Endocrine system

• Endocrine:

  Ductless – bloodstream

  Hormones e.g. insulin, adrenaline, cortisol
• Exocrine;

  Ducts – target specific area close by

  Mucus, digestive juices, sweat, tears, milk, bile
• Paracrine – targets neighbouring cell
• Autocrine – targets itself
• oxytocin from pituitary
• The pancreas and the adrenal glands are endocrine glands – they make a hormone which is released into the bloodstream
• Neuroendocrine is a neuron releasing a hormone into the blood (not the synaptic space)
• Types of hormones:

  Peptides, amines, steroids
• The hypothalamic-hypophyseal portal is important because it forms a “private link” between the hypothalamus and the anterior pituitary – more targeted control (hormones don’t have to travel around the entire body before they get to the anterior pituitary, more concentrated, quicker.
• Posterior Pituitary: Two distinct populations of neurons: supraoptic nucleus and paraventricular nucleus
• Posterior Pituitary:

  • antidiuretic hormone
  • Oxytocin
  • produced by cells in the hypothalamus
  • stored in terminals in the posterior pituitary
• •The posterior pituitary secretes vasopressin

  •The hypothalamic-hypophyseal portal is between the hypothalamus and the anterior pituitary

  •Prolactin and growth hormone are released from the anterior pituitary
• The axons of the neurosecretory neurons that produce the hypothalamic regulatory hormones terminate on the capillaries at the origin of the portal system.​
• ​Some endocrine control systems include both feedback control (which maintains a constant basal level of the hormone) and neuroendocrine reflexes (which cause sudden bursts in secretion in response to a sudden increased need for the hormone).
• How many body systems contribute to homeostasis?​

  11
• ​Where do hydrophilic peptide hormones dissolve?

  The blood
• What are the three actions that the body’s control system must perform in order to maintain homeostasis?

  ​Detect change, integrate information, and make appropriate adjustments.
• From what are catecholamines derived?​

  Tyrosine