Lesson Notes By Weeks and Term v4 - SHS 3
DISEASES AND DISORDERS
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DISEASES AND DISORDERS
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Subject: Biomedical Science
Class: SHS 3
Term: 1st Term
Week: 19
Grade code: 2.2.2.LI.3
Strand code: 2
Sub-strand code: 2
Content standard code: 2.2.2.CS.1
Indicator code: 2.2.2.LI.3
Theme: HUMAN BODY SYSTEMS
Subtheme: DISEASES AND DISORDERS
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Diabetes is a serious, lifelong condition that is becoming increasingly common in Ghana and across the world. You may know a family member, a friend, or a community elder living with this condition. The shift in our diets towards more processed foods and sugary drinks, combined with less active lifestyles, has made understanding diabetes more critical than ever for your own health and the health of your community. This lesson will move beyond a simple definition to explore the biological mechanisms behind diabetes, how it is diagnosed and managed, and the profound impact it has on a person's daily life. Understanding this disorder is a key part of biomedical science and public health.
A. Normal Blood Glucose Regulation: The Body's Balancing Act
Before we can understand a disorder, we must first understand the normal, healthy process. Glucose: The main sugar found in your blood. It comes from the food you eat (especially carbohydrates like kenkey, rice, yam, and banku) and is your body's main source of energy. The Pancreas: An organ located behind the stomach. It has special cells called the Islets of Langerhans. Beta (β) cells produce the hormone Insulin. Alpha (α) cells produce the hormone Glucagon. Insulin: Think of insulin as a key. Its job is to unlock the body's cells (especially muscle, liver, and fat cells) to allow glucose to enter from the bloodstream and be used for energy. When insulin works, the amount of glucose in the blood decreases. Glucagon: This hormone does the opposite of insulin. When your blood sugar is low (e.g., if you haven't eaten for a while), glucagon sends a signal to your liver to release stored glucose (called glycogen) into the blood. This makes the blood glucose level increase.
The Negative Feedback Loop in Action:
This system works constantly to keep your blood glucose in a narrow, healthy range (homeostasis). After a Meal (e.g., eating waakye): Carbohydrates are digested, and glucose is absorbed into the blood. Blood glucose level rises. The pancreas detects this rise and its beta cells release insulin. Insulin travels through the blood and binds to receptors on body cells, allowing them to absorb glucose. The liver also takes up glucose and stores it as glycogen. As cells absorb glucose, the blood glucose level falls back to normal. The drop in blood glucose signals the pancreas to stop releasing insulin. During Fasting or Exercise: Your cells use up glucose for energy. Blood glucose level falls. The pancreas detects this fall and its alpha cells release glucagon. Glucagon travels to the liver and tells it to break down stored glycogen into glucose (a process called *glycogenolysis*) and release it into the blood. Blood glucose level rises back to normal. This rise signals the pancreas to stop releasing glucagon.