Biology Questions: Lymphatic, Endocrine & Digestive Systems

SB Question 1 (4 marks) (T2 The Lymphatic System) Explain the function of the lymphatic system in responding to injury, including its role in immune defense, fluid balance, and tissue repair, using Fig.1 to support your answer....

SB Question 1 (4 marks) (T2 The Lymphatic System) Explain the function of the lymphatic system in responding to injury, including its role in immune defense, fluid balance, and tissue repair, using Fig.1 to support your answer. Fig. 1 Solution The lymphatic system plays a crucial role in injury response by: Fluid Regulation:Draining excess interstitial fluid to prevent swelling (edema) at the injury site. (1 Mark) Immune Defense : Transporting white blood cells and lymphocytes to combat infections. (1 Mark) Inflammatory Response : Facilitating antigen presentation and immune cell activation. (1 Mark) Tissue Repair : Removing cellular debris and aiding in wound healing.(1 Mark) This process ensures efficient recovery and prevents infections after an injury. Question 2 (4 marks) (T2, The Endocrine Hormone System) Explain four major functions of the endocrine system in maintaining body well-being, including its role in hormone regulation, metabolism, and homeostasis, using Fig.2 to support your answer.  Figure 2 Solution Glucose Regulation (1 Mark) The pancreas secretes insulin (from beta cells) to lower blood sugar and glucagon (from alpha cells) to increase blood sugar. In diabetes, insulin deficiency or resistance leads to hyperglycemia. Metabolism Control (1 Mark) The endocrine system regulates carbohydrate, fat, and protein metabolism. In diabetes, impaired insulin function causes lipolysis (fat breakdown) and muscle wasting due to reliance on alternative energy sources. Hormonal Imbalance (1 Mark) Other hormones like cortisol (stress hormone), growth hormone, and catecholamines can exacerbate insulin resistance, worsening blood sugar control in diabetic patients. Electrolyte and Fluid Balance (1 Mark) Diabetes affects the kidneys, leading to excessive urination (polyuria) and dehydration due to high glucose levels pulling water from the body (osmotic diuresis). Question 3 (4 marks) (T5 /The Digestive System, Liver) Explain four major functions of the liver in managing chemical exposure, including its role in detoxification, metabolism, and protection, using Fig.3 as a reference. Fig. 3 Solution Detoxification (1 Mark) The liver metabolizes and neutralizes toxins (e.g., heavy metals, alcohol, drugs) using enzymes like cytochrome to make them water-soluble for excretion. Metabolism and Biotransformation (1 Mark) Converts toxic substances into less harmful metabolites or active forms for elimination. Phase I (oxidation, reduction) and Phase II (conjugation) reactions play a role. Bile Secretion and Excretion (1 Mark) The liver produces bile, which helps eliminate fat-soluble toxins, heavy metals, and metabolic waste through feces. Inflammatory and Immune Response (1 Mark) Chemical exposure triggers the liver’s Kupffer cells to remove harmful substances and stimulate inflammatory cytokines, which can lead to fibrosis if exposure is prolonged. Question 4 (4 Marks) (T/2, The Reproductive System) Explain the process of fertilization by tracing the journey of sperm, its interaction with the egg, and the key stages leading to zygote formation, using Fig.4 as a reference. Fig. 4 Solution Sperm Transport & Capacitation (1 Mark) Millions of sperm travel through the female reproductive tract (vagina → cervix → uterus → fallopian tube). Sperm undergo capacitation, a process that enhances their motility and ability to penetrate the egg. Sperm-Egg Recognition & Binding (1 Mark) The sperm reaches the oocyte (egg) in the fallopian tube and binds to the zona pellucida (protective layer around the egg). Acrosomal Reaction & Penetration (1 Mark) The sperm releases enzymes from the acrosome to break down the zona pellucida, allowing one sperm to penetrate the egg’s membrane. Fusion & Zygote Formation (1 Mark) The sperm and egg membranes fuse, and the sperm’s nucleus enters the egg. The egg completes meiosis II, and their genetic material combines, forming a zygote (fertilized egg), Question 5 (4 Marks) (T1, 2) Explain how acid-base balance maintains cellular hydration by describing the role of buffer systems, organ function, and electrolyte regulation, using Fig.5 as a reference.  Fig. 5 Solution pH Regulation & Buffer Systems (1 Mark) The body maintains acid-base balance by regulating pH (7.35–7.45) using buffer systems like bicarbonate (HCO₃⁻), phosphate, and proteins to neutralize acids and bases. Role of the Kidneys & Lungs (1 Mark) Lungs regulate pH by controlling CO₂ levels (exhaling CO₂ reduces acidity). Kidneys help by excreting hydrogen ions (H⁺) and reabsorbing bicarbonate (HCO₃⁻) to stabilize pH. Cellular Hydration & Electrolyte Balance (1 Mark) Proper hydration is essential for ion transport; electrolytes like sodium (Na⁺), potassium (K⁺), and chloride (Cl) help balance intracellular (ICF) and extracellular (ECF) fluids, influencing pH stability. Effects of Imbalance (1 Mark) Acidosis (low pH) leads to cell dehydration, enzyme dysfunction, and metabolic stress. Alkalosis (high pH) can cause muscle weakness, nerve dysfunction, and fluid imbalances. Section C (Essay / Case Study) This section consist of THREE questions. Answer TWO questions only Question 1. (25 marks) (T7/The Physiological Response to Injury) Analyze the physiological mechanisms of the inflammatory response to injury by examining the stages of inflammation, cellular and molecular mediators involved, and their role in tissue repair and immune defense. Use Fig. 5 as a guide to support your answer Fig. 5 Solution Stages of Inflammation (10 Marks) Initiation (Vascular Response): Blood vessels dilate (vasodilation) to increase blood flow, causing redness and warmth. Capillary permeability increases, leading to swelling (edema). Cellular Response: White blood cells (neutrophils, macrophages) migrate to the site (chemotaxis) to destroy pathogens and clear debris. Resolution & Repair: Anti-inflammatory signals promote healing by reducing swelling, regenerating tissue, and restoring function. Cellular & Molecular Mediators (10 Marks) Pro-inflammatory Mediators: Histamine (causes vasodilation and swelling), Cytokines (regulate immune response), Prostaglandins (induce pain and fever). Anti-inflammatory Mediators: (promote healing and suppress inflammation). Role in Tissue Repair & Immune Defense (5 Marks) The inflammatory response removes pathogens, dead cells, and debris, allowing for new tissue formation. Immune cells initiate adaptive immunity for long-term protection. Fibroblasts aid in collagen deposition, ensuring proper tissue structure and function. This process is essential for preventing infections and ensuring effective healing after injury. Question 2 (25 marks) (T2 / The Endocrine, Metabolic System) Analyze how the failure of physiological functions in the endocrine system contributes to metabolic disorders leading to Diabetes Mellitus, including the role of hormone regulation and insulin dysfunction, using Fig.6 to illustrate your answer. Fig.6 Solution Endocrine System Failure & Metabolic Disorders Leading to Diabetes Mellitus, falls under three conditions 1. Endocrine Dysfunction & Hormonal Imbalance (10 Marks) Pancreatic Beta Cell Dysfunction: Reduced insulin production leads to hyperglycemia (Type 1 DM). Insulin Resistance: Cells fail to respond to insulin, increasing blood glucose (Type 2 DM). Glucagon Overproduction: Excess glucagon increases glucose release from the liver, worsening diabetes. 2. Metabolic Disruptions & Energy Imbalance (10 Marks) Carbohydrate Metabolism: Reduced glucose uptake leads to chronic hyperglycemia. Lipid Metabolism: Increased fat breakdown leads to ketone production, causing diabetic ketoacidosis (DKA). Protein Metabolism: Excess protein breakdown results in muscle wasting & weight loss. 3. Long-Term Physiological Complications (5 Marks) Cardiovascular Diseases: High blood sugar damages blood vessels, increasing the risk of hypertension & atherosclerosis. Kidney & Nerve Damage: Prolonged hyperglycemia causes neuropathy & nephropathy. Poor Wound Healing & Infections: Circulatory issues impair immune responses, leading to chronic ulcers & infections. Conclusion: The failure of the endocrine system disrupts metabolism, leading to Diabetes Mellitus & its complications. Solution (25 marks) (T2, / The Hormone, Metabolic System) Analyze how hormonal decline contributes to physiological dysfunctions that lead to memory impairment and the development of dementia. Discuss the specific endocrine factors involved, their impact on brain function, and the resulting cognitive decline. Using Fig.7 to illustrate your answer. Fig.7 Answer 1. Endocrine Dysfunction & Hormonal Decline (10 Marks) Cortisol Imbalance (Chronic Stress Exposure) that is Excessive cortisol damages the hippocampus, leading to memory decline. Insulin Resistance & Brain Glucose Metabolism Impairment lead to decreased insulin function in the brain disrupts neuronal communication, contributing to cognitive impairment. Thyroid Hormone Deficiency (Hypothyroidism) lead to reduces cognitive processing speed, causing brain fog and forgetfulness. 2. Neurodegenerative Changes & Memory Impairment (10 Marks) Estrogen & Testosterone Decline (Aging Effects) resulting hormonal decline reduces synaptic plasticity, affecting learning & recall ability. Growth Hormone & IGF-1 Reduction , therefore cause decreases neuronal regeneration, leading to brain atrophy. Acetylcholine Dysfunction , where, decreased production affects synaptic transmission, contributing to Alzheimer’s disease pathology. 3. Long-Term Physiological Effects Leading to Dementia (5 Marks) Amyloid Plaque Accumulation leas to disrupts neural networks, leading to progressive cognitive decline. Oxidative Stress & Inflammation lead to increases neuronal damage, accelerating brain aging. Vascular Changes & Hypoxia lead to poor blood supply to the brain worsens memory loss & dementia progression. Conclusion: Hormonal dysregulation accelerates cognitive decline, leading to dementia by impairing neuroprotection, neuronal communication, and memory retention.