Intro to Kidney Flashcards
What does the kidney do?
-REGULATION of water and electrolyte balance (input = output) and blood pressure -EXCRETION of metabolic wastes, bioactive substances -MAKES red blood cells, vitamin D
How do kidneys respond to us VARYING how much water and electrolytes we take in?
kidneys respond by VARYING the amount of WATER CONTENT in MINERALS in the URINE we put out of our body- this is HOW kidneys maintain HOMEOSTASIS!
Why do our kidneys excrete metabolic waste?
Our bodies continuously form metabolic waste. Not all products of metabolism are useful (=NONFUNCTIONAL) or good for us. Some end products don’t serve a useful function and in HIGH CONCENTRATIONs, they are even HARMFUL.
What are some examples of metabolic waste our kidneys excrete?
Urea (from proteins) Uric Acid (from nucleic acids) Creatinine (from Muscle creatine) Hb breakdown products Metabolites of various hormones (from endocrine system
What are examples of bioactive substances our kidneys excrete?
drugs (actively AND passively excreted), hormones (removed in parallel from the blood by kidneys too)
What does blood pressure ultimately depend on?
Blood volume
How do Kidneys regulate blood volume?
by maintaining sodium and water balance to regulate blood volume AND releasing VASOACTIVE substances to actively REGULATE SMOOTH MUSCLE in peripheral blood vessels
How do the kidneys regulate red blood cell production? And, how is secretion regulated?
by: 1. releasing erythropoietin (EPO) AND 2.controlling red blood cell production in bone marrow *Partial pressure of oxygen in the kidneys regulates how much EPO it makes and releases
What’s the pathway by which sunlight on skin is turned into a substance that the kidney makes to maintain calcium balance in body? And the pathway for dietary intake?
7-Dehydrocholesterol pathway: Sunlight on skin produces 7-Dehydrocholesterol into Cholecalciferol (vitamin D3) goes into LIVER to produce 25-hydroxyvitamin D3 goes into KIDNEY to make 1,25 DiHydroxyvitamin D3 Dietary intake: eat fish, meat (vitamin D3), supplements (D2) goes to LIVER which turns it into 25,hydroxyvitamin D3 which the KIDNEY turns into 1,25 dihyrdoxyvitamin D3
What substance does the Kidney make from Vitamin D precursors or vitamin D from our diet to maintain calcium balance in the body?
1,25-dihydroxyvitamin D3
The CNS can only use _______ for energy!
glucose!
When we don’t eat carbs, how does our body make new glucose? How does this help with maintaining acid-base homeostasis?
kidneys make glucose from non-carb sources so from amino acids and glycerol!
When we don’t eat carbs, how does our body make new glucose? How does this help with maintaining acid-base homeostasis?
kidneys make glucose from non-carb sources so from amino acids (ammonioagenesis) and glycerol! key pt: Kidney ammonioagenesis is critical to maintaining acid-base homeostasis!
What is the renal corpuscle?
It’s a compact bunch of interconnected capillary loops, surrounded by a hollow capsule. It includes bowman’s capsule and the glomerulus. Arterioles carry blood to Bowman’s capsule. There’s a fluid filled space within Bowman’s capsule that filters blood!
Where does most reabsorption happen in the nephron?
in Proximal Tubule! The proximal tubule is made of 2 segments: 1. proximal CONVOLUTED and 2. proximal STRAIGHT tubule
What’s the pathway by which the Kidneys filter blood? PUTTING THINGS TOGETHER
things go into Bowman’s capsule, are drained from there into proximal tubule
What is the area between the Loop of Henle and the Distal Tubule called?
Macula Densa
What creates and maintains an osmotic gradient in the medulla?
Loop of Henle