Lecture 10 - Hormonal Control During Exercise (Fluid and Electrolyte Control) Flashcards
organs/glands that correct fluid imbalances
- > posterior pituitary
- > adrenal cortex
- > kidneys
what happens to plasma levels during exercise, what does this cause
plasma volume decreases, causing…
- > inc. in hydrostatic pressure and tissue osmotic pressure
- > dec. in plasma water content via sweating
- > overall, decreased plasma volume can decrease BP and inc strain on the heart
the posterior pituitary secretes which hormones
antidiuretic hormone (ADH) and oxytocin
- > they are secreted upon neural signal from the hypothalamus, where they are secreted and sent via the nerves to post. pituitary
which hormones from the post pituitary are involved in exercise and what do they do
ADH
- > inc. water resorption at the kidneys
*leads to less water in urine
- > dec blood plasma levels
the adrenal cortex secretes which hormone during exercise
it secretes mineralocorticoids to maintain electrolyte balance
- > a major mineralocorticoid for exercise is aldosterone
effects of aldosterone
- > inc. Na retention by the kidneys which inc. water retention levels (Na follows water), which leads to…
- > inc K excretion
what causes the release of aldosterone
- > dec plasma Na
- > inc plasma K
- > dec. BP or BV
kidneys release ______ in response to ______
renin
- > decrease in BV and/or BP
- > sympathetic NS response
what is renin and ACE
enzyme, its main goal is to convert angiotensinogen to angiotensin 1
- > An1 will be converted into angiotensin 2 in the lungs with the help of angiotensin-converting enzyme (ace)
what does angiotensin 2 do
originally angiotensinogen converted by renin and ACE
- > it stimulates aldosterone release from adrenal cortex for Na and water resorption
how long do the effects of ADH and aldosterone last
- > 12-48hrs after exercise
- > this results in prolonged Na and water retention, increasing osmolarity and a prolonged rehydration state
what brain structure is the main appetite controller?
hypothalamus, sends signals to GI tract
hormones GI tract releases and when
cholecystokinin (CCK)
- > stimulated when stomach is full, suppresses appetite
Glucagon-like peptide 1 (GLP1) and peptide YY (YY)
- > secreted when from large and small intestines during and after eating to suppress hunger
Insulin
- > acts as a satiety hormone
Ghrelin
- > stimulates hunger by crossing the blood brain barrier and acts directly on the hypothalamus, after eating ghrelin levels decrease
leptin
secreted by adipose tissue to suppress hunger (opp effects of ghrelin)
acute vigorous exercise ______ levels of PYY and GLP-1
increases, reducing hunger
- > exercise does not affect ghrelin levels , except for when we are in an energy deficit
