Renal physiology Flashcards
What is the major function of the Kidney?
To maintain homeostasis for a large number of solutes and water
How is homeostasis maintained?
Through the kidney by changing its rate of excretion
What is the key solute in renal physiology?
Sodium (Na+)
In what fluid compartment is Na restricted to?
Sodium is restricted to the extracellular space.
What electrolyte determines the (ECFV) extracellular fluid volume
Total body sodium
What does ECFV determine?
Blood Pressure and Blood Volume
Since Na+ determines osmolality what does that influence?
Total body water
What is Vasopressin?
Peptide hormone that stimulates water reabsorption in principal cells of collecting ducts and constriction of arterioles
How does Vasopressin work?
Vasopressin regulates the body’s retention of water by acting to increase water absorption in the collecting ducts of the kidney nephron. Vasopressin increases water permeability of the kidney’s collecting duct and distal convoluted tubule by inducing translocation of aquaporin-CD water channels in the kidney nephron collecting duct plasma membrane.
Which is the major intracellular cation?
Potassium K+
What is the major extracellular anion?
Cl-
Which organ regulates the total body content of Cl-
Kidney
What is the other major extracellular anion?
Bicarbonate HCO3−
What is the percentage of Body water in humans?
Males:60% Females:50%
What is the major ECFV buffer?
Bicarbonate
What is the key factor in Acid-Base balance?
Bicarbonate
What is the normal body pH?
7.40
What are some of the waste materials that the kidney excretes?
- Urea (by-product of protein metabolism)
- Creatinine
- Uric acid
What glycoprotein produced by the kidney is responsible for rbc production?
Erythropoietin
In terms of anemia what what kind of anemia would reduced kidney function be associated with?
- Low reticulocyte count
2. Normocytic normochromic anemia
What is the major source of 1-alpha hydroxylase
Kidney
What are the minor sources of 1-alpha hydroxylase?
Skin (kerationocytes) Bone (osteoblasts) and immune cells
What is the function of 1-alpha hydroxylase?
1-alpha hydroxylase is located in the proximal tubule of the kidney and a variety of other tissues, including skin, immune cells, and bone. The enzyme catalyzes the hydroxylation of calcidiol to calcitriol which is the bioactive form of Vitamin D
Would reduced kidney function result in reduced 1-alpha hydroxylase as well as reduced Vitamin D?
Yes.
What is the Chief source of Renin in the body?
Kidney
What is Renin?
proteolytic enzyme produced by granular cells in the kidney that catalyzes the formation of angiotensin I from angiotensinogen
Where is renin produced?
Juxtaglomerular apparatus by specialized cells
granular cells
What is Bradykinin?
nonapeptide hormone that causes a slowly developing contraction of intestinal smooth muscle, vasodilation, and increased renal sodium excretion