Excretory Products & their Elimination Important Questions

Ans: Glomerulus

Ans: The ascending limb of Henle's loop is watertight. Water can pass through Henle's loop's descending limb.

Ans: Urine has a slightly acidic pH of 6.0.

Ans: 

1. Ammonotelism 
2. Ureotelism 
3. Uricotelism

Ans: Bowman's capsule epithelial cells are referred to as podocytes.

Ans: Aldosterone is a hormone that regulates the body's sodium levels.

Ans: Kidneys do not play a significant role in ammonia removal. Ammonia is a gas that dissolves easily in water and spreads throughout the body. Ammonia is expelled as ammonium ions through the gill surface.

Ans. The glomerular filtration rate is the amount of filtrate produced by the kidneys each minute. (GFR). The glomerular filtration rate (GFR) is a test that measures how well the kidneys work. It computes how much blood flows through the glomeruli each minute. Glomeruli are microscopic filters in the kidneys that filter waste from the blood.

In a healthy person, the normal GFR range is 100 to 130.

Ans. Vasa recta are capillaries with thin walls and a U shape that emerge from different arterioles and travel parallel to Henle's loop.

They maintain the osmolarity of the reabsorbed ions in the medullary tissue fluid.

Ans: The most common nitrogenous waste product produced by birds is uric acid.

Its benefits are as follows:

(I) Uric acid can be removed with little to no water.

(ii) Uric acid is far less dangerous and can be eliminated gradually.

Ans. The process of excreting urine from the urinary bladder is known as urination. Micturition is another name for it. The urinary bladder stores urine, a liquid containing waste products excreted by the body and collected from the bloodstream by the kidneys.

Ans: Micturition is the act of avoiding urine. It is accomplished by contracting the smooth muscles of the urine bladder wall while relaxing the skeletal muscular sphincters surrounding the bladder entrance. Stretch receptors in the bladder wall generate nerve impulses that are transmitted to sensory neurons in the spinal cord and brain, resulting in the sensation of fullness as the bladder membrane stretches due to urine collection. The sphincter muscles, on the other hand, can be voluntarily relaxed, allowing the smooth muscles of the bladder to contract under autonomic control, allowing the bladder to be emptied.

Ans: A dialysis machine is another name for an artificial kidney. When the kidneys fail, the blood is filtered. In dialysis, small solute molecules permeate across a semipermeable membrane to replace the glomerulus. It has a cellophane membrane through which blood from the patient can flow on one side and surrounding fluid on the other. Through the cellophane membrane, wastes from the blood enter the surrounding fluid. It is required when the kidney fails to function and urine cannot be formed.

Ans: The liver is a digestive organ that secretes bile to help with fat digestion.

The liver functions as an excretory organ, secreting bilirubin, biliverdin (haemoglobin degradation products), cholesterol, inactivated steroid hormones, medications, and other wastes into the bile, which is then excreted along with digestive wastes or faecal matter.

Ans: When the volume of the filtrate is compared to the volume of urine formed per day, which is 180 litres and 1.5 litres, it can be extrapolated that 99 percent of the filtrate must be reabsorbed by the renal tubules, a phenomenon known as reabsorption. Amino acids, Na+, and glucose are actively reabsorbed in the filtrate and thus do not appear in urine.

Ans. The urinary system consists of the organs listed below.

• A set of kidneys
• A ureter 
• The urinary bladder
• Urethra

The kidneys are situated in the abdomen, one on each side of the spinal column, just below the diaphragm, which is protected by the last two pairs of ribs. The left kidney is typically positioned higher than the right. Each kidney measures about 10cm in length, 4cm in thickness, and 5cm in width. Each kidney has a bean-like shape with a concavity along the inner border. At this point, blood vessels, lymph ducts, nerves, and ureters enter the kidney. Two distinct regions of the kidney's gross anatomy can be identified. 

Each kidney is composed of numerous microscopic units known as nephrons or uriniferous tubules, which are all structurally and functionally similar.

Each nephron is made up of a vascular component, a glomerulus, and a tubular component that are all connected by a network of capillaries. The tubule is made up of a single layer of epithelial cells that vary in structure and function depending on where they are in the tubule. 

Bowman's capsule is a blind sac with a single layer of thin epithelial cells lining it. Bowman's capsule eventually becomes associated with vascular glomerulus, which protrudes into the capsule and is completely covered by the capsule lining.

Bowman's capsule eventually becomes associated with vascular glomerulus, which protrudes into Bowman's capsule and is completely covered by the capsule's lining. The glomerulus is produced by a variety of arteries. Afferent arterioles bring blood to the tubule, and efferent arterioles remove blood. As a result, the blood in the glomerulus is separated from the space within the capsule by only a thin layer of tissue formed by the single-celled capillary lining.

Bowman's capsule's single-celled lining is made of

• The basement membrane is a layer of material.
• Bowman's capsule has a single-celled shaped lining.

Through this extremely thin barrier, fluid from the capillaries can be filtered into Bowman's capsule. Different arterioles are formed when glomerular capillaries join to form different arterioles, which then divide into numerous capillaries scattered across the surface of the tubule. These capillaries are known as capillaries. When these capillaries connect, venous channels form, which carries blood away from the kidney. 

Bowman's capsule opens in the tubule's proximal convoluted section, which is divided into three sections. The section after that is Henle's loop, and the section after that is the distal convoluted section, which eventually becomes a collecting duct.

The ureters are two tubes about 30 cm long that exit each kidney. They enter the urine bladder and run downward.

The urinary bladder is a bag-like structure in which urine is stored. The bladder has three openings: two for the ureters and one for the urethra.

Ans: There are two important hormonal controls of kidney function that can be identified via negative feedback circuits:

Antidiuretic Hormone (ADH) Control: ADH, which is produced in the hypothalamus of the brain and released into the bloodstream by the pituitary gland, increases fluid retention by causing the kidneys to reabsorb more water. 

The release of ADH is triggered when hypothalamic osmoreceptors detect an increase in blood osmolality. Thirst is also promoted by the osmoreceptor cells. Drinking lowers blood osmolarity, which inhibits ADB secretion and thus completes the feedback circuit.

Juxtaglomerular Apparatus (JGH) Control: It makes use of a multi hormonal Renin-Angiotensin-Aldosterone System (RAAS). JGA responds by lowering blood pressure and releasing the enzyme renin into the blood. The enzyme initiates chemical reactions in the blood that convert a plasma protein called angiotensinogen to a peptide called angiotensin II, which functions as a hormone.

Angiotensin II raises blood pressure and stimulates the adrenal gland to produce the hormone aldosterone. This causes an increase in blood volume and pressure, completing the feedback circuit by promoting renin release.

Another hormone, a peptide known as Atrial Natriuretic Factor ANF), opposes RAAS regulation.

Thus, ADH, RAAS, and ANF form a complex system of checks and balances that regulate kidney function in order to control the body.

Ans: The human skin contains glands that secrete sweat and sebum (from the sebaceous gland). Sweat contains sodium chloride (NaCl), lactic acid, urea, amino acids, and glucose. Sweat volume ranges from negligible to 14 L per day. Sweat's primary function is to cool the body's surface through evaporation.

Sebum is a waxy protective secretion that keeps the skin oily, and it eliminates some lipids like waxes, sterols, other hydrocarbons, and fatty acids. Many animals' integuments excrete ammonia into the environment via diffusion.

The role of the lungs in excretion: In normal resting conditions, human lungs eliminate approximately 18L of CO₂ per day and approximately 400 mL of water. Water loss through the lungs is small in hot humid climates and large in cold dry climates. The water loss through the lungs is also affected by the rate of ventilation and the pattern of ventilation. Different volatile materials are also easily eliminated through the lungs.

Ans: Urinary system diseases are as follows:

Polynephritis: It is a bacterial infection that causes inflammation of the kidney's renal pelvic nephrons and medullary tissues. It has an impact on the countercurrent mechanism. The most common symptoms are frequent and painful urination, fever, and lumbar pain.

Uremia: This condition is caused by a high concentration of urea, uric acid, creatinine, and other substances in the blood as a result of a bacterial infection or an obstruction in the urinary system's passage. The cells are poisoned by urea. It is not excreted in the urine and builds up in the blood.

Renal stones are formed when uric acid precipitates and accumulates in the nephrons of the kidneys, or when calcium phosphates and oxalates accumulate in the nephrons of the kidneys, resulting in renal stones. It causes urination blockage or frequent painful urination, as well as blood in the urine. Renal stones cause severe colic pain that radiates down to the front of the thigh, vulva, or testicle on that side.

Glomerulonephritis: This condition is distinguished by Glomeruliduct inflammation, kidney injury, an abnormal allergic reaction, or streptococci bacteria infection. Proteins and red blood cells are filtered out of the glomerular filtrate. In severe cases of infection, it can lead to kidney failure.

Oedema: It is characterised by an increase in the volume of interstitial fluid, which is primarily caused by the retention of excess Na+ ions, which causes water retention. Dining oedema is exacerbated by high blood pressure.