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.
What is clearance?
The rate at which a substance is removed from the blood.
What is the equation used to calculate clearance?
C = Ux * Vu / Px
What is vasopressin/antidiuretic hormone?
Increases water absorption via placing more aquaporins in the nephron. (decreasing urine output)
What is Aldosterone?
A hormone that increases sodium reabsorption and potassium reabsorption via ATpase pump which increases water reabsorption to follow the solutes. (decreases urine output).
What is atrial natriuretic peptide?
Increases GFR and inhibits ADH/aldosterone effects (increases urine output).
How does the cardiovascular fight dehyrdation when there is increased blood pressure and increased blood volume?
Increasing heart rate, increased contractility, and blood vessel constriction.
How does the renal system fight dehydration when there is increased osmolarity and decreased blood volume?
Increasing ADH
How does the renal system respond to dehydration when there is decreased blood volume and decreased blood pressure?
Increasing aldosterone
How does the renal system respond to dehydration when there is increased osmolarity?
Decreased aldosterone
What impacts the type of kidneys for different organisms?
The environment dictates kidneys nephron loop length. Need for more reabsorption will mean a longer loop of nephon.
What are the three ways nitrogen can be removed as waste?
Ammonia, urea, and uric acid.
What is ammonia?
Removes one nitrogen. Requires less energy, but increases water loss.
What is urea?
Removes two nitrogens and is between ammonia and uric acid for energy requirements.
What is uric acid?
Waste that removes four nitrogens takes more energy but decreases water loss.
What is the purpose of the digestive system?
Bring in nutrition and remove waste.
What are features of the digestive tract?
Increased surface area and mechanisms to digest/break down food for a specific diets
What is ingesting?
Bringing food into the body
What is egestion?
Removal of waste
What happens to food between ingestion and egestion?
Motility, secretions, digestion, and adsorption.
What is motility in the digestive system?
Movement of food and mechanical digestion.
What are secretions in the digestive system?
Communication and chemical digestion
What is digestion?
Mechanical and chemical break down of food.
What is adsorption in the digestive system?
Small chemical particles that are used by the organisms body primarily brought in by active transport.
What is gross energy?
Total energy brought into body via food.
What is indegestible energy?
Energy removed via feces or vomit.
What is unmetabolized energy?
Energy removed from the body by urine.
What is Specific dynamic action?
Energy cost to breaking down and using energy
What is net energy?
The energy that can be used for the rest of the metabolic processes.
What determines food consumption?
Dependent on availability of nutrients and needs of organism.
What is random/accidental ingestion of food?
Organisms that do not have a specific action/plan to get food
What is sense food/prey ingestion?
organisms that have limited movement but can sense nearby food and uses appendages like tentacles to get food.
What receptors sense food?
Chemoreceptors and electromagnetic receptors
What determines feeding structures?
Specific to types of food organisms needs to survive.
What are examples of different teeth depending on diet?
Carnivores have teeth better fit for ripping/shredding food and herbivores have broad/flat teeth for grinding grass
What are the two types of GI tracts?
Two way gut and one way gut
What is a two way gut?
GI systems that have one opening for intake and output. Ingestion and egestion occur along same path
What are ways to increase surface area of GI tract?
Invagination, mucosal fold lining GI tract, and villi by covering mucosal folds
What is a one way gut?
GI tracts that have different openings for ingestion and egestion. Usually contains specialized compartments and length of GI tract is related to digestibility of food
What is peristalsis?
Wave like contractions that move food from mouth to anus. Can be reversed through vomiting.
What is segmentation?
Alternating contractions to mix and digest food. Usually occurs in intestine and not in stomach.
What happens if peristalsis and segmentation happens at same time?
Increased time for reabsorption and digestion to occur.
What is the migrating motor complex?
Movement similar to peristalsis that happens from stomach to large intestine. Much larger contractions that clears out undigested materials of GI tract. Occurs between meals.
What neurons regulate GI tract movement?
Myenteric plexus that are between muscle layers of GI tract
What are the roles of the salivary glands?
Soften food and secrete enzymes
How do salivary glands soften food?
By H2O found in saliva.
What enzymes are secreted by salivary glands?
Amylase and lipase that will only break down a little of the biological molecules. These enzymes dont function at stomach pH
What are the gastric secretions of the intestine?
VIP, GIP, and secretin
What are the gastric secretions of the stomach?
Gastrin and secretin
What is VIP?
Vasoactive intestinal peptide that increases pepsinogen production and inhibits gastric acid secretion.
What is GIP?
Gastric inhibitory peptide that increases insulin production and decreases acid production
What is secretin?
Stimulates pancreas to increase bicarbonate production.
What is gastrin?
Increases acid production
What is secretin?
Decreases acid production
What are the three types of stomachs?
Crop, digastric stomach, and monogastric stomachs
What are crops?
Stomachs found in birds that have small stones to help grind seeds for mechanical digestion.
What is a monogastric stomach?
Stomachs with only one pouch
What are digastric stomachs?
Stomachs found in rumenants. One portion of the stomach has bacteria that breaks down fibers in grass. Higher pH protects esophagus.
What does acid do in the stomach?
Denatures proteins and kills bacteria/viruses.
What are characteristics of enzymes in the stomach?
Enzymes that work best at low pH
What is pepsinogen?
Inactive pepsin that is activated via acidic conditions in the stomach.
What is the role of mucous and bicarbonate in the stomach/intestine?
Covers stomach surface and HCO3- neutralizes stomach acid to protect stomach cells.
What is the role of VIP as an intestinal secretion?
Increases bicarbonate from the pancreas.
What is secretin?
Increases bile produced from liver
What is the role of GIP as an intestinal secretion?
Helps with reabsorption of digested materials.
What is CCK?
Cholecytoskline that increases secretions from pancreas and gallbladder.
What is motilin?
Released during fasting and stimulates migrating motor complex.
What is enteropeptidase?
An enterokinase that cuts phosphate. Cuts trypsinogen phosphate to change folding into trypsin.
What is trypsin?
Intestinal enzyme that activates other proeznymes in the intestines.
Why are enzymes in their inactive form in the intestine?
To act as a safety measure to protect from self digestion.
What are secretions from the pancreas?
Bicarbonate and enzymes for all macromolecules
What are secretions from the liver and gallbladder?
Bile that emulsifies fats/lipids to increase surface area for enzymes.
What are exocrine secretions?
Any secretion into the lumen of the GI tract.
What are enterosymbionts?
Organisms that live in the GI tract of other organisms to help with digestion.
What are exosymbionts?
Live on the outside of the body
What are endosymbionts?
Live in the body but not in the GI tract.
What are characteristics of adsorption of the digestive tract?
Relys on active transport, some diffusion, and mediated transport for selectivity.
What is the first step of lipid adsorption?
Must digest first via motility and bile that break down lipids into fat droplets.
What is the second step of lipid adsorption?
Enzymes digest fats on surface of droplets.
What is the third step of lipid reabsorption?
After entering cell fats are reassembled.
What is the fourth step of lipid reabsorption?
Released via exocytosis as chylomicrons.
What are lacteals?
Used to transport chylomicrons from intestine to vessels to the liver.
What is leptin?
Hormone that is produced by adipose tissue to decrease food intake. Long term
What is ghrelin?
Produced by stomach and increases intake of food. Short term.
What is peptide YY?
Produced by colon and decreases food intake
What is insulin?
Produced by pancrease in response to increased glucose concentrations in bloo. Decreases food intake
What is Ta?
Ambient temperature that determines how rapidly heat is gained or lost from the environment.
What is Tb?
Body temperature which is the organisms internal temp.
What factors effect gradient between Ta and Tb?
Behavior (amount of activity), biochemical (more chemical reactions means more heat released), and physiological (adaptation effecting heat generated)
How does surface area influence heat regulation?
Smaller organisms have a harder time maintaining temp because of increased energy exchange with the environment.
What factors influence insulation?
Thickness, density, and polarirty.
What are ectothermic organisms?
regulated by external temp
What are endotherms?
Regulates internal temperature
What are homeotherms?
Organisms whose internal temp can be only in a narrow range
What are poikilotherms?
Organisms whose internal temp can be in a wide range.
What are eurythermic organisms?
Wide environmental temp range that they maintain internal temp in
What are stenothermic organsisms?
Narrow environmental temp range that they can maintain internal temp.
