Lecture 9 - Exercise, Fluid balance and Renal Disease Flashcards
What is the function of water in the body?
Transport medium for most body nutrients & gases
• Moistens surfaces for nutrient transfer
• Medium for most waste elimination
• Lubricates joints (water & proteins)
• Gives structure & form to most body structures
• Provides cushioning for many body structures
• Contributes to maintenance of body temperature
Define Dehydration and Rehydration
Dehydration: Process of losing body water, Rehydration: Process of regaining body water to a euhydrated (optimal) state
What %age of water come from fluids, foods and through metabolism?
Flu: 50-60%, Food: 30-40%, Met: 10-15%
What kinds of food contain the most fluid?
Fruit & veg
How do we lose water
Urine: 50-60%, Faces: 5%, Sweat: 5%, Insensible losses from skin and lunges: 30-45%
How many more mL might we lose in hot climates?
NET 3750mL (thru insensible loss)
What infuences body fluid?
Osmolality of fluids via electrolytes (mostly Na+)
What does body fluid mainly affect?
Electrolyte balance, blood volume, arterial blood pressure, cardiac output/blood flow
What is the role of the renal system?
• Formation and excretion of urine
• Regulate blood volume and blood pressure
• Regulate electrolytes
• Stabilize blood pH
• Conserve nutrients
• Excrete waste
• Detoxify poisons
Regulation of body fluids and electrolytes are regulated by which receptors in which parts of the brain?
Osmoreceptors (hypoth.), arterial baroreceptors (mechanoreceptors of the heart), thirst centre/axis (hypoth.)
Name 4 hormones and modulators of the renal axis secreted or controlled by the brain/pituitary
ADH, Aldosterone, ACE, ANP
ADH: a) origin/endocrine gland, b) target tissue, c) mechanism of action, d) stimulators & inhibitors, e) effects or clinical significance
a) post. pituitary, b) collecting duct, c) ADH acts on the collecting duct to increase water reabsorbsion, d) S- osmolreceptors, atrial baroreceptors, thirst centre, angiotensin II. I- ANP , e) inc. water reabsorbsion, decrease urine output, increase atriolar constriction
Angiotensin II: a) origin/endocrine gland, b) target tissue, c) mechanism of action, d) stimulators & inhibitors, e) effects or clinical significance
a) precursor: angiotensin which originates from the liver, b) blood vessels, arenals, kidneys, brain, c) A-II causes vasoconstriction (BV), secrets aldosterone (Adr), enchances sodium reabsorbsion (Kid), acts on the thirst centre (Bra), d) S- mainly renin via the RAAS. I- -ve feedback, ANP, inc. BP and BV, ACE inhibitors, e) increase thirst, vasoconstriction, increases ADH release, increase aldosterone release
Aldosterone: a) origin/endocrine gland, b) target tissue, c) mechanism of action, d) stimulators & inhibitors, e) effects or clinical significance
a) adrenals, b) kidneys c) promotes Na2+ reabsorbsion d) S- mainly renin via the RAAS, hyperkalemia, hypoatremia, I-ANP, increase BP, cortisol
Renin: a) origin/endocrine gland, b) target tissue, c) mechanism of action, d) stimulators & inhibitors, e) effects or clinical significance
a) kidneys, b) angiotensin c) catalyses the conversion of angiotensin to angiotensin-I d) S- decreased BP, stress (SNS), reduced NaCl infiltrate, I- Angiotensin-II, increased BP an BV
ANP: a) origin/endocrine gland, b) target tissue, c) mechanism of action, d) stimulators & inhibitors, e) effects or clinical significance
a) heart b) kidneys, adrenal glands, and blood vessels, c) promote inhibition of sodium and water reabsorption in the kidneys, d) S- increased atrial pressure and volume expansion, I- SNS activation and angiotensin II, e) vasodilation, reduction in blood volume, and blood pressure regulation, as well as antagonism of the renin-angiotensin-aldosterone system.