The Renal System Flashcards
What are the functions of the kidneys?
To maintain homeostasis through elimination, secretion and regulation.
What is a nephron?
The functional unit of the kidney. It is a tubule that is closed at one end and opens into the collecting duct at the other.
Name the 5 distinct regions of the nephron.
Bowman's Capsule (Juxtaglomerular Apparatus and Glomerulus) Proximal Convoluted Tubule Loop of Henle Distal Convoluted Tubule Collecting Duct
What is the Juxtaglomerular Apparatus?
A microscopic structure that regulates the function of each nephron and the secretion of renin.
What is Filtration?
A form of passive transport. The passage through semi permeable walls of glomerulus from an area of high pressure to low pressure.
How much dilute filtrate do the kidneys form each day?
180 Litres. Most of which is reabsorbed, so urine volume per day is between 1 and 1.5 Litres.
What is Diffusion?
When ions or molecules move from an area of higher concentration to an area of lower concentration.
What is Osmosis?
The movement of fluid through a semi-permeable membrane from a solution with low solute concentration to a higher solute concentration.
What is Active Transport?
The movement of dissolved molecules into or out of a cell though the cell membrane from a region of lower concentration to a region of higher concentration. This requires energy.
What is Selective Reabsorption?
The process whereby certain molecules, after being filtered out of the capillaries are reabsorbed from the filtrate as they pass through the nephron. Takes place in Proximal Convoluted Tubule and Loop of Henle.
What is Secretion?
A process by which substances are produced and discharged from a cell, gland, or organ for a particular function in the organism or for excretion. Takes place in the Distal Convoluted Tubule.
Which hormones do the kidneys secrete?
Erythropoietin and Renin
What is the role of Renin in the body?
It is secreted by Juxtaglomerular Apparatus in response to a decrease in BP. It stimulates production of Angiotensin 1 which is then converted to Angiotensin 2 in the lungs which causes vasoconstriction, rising BP.
What is the role of Erythropoietin?
It stimulates RBC production in the bone marrow.
What is the trigone of the bladder?
A smooth triangular region of the internal urinary bladder formed by the 2 ureteral orifices and the internal urethral orifice. It is in the base of the bladder.
