2. The endocrine system

Cards (13)

  • Glands
    An organ in the body that synthesises hormones and secretes them
  • Thyroid gland
    • Neck, secretes thyroxine, controls the rate of metabolic reactions and increases heart rate
  • Adrenal gland
    • On top of each kidney, secretes adrenaline, responsible for our fight or flight responses
  • Testes
    • Scrotum, secretes testosterone in men, allows for male development - growing body hair, deepening of voice and maturation of muscles
  • Pituitary gland
    • Brain, 'master gland', controls the release of hormones from all other endocrine glands in the body
  • Fight or flight response

    The body's way of preparing. Becoming ready to fight an aggressor or flee
  • Adrenaline
    Released by adrenal glands and a part of the body's immediate stress response
  • What happens after the fight or flight response?
    • Once threat has passed, parasympathetic nervous system returns the body to normal resting state
  • Parasympathetic and sympathetic nervous systems
    Work in opposite - antagonistic
  • The endocrine system
    • One of the body's major information systems
    • Works alongside the nervous system to control vital function in the body. 
    • Instructs glands to release hormones directly into the bloodstream  
    • Hormones carried toward target organs in the body
    • Communication is via chemicals
  • Hormones
    • Chemical substances that circulate through the bloodstream and only affect target cells 
    • Produced in large quantities but disappear quickly AND Effects are very powerful  
  • Psychological changes triggered by adrenaline
    • Dilates pupils - focus on stressful situation  
    • Diverts blood to muscles - they increase blood flow and allow for muscle contraction   
    • High blood-glucose level 
    • Increase blood pressure  
    • Increased heart rate 
  • Process of fight or flight response
    1. Works with the autonomic nervous system - ANS 
    2. Stressor perceived  
    3. Hypothalamus triggers activity in the sympathetic part of the ANS 
    4. ANS changes from normal resting state to aroused state  
    5. Stress hormone - adrenaline released from adrenal medulla (part of the adrenal gland) into blood stream 
    6. Triggers psychological changes   
    7. Happens in an instant - acute response