| A | B |
|---|
| afferent arteriole | blood vessel supplying a nephron |
| aldosterone | hormone that acts on the distal tubules of the kidney to stimulate the reabsorption of sodium (Na+) and the passive flow of water from the filtrate |
| ammonia | very toxic molecule metabolic waste product of protein and nucleic acid metabolism |
| angiotensin II | stimulates constriction of precapillary arterioles and increases reabsorption of NaCl and water by the proximal tubules of the kidney increasing blood pressure and volume |
| anhydrobiosis | ability to survive in a dormant state when an organism’s habitat dries up a.k.a. cryptobiosis |
| antidiuretic hormone (ADH) | promotes water retention by the kidneys as part of an elaborate feedback scheme |
| atrial natriuretic factor (ANF) | hormone that opposes the renin-angiotensin-aldosterone system (RAAS) |
| Bowman’s capsule | cup-shaped receptacle in the vertebrate kidney where filtrate enters from the blood |
| collecting duct | location in the kidney where filtrate from renal tubules is collected |
| cortical nephrons | Nephrons located almost entirely in the renal cortex |
| countercurrent multiplier system | system in which energy is expended in active transport to facilitate exchange of materials and create concentration gradients |
| distal tubule | portion of a nephron that helps refine filtrate and empties it into a collecting duct |
| efferent arteriole | blood vessel draining a nephron |
| euryhaline | organisms that can tolerate substantial changes in external osmolarity |
| excretion | disposal of nitrogen-containing waste products of metabolism |
| filtrate | Fluid extracted by the excretory system from the blood or body cavity |
| filtration | extraction of water and small solutes including metabolic wastes from the blood by the nephrons |
| glomerulus | ball of capillaries surrounded by Bowman’s capsule in the nephron and serving as the site of filtration |
| juxtaglomerular apparatus (JGA) | located near the afferent arteriole that supplies blood to the glomerulus |
| juxtamedullary nephrons | Nephrons with well-developed loops of Henle that extend deeply into the renal medulla |
| loop of Henle | long hairpin turn of the renal tubule in the vertebrate kidney functions in water and salt reabsorption |
| Malpighian tubule | excretory organ of insects that empties into the digestive tract removes nitrogenous wastes from the blood |
| metanephridium | type of excretory tubule with internal openings called nephrostomes that collect body fluids and external openings called nephridiopores |
| nephron | tubular excretory unit of the vertebrate kidney |
| osmoconformer | does not actively adjust its internal osmolarity because it is isotonic with its environment |
| osmolarity | Solute concentration expressed as molarity |
| osmoregulation | regulation of solute and water concentrations in body fluids by organisms living in hyperosmotic hypoosmotic and terrestrial environments |
| osmoregulator | animal whose body fluids have a different osmolarity than the environment |
| peritubular capillaries | network of tiny blood vessels that surrounds the proximal and distal tubules in the kidney |
| protonephridium | flame-cell system of flatworms |
| proximal tubule | portion of a nephron immediately downstream from Bowman’s capsule that conveys and helps refine filtrate |
| renal artery | blood vessel bringing blood to the kidney |
| renal cortex | outer portion of the vertebrate kidney |
| renal medulla | inner portion of the vertebrate kidney beneath the renal cortex |
| renal pelvis | Funnel-shaped chamber receives processed filtrate from collecting ducts and is drained by the ureter |
| renal vein | blood vessel draining the kidney |
| renin-angiotensin-aldosterone system (RAAS) | complex feedback circuit that normally partners with antidiuretic hormone in osmoregulation |
| secretion | discharge of wastes from the blood into the filtrate from the nephron tubules |
| selective reabsorption | selective uptake of solutes from a filtrate of blood coelomic fluid or hemolymph in the excretory organs of animals |
| stenohaline | organisms that cannot tolerate substantial changes in external osmolarity |
| transport epithelium | specialized epithelial cells that regulate solute movements |
| urea | soluble nitrogenous waste excreted by mammals adult amphibians marine fishes and turtles |
| ureter | duct leading from the kidney to the urinary bladder |
| urethra | tube that releases urine from the body near the vagina in females and through the penis in males |
| uric acid | insoluble precipitate of nitrogenous waste excreted by land snails insects birds and some reptiles |
| urinary bladder | pouch where urine is stored prior to elimination |
| vasa recta | capillary system that serves the loop of Henle |
