ENDOCRINE SYSTEM

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Created by
Amelie R

Cards (7)

  • Endocrine system
    Information system that communicates with target organs through chemicals called hormones. The endocrine system works slower than the nervous system but has powerful and widespread effects. 
  • Functions of the endocrine system
    • Instructs glands to release hormones into the bloodstream. The hormones are carried towards target organs in the body. 
    • Works alongside the nervous system to control vital functions in the body. 
    • A gland is an organ in the body that synthesises hormones.  
    • Glands produce hormones – chemical substances in the bloodstream that affect target organs  
  • Thyroid gland

    Produces the hormone thyroxine, which affects cells in the heart and increases heart rate. It also affects other cells in the body to increase metabolic rates (chemical processes taking place in the cells). Affects growth rate.
  • Pituitary gland (master gland)

    Controls the release of hormones from all the other endocrine glands in the body. 
  • Adrenal gland

    Produces adrenaline. It is a stress hormone released from the adrenal medulla into the bloodstream. It is a part of the body’s immediate stress response and has a strong effect on the cells of the cardiovascular system such as stimulating heart rate, contracting blood vessels, and dilating air passages. It also prepares our body for fight or flight response.
  • Fight or flight (1-3)
    1. A stressor occurs (car crash, robbery, war) and the hypothalamus triggers the pituitary gland. 
    2. The ANS changes from its resting state (parasympathetic) to the physiologically aroused state (sympathetic). 
    3. The pituitary gland releases adrenocorticotrophic hormone (ACTH). 
  • Fight or flight (4-6)
    1. The ACTH affects the cells in the adrenal glands, causing them to release adrenaline (a hormone produced by the adrenal glands, as part of the stress response). 
    2. Adrenaline causes physiological changes in the body (e.g. increased heart rate and breathing rate, pupils dilate, inhibits digestion) which creates the physiological arousal necessary for the fight or flight response. 
    3. After the fight or flight, the parasympathetic nervous system returns the body to its resting state. This acts as a brake, slowing down activities.