Chapter 14 Flashcards
Describe the Endocrine system
Maintains homeostasis
glands that secrete hormones
Hormones travel through bloodstream to affect functioning of target cells
Describe the term hormone
Hormones are steroid or steroid like substances made from cholesterol or non steroidal.
Include: amines, glycoproteins, peptides, proteins made from AAs
What do steroid hormones do
Enter target cells and bind receptors forming complexes in nuclei
What do non steroid hormones do
Bind receptors in target cell membranes
Describe the site of production and action of oxytocin
Site:
posterior pituitary gland/hypothalamus
Action:
contracts uterine wall muscles
Contracts milk secreting gland muscles
Sexual behaviours
Describe the site of production and action of adrenaline
Site:
Medulla in adrenal glands
Action:
Increases heart rate and force of contraction
Dilates skeletal muscle vessels decreasing blood flow resistance
Systemic blood pressure increases somewhat cos of increased cardiac output
Dilates airways
Activates reticular brain formation
Promotes Glycogen to glucose breakdown. Increases BM concentration
Increases metabolic rate
Describe the production sites and actions of noradrenaline
Site:
Medulla in adrenal glands
Actions:
Same (increases rate and force of contraction)
Increases skeletal muscle blood flow because of constriction of blood vessels in skin and viscera
Increases systemic blood pressure greatly because of vasoconstriction
Dilates airways greatly
Has little effect on reticular brain formation
Same (increases metabolic rate)
What is the site of production and action of insulin
Site:
Pancreas. Beta cells secrete insulin
Action:
Decreases bm concentration
Promotes AA transport to cells
Increases protein synthesis
Stimulates adipose cells to make and store fat
Stimulates liver to form Glycogen from glucose
Describe the production site and action of glucagon
Site:
Pancreas
Alpha cells
Action:
Stimulates liver to breakdown Glycogen by Glycogenolysis to non carbs (AAs) into glucose (gluconeogenesis) increasing bm levels
What are the production sites and actions of aldosterone
Site:
Adrenal cortex
Action: regulates extra cellular electrolyte concentrations by conserving sodium and excreting potassium
Potassium channels = potassium leaves cell and excreted out via urine
Sodium channels = sodium enters cell and blood from urine.
Gains water. = increases BP
What are the production sites and actions of angiotensin
Site:
Liver
Action:
Stimulates cells of glomerulosa to release aldosterone to increase BP
When hypotension happens kidneys restore bp to normal.
Renin converts angiotensinogen to angiotensin 1.
Angiotensin converting enzyme in lungs acts on angiotensin 1 converting it to angiotensin 2which is a vasoconstrictor causing increase in BP
What are the production sites and actions of ANP
Atrial natriuretic peptide
Site: heart atria
Action: stimulates urinary sodium excretion
ANP Secreted in response to blood volume
Causes decrease in sodium reabsorption in kidneys
Causes vasodilation and decrease in BP
What is the production site and action of ADH
Anti diuretic hormone
Site:
Posterior pituitary gland
Action: regulates water concentration of body fluids by reducing water excretion by kidneys
