IGCSE Biology Homeostasis & Excretion

Flashcards for the CIE IGCSE Biology course. Topic: Homeostasis & Excretion
ADH (Anti-Diuretic Hormone)
A hormone released from the pituitary gland which helps water levels in the body.
Blood sugar
Glucose in the blood stream
A bag/sac in animals stores urine prior to urination
A thick layer of fat between the skin and the muscle layers of whales and other marine mammals, from which an oil is obtained.
Cortex (of the kidney)
The outer layer of the kidney.
A condition where little or no insulin is secreted by the pancreas in response to an increase in blood sugar level
The separation of smaller molecules from larger molecules in a solution by selective diffusion through a semi-permeable membrane
The movement of the molecules from an area of high concentration to an area of low concentration down a concentration gradient.
The act or process of discharging waste matter from blood, tissues, or organs
A polymer of glucose that is the main form of carbohydrate storage in animals and occurs primarily in the liver and the muscle tissue. It is readily converted into glucose as needed by the body to satisfy its energy needs.
The maintenance of a constant internal environment inside a living organism
A substance produced by one tissue and transported by the bloodstream to another to effect a physiological change.
A small structure at the base of the brain involved in controlling temperature
An abnormally low body temperature
A hormone secreted by the pancreas and involved in the regulation of the metabolism of carbohydrates in particular the conversion of glucose to glycogen, which lowers the blood glucose level.
A pair of organs that maintain proper water and electrolyte balance regulate acid-base concentration, and filter the blood of metabolic wastes which are then excreted as urine.
Medulla (of the kidney)
The central and more deeper part of the kidney.
The chemical processes occurring within a living cell or organism that are necessary for the maintenance of life. In metabolism some substances are broken down to yield energy for vital processes while other substances, necessary for life, are synthesised.
Negative feedback
Feedback that reduces the output of a system.
Renal artery
An artery originating from the aorta and supplying the kidney.
Renal vein
A vein that returns blood to the heart via the inferior vena cava.
Selective Reabsorption
Glucose, some salts and water are reabsorbed into the blood from the kidney tubule. More water is reabsorbed if the level of water in the body is low.
To excrete perspiration or moisture through the pores in the skin.
A water-soluble compound that forms the bulk of the nitrogen containing waste present in urine. It is the end product of protein metabolism.
The long, narrow duct that conveys urine from the kidney to the bladder.
The duct through which urine is discharged from the bladder and through which semen is discharged in the male.
The waste product secreted by the kidneys that in mammals is a yellow, slightly acid fluid discharged from the body through the urethra.
Constriction of a blood vessel, as a nerve or drug.
A process in which some of the molecules of a solution move across a semi-permeable membrane from a region where they are at high concentration to a region of where they are at zero or low concentration. It does not require respiration but does require living cell membranes
A long, irregularly shaped gland lying behind the stomach, the secrets pancreatic juice into the duodenum and insulin into the bloodstream.
Partially (or selectively) permeable membrane
A membrane which allows some substances to diffuse through, but not others.