B3 Urinary System Structure And Functions Flashcards
The renal vein function
Carries blood from the kidney
Urethra function is
Carrie urine out of the bladder
Bladder function
Stores urine
Ureter function
Carries urine from the kidney to the bladder
Renal artery functions
Supplies blood to the kidney
Kidney function
Performs excretion and osmoregulation
Nephron function
Microscopic filtration unit
What does the kidney have
Have two distinct and outer cortex and an inner medulla
Where is blood brought to by the kidney
From the renal artery and then it’s taken away from the kidney by the renal vein. Inside it then divides into smaller blood vessels called arteriolar
Inside of the kidney function
Lie the functioning units called the nephrons which is part of each is in the cortex and part in the medulla
Nephrons structure step by step
- Begins with a group of convoluted blood capillaries called the glomerulus
- Glomerulus is surrounded by a cup shaped structure called bowman’s capsule
- Bowman’s capsule leads a longer part of the nephrons the proximal convoluted tubule
- PCT Leeds into the hairpin shaped structure called loop of henle
- Loop of henle leads the distal convoluted tubule
- DCT finally leads into the collecting duct
Function of the urinary system
Consists of kidney, ureters, bladders and urthera
1. Urinary bladder is hollow muscular organs that collects urine from kidney before disposal by urination. The urine enters bladder through the ureter and urine leaves bladder by urethra
2. Two types of blood vessels attached to kidney. Renal arteries which deliver an oxygen rich blood supply to the cells in each kidney once blood has processed here it leaves the kidney through renal veins
3. Transport Into inferior vena cava back to the heart
Main organs of excretory system functions
- Excretion - removal from the body of toxic waste made in cells during metabolism
- Osmoregulation - homeostatic control of water by adjusting concentration of the cells and body fluids. Ensures that cells don’t burst or shrink which would affect metabolism
Kidney producers urine in two stages
- Small molecules and ions are filtered out of the blood into glomerulus and into the bowman’s capsule = ultrafiltration
- Any ions and molecules that are required by the body are taken back from the nephrons and moved back into the blood and process called selective reabsorption example glucose
Formation of glomerulus filtrate
- Done by ultrafiltration similar process used to force tissue fluid out of capillaries
- Blood enters kidney through renal artery which branches into millions tiny arterioles each which enter the renal bowman capsule
- Afferent arteriole that enters the capsule is wider in diameter than efferent arteriole that exist. Causes high hydrostatic pressure in capillaries within capsule. These capillaries are known as glomerulus
- Tissues fluid is formed the higher than normal hydrostatic pressure the glomerulus leads to water, glucose, urea and mineral ions being forced out of fenestration (pores) in the capillaries to form glomerular filtrate
- Blood cells and large plasma proteins cannot pass through the small hole and remains in the capillaries
- Filtrates can pass out of the glomerulus due to the holes in the capillaries through the connective tissue and through the spaces between branches of podocytes. The filtrates than moves into PCT where nearly 85% of it is reabsorbed back into blood
- Ultrafiltration is not specific and only filters by size a lot of useful molecules are filtered out that we don’t want to waste such as glucose. Then they’re reabsorbed and waste such as urea , excess water and excess ions are removed