Most Important Hemostasis MCQs with Answers | Biology MCQs

Kangaroo rats derive about 90% of their water from the cellular oxidation of carbohydrates found in the seeds they eat. This characteristic is called anhydrobiosis.

Ammonia is highly toxic and requires about 500 ml of water per gram of nitrogen to be diluted to a non-toxic level, making it suitable only for animals with constant access to water.

The efferent arteriole arises from the glomeruli and carries blood away from it after filtration has occurred.

The diameter of the efferent arteriole is about half that of the afferent arteriole, creating a bottleneck that significantly increases blood pressure within the glomerulus, which drives filtration.

Pyelonephritis is the medical term for an infection of the kidneys. An infection of the urethra is urethritis, and an infection of the bladder is cystitis.

The countercurrent multiplier mechanism, involving the loop of Henle and vasa recta, achieves the reabsorption of about 99.5% of water from the filtrate by creating a concentration gradient.

The dialysate absorbs waste by-products from the blood by creating a concentration gradient. To prevent the loss of essential substances, the fluid must have normal concentrations of minerals and electrolytes, but it contains no waste products.

When body temperature rises above 37°C (hyperthermia), one of the main physiological responses is sweating. Evaporation of the sweat produces a cooling effect.

Patients are required to take medications such as cyclosporine to suppress their immune system in order to prevent rejection of the transplanted kidney.

The vasa recta are a specialized part of the peritubular capillaries that course into the medulla along with the loops of Henle.

In ESWL, an instrument called a lithotripter generates shock waves from outside the patient's body, which are focused on the stone to break it into small pieces.

During dehydration, anti-diuretic hormone (ADH) promotes water reabsorption from the descending limb and collecting duct, while aldosterone promotes the transport of sodium chloride out of the ascending limb, which also aids water retention.

Tubular secretion is the process by which certain substances, like ammonium and hydrogen ions, are secreted by tubular epithelial cells into the filtrate to maintain the pH of urine.

Ectotherms produce metabolic heat at a low level and rely more on heat derived from the environment to raise their body temperature.

The glomerular filtrate has a chemical composition similar to that of blood plasma, but it lacks larger molecules like proteins, red blood cells, and platelets.

The nephron is the functional unit of the kidney, and it consists of a renal corpuscle and a renal tubule.

The higher risk of UTIs in women is mostly due to the shortness of the female urethra (1.5 inches compared to 8 inches in men), which allows bacteria to be more easily transferred to the bladder.

When urine is persistently acidic, there is a higher risk of forming uric acid type stones. Calcium phosphate stones tend to form in alkaline urine.

The thermoregulatory centre in the human body is located in the hypothalamus, which acts as a thermostat, detecting the temperature of the blood passing through it.

Juxtamedullary nephrons have long loops that extend deep into the medulla. This makes juxtamedullary nephrons key for water retention when water is in short supply.

In peritoneal dialysis, catheters are surgically inserted into the abdominal cavity, through which the dialysate enters and leaves.

Selective reabsorption is the process by which certain substances that have been filtered out of the blood are reabsorbed back into it.

Severe hemorrhage due to trauma is a cause of acute renal failure. Chronic renal failure may be caused by bacterial infections, high blood pressure, and diabetes mellitus.

The ureter begins as the funnel-shaped renal pelvis, which collects urine within the kidney.

Water passes out of the descending limb by osmosis, while the ascending limb actively transports sodium chloride out into the surrounding kidney interstitium.

The urethra is a tube that carries urine from the urinary bladder to the outside of the body.

The main purpose of secreting substances like hydrogen ions is to maintain the pH of the urine, which normally ranges from 4.8 to 7.5.

Homeotherms, like birds and mammals, are able to maintain a fairly constant body temperature by using physiological mechanisms.

Larger molecules like proteins, as well as red blood cells and platelets, are left behind in the blood and do not pass into the glomerular filtrate.

Increased calcium in the blood (hypercalcemia) causes high calcium in the urine (hypercalciuria), which along with high oxalate levels (hyperoxaluria) causes calcium oxalate stones.

The proximal convoluted tubule is where the reabsorption of water, ions, and all organic nutrients occurs.

Shivering is the spasmodic contraction of muscles, and this contraction produces heat which helps to raise the body temperature.

The urinary bladder is a hollow and distensible muscular organ that serves as a urine reservoir.

Animals which excrete urea as their major nitrogenous waste product are called ureotelic.

A fibrous connective tissue layer, called the fibrous capsule, encloses each kidney.

As osmoregulatory organs, the kidneys are concerned with the formation of diluted urine during flooding and concentrated urine during dehydration.

The movement of water out of the descending limb and collecting duct is promoted by anti-diuretic hormone (ADH), which is secreted from the posterior lobe of the pituitary.

The renal medulla consists of a number of cone-shaped renal pyramids.

Piloerection, or the 'erection of skin hair', traps air in the erected hair, which acts as an insulator for heat.

ABO blood group compatibility is essential for a kidney transplant, and it is also usual to select donor kidneys on the basis of human leucocytes antigen (HLA) matching to improve graft survival.

Humans excrete small quantities of uric acid, but this is produced from the breakdown of nucleic acids, not proteins.

The distal convoluted tubule is connected to the collecting duct, which receives filtrate from many nephrons.

Chronic kidney failure can progress to end-stage renal disease (ESRD) and uremia, which is fatal unless treated with dialysis or a transplant.

A behavioral response, such as changing clothing, is voluntary and often corrects a temperature imbalance without the need for a physiological response like shivering or sweating.

The medial side of the kidney is concave, and the entrance to the hollow chamber (renal sinus) is termed the hilum, where the renal artery and nerves enter, and the renal vein and ureter exit.

Peritoneal dialysis involves the use of a natural membrane in the body, the peritoneum, which encloses the abdominal cavity.

The liver supports the excretory role of the kidney by producing ammonia, urea, and uric acid from the nitrogen of amino acids.

Acute renal failure may be caused by an obstruction of the ureters, bladder, or urethra by a kidney stone. Diabetes and high blood pressure are causes of chronic renal failure.

The formation of hypertonic (concentrated) urine is dependent on the reabsorption of water from the loop of Henle and collecting duct, achieved by the countercurrent multiplier mechanism.

Vasodilation is the expansion of blood capillaries beneath the skin, which increases blood flow and allows heat to be carried away from the blood through the skin.

Organisms invest energy to convert ammonia into urea, which is 100,000 times less toxic than ammonia.

The science concerned with the structure, functions, and diseases of the kidneys is called nephrology.

The movement of sodium chloride out of the ascending limb is controlled by the hormone aldosterone.

The renal tubule leads away from the Bowman's capsule and becomes the proximal convoluted tubule (PCT), which then forms the loop of Henle, followed by the distal convoluted tubule (DCT), and finally connects to the collecting duct.

In PCNL, a tube is inserted from the patient's back into the kidney to create a tract, through which a scope and equipment can be inserted to break up and remove the stone.

Animals are classified as poikilotherms if they are unable to maintain their body temperature within narrow limits, and as homeotherms if they are able to maintain a fairly constant body temperature.

Kidney failure is a decline in kidney function, particularly the efficiency of the filtering process. This leads to a buildup of nitrogenous wastes like urea in the blood.

Vasodilation is the expansion of blood capillaries which lie just beneath the epidermis of the skin, leading to more blood flow and subsequent heat loss.

A branching stone that can fill the renal pelvis is called a staghorn stone.

Homeotherms (maintaining constant temperature) include birds and mammals. Endotherms (producing their own heat) also include birds and mammals. Humans are mammals.