nervous, endocrine & fight or flight response

• What are the two main components of the nervous system?

  The brain and the spinal cord
• What are the two subdivisions of the peripheral nervous system?

  The autonomic nervous system and the somatic nervous system
• What functions does the autonomic nervous system control?

  Involuntary, vital functions of the body, such as heart rates and breathing rates
• What is the function of the somatic nervous system?

  It is responsible for conscious perception and voluntary movement of skeletal muscles
• What are the two branches of the autonomic nervous system?

  The sympathetic and parasympathetic branches
• How do the sympathetic and parasympathetic branches work together?

  They function as an antagonistic pair during the 'rest and digest' response
• What physiological changes does the sympathetic nervous system induce?

  Increases heart rate, breathing rate, causes vasoconstriction, and pupil dilation
• What physiological changes does the parasympathetic nervous system induce?

  Decreases heart rate, breathing rates, causes vasodilation, and pupil constriction
• What is the main function of the endocrine system?

  It serves as the main chemical messenger system of the body
• What is the role of hormones in the endocrine system?


  They are secreted into the bloodstream and transported to target cells
• Why is the pituitary gland referred to as the 'master' gland?

  Because it controls the release of hormones from all other glands in the body
• What hormone does the thyroid release and what is its effect?

  Thyroxine, which increases heart rate and growth rate
• What hormone does the adrenal gland release and what is its role?

  Adrenaline, which creates physiological arousal for the fight or flight response
• What are the steps of the fight or flight response?

  1. Body senses a stressor (e.g., sound of a speeding car)
  2. Information sent to the hypothalamus via sensory neurones
  3. Adrenaline released from adrenal medulla
  4. Physiological changes occur (e.g., increased heart rate)
  5. Once the threat is gone, the hypothalamus triggers the rest and digest response
• What happens to the body when a stressor is detected?

  The hypothalamus coordinates a response and triggers increased activity in the sympathetic branch
• What physiological responses occur due to adrenaline release?

  Rectum contracts, saliva production inhibited, and breathing rate increases
• What is the adaptive purpose of the fight or flight response?

  To enable escape from the stressor and increase the likelihood of survival
• What occurs once the stressor is no longer a threat?

  The hypothalamus triggers less activity in the sympathetic branch and more in the parasympathetic branch
• What is the rest and digest response?

  It is when the parasympathetic branch decreases the activity increased by the sympathetic branch
• what is the role of the PNS 


  caries information to and from the CNS to the body
• function of the autonomic nervous system


  responsible for involuntary actions, such as reflex and organ function