AP Bio Ch. 44 Vocab
Terms
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- Thermoregulation
- the maintenance of body temperature within a range that enables cells to function efficiently.
- Conduction
- direct transfer of thermal motion between molecules of the environment and those of the body surface.
- Convection
- transfer of heat by the movement of air or piqued past the surface of a body.
- Radiation
- emission of electromagnetic waves produced by all objects warmer than absolute zero.
- Evaporation
- loss of heat from the surface of a liquid that is losing some of its molecules as gas.
- Ectotherm
- warms its body mainly by absorbing heat from its surroundings. The amount of heat it derives from its own metabolism is usually negligible.
- Endotherm
- derives most or all of its body heat from its own metabolism.
- Vasodilation
- increase in the diameter of superficial blood vessels.
- Vasoconstriction
- reduces blood flow and heat loss by decreasing the diameter of superficial vessels.
- Countercurrent heat exchanger
- a special arrangement of arteries and veins.
- Nonshivering thermogenesis
- hormonal triggering of heat production.
- Brown fat
- a tissue in the neck and between the shoulders that Is specialized for rapid heat production.
- Acclimatization
- adjusting to a new range of environmental temperatures over a period of days or weeks.
- Stress-induced proteins
- special molecules including heat shock proteins.
- Hibernation
- long-term torpor during which the body temperature is lowered as an adaptation to winter cold and food scarcity.
- Estivation
- or summer torpor, characterized by slow metabolism and inactivity. It enables an animal to survive long periods of high temperatures and scarce water supplies.
- Transport epithelium
- a layer or layers of specialized epithelial cells that regulate solute movements.
- Ammonia
- nitrogenous wastes excreted by most aquatic animals.
- Urea
- mammals, most adult amphibians, and many marine fishes and turtles excrete it; about 100,000 times less toxic than ammonia. Urea is produced in the vertebrate liver by a metabolic cycle that combines ammonia with carbon dioxide.
- Uric acid
- land snails, insects, birds, and many reptiles excrete it; is 1,000 times less soluble in water than either ammonia or urea. It can be excreted in a pastelike form with very little loss of water.
- Osmolarity
- occurs whenever two solutions separated by the membrane differ in osmotic pressure.
- Osmoconformer
- an animal which does not actively adjust its internal osmolarity.
- Osmoregulator
- an animal that must adjust its internal osmolarity, since its body fluids are not isoosmotic with the outside environment.
- Stenohaline
- narrow
- Euryhaline
- broad
- Anhydrobiosis
- Dehydration dooms most animals, but some aquatic invertebrates living in temporary ponds and films of water around soil particles can lose almost all their body water and survive in a dormant state when their habitats dry up.
- Filtration
- when blood or other body fluids, depending on the type of excretory system, is exposed to a filtering device made of the selectively permeable membranes of transport epithelia.
- Reabsorption
- selective transport of water and valuable solutes from the filtrate back into the body fluids.
- Secretion
- solutes are removed from the animal's body fluids and added to the filtrate.
- Protonephridium
- a network of closed tubules lacking internal openings.
- Metanephridium
- another type of tubular excretory system that has internal openings that collect body fluids. They are found in most annelids, including earthworms.
- Malpighian tubules
- the excretory organs of insects and other terrestrial arthropods.
- Renal artery
- where blood enters each kidney.
- Renal vein
- where blood leaves each kidney.
- Ureter
- a duct through which urine exits the kidney.
- Urinary bladder
- where the ureters of both kidneys drain.
- Urethra
- a tube where, during urination, urine leaves the body from the urinary bladder, which empties near the vagina in females or through the penis in males.
- Renal cortex
- the outer distinct region of the mammalian kidney.
- Renal medulla
- the inner distinct region of the mammalian kidney.
- Nephron
- the functional unit of the vertebrate kidney, consists of a single long tubule and a ball of capillaries.
- Glomerulus
- a single long tubule and a ball of capillaries.
- Bowman's capsule
- where the blind end of the tubule forms a cup shaped swelling, which surrounds the glomerulus.
- Podocytes
- function as a filter, being permeable to water and small solutes but not to blood cells or large molecules such as plasma proteins.
- Secretion
- a very selective process involving both passive and active transport.
- Antidiuretic hormone (ADH)
- hormone in osmoregulation. It is produced in the hypothalamus and is stored and released from the pituitary gland.
- Juxtaglomerular apparatus (JGA)
- regulates kidney function and is located in the vicinity of the afferent arteriole, which supplies blood to the glomerulus.
- Angiotensin II
- chemical reactions that convert a plasma protein called angiotensinogen to a peptide.
- Aldosterone
- hormone that acts on the nephrons distal tubules, making them rabsorb more sodium and water and increasing blood volume and pressure.
- Renin-angiotensin-aldosterone system (RAAS)
- is part of a complex feedback circuit that functions in homeostasis.
- Atrial natriuretic factor (ANF)
- is released in response to an increase in blood volume and pressure. ANF inhibits the release of rennin from the JGA, inhibits NaCl reabosorbtion by the collecting ducts, and reduces aldosterone release from the adrenal glands