Endocrine System

Grade 12 · Biology

Semester 2 | Period 5 | Week 29

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Subject: Biology

Semester: 2

Period: 5

Week: 29

School Name:
Teacher’s Name:
Subject: Biology
Grade Level: Grade 12
Week & Period: Week 29, Period V
Date:
Topic: Endocrine System
Sub-topic: Endocrine Glands, Hormones, Hormone Action, Hormone Regulation, Endocrine Disorders, and the Role of Other Organs as Endocrine Glands

 

Learning Objectives

By the end of the lesson, learners should be able to:

  1. Define endocrine glands and distinguish them from exocrine glands.
  2. Identify the major endocrine glands and the hormones they secrete.
  3. Explain the mechanism of hormone action and regulation via negative feedback.
  4. State the roles of the testes, ovaries, liver, kidneys, and stomach as endocrine glands.
  5. Describe common hormone deficiency diseases and their effects.

 

Previous Knowledge

Learners are familiar with the structure and function of the nervous system, and have studied how the body responds to internal and external stimuli.

 

Instructional Materials

  • Charts/diagrams of the endocrine system
  • Flashcards with names and functions of hormones
  • Printed case studies on endocrine disorders (e.g. diabetes, goiter)
  • Poster of feedback loops (e.g. insulin-glucose)

 

Anticipation (Warm-Up) – 5 minutes

Ask:

  • “Why do we grow taller at certain stages?”
  • “Why does stress cause sweating or a fast heartbeat?”

Lead into: This is because of hormones – chemical messengers made by special organs called endocrine glands.

 

Building Knowledge (Main Lesson) – 25 minutes

  1. Endocrine vs Exocrine Glands
  • Endocrine glands secrete hormones directly into the blood (e.g. pituitary, thyroid).
  • Exocrine glands have ducts and secrete outside the blood (e.g. sweat glands, salivary glands).
  1. Major Endocrine Glands & Hormones
  • Pituitary gland: master gland; controls growth (GH), reproduction (LH, FSH)
  • Thyroid: metabolism (thyroxine)
  • Pancreas: blood sugar regulation (insulin, glucagon)
  • Adrenal glands: stress hormones (adrenaline, cortisol)
  1. Hormone Action & Regulation
  • Hormones travel in blood to target organs.
  • Use the lock and key model: hormone fits into receptor like a key into a lock.
  • Negative feedback helps regulate hormone levels (e.g. high sugar triggers insulin; low sugar reduces insulin).
  1. Other Organs Acting as Endocrine Glands
  • Testes – secrete testosterone
  • Ovaries – secrete estrogen and progesterone
  • Liver – secretes IGF (insulin-like growth factors)
  • Kidneys – produce erythropoietin (stimulates red blood cell production)
  • Stomach – secretes gastrin (stimulates digestion)
  1. Hormone Deficiency Diseases
  • Diabetes mellitus – lack of insulin
  • Goiter – iodine deficiency leads to low thyroxine
  • Dwarfism – low growth hormone in childhood
  • Gigantism/Acromegaly – excess growth hormone
  • Infertility – due to hormonal imbalance in ovaries/testes

 

Learners’ Activities

  • Match glands with the hormones they secrete.
  • Trace a feedback loop (e.g. glucose–insulin–liver).
  • Case study review: symptoms and treatment of a hormone disorder.
  • Group activity: Present the role of one non-traditional endocrine organ.

 

Consolidation (Review and Assessment) – 10 minutes

Oral Questions:

  1. What makes a gland endocrine?
  2. How does negative feedback work in hormone regulation?
  3. Name one hormone secreted by the kidneys and its function.

Homework/Assignment:

  • Write short notes on any two endocrine disorders and how they can be managed.
  • Create a chart showing at least 5 endocrine glands, the hormones they release, and their function.

 

Short Notes (For Learners)

The endocrine system controls body functions using hormones, which are chemical messengers.

Major glands include the pituitary, thyroid, pancreas, adrenal glands, testes, and ovaries. Other organs like the liver, kidneys, and stomach also release hormones.

Hormones are regulated by negative feedback, meaning when enough is produced, the body stops making more.

Hormone deficiency diseases include diabetes, goiter, dwarfism, and infertility.

 

Expanded Notes/Instructions

  • Encourage learners to think of hormonal disorders they’ve heard about and how lifestyle or nutrition can influence them.
  • Provide real-world examples (e.g. insulin injections for diabetic patients).
  • Use models or interactive charts where possible to visualize gland locations.

Inclusive/Differentiation

  • Diagrams and visuals for visual learners
  • Group presentations for collaborative learners
  • Individual hormone charts for kinesthetic learners
  • Real-life stories or case studies for emotional engagement