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Question Question 1
Endocrine and exocrine glands
| Sl. No. | Endocrine glands | Exocrine glands |
|---|---|---|
| 1. | Endocrine glands are specialized glands which release their secretions directly into cells or the surrounding tissue. | Exocrine glands are glands which release their secretions through ducts to the target organ. |
| 2. | Endocrine glands are ductless glands. | Exocrine glands are glands with ducts. |
| 3. | Endocrine glands secrete hormones. | Exocrine glands secrete enzymes. |
| 4. | Response time is slower since the secretion has to be carried through blood. | Response time is fast since the secretion is carried through ducts. |
| 5. | They control long term activities of the target organ. | They control short term activity. |
| 6. | Examples are: Pituitary gland and thyroid gland | Examples are: Salivary glands and sweat glands |
BRIGHT TUTORIALS
BRIGHT TUTORIALS
ICSE Class VIII | Academic Year 2026-2027
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Biology | Chapter 7: Endocrine SystemWeb Content
Endocrine System – Interactive Study Guide
Quick Overview
The endocrine system consists of ductless glands that secrete hormones into the blood. Hormones are chemical messengers that regulate growth, metabolism, reproduction, and response to stress.
Endocrine vs Exocrine at a Glance
| Feature | Endocrine | Exocrine |
|---|---|---|
| Ducts | Ductless | Have ducts |
| Secretion | Hormones (into blood) | Enzymes, sweat (through ducts) |
| Examples | Pituitary, thyroid, adrenal | Salivary, sweat, liver |
Master Table: Glands, Hormones, Functions
| Gland | Hormone | Function | Disorder |
|---|---|---|---|
| Pituitary | GH | Growth | Dwarfism / Gigantism |
| Thyroid | Thyroxine | Metabolism (needs iodine) | Goitre / Cretinism |
| Parathyroid | Parathormone | Calcium regulation | Tetany |
| Adrenal | Adrenaline | Fight-or-flight | Addison's disease |
| Pancreas | Insulin / Glucagon | Blood sugar regulation | Diabetes mellitus |
| Testes | Testosterone | Male characters | — |
| Ovaries | Oestrogen | Female characters | — |
Feedback Mechanism
How It Works
High hormone level → Gland reduces production. Low hormone level → Gland increases production.
Example: High blood sugar → Insulin released → Sugar absorbed by cells → Sugar drops → Insulin production stops.
Self-Test Questions
Test Yourself
- Why is the pituitary gland called the master gland?
- What is goitre? How can it be prevented?
- Differentiate between insulin and glucagon.
- What happens during a fight-or-flight response?
- Explain the feedback mechanism with the example of blood sugar.