7 Most FAQ’s of Excretion Chapter in Class 10th Biology (TS/AP)

8 Marks

LAQ-1 : What is osmo regulation? How is it maintained in the human body? (OR) What is the role of kidney in maintaining the osmo-regulation in the body?

Introduction

Osmo-regulation refers to the process through which the human body maintains a balance of water and dissolved solutes, crucial for preventing dehydration or overhydration. This balance is essential for the proper functioning of cells and tissues. The kidneys play a central role in osmoregulation, but other organs also contribute. Let’s explore how osmoregulation is maintained in the human body, focusing on the role of the kidneys.

Understanding Osmo-Regulation

Osmo-regulation is the maintenance of water balance and ion concentration within the body, involving both the intake and excretion of fluids.

Role of Kidneys in Osmo-Regulation

1. Primary Excretory Organs:
   The kidneys are the chief excretory organs in maintaining osmoregulation. They filter the blood and form urine, removing excess water and waste products while regulating the volume and concentration of bodily fluids.
2. Nephron Function:
   Nephrons, the functional units of the kidney, are responsible for filtration. They selectively reabsorb water and essential nutrients, allowing waste products and excess electrolytes to be eliminated.
3. Hormone Regulation:
   The hormone vasopressin (or antidiuretic hormone) is released when the concentration of urine needs to be increased. It regulates the permeability of kidney tubules to water, helping maintain the balance of water and solutes.
4. Drinking Water Effect:
   If a person drinks a lot of water, less reabsorption of water is required, and vasopressin is not secreted. This response helps to eliminate excess water through urine.
5. Diseases Related to Osmo-Regulation:
   A deficiency of vasopressin can lead to diabetes insipidus, a rare condition resulting in excessive, repeated, and dilute urination.
6. Other Organs Involved:
   Besides kidneys, organs such as the lungs, skin, and liver also play roles in excretion and maintaining osmoregulation. For instance, lungs expel water vapor, and the skin releases sweat.

Summary

Osmoregulation is vital for the health and proper functioning of the human body. It ensures a stable internal environment for cells by balancing water and dissolved solutes. The kidneys are central to this process, filtering blood and regulating water reabsorption through complex mechanisms involving nephrons and hormones. Understanding osmoregulation highlights the intricate balance maintained within our bodies and the essential role played by our kidneys and other organs.

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LAQ-2 : Read the following table and answer the following questions.

S.No.	Structure	Location
1.	Tricuspid values	Right auriculo – ventricular aperture
2.	Gaurd cells	Epidermis of leaves
3.	Glomerulus	Nephron
4.	Alveoli	Lungs
5.	Acrosome	Above the head of a sperm

1. “Tricuspid value” is corrected to “Tricuspid Valve,” which is a structure of the heart.
2. For the Acrosome, the explanation is refined for accuracy: it helps in the penetration of the sperm into the egg, not the ovary.
3. “Guard cells” are replaced with “Stomata” as they are more directly associated with gaseous exchange, alongside Alveoli.
4. “Glomerulus” is correctly identified as part of the excretory system.

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LAQ-3 : What is meant by excretion? Explain the process of formation urine? (OR) Give the mechanism of urine formation.

Introduction

Excretion is a crucial biological process in the human body where waste or non-useful products are eliminated. A primary function of excretion is the formation of urine in the kidneys. The mechanism of urine formation involves several stages: filtration, re-absorption, secretion, and concentration.

Mechanism of Urine Formation

1. Glomerular Filtration:
   • Blood enters the glomerulus in the kidney through an afferent arteriole.
   • The efferent arteriole, being smaller in diameter, causes blood to flow under high pressure.
   • This pressure aids in ultrafiltration, where waste products, nutrients, and water are filtered into the Bowman’s capsule.
   • The filtrate formed is known as primary urine.
2. Tubular Re-absorption:
   • The chemical composition of primary urine is similar to blood, excluding blood cells.
   • The filtrate moves into the Proximal Convoluted Tubule (PCT), where useful substances are re-absorbed.
   • The peritubular capillary network around the PCT assists in this re-absorption.
3. Tubular Secretion:
   • Some waste products not filtered initially are secreted in the Distal Convoluted Tubule (DCT).
   • The peritubular network around the Loop of Henle and DCT secretes additional waste products like salts and ions.
   • This process is vital in maintaining the pH level and concentration of urine.
   • Some secretion also occurs at the Proximal Convoluted Tubule (PCT).
4. Formation of Concentrated Urine:
   • Further concentration of urine occurs in the collecting ducts.
   • The hormone vasopressin regulates this process.
   • A deficiency of vasopressin can lead to Diabetes Insipidus, characterized by excessive and dilute urination.

Summary

Excretion is an essential bodily process responsible for removing waste products and maintaining homeostasis. Urine formation, a key aspect of excretion, occurs through a series of well-coordinated stages in the kidneys: filtration, re-absorption, secretion, and concentration. This complex process ensures the body retains necessary nutrients while eliminating unwanted substances, contributing to overall health and homeostasis.

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LAQ-4 : Name different excretory organs in human body and excretory material generated by them? (OR) Write about the accessory excretory organs and their excretory products in human body. (OR) What are the necessary excretory organs in human body? How does the liver carry out excretion as a secondary function. (OR) Write about the necessary excretory organs and their excretory substances in human beings.

Introduction

Excretion is the biological process of removing waste products from the body. While the kidneys are the primary excretory organs, several other organs also contribute to excretion as secondary functions. These are known as accessory excretory organs.

Chief and Accessory Excretory Organs

1. Kidneys:
   The chief excretory organs play a pivotal role in the body’s homeostasis by primarily serving to eliminate waste products and excess water. This excretory process results in the production of urine, which serves as the excretory material and is subsequently expelled from the body, allowing for the regulation of internal balance and the removal of metabolic byproducts.
2. Lungs:
   Accessory excretory organs serve a dual purpose in the body, contributing to both the excretory and respiratory processes. Their main excretory function involves expelling metabolic waste products, namely carbon dioxide (CO₂) and water (H₂O), which are produced during respiration. In addition to facilitating gas exchange, these organs play a crucial role in maintaining the body’s acid-base balance and ensuring the removal of these waste materials from the body, contributing to overall physiological stability.
3. Skin:
   Accessory excretory organs encompass both sweat and sebaceous glands, each serving distinct roles in maintaining the body’s health. Sweat glands are responsible for excreting water and small quantities of salts, which contribute to thermoregulation and waste removal through perspiration. On the other hand, sebaceous glands play a crucial role by excreting sebum, a substance rich in compounds like waxes, sterols, hydrocarbons, and fatty acids. Sebum is essential for skin health, as it helps moisturize and protect the skin, while also preventing it from becoming dry or prone to infections.
4. Liver:
   The accessory excretory organ serves a multifaceted role in the body, involving the breakdown of old red blood cells and the production of bile pigments. As an excretory organ, it discharges a diverse array of metabolic waste materials, including bilirubin, biliverdin, urochrome, cholesterol, derivatives of steroid hormones, drugs, vitamins, alkaline salts, and it also contributes to the synthesis of urea. This intricate excretory process is essential for maintaining metabolic equilibrium and ensuring the elimination of waste products from the body.
5. Large Intestine:
   The accessory excretory organ relies on its epithelial cells to assist in the excretion of various waste materials. It primarily excretes surplus calcium, magnesium, and iron salts, along with waste products eliminated through feces. Furthermore, this organ plays a role in the elimination of minor quantities of nitrogenous waste through saliva and tears, contributing to the body’s overall waste removal mechanisms.

Liver’s Role in Excretion

The liver plays a specific role in excretion:

1. It destroys old red blood cells after their lifespan of 120 days.
2. It produces metabolic waste such as bile pigments (bilirubin, biliverdin, and urochrome) from the hemoglobin of dead red blood cells.
3. Urochrome is excreted through urine, while other substances are excreted with bile.

Summary

The human body has developed a sophisticated excretory system, involving not only the kidneys but also accessory organs like the lungs, skin, liver, and large intestine. Each organ plays a unique role in removing different types of waste products, ensuring that the body remains free of harmful substances. The liver’s multifaceted role in breaking down red blood cells and producing various waste products showcases the complexity and efficiency of the human excretory system.

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LAQ-5 : Describe the structure of nephron with the help of a diagram?

Introduction

The nephron is the fundamental structural and functional unit of the kidney, responsible for filtering blood and forming urine. Each kidney contains approximately 1.3 to 1.8 million nephrons. Each nephron is composed of two main parts: the Malpighian Body and the Renal Tubule. Here’s a detailed breakdown of the structure:

Structure of Nephron

1. Malpighian Body: The Malpighian Body, also known as the renal corpuscle, consists of:
   • Bowman’s Capsule:
     • A cup-shaped structure that encloses the glomerulus.
     • Located at the broader end of the nephron.
     • Lined with squamous epithelial cells known as podocytes, which have pores between them to assist in filtration.
     • Facilitates the flow of filtered materials from the glomerulus.
   • Glomerulus:
     • A network of blood capillaries.
     • Formed by the division of the afferent arteriole into fine capillaries that then reunite to form the efferent arteriole.
     • The afferent arteriole has a larger diameter, creating high pressure in the glomerulus, aiding in filtration.
2. Renal Tubule: The Renal Tubule is divided into three sections:
   • Proximal Convoluted Tubule (PCT):
     • Connects Bowman’s capsule and the Loop of Henle.
     • Involved in the reabsorption of nutrients from the filtrate.
   • Loop of Henle:
     • A U-shaped structure.
     • Responsible for further reabsorption of nutrients.
   • Distal Convoluted Tubule (DCT):
     • Maintains the pH and concentration of the urine.
     • Ends at the collecting duct, leading to the renal pyramids, calyces, renal pelvis, and finally the ureter.

Peritubular Capillaries:

1. A network of capillaries surrounding all parts of the renal tubule.
2. Originate from the efferent arteriole and combine to form the renal venule, which then gives rise to the renal vein.

Summary

The nephron is a highly complex structure, designed to effectively filter blood and produce urine. It consists of two main parts, the Malpighian Body and the Renal Tubule, with multiple components within each part working synergistically. Understanding the nephron’s structure

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LAQ-6 : Explain the procedure and observations of the experiment conducted to observe internal structure of the kidney?

Introduction

Understanding the internal and external structure of the kidney is essential for comprehending how this vital organ functions within the body. An experiment to study these aspects can offer firsthand experience and deepen knowledge about the kidney’s anatomy. Below is a detailed guide to the procedure and observations from this experiment:

Procedure

Aim: To observe both the external and internal features of a kidney.

Materials Required

1. Specimen of a goat’s or sheep’s kidney
2. Scalpel or sharp blade
3. Tray
4. Water

Steps

1. Washing: Rinse the kidney thoroughly with water to remove all traces of blood.
2. Placement: Position the kidney in the tray for examination.
3. Cutting: Carefully make a longitudinal section (lengthwise cut) through the kidney using a scalpel or sharp blade.
4. Study: Examine the internal structures, focusing on identifying key features.

Observations

1. Shape: The kidney has a bean-shaped appearance, a characteristic and recognizable feature.
2. Color: The kidney is typically reddish-brown, indicative of its blood-rich nature.
3. Adrenal Gland: Located on the upper portion of the kidney, the adrenal gland appears as a cap-like structure.
4. Longitudinal Section (L.S.): In the longitudinal section, a distinct dark brown colored portion is observed in the outer zone of the kidney.
5. Tubes: From the hilum (not fissure) of the kidney, two tubes, known as ureters, are visible. These ureters carry urine to the bladder.

Summary

This simple yet illustrative experiment provides valuable insights into the kidney’s internal and external features. Through careful dissection and observation, students can enhance their understanding of the kidney’s anatomy. This experiment, utilizing readily available materials and straightforward techniques, offers a practical approach to learning about renal structure and function.

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LAQ-7 : Explain the temporary and permanent methods to be adapted for kidney failure (ESRD) person.

Introduction

Kidney failure, or End-Stage Renal Disease (ESRD), is a serious condition where the kidneys can no longer function effectively. This inability to filter waste products from the blood necessitates medical intervention. Two primary approaches are used: temporary solutions like dialysis and a more permanent option, kidney transplantation. Below is an explanation of both methods:

Definition: Dialysis is a lifesaving medical procedure that acts as an artificial kidney. It’s used when the kidneys can’t remove waste and excess substances from the blood.

Procedure

1. Blood Extraction:
   Blood is drawn from a vein (not the main artery) and mixed with an anticoagulant like heparin to prevent clotting.
2. Dialyzer Use:
   The blood then flows into a dialyzer, where it’s separated from dialyzing fluid by cellophane tubes.
3. Filtration Process:
   The cellophane membrane filters waste products from the blood. These wastes move into the dialyzing fluid through diffusion.
4. Returning Blood to the Body:
   The cleansed blood is returned to the body through a vein, often with the addition of an anticoagulant.
5. Time Frame of Dialysis:
   A typical dialysis session lasts about 3 to 6 hours and is a common treatment for kidney failure.

Permanent Method: Kidney Transplantation

Definition: Kidney transplantation is a long-term solution for kidney failure. It involves surgically placing a healthy kidney from a donor into a recipient.

Procedure

1. Donor Selection:
   The donor is usually a living relative or a deceased donor. The goal is to find a kidney that matches the recipient closely to reduce the risk of rejection.
2. Immune System Challenges:
   The recipient’s immune system may reject the transplanted kidney. Anti-rejection medications are often used to prevent this.
3. Modern Techniques:
   Advances in medical technology have significantly improved the success rate of kidney transplants.
4. Organ Donation:
   Organ donation from brain-dead individuals plays a crucial role in providing kidneys for transplantation.

Summary

Dealing with kidney failure (ESRD) requires immediate and effective medical solutions. Dialysis offers a temporary fix by artificially cleaning the blood, whereas kidney transplantation provides a more permanent remedy by replacing the diseased kidney with a healthy one from a donor. Both methods have their unique challenges and considerations but are vital for those with severe kidney conditions. Understanding these treatments helps in managing and mitigating the impacts of ESRD.