Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
57 Cards in this Set
- Front
- Back
Osmoregulators
|
Animals that maintain an internal osmolarity different from the medium in which that are immersed have been termed osmoregulators.
|
|
Osmoconformer
|
An animal that does not actively control the osmotic condition of its body fluids and instead conforms to the osmolarity of the surrounding medium is termed an osmoconformer.
|
|
Osmolytes
|
Osmolar homeostasis is achieved by increasing the concentration of intracellular organic osmolyes, substances that, by their presence in high concentrations, act to increase intracellular osmolarity.
|
|
Trimethylamine oxide (TMAO)
|
A nitrogenous waste product, probably form choline decomposition.
|
|
Urea
|
(NH2)2CO, the primary nitrogenous waste product in the urine of mammals.
|
|
Obligatory osmotic exchanges
|
Obligatory osmotic exchanges occur mainly in response to physical factors over which the animal has little or no physiological control.
|
|
Regulated osmotic exchanges
|
Regulated osmotic exchanges are physiologically controlled and serve to aid in maintaining internal homeostasis.
|
|
Arginine vasotocin (AVT)
|
The permeability of amphibian skin is controlled by a hormone called arginine vasotocin (AVT) or, more simply, vasotocin; like the mammalian antidiuretic hormone (ADH; also called vasopressin), vasotocin enhances water permeability.
|
|
Metabolic water
|
Although water is an end product of cellular metabolism, it is produced in small enough quantities that its elimination is not problematic. In fact, this so-called metabolic water is the major source of water for many desert dwellers.
|
|
Countercurrent multiplication
|
(note: involves the loop of Henle) the kidneys of binds and mammals utilize countercurrent multiplication to produce hyperosmotic urine, which is more concentrated than the blood plasma.
|
|
Loop of Henle
|
The U-shaped portion of the renal tubule that lies in the renal medulla.
|
|
Temporal countercurrent system
|
The respiratory loss of water via exhaled air is minimized through a mechanism first discovered in the nose of the desert-dwelling kangaroo rat. This mechanism, termed a temporal countercurrent system, retains most of the respiratory water vapor by condensing it on cooled nasal passages during exhalation.
|
|
Euryhaline
|
Euryhaline aquatic animals can tolerate a wide range of salinities.
|
|
Stenohaline
|
Stenohaline animals can tolerate only a narrow osmotic range of salinities.
|
|
Chloride cells
|
Epithelial cells of fish gills that engage in active transport of salts.
|
|
Salt glands
|
Osmoregularory organs that form a hypertonic aqueous exudates by means of active salt secretion into small tubules situated above the eyes, which is excreted via the nostrils; found in many birds and reptiles that live in desert or marine environments.
|
|
Apical
|
The apical surface (sometimes referred to as the mucosal or luminal surface) of an epithelial cell faces a space that is continuous with the external world (such as the sea, the pond, the lumen of the gut, or the lumen of a kidney tubule.)
|
|
Basal
|
The basal surface (sometimes referred to as the serosal surface) generally bears deep basal clefts and faces an internal compartment containing extracellular fluid.
|
|
F-ATP synthases
|
One type of ion-motive ATPase, or pump, found in mitochondria and chloroplasts, which use a proton electrochemical gradient to make ATP.
|
|
V-ATPases
|
V-ATPases, or vacuolar-type ATPases, hydrolyze ATP to generate electrochemical gradients, as do P-ATPases.
|
|
P-ATPases
|
V-ATPases, or vacuolar-type ATPases, hydrolyze ATP to generate electrochemical gradients, as do P-ATPases.
|
|
Cortex
|
The outer layer of the kidney is termed the cortex.
|
|
Medulla
|
The inner layer of the kidney, the medulla, sends papillae projecting in to the renal pelvis.
|
|
Renal pelvis
|
Cavity at base of each kidney; receives urine from collecting duct system and empties it into ureter.
|
|
Micturition
|
Urination
|
|
Urethra
|
A channel that passes urine from the bladder out of the body.
|
|
Nephron
|
The morphologic and functional unit of the vertebrate kidney; composed of the glomerulus and Bowmans capsule, the proximal and distal tubules, the loop of Henle (in birds and mammals), and a collecting duct.
|
|
Collecting ducts
|
The portion of the mammalian renal tubule in which the final concentration of urine occurs.
|
|
Bowmans capsule
|
(glomerular capsule) A globular expansion at the beginning of a renal tubule that surrounds the glomerulus.
|
|
Glomerulus
|
A coiled mass of capillaries.
|
|
Proximal tubule
|
The coiled portion of the renal tubule located in the renal cortex, beginning at the glomerulus and leading to (and continuous with) the descending limb of the loop of Henle.
|
|
Distal tubule
|
The potion of a renal tubule located in the renal cortex, leading from (and continuous with) the ascending limb of the loop of Henle to the collecting duct.
|
|
Juxtamedullary nephrons
|
Juxtamedullary nephrons, which have their glomeruli in the inner part of the cortex and long loops of Henle that plunge deeply into the medulla.
|
|
Cortical nephrons
|
Cortical nephrons, which have their glomeruli in the outer cortex and relatively short loops of Henle that extend only a short distance into the medulla.
|
|
Afferent arterioles
|
Supplies blood to the nephrons
|
|
Efferent arterioles
|
Unlike most other capillary beds, which would join to form veins, the capillaries of the glomerulus come together to form an efferent arteriole.
|
|
Vasa recta
|
The capillary network that surrounds the loop of Henle in the tubules of the mammalian kidney.
|
|
Filtration slits and pedicels
|
The hydraulic properties of the glomerular apparatus depend primarily on the sievelike filtration slits, which are formed from a rather remarkable assemblage of fine cellular processes termed pedicels.
|
|
Podocytes
|
Epithelial cells lining Bowmans capsule whose foot processes form filtration slits.
|
|
Juxtaglomerular apparatus
|
A group of specialized cells situated between the distal renal tubule and the afferent glomerular arterioles that modulate renal blood flow.
|
|
Macula densa
|
One of the two specialized cells of the juxtaglomerular apparatus is modified distal-tubule cells, which form the macula densa and monitor the osmolarity and flow of fluid in the distal tubule.
|
|
Juxtaglomerular cells
|
One of the two specialized cells of the juxtaglomerular is modified smooth-muscle cells called granular or juxtaglomerular cells, which are located primarily in the wall of the afferent arteriole.
|
|
renin
|
A proteolytic enzyme produced by specialized cells in renal arterioles, which converts angiotensinogen to angiotensin.
|
|
Renal clearance
|
That volume of plasma containing the quantity of a freely filtered substance that appears in the glomerular filtrate per unit time. Total renal clearance ins the amount of ultrafiltrate produced by the kidney per unit time.
|
|
Brush border
|
A free epithelial cell surface bearing numerous microvilli.
|
|
Aldosterone
|
A mineralocorticoid secreted by the adrenal cortex; the most important electrolyte controlling steroid, which acts in the renal tubules to increase the reabsorption of sodium.
|
|
3 mechanisms that account for the aldosterone-induced increase in sodium
|
Sodium pump hypothesis, Metabolic hypothesis, Permease hypothesis
|
|
Sodium pump hypothesis
|
Activity of the Na+/K+ pump in the basolateral membrane increases, perhaps due to changes in membrane structure that enhance ATPase activity as well as increased synthesis of the pump protein.
|
|
Metabolic hypothesis
|
The production of ATP increases, providing more APT to power the Na+/K+ pump, perhaps due to an aldosterone-stimulated increase in fatty acid metabolism.
|
|
Permease hypothesis
|
The permeability of the apical membrane to Na+ ions increases, presumably due to an increase in the number of sodium channels in the membrane.
|
|
Atrial natriuretic peptide (ANP)
|
(ANP) One of a family of peptide hormones cleaved from a single precursor peptide and produced in the cardiac atria; its physiological effects in clued increased urine output, increased sodium excretion, and receptor-mediated vasodilation, the net result of which is lowered blood pressure.
|
|
Malpighian tubules
|
Insect excretory organs responsible for the active secretion of waste products and the formation of urine.
|
|
Ammonotelic
|
Pertaining to the excretion of nitrogen in the form of ammonia.
|
|
Ureotelic
|
Excreting nitrogen in the form of urea.
|
|
Ornithine-urea cycle
|
A cycle succession of reactions that eliminate ammonia and produce urea in the liver of ureotelic organisms.
|
|
Uricolytic pathway
|
The pathway through which uric acid or urates are broken down.
|
|
Uricotelic
|
Excreting nitrogen in the form of uric acid.
|