Human Biology - 4HB1 PearsonEdexcel

Temperature Regulation And Excretion

Overview

Your core body temperature holds steady at about 37 degrees Celsius whether you are standing in a snowstorm or running a marathon, and your blood glucose stays within a narrow band whether you have just eaten a meal or skipped one. Neither of these is an accident: both are the output of automatic control systems working every second to keep your internal environment stable.

This lesson builds the machinery behind that stability. You will learn how the skin regulates temperature, how the kidneys filter blood and balance its water content, how the liver and pancreas keep blood glucose steady, and how negative feedback ties all of these systems together into one coherent principle.

Objectives

  1. Know the structure and functions of the skin and explain the role of sweat glands, vasoconstriction, vasodilation and shivering in temperature regulation
  2. Know the definition of excretion: the removal of metabolic waste, including urea, carbon dioxide and water
  3. Know the structure and functions of the renal system
  4. Explain why the composition of urine may vary
  5. Describe the role of the hypothalamus and pituitary gland in osmoregulation
  6. Explain the role of ADH in regulating the water content of the blood
  7. Understand the roles of insulin and glucagon in maintaining blood glucose levels
  8. Understand the concept of homeostasis and the role of negative feedback, with particular reference to temperature control and blood glucose concentration
  9. Describe the advantages and disadvantages of kidney transplants and kidney dialysis
  10. Investigate diffusion using a partially-permeable membrane such as Visking tubing
  11. Describe the functions of the liver in bile production, regulation of blood sugar, urea formation and detoxification including the breakdown of alcohol

Lesson Note

Every cell in your body works best within a narrow range of temperature, water content and glucose concentration. Stray outside that range and enzymes lose their shape, reactions slow or stop, and cells are damaged. Keeping conditions inside the body constant despite a changing outside world is called homeostasis, and it is maintained automatically by feedback systems in the skin, kidneys, liver and pancreas.

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Lesson Evaluation

Congratulations on completing the lesson on Temperature Regulation And Excretion. 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. Which gland releases ADH into the bloodstream? A) Pancreas B) Pituitary gland C) Liver D) Adrenal gland Answer: B
  2. Which part of the nephron is responsible for ultrafiltration? A) Collecting duct B) Loop of Henle C) Glomerulus and Bowman's capsule D) Distal convoluted tubule Answer: C
  3. A fall in blood glucose concentration causes the pancreas to release: A) Insulin B) Glucagon C) ADH D) Adrenaline Answer: B
  4. Which skin response helps to increase heat loss on a hot day? A) Vasoconstriction B) Shivering C) Vasodilation D) Hair-erector muscles contracting Answer: C
  5. Urea is produced in the liver by which process? A) Ultrafiltration B) Deamination C) Osmoregulation D) Assimilation 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
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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

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