Biopsychology

Biopsychology

1. Nervous system

   • Central nervous system
     • Spinal cord
       • - Relays information between brain and body, allows monitoring and contains nerve cells to allow simple reflexes
     • The brain
       • Contains the cerebrum, diencephalon, brain stem and cerebellum
         • Cerebrum is split into 2 hemispheres which communicate through the corpus collosum
         • Diencephalon contains hypothalamus and thalamus where the hypothalamus regulates body temp, hunger etc
         • Brain stem regulates the autonomic functions such as breathing, heart beat and swallowing
         • Cerebellum monitors motor skills, balance, co-ordination
   • Peripheral Nervous System (relays nerve impulses from CNS to the body and back)
     • Somatic Nervous System
       • - Has 12 pairs of cranial nerves and 31 pairs of spinal nerves. They both have sensory neurons and are involved in reflex actions
     • Autonomic Nervous System
       • Contains the sympathetic branch (hypes up the body) and the parasympathetic brain (brings body back to normal)
       • Sympathetic Branch - helps to deal with flight or fight and releases noradrenaline
       • Parasympathetic Branch - relaxes the body and releases acetylcholine (rest and digest)

2. Neurons and Synaptic Transmission

   • Structure and function of neurons
     • They carry neural information and consist of a cell body, dendrites and an axon.
       • Sensory Neurons carry impulses from sensory receptors TO the CNS
       • Relay Neurons allow sensory and motor neurons to communicate
       • Motor Neurons form synapses with muscles and control contractions
   • Synaptic Transmission
     • Is an electrical impulse (action potential) arrives at end of axon. Crosses synaptic gap and neurotransmitters are released. They bind to receptors and produce excititary or inhibitory effect.
     • Excitatory Neurotransmitters releases noradrenaline and is a positive charge.
     • Inhibitory Neurotransmitters releases serotonin and has a negative charge

3. The Endocrine System

   • A network of glands that manufacture and secrete chemical messengers known as hormones
     • Signals are sent from the hypothalamus to the piuitary gland in the form of a releasing hormone. This causes the pituitary gland to secrete a stimulating hormone into the bloodstream.
       • Too many hormones or too little hormones at one time can result in dsyfunction of bodily systems
   • Adrenal glands
     • Adrenal glands sit on top of the kidneys. It contains the adrenal cortex (outer part) and the adrenal medulla (inner part)
       • Adrenal cortex produces cortisol which controls cardiovascular functions. Adrenal medulla releases adrenaline
   • Pituitary glands
     • Pituitary glands produce hormones whose primary function is to influence the release of hormones to other glands. It is the master gland and is controlled by the hypothalamus
       • Anterior hormones release ACTH as a response to stress and posterior hormones releases oxytocin to help stimulate contractions in childbirth

4. Fight or flight response

   • Homeostasis is the tendency of an organism to maintain an internal equilibrium by adjusting physiological processes
   • Amydgala TO hypothalamus TO autonomic nervous system (sympathetic) TO adrenal medulla - HANSAM
     • Amydgala and Hypothalamus - brain area is mobilised and a distress signal is given to hypothalamus (acute and chronic stressors)
       • Sympathetic Nervous System begins process of preparing body for fight or flight and sends a signal to the adrenal medulla which releases adrenaline and noradrenaline
         • Adrenaline makes the heart beats faster, pushes blood to the muscles and triggers the release of glucose to supply energy
           • Parasympathetic Nervous System dampens down the stress response and slows down processes
   • I; Gray argues that the first phase of a reaction to a threat is not to fight or flee but to avoid confrontation. J; He suggested that many animals show the 'freeze' response before making a response and that this response is essentially 'stop, look and listen'. E; This shows that fight or flight doesn't tell the whole story.
     • I; Research shows that there are some negative consequences of fight or flight. J; The problem arises when the stress response is repeatedly activated, as the blood pressure is induced from the SNS can damage blood vessels. E; This means that it is a problem for modern day life
       • I; Taylor suggested females behaviour response to stress is more characterised by tend and befriend. J; Studies show there may be a physiological response as the release of oxytocin in women increases relaxation and makes them more nurturing. E; This shows there are some gender differences.

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