Test: Excretion in Humans - JSS 2 MCQ

Kidney failure leads to the accumulation of waste products in the blood, as the kidneys are unable to effectively filter and excrete these substances. This condition can be life-threatening and may require treatments such as dialysis or kidney transplantation to manage.

The kidneys play a crucial role in the excretory system by filtering blood to remove waste products such as urea, excess water, and salts. This filtration process forms urine, which is subsequently transported to the urinary bladder for storage. The kidneys also help maintain the body's fluid and electrolyte balance, ensuring homeostasis.

The liver is responsible for breaking down amino acids and producing urea, which is then sent to the kidneys for excretion. Additionally, it helps eliminate bile pigments and excess vitamins. This detoxification process is vital for maintaining the body's internal environment and preventing toxic buildup.

The urethra is the tube that carries urine from the urinary bladder to the outside of the body. While the kidneys produce urine and the bladder stores it, the urethra has the critical role of expelling urine during urination.

The Bowman's capsule is the cup-like structure at the beginning of the nephron that collects filtrate from the blood during the filtration process. It is essential for initiating urine formation by containing the glomerulus, where blood is filtered to remove waste products.

The ureters are narrow tubes that carry urine from each kidney to the urinary bladder. They play a crucial role in the excretory system by ensuring that urine produced in the kidneys is effectively transported for storage prior to elimination.

Osmoregulation refers to the process by which the body maintains the balance of water and salts in the blood. This is primarily managed by the kidneys, which adjust urine concentration based on hydration levels and electrolyte needs, ensuring that bodily functions remain stable.

Glucose is normally reabsorbed by the kidneys and not excreted in urine under healthy conditions. The kidneys filter out waste products like urea, uric acid, and excess salts, but they typically reabsorb glucose back into the bloodstream to be utilized by the body for energy.

Severe abdominal pain is a common symptom of kidney stones, often described as sharp or cramping pain that may radiate to the lower back or groin. This pain occurs when the stones obstruct the urinary tract, leading to discomfort and potential complications.

The average daily urine output for a healthy individual is approximately 1.2 liters. This amount can vary based on factors such as fluid intake, climate, and physical activity, reflecting the body’s need to maintain fluid balance.

Urinary tract infections (UTIs) are primarily caused by bacterial infections that affect the kidneys, ureters, bladder, or urethra. Symptoms often include a frequent urge to urinate and pain during urination, and they are typically treated with antibiotics to clear the infection.

The lungs play a vital role in excretion by removing carbon dioxide, a waste product of cellular respiration. Carbon dioxide is transported from the blood to the lungs, where it is exhaled, helping to regulate the body’s pH and gas exchange.

Nephrons are the functional units of the kidneys, responsible for filtering blood, removing waste products, and forming urine. Each nephron consists of a glomerulus and a renal tubule, where various substances are reabsorbed or excreted based on the body’s needs.

The renal pelvis is the funnel-shaped structure in the kidney that collects urine from the nephrons before it is transported through the ureters to the urinary bladder. It acts as a conduit for urine, ensuring efficient drainage from the kidney.

Excess salts, such as sodium chloride, are typically excreted through urine. The kidneys filter out these excess minerals to help maintain electrolyte balance in the body, which is essential for various physiological functions.

Kidney stones are a common disorder of the urinary system, formed when substances like calcium or uric acid crystallize in urine. They can cause significant pain and may block urine flow, often requiring medical intervention. Staying hydrated is essential in preventing their formation.

The kidneys help regulate blood pressure by producing hormones such as renin, which plays a role in the renin-angiotensin-aldosterone system (RAAS). This system helps control blood volume and systemic vascular resistance, crucial factors in maintaining blood pressure.

Urea is the primary waste product formed from the breakdown of proteins and is removed from the body through urine. It is produced in the liver from ammonia, which is toxic, and is much less harmful, making it a safe way to excrete nitrogenous waste.

Excess water-soluble vitamins, particularly vitamins B and C, are typically excreted through urine. Unlike fat-soluble vitamins, which the body can store, water-soluble vitamins need to be regularly consumed, and any surplus is eliminated to prevent toxicity.

The skin contributes to excretion by secreting sweat through sweat glands. Sweat contains excess water, salts, and small amounts of urea, helping to regulate body temperature and remove some waste products from the body.