biopsychology

• the human nervous system

  central and peripheral nervous system
• central nervous system role

  controls most functions of the body and mind passing messages to and from the brain connecting nerves to PNS
• what is the central nervous system made up of

  brain and spinal cord
• brain function


  centre of all conscious awareness 

  outer layer is cerebral cortex which is highly developed and what makes humans of higher mental function 

  • divided into 2 hemispheres (psychological and physiological)
• spinal cord function

  an extension of the brain responsible for reflex actions 

  • transmits info to and from the brain
• peripheral nervous system function


  collects, processes and responds to information and co-ordinates working different organs and cells 

  • transmits messages via neurons to and from CNS
• peripheral nervous system made up of

  somatic nervous system and autonomic nervous system
• autonomic nervous system


  governs vital functions to the body 

  • breathing 
  • heart rate 
  • sexual arousal 
  • stress response 
  • digestion
• what is the autonomic nervous system made up of

  sympathetic and parasympathetic nervous system
• sympathetic nervous system

  the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations
• parasympathetic nervous system

  the division of the autonomic nervous system that calms the body, conserving its energy
• somatic nervous system


  controls muscle movement receiving info from sensory receptors 

  transmits info from receptor cells in sense organs 

  • connect brain with environment
• preparation for fight or flight

  • the situation is appraised and perceived as scary/stressful
  • the hypothalamus alerted. it recognizes the stress is a cue so activates the sympathetic branch of the ANS
  • this stimulates the adrenal medulla which is part of the adrenal gland (above the kidney)
  • the adrenal medulla secretes the hormone adrenaline and indirectly the neurotransmitter noradrenaline into the bloodstream
  • this prepares the body for fight or flight causing several physiological changes
• physiological changes when fight or flight is activated + why

  • heart rate (O2 to muscles increased blood flow)
  • pupils dilated (more aware of surroundings) 
  • increased blood pressure (blood moves out of the digestion system)
  • vasoconstriction (sweaty hands keeping the body cool)
  • increased breathing rate (increase O2 around the body)
  • nausea (distribution of blood)

  these changes allow more O2 to the muscles to allow them to work better or allow more O2 to the brain allowing for quicker thinking and problem-solving
• why flight or fight cannot be maintained

  however, the body cannot maintain this increased stress level of activity for long periods of time as it takes too much energy. so after a few minutes the parasympathetic branch of the nervous system is activated. this is antagonistic to the sympathetic nervous system and acts as a brake response. it serves to return the body back to its natural state reducing heart rate, respiration rate and activity in the digestion system
• the endocrine system


  the endocrine system works alongside the nervous system to control vital functions in the body. glands are organs in the body which produce hormones which are secreted into the bloodstream and affect any cell that has a receptor for that hormone. the pituitary gland is known as the master gland as it controls the release of hormones from all other glands
• pineal gland (hormone released, need and explanation)

  • melatonin 
  • metabolism 
  • regulates sleep/wake cycle
• pituitary gland (hormone released, need and explanation)

  • FSH+LH
  • metabolism+reproduction
  • allows the growth and release of eggs in females
• thyroid gland (hormone released, need and explanation)

  • thyroxine
  • metabolism
  • regulates weight loss/gain
• thymus gland (hormone released, need and explanation)

  • thymosin
  • metabolism
  • T cells (immune system)
• adrenal gland (hormone released, need and explanation)

  • adrenaline
  • metabolism
  • increases+regulates of visceral function
• pancreas gland (hormone released, need and explanation)

  • insulin
  • metabolism
  • regulation of blood glucose levels
• ovaries

  • oestrogen 
  • reproduction
  • regulates menstrual cycle
• testes

  • testosterone
  • reproduction
  • development of male characteristics
• neurons

  Individual cells in the nervous system receive, integrate, and transmit information.
• dendrites


  a short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body
• myelin sheaths

  cover the axon and work like insulation to help keep electrical signals inside the cell, which allows them to move more quickly
• axon terminal

  the ending of one neuron is separated from the next neuron by a small gap called a synapse (electrical impulse)
• nucleus

  contains the cell DNA
• axon


  a long thread-like part of a nerve cell along which impulses are conducted from the cell body to other cells
• schwann cells

  the cells which produce myelin sheath
• nodes of ranvier


  these speed up the transmission of the impulse by forcing it to jump across gaps in the axon
• cell body


  the main part of the neuron in which the dendrites branch off from
• sensory neuron

  carry messages from PNS (receptors) to CNS. leading to sensations such as vision, touch, hearing and taste
• relay neuron


  these connect the sensory neurons which receive the sensory input to the motor neurons which leads to a movement output
• motor neuron


  connect CNS to effectors such as muscles and glands when stimulated they release neurotransmitters that bind to receptors on muscles which trigger movement
• What is synaptic transmission?


  The process by which one neuron communicates with another
• How is information passed down the axon of a neuron?

  As an electrical impulse known as action potential
• What happens when the action potential reaches the end of the axon?

  It needs to be transferred to another neuron or tissue
• What must the action potential cross to communicate with another neuron?

  The synaptic cleft