Excretory System MCQ Quiz - Objective Question with Answer for Excretory System - Download Free PDF

Explanation:

• The human excretory system includes certain organs that eliminate the wastes such as salts, carbon dioxide, urea, uric acid and water produced by the body.
• The path of the urine in the human excretory system is -

• After filtering from kidney → The urine through Ureter → Stored in Urinary bladder → Exit through urethra.

⇒ Option 4 is correct

Concept: 

Human Excretory system:

• The system of the organ which is used to remove the waste product out from the body is called the human excretory system.
• The major waste product generated in the human body is urea, along with which some other toxins are also generated.
• Urea is eliminated by kidneys by the process of urination and solid wastes are removed from the body by the intestines.

Explanation:

• The human excretory system includes certain organs that eliminate the wastes such as salts, carbon dioxide, urea, uric acid and water produced by the body.
• The path of the urine in the human excretory system is -

• After filtering from the kidney → Urine through Ureter → Stored in the Urinary bladder → Exit through the urethra.

So, the correct option  is, Kidney → Ureter → Urinary bladder → Urethra 

Key Points

• Nephrons are the basic structural and functional units of the kidney responsible for filtration and excretion of waste products from the blood.
• Each human kidney contains approximately 1 million nephrons, which work together to maintain the body's fluid and electrolyte balance.
• Nephrons perform processes such as filtration, reabsorption, and secretion to produce urine, effectively removing waste products like urea and creatinine.
• The nephron consists of several components, including the glomerulus, Bowman's capsule, proximal tubule, loop of Henle, distal tubule, and collecting duct, each playing a crucial role in excretion and maintaining homeostasis.

Additional Information

• Key Components of the Nephron:
  • Glomerulus: A cluster of capillaries where blood is filtered under high pressure. It is surrounded by Bowman's capsule.
  • Bowman's Capsule: A cup-shaped structure that collects the filtrate produced by the glomerulus.
  • Proximal Tubule: Responsible for reabsorbing water, glucose, amino acids, and ions back into the bloodstream.
  • Loop of Henle: Concentrates the urine by reabsorbing water and salts. It has descending and ascending limbs.
  • Distal Tubule: Further adjusts the composition of the filtrate by secretion and reabsorption processes.
  • Collecting Duct: Final site for urine concentration and water reabsorption before urine is transported to the bladder.
• Other Terms:
  • Pancreas: An organ involved in digestion and regulation of blood sugar levels but not in excretion.
  • Palate: The roof of the mouth, unrelated to excretion.
  • Neurons: Nerve cells responsible for transmitting signals in the nervous system, not involved in excretion.

The correct answer is Excretion.

Key Points

• Excretion is the biological process by which organisms eliminate metabolic waste products and toxic substances from the body.
• In humans, the primary organs involved in excretion are the kidneys, which filter blood to form urine containing urea and other waste products.
• The liver also plays a crucial role in detoxifying harmful substances and converting ammonia to urea.
• The skin, lungs, and intestines also participate in excretion by removing excess salts, water, and carbon dioxide.

Additional Information

• Urea: A nitrogenous waste product formed in the liver through the urea cycle; it is less toxic and more water-soluble than ammonia.
• Kidneys: Organs that filter blood to produce urine, which contains waste products like urea, creatinine, and excess salts.
• Nephrons: The functional units of the kidney, each nephron filters blood, reabsorbs needed substances, and excretes waste as urine.
• Homeostasis: The process by which the body maintains a stable internal environment, including the regulation of waste product removal and water balance.
• Dialysis: A medical procedure that mimics kidney function by removing waste products and excess fluid from the blood in patients with renal failure.

The correct answer is Kidney.

Key Points

• Humans and animals have a pair of bean-shaped organs called the kidneys.
• They get rid of waste items, keep electrolyte levels regulated, and keep blood pressure under control.
• The location of the kidneys is right below the rib cage, and they are present as a pair of two.
• There is one Kidney on each side of the spine.
• Because there is less room between the liver and the right Kidney, the right Kidney is often positioned somewhat lower than the left Kidney.
• The kidneys are responsible for regulating homeostasis as their primary function.
• They ensure that the fluid levels, electrolyte balance, and other elements that maintain the body's internal environment are comfortable and stable.
• Tubules in the kidneys can reabsorb nutrients from the blood and then transport them to where the body needs them the most.
• They absorb nutrients like glucose, sodium, chlorine, potassium, water, etc.

Additional Information

• Urinary Bladder

  • The urinary bladder is an organ that stores urine until it is expelled by urination.
  • Its primary function is to collect urine.
  • After the urine has been filtered via the kidneys, the Urinary bladder allows for reabsorption using a feedback mechanism if needed.
  • The transitional epithelium that lines the urine bladder is responsible for the absence of mucus production in this organ.

• Ureter

  • Urine is transported from the Kidney to the urinary bladder through the ureter, a tube in the body.
  • There is one ureter connected to each Kidney, making a total of two.
  • The pelvis region is home to the lower portion of the ureter, whereas the abdominal cavity houses the higher portion of this organ.
  • The tube has strong walls capable of contracting and is made of a mucus coat, a muscle coat, and a coat of fibrous tissue.

• Urethra

  • Urine is expelled from the body via a tube called the urethra, a small tube connected to the bladder.
  • The female urethra small about 1.5 inches long, whereas the length of the male urethra, ranges from 7 to 8 inches.
  • Three sections make up the male urethra. These sections include the prostatic urethra, the membranous urethra, and the spongy urethra.
  • The female urethra is somewhat less complicated than the male one since it needs to travel a shorter distance.
  • Its main function is to facilitate the passage of urine from the bladder and out of the body.
  • When an animal urinates, the brain signals to the bladder that it is time to squeeze. The bladder responds by relaxing the sphincter muscle, allowing urine to pass through the urethra.

• The prostate gland is present below the urinary bladder.
• The prostate gland in male helps to control urination from the bladder.
• The prostate is a gland connected to the testicles at one end and the penis on the other end.
• While ejaculation the prostate stores semen and makes fluid which liquefies it before it ejects out of the penis.
• DIAGRAM

The correct answer is Urea.

• When our cells perform their functions, certain waste products are released. These are toxic and hence need to be removed from the body.
• The process of removal of wastes produced in the cells of the living organisms is called excretion. The parts involved in excretion from the excretory system.
• Human excretory system: A mechanism to filter the blood is required and done by the blood capillaries in the kidneys. When the blood reaches the two kidneys, it contains both useful and harmful substances. The useful substances are absorbed back into the blood. The wastes dissolved in water are removed as urine.

• Aquatic animals like fishes, excrete cell waste as ammonia which directly dissolves in water.
• The major excretory product in humans is urea.

Important Points

• An adult human being normally passes about 1–1.8 L of urine in 24 hours. The urine consists of 95% water, 2.5% urea, and 2.5% other waste products.

Concept:

Human Excretory system:

• The system of the organ which is used to remove the waste product out from the body is called the human excretory system.
• The major waste product generated in the human body is urea, along with which some other toxins are also generated.
• Urea is eliminated by kidneys by the process of urination and solid wastes are removed from the body by the intestines.

Excretory system organs:

1. Kidneys:It is a bean shaped organ. Its function is to clean blood and eliminate the waste from the blood in form of urine

• It is present in the abdomen, just below the diaphragm, and is protected by ribs.
• Each kidney weighs 120g to 170 g and 10-12 cm long and 5-7 cm wide and is the size of a fist.
• Kidneys are made up of subunits called Nephron

      2.Ureters: ​Each kidney is connected to the rinal pelvis by a thin muscular tube, this tube is called as Ureter.

• Its function is to propel urine from the kidney to the urinary Bladder from time to time.

      3.Bladders: It's the organ that controls the passage of urine, it is a muscular sac-like structure.

• The average capacity of the bladder is 400-600 ml.
• It holds urine until its capacity expels, or till it gets full.

    4.Urethra: The Urethra is a tube made up of fibro muscular tissue that arises from the lower opening of the bladder, and open to the external uretral orifice.

• It helps to expel urine through the body, in the male it is also the tube that consist of the sperms.

Explanation:

• In kidneys, the Nephron is the functional unit, each kidney has as many as 1 million nephrons in each human kidney.
• The basic functions of the nephron are to carry out secretion as well as the process of excretion and also called as filtration unit of the human excretory system.
• Each nephron is made up of a Malpighian body.
• Nephrons are of two types which are Cortical Nephrons and Juxtamedullary Nephrons.

So, the Nephron is the part that is also called as filtration unit of the Excretory unit.

Explanation:

• Loop of Henle is part of Nephron.
• It is a functional and structural unit of the kidney which plays major role in Excretion. 
• Loop of Henle, long U-shaped portion of the tubule that conducts urine within each nephron of the kidney of reptiles, birds, and mammals.
• The principal function of the Loop of Henle is in the recovery of water and sodium chloride from urine.

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So the correct option is Excretion.

• The urethra is a tube that carries urine from the Urinary bladder.
• In females, urethra contains only urine, while in males, it contains both urine and sperms.
• Additional Information:

1. Vas deferens, present in males, which carry the sperm from the epididymis to the ejaculatory ducts.
2. Ureter carries urine from a kidney to the urinary bladder.
3. The oviduct is a tube through which the ovum passes from the ovary to uterine cavity.

The correct answer is Urethra.

• Urethra the duct which takes the urine out from the urinary bladder to the outside of the body.
• ​The urethra is a tube that binds the urinary bladder to the urinary meatus for the removal of both female and male urine from the body.
• It ties up with the urinary meatus above the vagina in human females and other primates.
• The ureters are tubes formed from smooth muscle fibres that carry urine to the urinary bladder from the kidneys.
• The dorsal aorta is a blood vessel that brings oxygenated blood from the gills to the rest of the body in a single pass circulatory system.

The correct answer is Excretion.

Key Points 

• In humans, the kidney is one of the main organs of the excretory system.
• The kidney's function is the filtration of the blood and removing waste(toxic) products.
• Waste products and excess fluid are removed through the urine.
• If the kidney fails person needs to undergo dialysis.
• Dialysis is a treatment that filters and purifies the blood using a machine
• The human excretory system includes certain organs that eliminate the wastes such as salts, carbon dioxide, urea, uric acid and water produced by the body.
• The path of the urine in the human excretory system is -
• After filtering from the kidney → The urine through Ureter → Stored in the Urinary bladder → Exits through the urethra.

Additional Information 

• Respiration- It is the movement of oxygen from the environment and the transport of carbon dioxide back to the environment.
• Transportation- The blood is responsible to transport hormones, oxygen, food, and waste materials in human bodies.

The correct answer is Ureter.

Key Points

• In humans, the kidney is one of the main organs of the excretory system.
• The kidney's function is the filtration of the blood and removing waste(toxic) products.
• Waste products and excess fluid are removed through the urine.
• If the kidney fails person needs to undergo dialysis.
• Dialysis is a treatment that filters and purifies the blood using a machine
• The human excretory system includes certain organs that eliminate the wastes such as salts, carbon dioxide, urea, uric acid and water produced by the body.
• The path of the urine in the human excretory system is -
• After filtering from the kidney → The urine through Ureter → Stored in the Urinary bladder → Exits through the urethra.

The correct answer is Urobilin or Urochrome.

• The yellow colour of the urine is due to the presence of pigment urochrome.

Key Points

• Normal urine colour ranges from pale yellow to deep amber 
• Pigments and other compounds in certain foods and medications can change your urine colour.
• Additional Information

• During summer when the surrounding temperature is high, we lose water in the form of sweat.
• Hence kidneys retain water for maintaining the fluidity of the blood and less urine is formed. 
• But during winter, the surrounding temperature will be very low.
• There will not be any sweating, no evaporation losses.
• Moreover, to keep the body temperature constant, the blood capillaries in the skin get constricted and the blood pressure is increased.
• The result is that our body gets warmed up.
• In order to maintain the blood pressure normal, the excess water along with the wastes is excreted mostly in the form of urine.
• This is the reason for more urine output and frequent urination under very cool conditions and in winter.

The correct answer is Liver.

Key Points

• Liver
  • The liver is the largest exocrine gland in the human body.
  • The liver is the largest gland of the body weighing about 1.2 to 1.5 kg in an adult human.
  • The exocrine glands have sweat glands, salivary glands, mammary glands, and many glands of the digestive system.
  • The structure of the exocrine glands is divided into two parts:- Ductal portion and the Glandular portion.​

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