Biopsychology Flashcards
What is the response to acute stress?
Amygdala (sends a message)—– Hypothalamus (causes the)——— Adrenal medulla (to release; adrenaline & noradrenaline)——– adrenaline.
Difference between chronic and acute stressors
Acute- something small and temporary such as a spider
Chronic- something long term and ongoing such as a stressful job.
What is the response to chronic stress?
- Hypothalamus detects stress
- This stimulates corticotrophin releasing hormone (CRH)
- Released into the blood stream
- CRH causes pituitary gland to release ACTH
- Adrenal gland releases cortisol (good for quick bursts if energy but bad for cognitive performance and the immune system)
- ACTH transported to bloodstream, target site adrenal glands
- ACTH stimulates adrenal cortex.
Describe divisions of nervous system.
- made up of several divisions
- largest divisions being central nervous system (CNS) and the peripheral nervous system (PNS)
- CNS made of brain and spinal cord (connected by complex web of neurons)
- PNS divided into somatic and autonomic
Somatic; consists of sensory and motor neurones, enables reflex actions - Autonomic; largely unconscious and involuntary. Divided into parasympathetic (PS) and sympathetic (SS) NS.
- PS regulated body functions during non stressful situations
- SS prepares us for fight or flight.
Structure and function of a sensory neurone
- long dendrites and short axons.
- Carry impulses from sensory receptors to the spinal cord & the brain
- convert info from receptors into neural impulses, when reaches the brain a sensation is felt.
Structure and function of a relay neurone
- lots of short dendrites, cell body and short axon
- allows sensory and motor neurones to communicate with each other and brain and spinal cord.
Structure and function of a motor neurone
- short dendrites & long axon
- controls muscle movements
- when stimulated they release a neurotransmitter which triggers a response.
What is a neurotransmitter?
- brain chemicals released from synaptic vessels
- bind to receptors on a post-synaptic cell. Create an inhibitory or excitatory action.
What is synaptic transmission?
- process in which a nerve impulse passes the synaptic cleft from a pre to post synaptic neurone.
Describe the process of synaptic transmission (6 marks)
- an action arrives at the terminal button at the end of the axon, this needs to be transferred to another neurone or tissue
- must cross the synaptic gap
- at the axon of a nerve, synaptic vesicles (sacs containing neurotransmitters) are stimulated by the action. This process causes the vesicles to release their contents (exocytosis)
- the released contents diffuses across the synaptic gap and binds to specialised receptor cells on the surface of the post-synaptic neurone.
- this activates the cell, producing either excitatory or inhibitory effects on the post synaptic neurone.
Explain excitatory effect
- occurs when receptor stimulation results in an increase in the positive charge of of the post- SN & increases the likelihood of the neurone firing and passing on the impulse.
Explain inhibitory effect
- receptor stimulation increases the negative charge of the receiving neurone & decreases the likelihood of the neurone firing and passing on the impulse.
What is summation?
- addition of positive and negative postsynaptic potentials. Can receive pos and neg simultaneously. Overall is summed, excitatory or inhibitory is produced.
What is the endocrine system?
- network of glands throughout the body
- works very closely with nervous systems
- releases hormones into the bloodstream to regulate physiological processes
What’s a gland?
- they produce and secrete hormones.
- main glands; pituitary, adrenal, ovaries, testes.
- regulates the activity of organs & tissues.
What’s a hormone?
- chemicals that circulate the body and are carried to target sites
- target cells only respond to specific hormones (specialised).
Hormone & function of pituitary gland.
- ACTH
- stimulates the adrenal cortex during the stress response
Hormone & function of Adrenal cortex.
- Cortisol
- stimulates the body to release glucose to provide energy for the flight-or-fight response
Hormone & function of Adrenal medulla
- Adrenaline
- Triggers physiological changes; increased heart rate, which creates arousal needed for fight-or-flight
Hormone & function of Pineal gland
- Melatonin
- responsible for biological rhythms; sleep-wake cycle
Hormone & function of Thyroid gland
- thyroxine
- increases metabolic rates
Hormone & function of Ovaries
- oestrogen
- regulation of female reproductive system
Hormone & function of Testes
- testosterone
- development of male sexual characteristics during puberty, promotes muscle growth
Explain the flight or fight response (include reference to adrenaline)
When something is perceived as a stressor or threat, the amygdala is activated which sends a distress signal to the hypothalamus. This then activates the sympathetic medullary pathway (SAM). This activates the adrenal medulla, which then releases adrenaline and noradrenaline into the blood stream. Adrenaline triggers physiological changes within the body (increased heart rate, breathing rate, pressure) which creates the arousal needed to either fight or flight.
Evaluation of flight or fight response.
limitation; The fight-or-flight response is not the only reaction by humans facing dangerous situations. Gray suggests that the first response to danger is to avoid the confrontation, which is demonstrated by the freeze response. During this, individuals are hypervigilant while they assess the situation and work out what to do. An example of this is victims of sexual crimes. TMB the freeze reaction is not a recognised trauma response, this sometimes means that prosecutors are not table to help the victim or convict the criminal. Thus, lacking validity.
limitation; The fight-or-flight response is typically a male response to danger. Taylor et al. (2002) suggests that females adopt a ‘tend or befriend’ response in a stressful/dangerous situation. This is because women are more likely to protect their offspring (tending) and form alliances with other women (befriend), rather than fight or run away. The focus on the fight-or-flight response arose due to research being conducted on males and assuming the findings could be generalised to females (beta bias). Thus limiting fight or flight response
limitation; Flight or fight response is maladaptive. It aided survival in our evolutionary past, but it can have a negative effect on health, especially in modern-day life. Modern-day stressors tend to be non-life-threatening. However, they still trigger the release of adrenaline and other stress hormones which, over time, can have devastating consequences on health. This suggests it is a maladaptive response in modern life. Thus limiting fight or flight response.
What is localisation?
idea that specific locations of the brain have specific functions in the body/ behaviour.
Motor cortex
- generation of voluntary motor movements
- in frontal lobe along the bumpy region
- both hemispheres
- arranged logically (in order of the way our bodies look in terms of what it controls)
Somatosensory cortex
- detects sensory events
- in parietal lobe
- processing info from touch, produces sensations
- both hemispheres
Visual cortex
- occipital lobe
- both hemispheres
- contains different areas that process different info (colour/shape)
Auditory center
- hearing
- temporal lobe
- both hemispheres
- inner ear, sounds waves converted to nerve impulses
- travels to thalamus then brain stem to be decoded, then back to auditory cortex where response.
Language centres- Broca’s area
- in the back of portion of the frontal lobe
- critical for speech production
- Broca’s aphasia- damage to Broca’s area causing inability to produce speech.
- left hemisphere only
Language centres- Wernicke’s area
- back portion of left temporal lobe
- deals with understanding of language
- if damaged the indiviudal is able to talk but unable to understand language
Evaluation of localisation of function?
strength; has research support of localisation in the brain. For example, Broca’s aphasia is an impaired ability to produce speech, this comes from damage to the Broca’s area in the back portion of the frontal lobe in the left hemisphere. TMB, shows that some parts of the brain have specialised functions, such as being part of
the language centre. Thus strengthening localisation of function.
limitation; individual in language areas of the brain. Harasty found that women have larger language centres than men, this may be because they talk more and use language to express themselves. TMB, cannot apply localisation of brain function in the same way to everyone as there may be individual variations in how brains are structured,. Thus limiting loc of function.
limitation; loc of function may not be as important as intercommunication. Dejerine argued that Wernicke’s
aphasia was due more to damage to the
pathway between the visual cortex and Wernicke’s area than damage to the area itself. TMB, shows that the neural pathways between the areas are more vital than the actual areas themselves. Thus limiting loc of function to explain human behaviour.
limitation; Evidence that challenges localisation. For example, Lashley claimed that higher
mental functions were not localised, only basic
ones were. This means when one part
of the brain is damaged, other intact areas are
often able to adapt to take on the function it used
to perform. TMB, suggests that the extent of the damage is more important than its actual location, and that
the brain has the ability to adapt when there is
damage in order to maintain key functions, which is
known as functional recovery. Thus limiting importance of loc of function
