Unit 4 - Kidneys Flashcards
How is the human body continuously challenged in its attempt to maintain homeostasis?
Metabolic processes require fuel
- produces chemical waste
What parameters of the body need to be carefully regulated in order for processes to function effectively?
pH of the body’s blood and other fluids
What needs to be carefully controlled in the body?
Water
Key electrolytes
What is the water permeability of the glomerulus, proximal convoluted tubule and thick descending limb of Henle’s loop?
High to extremely high
What is the function of the kidneys ?
Kidneys clear our waste products by passing fluid through a filter - glomerulus
Filtered fluid reclaimed by the portion of the nephron known as the renal tubule
Electrolytes, minerals and other critical particles are reabsorbed while leaving waste and excess fluid for excretion
Kidney has the ability to determine water and electrolyte balance while simultaneously removing body’s waste.
Hormones from brain, heart, adrenal gland and other organs which constantly monitor internal state of body regulate this process.
Has to account example for days when we ingest or lose large amounts of water.
What is the water permeability of the thick ascending limb of Henle’s loop, and distal convoluted tubule?
Very low
What is the function and permeability of the glomerulus?
Function - formation of glomerular filtrate
Water Permeability - Extremely high
What is the function and permeability of the proximal convoluted tubule ?
Reabsorbtion of 65% of filtered Na+/K+/Ca2+ and Mg2+; 85% of NaHCO3, and nearly 100% of glucose and amino acids. Isosmotic reabsorption of water.
Water permeability - Very high
What is the function and permeability of the Proximal tubule, straight segments?
Secretion and reabsorption of organic acids and bases, including uric acid and most diuretics
Permeability - very high
What is the function and permeability of the thin descending limb of Henle’s Loop ?
Passive reabsorption of water
Permeability - High
What is the function and permeability of the thick ascending limb of Henle’s loop ?
Active reabsorption of 15-25% of filtered Na+/K+/Cl-; secondary reabsorption of Ca2+ and MG2+
Permeability - Very low
What is the function and permeability of the Distal convoluted tubule ?
Active reabsorption of 4-8% of filtered Na+ and Cl-; Ca2+ reabsorption under parathyroid hormone control
Permeability - Very low
What is the function and permeability of the Cortical collecting tubule ?
Na+ reabsorption (2-5%) coupled to K+ and H+ secretion
Water permeability - Variable
What is the function and permeability of the medullary collecting duct?
Water reabsorption under vasopressin control
Water permeability - Variable
What are the three major compartments for water in the body?
Intracellular space (66%) - inside cells Intravascular space (11%) - inside blood vessels Interstitial space (22%) - tissue fluid