The Bio Brief

Besides sex hormones, our body has many other hormones that control growth, metabolism, stress, and body balance.

These hormones are released by endocrine glands.

 The pituitary gland controls many of these glands, so it is called the master gland.

 Major Endocrine Glands in the Body

Important glands (other than testes and ovaries):

• Pituitary
• Thyroid
• Pancreas
• Adrenal glands

 Control by Pituitary (Flow Chart)

Pituitary gland (master gland)
            ↓
Sends signals (hormones)
            ↓
Other endocrine glands get activated
            ↓
They release their hormones
            ↓
Body functions are controlled

 1. Pituitary Gland

 Location: Attached to the brain
 Called the master gland

 Functions

• Controls other endocrine glands
• Releases growth hormone
• Stimulates testes and ovaries

 Growth Hormone

• Necessary for normal growth
• Too little → dwarfism
• Too much → gigantism

 2. Thyroid Gland

 Location: Neck (throat region)

 Hormone Produced

• Thyroxine

 Functions

• Controls body metabolism
• Helps in growth and development

 Thyroid Disorder: Goitre

Cause: Lack of thyroxine (often due to iodine deficiency)

Symptom:

• Swollen, bulging neck

 Iodised salt helps prevent goitre.

 3. Pancreas

 Location: Near stomach

 Hormone Produced

• Insulin

 Function

• Controls sugar level in blood

 Pancreatic Disorder: Diabetes

Cause: Insufficient insulin

Effect:

• High blood sugar levels

 4. Adrenal Glands

 Location: Above the kidneys

 Hormones Produced

(a) Adrenalin

• Prepares body for emergency
• Helps during:
  • Fear
  • Anger
  • Stress
  • Embarrassment

 Called “fight or flight” hormone

(b) Salt-balance hormones

• Maintain proper salt balance in blood

Adrenal Action (Flow Chart)

Stress / fear / anger
        ↓
Adrenal glands release adrenalin
        ↓
Heart beats faster
Breathing increases
Body becomes alert

 Important Control Chain

Pituitary gland
      ↓
Thyroid / Adrenals / Gonads
      ↓
Hormones released
      ↓
Body functions regulated

 Are Hormones Present in Other Animals?

 Yes

• Other animals also have hormones
• Hormones control:
  • Growth
  • Development
  • Reproduction

 Hormonal control is common in many animals.

 Quick Revision Box

 Pituitary is the master gland
 It controls many endocrine glands
 Thyroid produces thyroxine
 Lack of thyroxine causes goitre
 Pancreas produces insulin
 Lack of insulin causes diabetes
 Adrenals produce adrenalin
 Hormones are present in other animals too

 In Simple Words

Apart from sex hormones, our body has many other hormones released by endocrine glands like thyroid, pancreas, and adrenals. The pituitary gland controls most of them. These hormones help in growth, sugar control, stress response, and body balance. Similar hormone systems are also present in other animals.