Lesson Notes By Weeks and Term v3 - Senior Secondary 2
system of the body III
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system of the body III
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Subject: Health Education
Class: Senior Secondary 2
Term: 1st Term
Week: 1
Theme: Human Anatomy And Physiology
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Differentiate between the nature of respiratory and excretory system. Describe the nature of nervous system
This section provides in-depth content for the teacher to deliver the lesson comprehensively. This section outlines practical activities for the teacher and students. | Step | Teacher Activities The respiratory system is responsible for the exchange of gases (oxygen and carbon dioxide) between the body and the external environment. This process, known as respiration, is vital for cellular energy production.
Nature and Function: Inhalation (Breathing in): Oxygen-rich air from the atmosphere is drawn into the lungs. The diaphragm contracts and moves downwards, while the intercostal muscles contract, pulling the rib cage upwards and outwards. This increases the volume of the thoracic cavity, reducing pressure, and air rushes in.
Exhalation (Breathing out): Carbon dioxide-rich air is expelled from the lungs. The diaphragm relaxes and moves upwards, while the intercostal muscles relax, allowing the rib cage to move downwards and inwards. This decreases the volume of the thoracic cavity, increasing pressure, and air is forced out.
Gas Exchange: Occurs in the alveoli (tiny air sacs) of the lungs. Oxygen diffuses from the alveoli into the blood capillaries, while carbon dioxide diffuses from the blood capillaries into the alveoli to be exhaled.
Major Organs: Nose/Nasal Cavity: Filters, warms, and moistens incoming air.
Pharynx (Throat): Passageway for both food and air.
Larynx (Voice box): Contains vocal cords, produces sound.
Trachea (Windpipe): Cartilaginous tube extending from the larynx, divides into bronchi.
Bronchi: Two main tubes branching from the trachea, leading to the lungs.
Bronchioles: Smaller branches within the lungs.
Alveoli: Tiny air sacs where gas exchange takes place.
Lungs: The primary organs of respiration, containing bronchioles and alveoli.
Diaphragm: A sheet of muscle below the lungs crucial for breathing mechanics. Common Diseases of the Respiratory System (Nigerian Context): Asthma: A chronic condition where airways narrow and swell, producing extra mucus, making breathing difficult. Triggers can include dust, pollen, smoke, or certain foods.
Tuberculosis (TB): A bacterial infection primarily affecting the lungs, spread through airborne droplets. It is a significant public health challenge in Nigeria.
Pneumonia: An infection that inflames the air sacs in one or both lungs, which may fill with fluid or pus, causing cough, fever, chills, and difficulty breathing.
Bronchitis: Inflammation of the lining of the bronchial tubes, often caused by viral infections or exposure to irritants like cigarette smoke or pollution. The excretory system is responsible for removing metabolic waste products and excess substances from the body, maintaining homeostasis (stable internal environment). While several organs contribute to excretion (lungs remove CO2, skin removes sweat, liver processes toxins), the primary focus here is the urinary system.
Nature and Function: Filtration: The kidneys filter blood, removing waste products like urea, creatinine, uric acid, and excess salts and water.
Reabsorption: Useful substances (glucose, amino acids, some salts, and water) are reabsorbed back into the blood.
Secretion: Additional waste products are secreted from the blood into the urine.
Formation of Urine: The filtered and processed fluid becomes urine.
Elimination: Urine is transported out of the body.
Osmoregulation: Regulates water and salt balance in the body, maintaining blood pressure. Major Organs of the Urinary Excretory System: Kidneys (2): Bean-shaped organs located on either side of the spine, below the rib cage. They filter blood, remove waste, and produce urine.
Ureters (2): Tubes connecting each kidney to the urinary bladder, transporting urine.
Urinary Bladder: A muscular sac that stores urine until it is expelled from the body.
Urethra: A tube that carries urine from the bladder out of the body. Common Diseases of the Excretory System (Urinary System - Nigerian Context): Urinary Tract Infections (UTIs): Bacterial infections that can affect any part of the urinary system (kidneys, ureters, bladder, or urethra). More common in females.
Kidney Stones (Renal Calculi): Hard deposits made of minerals and salts that form inside the kidneys. They can be very painful when passing through the urinary tract.
Kidney Failure (Renal Failure): A condition in which the kidneys lose their ability to remove waste products and concentrate urine, leading to a build-up of toxins in the body. This can be acute or chronic and often requires dialysis or transplantation in severe cases.
Hypertension (High Blood Pressure): While not exclusively an excretory system disease, uncontrolled hypertension is a major cause of kidney damage and kidney failure in Nigeria.