renal system Flashcards
role of the kidneys
- regulation of extracellular fluid volume and blood pressure
- regulation of osmolarity (290)
- maintenance of ion balance
- regulation of acid base balance
- exertion of metabolic waste products and foreign chemical
-secretion, metabolism, and exertion of hormones
solutes are filtered from the blood into Bowmans capsule
glomerulus
process of filtration
- filtration
- reabsorption
- secretion
-excretion
excretion =
filtration - reabsorption + secretion
purpose of these regulation processes?
needs of the boy to maintain homeostasis
Ions the kidneys are balancing
- water and sodium
- potassium
- calcium
- H+ and HCO3-
importance of water and sodium
maintains ECF and volume
- important for osmolarity
potassium
-important for maintain membrane potential of excitable cells
- disruption: arrhythmias, muscle dysfunction
Calcium
- important for muscle contraction
- bone formation
- blood clotting
H+ and HCO3-
important for maintaining pH
excess fluid volume is exerted by the kidneys known as
diuresis
nephron reabsorb solute without
reabsorbing water
lost fluid volume cannot be replaced by the kidneys; they can only conserve it. therefore nephrons job is to
reabsorb water without the reabsorbing solute
ADH is stimulated by
increase in ECF osmolarity or a fall in blood pressure
- posterior pituitar
- controls the collecting duct permeability to water via insertion of aquaporins
ADH acts on the
collecting duct
ADH increases
BP
the total amount of sodium in the body is a primary determinant of
ECF
how long does it take kidneys to adapt
2 to 3 days
major hormone that regulates sodium is
aldosterone from the adrenal cortex
purpose of aldosterone
increases sodium reabsorption
- released form adrenal cortex
- works on the cells of the distal connoted tubule and collecting duct
- increase osmolarity of the blood
RAAS stands for
renin angiotensin aldosteron system
renin is a protein enzyme that is
synthesized and stored in an inactive form in the juxtaglomerular cells
what’s store in the JG cells
renin
what happens to JG cells when pressure release?
release renin
where is macula dense?
distal convoluted tubule
macula dense measures
sodium chloride
incread of sodium chloride results
the release of renin from the macula dense
effects of rennin release
- vasoconstriction
- ADH increase
- Thirst increase
-Aldosterone level increase
atrial natriuretic peptide ANP
- synthesized by special atrial cells
-released in response to atrial stretch due to increased blood volume - increases salt and water excretion by suppression renin, aldosterone, and ADH hormones
brain natriuretic peptide BNP
- synthesized by special myocardial ventricular cells and brain neurons
- released in response to increased ventricular pressure and stretch
- used as a biological marker for heart failure
when HCO3- is lost from the body, its is the same as if the body
gained a H+
the kidney eliminate or replenish H+ by
altering plasma HCO3+ concentration
