Feline Frenzy: Cracking The Case of A Shrinking Cat

Instructional Guide

Learners will learn the location, function, and effects of the thyroid gland as well as why it can result in weight loss. The lesson will include a short reading, two activities, and a short quiz. 

Intended Grade Level

Grades 9-12. Students should have basic understanding of anatomy including the alimentary canal, thyroid gland, cells, heart, and lungs. Students should have a basic understanding of physiology including metabolism and basal metabolic tone.

Learning objectives

• Students will learn about anatomy that pertains to hyperthyroidism induced weight loss.
• Students will be able to describe the roles of thyroid hormone and how they affect metabolism.
• Students can relate the roles of thyroid hormone and how they increase energy demands for the body.
• Students can describe why hyperthyroidism can result in weight-loss.

Lesson Format

Background reading

Students will familiarize themselves with thyroid glands, thyroid hormones, hyperthyroidism, hyperthyroidism signs and symptoms, diagnosis, and treatment by reading through the lesson. Allow 5 minutes for students to read the lesson.

Activity 1

Independent work. Thyroid hormones affect many organs and organ systems in the body; the activity asks students to match the thyroid hormone effects to the organ system affected. Allow 5 minutes to complete this activity.

Open up a post activity discussion to answer the following questions. Allow 5 minutes for the discussion.

• • What did you learn after completion of the activity?
  • What were the organs affected by thyroid hormone?
  • How might the effects of thyroid hormone affect the energy demands of cats?

Activity 2

This activity involves throwing soft objects to demonstrate energy consumption. Provide 15 minutes for activity two. Have students read the short paragraph before the activity instructions to help them understand the relevance before the activity begins (1 minute).

See the student page for directions

Open up a class discussion to answer the following questions (5 minutes):

• • What did you notice about the calories burned vs. the calories consumed?
  • How does this activity relate to the previous activity?
  • Why would having more calories burned vs. calories consumed result in weight loss?

Assessment

• The assessment is a case with 3 questions
• Can be done individually or with partners (7 minutes)
• After the assessment, come together as a group and discuss the correct answer and why the incorrect answers are incorrect. Provide ~ 5 minutes.

Expected Answers (Teacher Key)

1. The thyroid gland is located in the neck and produces hormones (T3 and T4) that regulate metabolism throughout the body.
2. The thyroid gland in cats produces hormones, T3 and T4, which regulate metabolism. These hormones influence the body’s energy use, heart rate, digestion, temperature regulation, and overall growth and development, affecting almost every organ system.
3. Thyroid hormones increase the rate of metabolism, causing the body to burn more energy for heat and activity. This can lead to weight loss if the energy burned exceeds the energy consumed.
4. If hyperthyroidism disrupts the ileal brake, digestion might speed up too much, reducing nutrient absorption and preventing the body from signaling satiety. This could worsen weight loss, as the cat may not effectively absorb the calories it consumes.

Extension

If there is time, discuss some of the common misconceptions about the thyroid gland in cats. Alternatively, individual students or groups of students can move on to the further exploration section and learn more about complications of hyperthyroidism. Some of these materials push for more critical thinking of the body as a whole and will provide a challenge for students that would benefit from them.

Common misconceptions and challenge points

Misconceptions About the Thyroid Gland’s Location:

1. “The thyroid gland is located in the brain.”
   (The thyroid gland is in the neck, near the trachea, not in the brain.)
2. “Cats only have one thyroid gland.”
   (Cats, like most mammals, have two lobes of the thyroid gland, one on each side of the trachea.)
3. “The thyroid gland is part of the digestive system.”
   (The thyroid gland is part of the endocrine system, not the digestive system, though its hormones indirectly influence digestion.)

Misconceptions About Thyroid Gland Function:

1. “The thyroid gland only controls weight.”
   (The thyroid gland regulates overall metabolism, heart rate, body temperature, energy levels, and growth, not just weight.)
2. “Thyroid hormones always slow the body down.”
   (Thyroid hormones (T3 and T4) typically speed up metabolism, especially in hyperthyroidism.)
3. “The thyroid gland works independently of other systems.”
   (The thyroid gland is regulated by the hypothalamus and pituitary gland and interacts with multiple body systems.)

Misconceptions About Thyroid Hormones and Effects:

1. “Thyroid hormones only affect the thyroid gland itself.”
   (Thyroid hormones influence nearly every organ system, affecting energy production, heart function, and thermoregulation.)
2. “Thyroid problems only cause weight gain.”
   (While hypothyroidism may cause weight gain, hyperthyroidism often leads to weight loss due to increased metabolism.)
3. “Thyroid hormones directly break down fat in the body.”
   (Thyroid hormones increase overall metabolic rate, which may lead to fat and muscle loss due to higher energy demands.)

Misconceptions About Weight Loss in Hyperthyroid Cats:

1. “Cats lose weight because they eat less food.”
   (Hyperthyroid cats often eat more (polyphagia) because of increased energy demands, but they still lose weight due to excessive metabolism and reduced nutrient absorption.)
2. “The weight loss is caused by the thyroid gland physically shrinking.”
   (The weight loss results from metabolic changes, not structural changes in the thyroid gland.)
3. “Weight loss in hyperthyroid cats is caused by fat being burned faster, but muscle is unaffected.”
   (Hyperthyroidism can lead to both fat and muscle loss due to the body’s inability to meet heightened energy demands.)