodstream and affect target cells with receptors that they can bind to
• outline the 5 main glands and the hormones they secrete

  - pituitary gland - 'master gland' that causes other glands to secrete their hormones, and also directly secretes some hormones such as oxytocin

  
  

  - adrenal gland - secretes adrenaline which affects the sympathetic division of the nervous system and is responsible for the fight or flight response

  
  

  - thyroid gland - secretes thyroxine which controls metabolic rate

  
  

  - ovaries - in women secrete oestrogen and progesterone which enables female puberty

  
  

  - testes - in men secrete testosterone which enables male puberty
• outline the fight or flight response

  - involuntary response of the body to a short term stressor triggered by the symapthetic branch of the autonomic nervous system

  - hypothalamus activates sympathetic branch of ANS

  - causes adrenal glands to secrete adrenaline which causes heart rate and blood pressure to increase

  - also causes digestive functions to pause which can cause dry mouth
• what is meant by "localisation of function" of the brain

  - specific areas of the brain are responsible for different functions, such as movement, speech and memory
• what are the four lobes of the brain

  - frontal lobe

  - parietal lobe

  - temporal lobe

  - occipital lobe
• draw and label a diagram of the brain including

  - all four lobes

  - motor cortex, somatosensory cortex, visual cortex, auditory cortex

  - broca's area

  - wernike's area

  - motor cortex in the BACK of the frontal lobe

  - somatosensory cortex in the FRONT of the parietal lobe

  - visual cortex at the BOTTOM of the occipital lobe

  - auditiory cortex on the LEFT SIDE of the temporal lobe

  - broca's area in the BOTTOM RIGHT of the frontal lobe

  - wernike's area in the MIDDLE of the temporal lobe

  
• what is meant by "contralateral"

  - each hemisphere of the brain controls the opposite side of the body, including motor and sensory pathways, and the visual field
• what is meant by "hemispheric lateralisation" of the brain

  - each hemisphere of the brain is specialised to perform different functions

  - left hemisphere is responsible for LANGUAGE

  - right hemisphere is responsible for RECOGNISING EMOTIONS and VISUOSPATIAL TASKS
• outline the role of the motor cortex/centre/area and what may happen if damaged

  - the area of the brain responsible for voluntary movement by sending electrical impulses to the muscles through the CNS and PNS

  - one found in each hemisphere, so the left motor cortex controls movement in the right side of the body due to the brain being contralateral

  - damage to one motor cortex may result in loss of muscle of paralysis on the opposite side of the body
• outline the role of the somatosensory cortex/centre/area and what may happen if damaged

  - area of the brain responsible for receiving sensations from around the body

  - contralateral, so sensations felt on the left side of the body will be processed in the right somatosensory cortex

  - more sensitive areas of the body such as the face and hands require a larger area of the somatosensory cortex

  - damage to one somatosensory cortex may result in loss of sensation to the opposite side of the body
• outline the role of the visual cortex/centre/area and what may happen if damaged

  - the area of the brain responsible for processing visual information

  - one found in each hemisphere, so information from the right visual field will be sent to the left visual cortex due to the brain being contralateral

  - damage to visual cortex in one hemisphere may result in blindness in the opposite visual field

  - damage to visual cortex may result in "blindsight" - where the eyes work but the visual cortex cannot process the information, so the individual can locate an object in their visual field but be unable to determine what the object is
• outline the role of the auditory cortex/centre/area and what may happen if damaged

  - area of the brain responsible for perceiving and processing sound information from the ears

  - contralateral, so sound from the right ear is processed by the left auditory cortex and vice versa

  - damage to the auditory cortex may result in partial deafness - the individual is still able to hear sounds as there is no damage to the ears, but is unable to process the sounds
• outline the role of broca's area and what may happen if damaged

  - area of the brain found in the left hemisphere only responsible for speech production

  - damage may lead to BROCA'S APHASIA - the individual experiences difficulties producing fluent speech, speech often appears broken and slow and requires a large amount of effort
• outline the role of wernike's area and what may happen if damaged

  - area of the brain found in the left hemisphere only responsible for speech comprehension

  - damage may lead to WERNIKE'S APHASIA - the individual has difficulty understanding speech or written language, speech sounds fluent but does not make sense
• state 3 research studies that support the localisation of function in the brain

  - Broca conducted a post mortem examination on a 51 year old patient who had epilepsy and eventually lost the ability to speak, and found damage to the left temporal lobe whilst the right temporal lobe was intact. this suggested that part of the left temporal lobe (broca's area) is responsible for the localised function of speech production

  
  

  - wernike (1874) found that damage to the an area next to the auditory cortex in the temporal lobe (wernike's area) resulted in an inability to process language, either spoken or written, and can still talk although their speech did not make sense. this suggested that this area was responsible for the localised function of language comprehension

  
  

  - macmillan (2002) reported on the case study of phineas gage, who had a metal pole impale his brain due to an explosion whilst working on a railroad. this reportedly caused personality changes in gage, although it did not kill him and he was still able to talk. suggests that specific areas of the brain are responsible for controlling vital functions such as heart rate and breathing, whilst other areas are responsible for regulating emotions and personality (functions are localised)- ca