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BIO 202: Exam 4
urinary/digestive systems, electrolyte, acid/base balance
Question | Answer |
---|---|
In life-threatening starvation, the kidneys synthesize glucose by what method? | gluconeogenesis |
What byproduct of protein catabolism constitutes approximately one-half of all nitrogenous waste? | urea |
What are the functions of the kidney? | filter blood plasma, separate waste from useful chemicals, returns useful substances to blood, eliminates wastes, regulates blood volume/pressure by eliminating/conserving water, regulate osmolarity of body fluids, secretes renin |
A renal pyramid voids urine into what structure(s)? | collecting tubules |
Where does the transition from an afferent arteriole to an efferent arteriole occur in the nephron? | glomerulus |
What structures form the inner layer of the glomerular capsule and wraps around the capillaries of the glomerulus? | podocytes |
Which area of the nephron and kidney is primarily responsible for maintaining the salinity gradient of the renal medulla? | juxtamedullary nephrons |
By what process(es) are glucose and amino acids reabsorbed from the glomerular filtrate? | in the proximal convoluted tubule by active transport |
In a healthy kidney, what substances are not filtered by the glomerulus? | protein, blood cells, large anions, minerals, hormones, and molecules >8nm in diameter |
What situations would reduce the glomerular filtration rate? | (this refers to different pressures; high to low) Vasoconstriction of the afferent arteriole |
When there is a significant drop in blood pressure what substance stimulates constriction of the glomerular inlet and even greater constriction of the outlet? | angiotensin II |
What area of the nephron demonstrates a great deal of active transport, collectively accounting for about 6% of one's daily resting ATP and caloric consumption? | Active transport from one’s daily resting ATPproximal convoluted tubule of all the nephons |
What is the direct result of antidiuretic hormone? | Decrease in urine volume. ADH is an antidiuretic hormone secreted by the posterior lobe of the pituitary and functions to make a collecting duct more permeable to water. |
Which component structure of the nephron is responsible for producing hypertonic urine by reabsorbing water while allowing metabolic wastes and NaCl to pass through? | Collecting duct (Proximal convoluted tubule; distal convoluted tubule) |
What should normal urine from a healthy person not contain? | blood, WBCs, sugar (glucose)—diabetes |
If you know the urine output of a patient in the hospital (mL/min) & the concentration of urea in mg/mL; and you are then told the urea concentration of 0.4 mg/mL in the blood, be able to calculate the percentage of cleared urea from glomerular filtrate? | a. C=UV/P (C=renal clearance, U=waste concentration of urine, V=rate of urine output, P=waste concentration of plasma) |
What is micturition and what governs its onset? | elimination of urine from the body and its onset is governed by the filling of the bladder |
Is the thick or thin segment of the nephron loop impermeable to water? | thin segment |
Why does glomerular filtration occur in respect to glomerular oncotic pressure and glomerular blood pressure? | when glomerular oncotic and blood pressures are high, glomerular filtration will occur |
What regulates chloride homeostasis and how is it related to sodium homeostasis? | sodium homeostasis; as sodium is retained or excreted, chloride ions passively flow |
How does the buffering capability of the kidneys compare to other organs? | the buffers help to stabilize the pH of body fluids |
Where is most of the body water located? | blood cells |
When edema occurs, where and in which compartment would fluid be expected to accumulate? | in the extracellular fluid of the leg; in interstitial spaces |
Where is a person’s fluid intake regulated and what type of sensor is involved? | via the skin and the kidneys; osmoreceptors in hypothalamus |
What is the role of antidiuretic hormone (ADH)? | increases water retention by the kidneys, reduces urine volume, and helps prevent dehydration |
Explain how dehydration increases blood and ECF osmolarity. | dehydration results in an increased blood and ECF osmolarity. Osmoreceptors stimulate ADH secretion by the hypothalamus increasing water absorption in the DCT and CD |
What are the principal cations in the ICF and ECF? | ICF-potassium; ECF-sodium |
What is the role of aldosterone? | ”salt retaining hormone;” increases Na+ reabsorption and water and the release of K secretion. This increases blood volume, therefore increases blood pressure. |
Why do women have a tendency to retain water during part of the menstrual cycle? | estrogen mimics the action of aldosterone |
What cation or anion is largely responsible for maintaining intracellular volume? | potassium |
What is the equation that represents the complete chemical reaction for the bicarbonate buffer system? | CO2+H2O=H2CO3=HCO3-+H+ |
What is the normal Ph range of tissue fluid? | 7.35-7.45 |
What are the main buffers for intracellular fluid? | proteins |
How do the kidneys respond to acidosis? | The kidneys will secrete H2PO4. The kidneys compensate for pH imbalances of respiratory origin. |
What happens if an excess of antacids is taken? | metabolic alkalosis—too much bicarbonate in the blood—pH of tissue is elevated beyond normal range |
If you breathe with your head inside a plastic bag what will happen? | The bag will allow CO2 to increase and the respiratory centers are signaled to increase the rate and depth of breathing—return to normal CO2 and slows the breathing rate |
How are fats digested? (Which enzymes are used and where are they located?) | lipases located in pancreas |
What does the large intestine absorb? | Water, Na+ and K, bacteria that multiply and live off the substances in the intestine |
Which nutrients are absorbed without digestion? | Vitamins, free amino acids, minerals, cholesterol, and water |
Anatomically, what are the small and large intestine suspended from the abdominal wall? | peritoneum |
What regulates digestive motility? | enteric nervous system |
What regulates digestive tract secretions? | enteric nervous system |
What regulates digestive tract blood flow? | enteric nervous system |
What cells secrete hydrochloric acid? | parietal cells |
What is the function of chief cells and where are they located? | secrete gastric lipase and pepsinogen; located in lower half of gastric glands |
What is pepsinogen, where is it produced, and by what cells? | a zymogen and a protein; produced in the stomach (gastric glands) by chief cells |
What activates the secretion of pepsinogen? | HCl (hydrochloric acid) |
What are the components of bile and which one has digestive properties? | Bilirubin (pigment), Urobilinogen (brown color of feces), bile acids (steroids synthesized from cholesterol), and Lecithin (a phospholipid—aids in digestion) |
Explain the sodium-glucose transport protein and its role. | a family of glucose transporters; transport glucose across the apical membrane against an uphill glucose gradient |
What is the makeup of feces by weight? | 75% water, 25% solids; 30% bacteria, 30% undigested fiber, 10% to 20% fat |
What stimulates the process of defecation? | stretching of rectum |
What organ systems excrete waste products? | liver, kidneys, lungs, skin (sweat glands) |