Endocrine System

• Endocrine Glands


  - produce and secrete hormones.

  - pituitary, adrenal glands and reproductive organs.
• Hormones


  - chemicals that circulate in the bloodstream and are carried to target sites throughout the body.

  - timing of hormone release is critical for normal functioning, as are levels of hormones released.

  - either directly cause changes in physiological processes in the body or stimulate other glands to produce other hormones.
• Pituitary Gland


  master gland

  - primary function is to influence the release of hormones from other glands.

  - controlled by the hypothalamus
• Hormones produced in the Pituitary Gland

  - Anterior pituitary produces ACTH - response to stress.

  - ACTH stimulates the adrenal glands to produce cortisol.

  LH and FSH - anterior pituitary

  - Posterior pituitary releases oxytocin - stimulates contraction of the uterus in childbirth, important for mother-infant bonding.
• Adrenal Gland


  - sit on top of the kidneys.

  - adrenal cortex - releases hormones necessary for life.

  - adrenal medulla - releases hormones that aren't.
• Hormones produced by the adrenal gland

  adrenal cortex produces cortisol

  - functions such as cardiovascular and anti-inflammatory functions.

  - if cortisol levels are low, the individual has low blood pressure, poor immune function and inability to deal with stress.

  - produces aldosterone - maintains blood volume and pressure.

  adrenal medulla releases adrenaline and noradrenaline

  - hormones prepare body for fight or flight response.

  - increases heart rate and blood flow to muscles and brain.

  - noradrenaline constricts the blood vessels, causing blood pressure to increase.
• Ovaries


  - responsible for the production of eggs and hormones oestrogen and progesterone.

  - progesterone is important in post-ovulation phase of menstrual cycle.
• Testes


  - produce testosterone

  - development of male characteristics - growth of facial hair, deepening of voice, growth spurts.

  - controlled by hypothalamus and pituitary gland.

  - plays a role in sex drive, sperm production, maintenance of muscle strength.