Human Excretory System - 1 - Free MCQ Practice Test with solutions, NEET

The left kidney is located slightly more superior than the right kidney due to the larger size of the liver on the right side of the body. Unlike the other abdominal organs, the kidneys lie behind the peritoneum that lines the abdominal cavity and are thus considered to be retroperitoneal organs.

In mines there is high temperature and  water is lost along with salts in the form of sweat so dehydration occurs.

All parts of nephron other than loop of henle lie in the cortex of kidney but the loop of henle lie in medulla of kidney

Excretion is the process by which the body gets rid of waste products and the nitrogenous by-products of metabolism. Through excretion, organisms control osmotic pressure, the balance between inorganic ions and water, and maintain acid-base balance. The process thus promotes homeostasis.

Excretion is the disposal of overabundance particles, water, and metabolic squander from the body. As in all life forms, excretion in creepy crawlies serves to advance the suitable guideline (homeostasis) of the intracellular condition as the way to organismal prosperity and endurance.

Hence, the right answer is option b "removal of useless  substances present in excess."

The urinary bladder is the organ that collects urine excreted by the kidneys before disposal by urination. Urine enters the bladder via the ureters and exits via the urethra.

Mammals excrete urea as their primary nitrogenous waste.

This process occurs because:

• Mammals are classified as ureotelic, meaning they convert ammonia into urea.
• Urea is less toxic than ammonia and requires less water for excretion.
• This adaptation helps conserve water, which is crucial for survival in terrestrial environments.

In summary, the excretory product of mammals is urea, produced through metabolic processes in the liver and eliminated via the kidneys.

Malpighian corpuscles are a number of small, round, deep-red bodies in the cortex of the kidney, each communicating with a renal tubule. Malpighian corpuscles average about 0.2 mm in diameter. Each capsule is composed of two parts: a central glomerulus and a glomerular capsule or Bowman's capsule. The corpuscles are part of a filtering system through which nonprotein components of blood plasma enter the tubules for urinary excretion.

The uriniferous tubule or the kidney tubule is a fine, long, convoluted tubule that is involved in excretory functions. This tubule basically conveys urine from the glomerulus to the renal pelvis. A large amount of water and salts are reabsorbed during the passage of urine through it At certain locations in the kidney tubule, some ions are also secreted into the urine. It includes the Henle's loop, the DCT and PCT, and the collecting tubule.

So, the correct answer is 'Glomerulus'.

In the kidney, the loop of Henle (or Henle's loop, Henle loop, nephron loop or its Latin counterpart ansa nephroni) is the portion of a nephron that leads from the proximal convoluted tubule to the distal convoluted tubule.

The basic functional unit of the kidney is the uriniferous tubule. This is a continuous tubule, which can be divided into a nephron (3 to 4 cm in length) and a collecting duct (2 cm long). Each collecting duct receives urine from several nephrons and carries the urine through a renal pyramid to the renal pelvis.

A notch present on the medial side of the kidney is known as the renal hilum. This is the area where the renal artery, renal vein, nerves, and ureter enter or exit the kidney. However, if you're specifically referring to a notch-like feature, it is often termed as the renal sinus, which houses these structures.

Nephron, which separate the  water and ions from the blood and filter the waste molecules and resend the wanted molecules to the blood. Nephron function through ultrafiltration

Nephron consists of a cup-shaped structure at one end called the Bowman's capsule. It extends into a long urinary tubule,that is surrounded by a network of renal capillaries. The urinary tubules of nephrons in each kidney join to form a common tube called the ureter.

It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and an encompassing Bowman's capsule.The capsule and tubule are connected and are composed of epithelial cells with a lumen. A healthy adult has 0.8 to 1.5 million nephrons in each kidney.

Renin- is the term used in RAS system in excretion to control glomerular blood pressure. Rennin-is the term used in digestion which is present in stomach of infants.

The kidneys are highly vascular (contain a lot of blood vessels) and are divided into three main regions: renal cortex (outer region which contains about 1.25 million renal tubules), renal medulla (middle region which acts as a collecting chamber), and renal pelvis (inner region which receives urine through the major calyces).

Kidneys are reddish-brown, bean-shaped structures situated between the levels of the last thoracic and third lumbar vertebra close to the dorsal inner wall of the abdominal cavity.

Loop of Henle. The Loop of Henle (LoH) is a long, straight, tubular segment connecting the proximal tubule to the distal convoluted tubule and lies parallel to the collecting ducts. The LoH descends from the cortex or medulla (depending on the size/length of the nephron) into the papilla of the kidney.
The loop of Henle is located in the medulla of the kidneys, it is the next step in the renal tubule process after the proximal tubule.

Each kidney of an adult human measures for about 10-12 cm in length, 5-7 cm in width, and 2-3 cm in thickness with an average weight of 120-170 grams.

The inner lining of the urinary bladder is a mucous membrane of transitional epithelium that is continuous with that in the ureters. The second layer in the walls is the submucosa, which supports the mucous membrane. It is composed of connective tissue with elastic fibers.

Liver: This is the main site for the formation and production of bile pigments from hemoglobin.

Spleen: While red blood cells are also broken down in the spleen, leading to the formation of some bile pigments, the liver is the primary organ for this process.

Every body cells: This is incorrect; bile pigments are a product of a specific metabolic process, not a function of all cells.

Excretory formed in every body cell. blood takes the all excretory material & it is purified through the kidney every body cell has the unwanted materials which is not required by the cell.

Sulphates, phosphates, and carbonates of calcium are excreted by the kidney.

The kidneys are responsible for filtering waste products and excess fluids from the blood and excreting them from the body in the form of urine. One of the waste products that the kidneys filter out of the blood is excess calcium, which can be present in the form of sulphates, phosphates, or carbonates. The liver, spleen, and colon are not involved in the excretion of calcium or other waste products from the body.

Through the hilum, the nerves, the ureters and the blood vessels enter the kidneys. The hilum is a notch which is present towards the centre of the inner concave surface of the kidney.

• Cortex is mainly responsible for the formation of columns of Bertini.
• The portion of the cortex which extends in between the medullary pyramids as renal columns form the columns of Bertini.
• The medulla region of the kidney is divided into a few conical masses called medullary pyramids which project into the calyces.

In humans, the kidneys are located in the abdominal cavity. The right kidney is placed at a slightly lower level than the left kidney in order to accommodate the largest gland/organ of the body, the liver. The liver bulges out on the right side of the body and then, tapers off to the left.

Correct option: C

Renal papilla is the tip or apex of a renal pyramid.

The medullary collecting ducts converge into papillary ducts (ducts of Bellini), which open at the papilla; urine from these ducts is discharged into the minor calyx.

Hence, the papilla is structurally part of the renal pyramid and projects into the minor calyx; it is not part of the pelvis or a calyx itself.

renal artery: These arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood.

renal vein: The veins that drain the kidney and connect the kidney to the inferior vena cava.

Renin is released from the juxtaglomerular (JG) cells in response to a decrease in glomerular blood flow, which is crucial for regulating blood pressure.

Statement 1 is correct. The juxtaglomerular (JG) cells respond to a decrease in glomerular blood flow or pressure by releasing renin. This initiates the renin-angiotensin-aldosterone system (RAAS), which works to raise blood pressure and glomerular filtration rate (GFR).

Statement 2 is incorrect. Angiotensin II is a potent vasoconstrictor, which increases blood pressure, and it stimulates the adrenal cortex to release aldosterone. Aldosterone promotes sodium and water reabsorption, which further increases blood volume and blood pressure. Thus, rather than reducing blood pressure, angiotensin II has the opposite effect. Therefore, only Statement 1 is correct.