Urinary System Flashcards
What is in the urinary system involved in regulating?
The composition od the blood by removing wastes, the volume of blood by removing or retaining water, the pH of the blood by removing H+ ions and blood pressure.
What does the mammalian urinary system consist of?
Left and right kidneys, left and right ureters, bladder, urethra, renal arteries and veins.
What do kidneys do?
They carry out the work of the urinary system, including excretion of wastes from the blood. They also regulate blood volume, blood pressure and release hormones.
What are the glands that sit on each kidney called?
Adrenal glands.
What are the tubes that connect the kidneys to the bladder called?
Ureters.
What is the tube that excretes urine from the bladder called?
Urethra.
What is the muscle that holds the urethra shut?
The sphincter muscle.
What are nephrons?
Microscopic units that filter blood and remove wastes from it. The fluid excreted by the kidneys is called urine. They are 3cm long, one end is closed and the other opens into a collecting duct. The closed end forms the nephron capsule. The rest of the tubule is coiled and closely associated with the blood capillary network.
What is the outer capsule of the kidney called?
Renal capsule.
What is the inner centre of the kidney called?
Renal pelvis.
What is the outer layer inside the kidney called?
Cortex.
What are the petal-shaped bits in the internal centre of the kidney called?
Medulla.
How is urine produced?
Filtration under pressure in nephron capsule, selective reabsorption in tubules, active secretion into tubules.
How do nephrons work?
Blood is brought to the nephron capsule for filtration. Filtrate is formed which moves along the tubule. Much of the water and other useful substaces in the filtrate are reabsorbed back into the blood capillary network. Certain ions and toxins may be actively secreted from the blood into the filtrate. The filtrate is gradually transformed into urine as it moves along the tubule.
What substances are filtered from the blood into the nephron capsule?
Water, glucose, amino acids, urea, uric acid, ions.