Anatomy and Physiology: The Kidneys Flashcards
Kidney Functions
- Regulating water and electrolyte balance
- Maintains acid:base homeostasis
- Retains glucose and protein
- Excretes wastes and toxins
- Endocrine functions - secrete hormones
Define
Acid
Relative to Kidneys
Releases hydrogen ions
* pH <7
Define
Base
Relative to Kidneys
Accepts hydrogen ions
* pH >7
Define
Nephron
Functional unit of kidney
* made up of glomerulus and its tubules
Glomerulus
Part of the nephron (kidney)
* surrounded by Bowman’s capsule
* filtration through capillaries
GFR
Glomerular Filtration Rate
* driven by hydrostatic pressure from arterial pressure
* best indicator of true kidney function
Kidney Tubule
Sectioned into
* proximal tubule
* loop of Henle
* distal tubule
* collecting ducts
Proximal Tubule
Part of nephron (kidney)
* resorbs all glucose and amino acids
* resorbs most bicarbonate, phosphate, and water
Loop of Henle
Part of the nephron (kidney)
* responsible for urine concentration
* resorbes sodium and chloride
Renin
Secreted by the kidney
* regulates blood pressure
* increases angiotensin II production
Angiotensin II
Released when intravascular volume drops; causes
* aldosterone release
* increased release of ADH
* increased thirst
* constriction of efferent arteriole (maintain GFR)
Aldosterone
Stimulates sodium and water resorption in DT and collecting ducts
* function of kidney
* released from adrenal cortex when sodium is low
Sodium Exchange in Kidneys
Occurs in the distal tubules and collecting ducts
* sodium exchanges for potassium and hydrogen
* low sodium = alkalosis
ADH
Antidiuretic Hormone
* function of kidney
* stimulates water reabsorption - DT and collecting ducts more permeable to water
* more water = more concentration
* posterior pituitary gland secretes when osmotic pressure rises
Vitamin D
Produced by the kidneys
* can also be called calcitriol
* promotes calcium absorption from intestine
