Final Exam Flashcards
How do organisms maintain ion and water balance?
Osmotic homeostasis, ionic homeostasis, removal of nitrogen.
What are regulators?
Organisms that have an internal environment different than the external environement.
What are conformers?
Organisms with a similar internal and external environment.
What are examples of conformers or regulators?
Iono or osmo conformers/regulators. Can be either/ or.
What impacts ion and water balance?
The environment and ingested materials (food/water)
What are stenohaline organisms?
Organisms that have a narrow range of external environment they can survive in.
What are euryhaline organisms?
Organisms that have a broad range of external environments they can survive in.
What is a perturbing solute?
Solutes that are most likely to affect protein function.
What is a compatible solute?
Solutes that have less affect on protein function.
What are counteracting solutes?
Two solutes may individually act as perturbing solutes but together act as compatible.
What affects cell volume?
Osmotic gradients affect cell volume and the ability of cells to transmit electrical signals. Water follows osmotic gradients.
What will cause an increase of cell volume?
A net input of particles into the cell that causes water to follow and swell the cell.
What causes a decrease of cell volume?
A net output of particles (active transport) causing water to follow and shrink the cell.
How do sea organisms maintain osmotic/ionic balance?
An increased amount of salt in the environment causes the organisms to implement ways to increase salt secretion and keep water.
How do fresh water organisms maintain osmotic/ionic balance?
These organisms bring in both water and particles (salt) and secrete both water and particles.
What is role of epithelial tissue in osmotic/ionic balance?
Tight junctions between cells allow separation of water and particles so that the body has to selectively move particles across membranes via different transporters. Lots of mitochondria present for active transport.
Where does adsorption and reabsorption occur across epithelial cells?
Via the luminal surface through the cell and then across the basolateral membrane.
Where does secretion/excretion occur across epithelial tissues?
Via the basolateral membrane through the cell and then out via the luminal surface.
How does the skin regulate aquaporins?
depending on the environment the integument will have an increased or decreased concentration of aquaporins.
What is the function of aquaporins?
Aquaporins increase the amount of water that can move in and of an organisms renal system. Decreased in desert environments and water environments.
What are strategies used by organisms to decrease water loss?
Hydrophobic substances (lipids, mucous, wax), cuticle, and stratum corneum.
What are cells found in fish gills that help import solutes?
Pavement cells that bring in sodium and chloride cells that bring in chloride. Important for keeping salt in fresh water envrionments.
What are salt glands?
A mechanism utilized by birds and reptiles in desert environments where they have high concentrations of salt and want to get rid of it. Salt moved from blood stream into lumen of secretory tubule via counter current flow.
What are rectal glands (elasmobranchs)?
A mechanism utilized by sharks to get rid of salt due to the sea water environment they are in. Active transport moves NaCl across the invagintaed basolateral membrane into the lumen of the cell and then out of luminal surface via channels.
Why is the basolateral membrane invaginated?
To increase the surface area to increase the number of ion pumps that can be placed along the membrane.
What do vertrebrate kidneys regulate?
Ions, osmolarity, blood pressure, pH, excretion and hormone production.
What is a nephron?
The basic working unit of the kidney.
What are the four functions of the nephron?
Filtration, reabsoprtion, secretion, and excretion.
What is filtration?
A substance leaving the blood to the nephron and will eventually leave the body. The result of bulk flow.
What is reabsorption?
Substances moving from the nephron to the blood (mostly selective).
What is secretion?
Substances moving from the blood to the nephron. An entirely selective process and proteins must bind substances to cross into the nephron.
What is excretion?
The removal of anything left in the nephron. (Excretion = filtration - reabsorption +secretion)
What is a juxtamedullary nephron?
Nephrons found mostly in the medulla and have longer loops of henle for more reabsoprtion to occur.
What is a a cortical nephron?
Found in the cortex of the kidney and have shorter loops of henle.
What is the glomerulus?
Bundle of capillaries in bowmans capsule where capillary fluid is filtered out.
What is bowmans capsule?
Surrounds the glomerulus to capture filtered fluid.
What structures of the nephron are associated with reabsorption?
Proximal tubule, loop of henle, distal tubule, and collecting duct.
What is the goal of the distal tubule and collecting duct?
secretion and rest of reabsorption occurs depending on the environment.
What is the goal of the loop of Henle?
Sets up gradient for urine concentration via reabsorption.
What does filtration depend on?
Blood pressure, interstitial pressure, and oncotic pressure.
Which way does blood pressure force filtration?
From the capillary to the bowmans capsule.
Which way does interstitial and oncotic force filtration?
From bowmans capsule to the capillaries of the glomerulus.
What is the equation for net filtration?
Net filtration = blood pressure - interstitial pressure - oncotic pressure.
What are podocytes?
Can cover more or less depending need for surface area for filtration.
What is the basement membrane?
Membrane in the glomerulus that prevents large proteins from leaving.
What does water reabsorption work?
Water reabsorption depends on the osmotic gradient. When solutes move via mediated transport water will follow the higher concentration of solutes.
Where is the final concentration of urine determined?
The collecting duct.
What is renal threshold?
The max amount of substance that can be reabsorbed. This happens because mediated transporters are fully saturated and cannot be reabsorbed.
How can renal threshold be increased?
Adding more membrane transporters in the membrane or reabsorbing the product before it reaches the kidney,
How does pH change in tissues when there is increased CO2?
The bicarbonate equation pushed to the right and pH decreases.
What happens to pH when there is less CO2 in the gas exchange organ?
The bicarbonate equation is pushed to the left and pH increases.
What does the concentration of CO2 llook like in the blood?
Dissolved (10%), bound to hemoglobin (<25%), and bicarbonate (<75%)
What causes an increase release of O2 from hemoglobin?
Decreased pH, increased CO2, increased temp, and increased DPG.
How do these factors increase O2 release?
Changes folding of hemoglobin to have a lower affinity for O2 which means increased release of O2 to cells and tissues.
What is the haldane effect?
Oxyngenated blood releases CO2 and H+.
How does a chloride shift affect CO2 concentration?
When chloride leaves cells CO2 is removed and when chloride enters the cell there is an increase in CO2 release.
How does the renal system maintain pH levels>
Changing the secretion and reabsorption levels of H+ and HCO3-.
What is the glomerular filtration rate?
The rate at which stuff moves into the nephron. Affected by pressure gradients and surface area.
What are the ways that Glomerular filtration rate if affected?
Myogenic regulation, tubuloglomerular feedback, messangial control, and pressure natriuresis.
What is myogenic regulation?
Response to stretch to contract back down. Decreases blood pressure before reaching capillaries.
What is tubuloglomerular feedback?
Feedback between the distal tubule and the glomerulus to check levels of reabsorption of solutes. (filtration and reabsorption rates are inversely related).
What is messangial control?
The ability of podocytes of the glormerulus to spread out and contract to provide more surface area for reabsorprtion.
What is pressure natruesis>
Loss of sodium that causes water to follow.