Excretory Organ Flashcards PDF

**Flashcard 1:** - **Q:** What are the major forms of nitrogenous waste excreted by animals? - **A:** Ammonia, urea, and uric acid. **Flashcard 2:** - **Q:** Which process refers to the excretion of ammonia? - **A:** Ammonotelism. **Flashcard 3:** - **Q:** What are ureotelic ani...

**Flashcard 1:** - **Q:** What are the major forms of nitrogenous waste excreted by animals? - **A:** Ammonia, urea, and uric acid. **Flashcard 2:** - **Q:** Which process refers to the excretion of ammonia? - **A:** Ammonotelism. **Flashcard 3:** - **Q:** What are ureotelic animals? - **A:** Animals that excrete urea as their major nitrogenous waste. **Flashcard 4:** - **Q:** Name the excretory structures in Platyhelminthes, like Planaria. - **A:** Protonephridia or flame cells. **Flashcard 5:** - **Q:** What is the role of Malpighian tubules in insects? - **A:** They help in removing nitrogenous waste and in osmoregulation. **Flashcard 6:** - **Q:** What is the primary function of Henle\'s loop in the nephron? - **A:** It maintains high osmolarity in the medullary interstitial fluid. **Flashcard 7:** - **Q:** What is the approximate glomerular filtration rate (GFR) in a healthy human? - **A:** 125 ml/min (180 liters/day). **Flashcard 8:** - **Q:** Which hormone facilitates water reabsorption in the kidneys? - **A:** Antidiuretic hormone (ADH). - **Q:** What are the two main parts of a nephron? - **A:** Glomerulus and renal tubule. - - **Q:** What is the role of the juxta glomerular apparatus (JGA)? - **A:** It regulates the glomerular filtration rate (GFR) and blood pressure through the renin-angiotensin mechanism. - **Flashcard 11:** - **Q:** What is micturition? - **A:** The process of expelling urine from the urinary bladder. - - **Flashcard 12:** - **Q:** Which structure in the nephron is primarily responsible for filtering blood? - **A:** The glomerulus. - - **Flashcard 13:** - **Q:** What are the excretory structures in earthworms called? - **A:** Nephridia. - - **Flashcard 14:** - **Q:** What is the significance of the counter current mechanism in the kidneys? - **A:** It helps maintain a concentration gradient, allowing water reabsorption and urine concentration. - - **Flashcard 15:** - **Q:** What substances are actively secreted by the distal convoluted tubule (DCT)? - **A:** Hydrogen ions (H+), potassium ions (K+), and ammonia (NH3). - - **Flashcard 16:** - **Q:** What is the term for kidney stones? - **A:** Renal calculi. - - **Flashcard 17:** - **Q:** How does the hormone aldosterone affect the kidneys? - **A:** It promotes the reabsorption of sodium (Na+) and water, increasing blood pressure and GFR. - - **Flashcard 18:** - **Q:** What condition is characterized by the accumulation of urea in the blood? - **A:** Uremia. - **Q:** What are the three main processes involved in urine formation? - **A:** Glomerular filtration, reabsorption, and secretion. - **Q:** What is glomerular filtration? - **A:** It is the process of filtering blood through the glomerulus, where plasma and dissolved substances pass through the filtration slits into Bowman's capsule. - **Q:** What is the role of the proximal convoluted tubule (PCT) in urine formation? - **A:** The PCT reabsorbs essential nutrients, electrolytes, and water, and helps maintain the pH and ionic balance by selective secretion of hydrogen ions and ammonia. - **Q:** What happens in the descending limb of Henle's loop? - **A:** It is permeable to water but almost impermeable to electrolytes, concentrating the filtrate as water is reabsorbed. - **Q:** What is the function of the ascending limb of Henle's loop? - **A:** It is impermeable to water but allows the active or passive transport of electrolytes, diluting the filtrate as it moves upward. - **Q:** What is the main function of the distal convoluted tubule (DCT)? - **A:** It reabsorbs sodium (Na+) and water conditionally and also secretes hydrogen ions (H+), potassium ions (K+), and ammonia (NH3) to maintain pH and ionic balance. - **Q:** How does the collecting duct contribute to urine concentration? - **A:** The collecting duct reabsorbs large amounts of water and allows the passage of small amounts of urea to maintain medullary osmolarity, producing concentrated urine. - **Q:** What percentage of the filtrate is reabsorbed in the nephron during urine formation? - **A:** Approximately 99% of the filtrate is reabsorbed. - **Q:** What is the role of the counter current mechanism in the kidneys? - **A:** It helps create a concentration gradient in the medullary interstitium, which facilitates water reabsorption and urine concentration through the loop of Henle and vasa recta. - **Q:** What is glomerular filtration rate (GFR)? - **A:** GFR is the amount of filtrate formed by the kidneys per minute, approximately 125 ml/min (180 liters/day) in a healthy individual. - **Q:** Which hormone is released by the hypothalamus to regulate water reabsorption in the kidneys? - **A:** Antidiuretic hormone (ADH), also known as vasopressin. - **Q:** How does ADH affect kidney function? - **A:** ADH increases water reabsorption in the distal convoluted tubule (DCT) and collecting duct, reducing urine volume and preventing dehydration. - **Q:** What is the function of the juxta glomerular apparatus (JGA)? - **A:** The JGA regulates the glomerular filtration rate (GFR) and blood pressure by releasing renin in response to low blood pressure or GFR. - **Q:** What is the role of renin in the renin-angiotensin mechanism? - **A:** Renin converts angiotensinogen in the blood into angiotensin I, which is then converted to angiotensin II, a vasoconstrictor that increases blood pressure and GFR. - **Q:** How does angiotensin II regulate kidney function? - **A:** Angiotensin II constricts blood vessels, increases blood pressure, stimulates aldosterone release, and increases sodium and water reabsorption in the kidneys. - **Q:** What is the role of aldosterone in kidney regulation? - **A:** Aldosterone promotes the reabsorption of sodium (Na+) and water from the distal parts of the nephron, helping to increase blood pressure and GFR. - **Q:** What effect does Atrial Natriuretic Factor (ANF) have on kidney function? - **A:** ANF causes vasodilation, reducing blood pressure and acting as a check on the renin-angiotensin mechanism. - **Q:** What triggers the release of ADH from the hypothalamus? - **A:** The osmoreceptors in the body sense changes in blood volume, fluid volume, and ionic concentration, triggering the release of ADH when there is excessive fluid loss. - **Q:** How does the renin-angiotensin mechanism restore GFR during low blood pressure? - **A:** It increases blood pressure through vasoconstriction and promotes sodium and water reabsorption, restoring GFR to normal levels. - **Q:** What happens when the body fluid volume increases? - **A:** Osmoreceptors are deactivated, reducing ADH release, which leads to a decrease in water reabsorption, resulting in more dilute urine. - **Q:** What is uremia? - **A:** Uremia is a condition where there is an accumulation of urea in the blood, often leading to kidney failure. - **Q:** How is uremia treated in patients with kidney failure? - **A:** Uremia can be treated using **hemodialysis**, a process where blood is filtered through an artificial kidney (dialyzing unit) to remove urea and other waste products. - **Q:** What is kidney transplantation? - **A:** Kidney transplantation is the surgical replacement of a failing kidney with a healthy kidney from a donor, often a close relative to reduce the chance of rejection. - **Q:** What are renal calculi? - **A:** Renal calculi are kidney stones, which are insoluble masses of crystallized salts like oxalates that form within the kidney. - **Q:** What is glomerulonephritis? - **A:** Glomerulonephritis is an inflammation of the glomeruli in the kidneys, which can impair their function. - **Q:** What is the main function of hemodialysis? - **A:** Hemodialysis filters blood to remove nitrogenous wastes like urea when the kidneys are unable to perform this function naturally. - **Q:** What is the function of the dialysis fluid in hemodialysis? - **A:** The dialysis fluid has a composition similar to plasma, except it lacks nitrogenous wastes, allowing waste products to diffuse out of the blood through a semi-permeable membrane. - **Q:** Why is a close relative often preferred as a kidney donor for transplantation? - **A:** A close relative is preferred to minimize the chances of the kidney being rejected by the recipient\'s immune system. - **Q:** What happens during glomerulonephritis? - **A:** Inflammation of the glomeruli impairs the kidney's ability to filter waste, leading to the buildup of harmful substances in the blood. - **Q:** What are the potential consequences of untreated uremia? - **A:** Untreated uremia can lead to severe health complications, including coma and death, due to the accumulation of toxic waste products in the blood.