Flashcards in Excretion Deck (39):
Removal of metabolic waste from the body.
It consists of waste substances that may be toxic or are produced in excess by the reactions inside cells.
The removal of the amine group from an amino acid to produce ammonia.
Hepatic portal vein
Blood vessel that has capillaries at both ends- it carries blood from the digestive system to the liver.
Cells that breakdown and recycle old red blood cells.
Waste product from the breakdown of haemoglobin.
Excretory product formed from the breakdown of excess amino acids.
The process in which ammonia is converted to urea. it occurs partly in the cytosol and partly in mitochondria, as ATP is used.
The conversion of toxic molecules to less toxic or non-toxic molecules.
Functional unit of the kidney. A microscopic tubule that receives fluid from the blood capillaries in the cortex and converts this to urine, which drains in the ureter.
Fine network of blood capillaries that increases the local blood pressure to squeeze fluid out of the blood. Surrounded by a cup or funnel-shaped capsule which collects the fluid and leads into the nephron.
Where useful substances are reabsorbed from the nephron into the bloodstream while other excretory substances remain in the nephron.
Brings blood into the organ.
Carry blood away from the organ.
Filtration at a molecular level. Where in the glomerulus, large molecules and cells are left in the blood and smaller molecules pass into the Bowman's capsule.
Specialised cells that make up the lining of the Bowman's capsule.
Microscopic folds of the cell surface membrane that increase the surface area of the cell.
Proteins in the cell surface membrane that allow the facilitated diffusion of simple ions to be accompanied by transport of a larger molecule such as glucose.
Diffusion that is enhanced by the action of proteins in the cell membrane.
Special proteins in the cell surface membrane that actively transport sodium and potassium ions against their concentration gradients.
Hairpin countercurrent multiplier
Arrangement of a tubule in a sharp hairpin so that one part of the tubule passes close to another part of the tubule with the fluid flowing in opposite directions. This allows exchange between the contents and can be used to create a very high concentration of solutes.
The control and regulation of the water potential of the blood and body fluids. In humans the kidney controls the water potential of the blood.
Distal convoluted tubule
The coiled portion of the nephron between the loop of Henle and the collecting duct.
Antidiuretic hormone (ADH)
Released from the pituitary gland and acts on the collecting ducts in the kidneys to increase their reabsorption of water.
Receptor cells that monitor the water potential of the blood. If blood has a low water potential then water is moved out of the osmoreceptor cells by osmosis, causing them to shrink. This causes stimulation of the neurosecretory cells.
Part of the brain that contains neurosecretory cells and various receptors that monitor the blood.
Specialised cells that act like nerve cells but release a hormone into the blood. ADH is made in cell body and passed down axon to be stored in terminal bulb. If an action potential passes down the axon, then ADH is released from the terminal bulb.
Posterior pituitary gland
Hind part of the pituitary gland which releases ADH.
Half-life of a substance
Time taken for its concentration to drop to half its original value.
Use of a partially permeable membrane to filter the blood.
Partially permeable membrane that separates the dialysis fluid from the patient's blood in a dialysis machine,
Complex solution that matches the composition of body fluids.
Process when blood is taken from a vein and passed through a dialysis machine so that exchange can occur across an artificial partially permeable membrane.
Dialysis fluid is pumped into the body cavity so that exchange can occur across the peritoneal membrane.
human Chorionic Gonadotrophin (hCG)
Hormone released by human embryos; its presence in the mother's urine confirms pregnancy.
Antibodies that are identical as they have been produced by cells that are clones of one original cell.
Drugs that mimic the action of steroid hormones that increases muscle growth.
Technique used to separate substances in a gaseous state.