Sciences - Co-ordinated (9-1) - 0973 CIE

Homeostasis

Overview

Whether you are sunbathing or shivering in the snow, your core body temperature stays close to 37 degrees Celsius. Whether you have just eaten a sugary meal or skipped breakfast, your blood glucose stays within narrow limits. This steady internal world is called homeostasis, and your body works constantly to maintain it.

In this lesson you will learn what homeostasis is, how negative feedback keeps conditions near a set point, how insulin and glucagon control blood glucose, how Type 1 diabetes is treated, and how the skin keeps your temperature constant through sweating, shivering, vasodilation and vasoconstriction.

Objectives

  1. Describe homeostasis as the maintenance of a constant internal environment
  2. State that insulin decreases blood glucose concentration
  3. [Supplement] Explain the concept of homeostatic control by negative feedback with reference to a set point
  4. [Supplement] Describe the control of blood glucose concentration by the liver and the roles of insulin and glucagon
  5. [Supplement] Outline the treatment of Type 1 diabetes
  6. [Supplement] Identify in diagrams and images of the skin: hairs, hair erector muscles, sweat glands, receptors, sensory neurones, blood vessels and fatty tissue
  7. [Supplement] Describe the maintenance of a constant internal body temperature in mammals in terms of: insulation, sweating, shivering and the role of the brain
  8. [Supplement] Describe the maintenance of a constant internal body temperature in mammals in terms of vasodilation and vasoconstriction of arterioles supplying skin surface capillaries

Lesson Note

Enzymes that run every cell reaction only work well within a narrow range of temperature and concentration. Homeostasis keeps those conditions steady so the reactions of life can continue reliably. Blood glucose control and temperature control are favourite exam topics, and both rely on the same idea: negative feedback.

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
AI-powered learning assistant
Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Lesson Evaluation

Congratulations on completing the lesson on Homeostasis. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.

You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.

Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.

  1. Homeostasis is the maintenance of a constant: A. external environment B. internal environment C. body mass D. heart rate Answer: B
  2. After a sugary meal the blood glucose level rises, and the pancreas releases a hormone that brings it back down. Which hormone is this? A. glucagon B. insulin C. adrenaline D. testosterone Answer: B
  3. When the body is too hot, the skin arterioles: A. narrow (vasoconstriction) B. widen (vasodilation) C. disappear D. stop carrying blood Answer: B
  4. Shivering helps to warm the body because muscle contraction releases heat from: A. evaporation B. respiration C. digestion D. excretion Answer: B
  5. Type 1 diabetes is treated mainly with regular: A. glucagon tablets B. insulin injections C. adrenaline injections D. extra sugar Answer: B

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
AI-powered learning assistant
Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Available on the Green Bridge App

Download the Green Bridge CBT app on your phone or computer to access full lesson notes, practice questions, and more.

Full lesson notes with diagrams
AI-powered learning assistant
Study offline, anytime, anywhere
Available on Android, Windows, macOS, and Linux

Practice Mock Questions

Want to practice mock questions on Homeostasis? Download the Green Bridge CBT app to access mock questions and full practice assessments for this topic.

Download The App On Google Playstore

Everything you need to excel in JAMB, WAEC & NECO

Green Bridge CBT Mobile App
Personalized AI Learning Chat Assistant
Thousands of JAMB, WAEC & NECO Past Questions
Over 1200 Lesson Notes
Offline Support - Learn Anytime, Anywhere
Green Bridge Timetable
Literature Summaries & Potential Questions
Track Your Performance & Progress
In-depth Explanations for Comprehensive Learning