Endocrine System in Humans – Long Answer Questions

Medium Level (Application & Explanation)

Answer:

The endocrine system and the nervous system both help coordinate body functions, but they work differently.
The nervous system uses electrical signals through nerves for fast, short-term responses (like moving your hand away from a hot object).
The endocrine system uses chemical messengers called hormones for slow, long-lasting control (such as growth or metabolism).
Hormones travel in the bloodstream and affect many body parts, while nerves act only in specific spots.
For example, when you are scared suddenly, your nerves make you jump, but your adrenal glands (endocrine system) slowly release adrenaline for prolonged alertness.

Answer:

The pituitary gland is called the "master gland" because it controls other endocrine glands and several body functions.
It secretes growth hormone, which helps in the growth of bones and tissues, and other hormones like TSH and ACTH to control the thyroid and adrenal glands.
If the growth hormone is less, a child may suffer from dwarfism (small height).
If too much growth hormone is released, it can cause gigantism (abnormally tall growth).
Thus, the pituitary gland’s proper working is essential for normal development.

Answer:

Thyroxine, produced by the thyroid gland, controls how quickly the body uses energy (metabolism) and helps with growth and development.
If the thyroid gland does not produce enough thyroxine, a person may suffer from hypothyroidism.
Symptoms include slow metabolism, tiredness, weight gain, and, in children, delayed growth.
Lack of iodine in the diet can cause goitre, where the thyroid gland swells.
Overproduction of thyroxine leads to hyperactivity and weight loss.
Thus, balanced thyroxine is necessary for health.

Answer:

The adrenal glands produce adrenaline, known as the "emergency hormone."
During stress or fear, adrenaline is released into the blood.
It increases heartbeat, breathing rate, and sends more blood to muscles, preparing us to "fight or flee."
For example, when you see a dog suddenly chasing you, your body reacts immediately – fast heartbeat and quick running – due to adrenaline.
Besides emergencies, adrenal glands also control water and salt balance with other hormones like cortisol.

Answer:

The pancreas releases two important hormones: insulin and glucagon.
Insulin lowers blood sugar by helping cells absorb glucose, while glucagon increases blood sugar by releasing glucose from the liver.
If the pancreas does not produce enough insulin, blood sugar remains high, leading to a disease called diabetes mellitus.
Diabetic people may feel thirsty, tired, or lose weight quickly.
In severe cases, they might need insulin injections to control their blood sugar.
Hence, insulin is crucial for energy and health.

Answer:

Puberty in boys and girls is controlled by sex hormones released by testes (in boys) and ovaries (in girls).
In girls like Radha, estrogen and progesterone cause changes such as the development of breasts, start of menstruation, and widening of hips.
In boys like Ravi, testosterone leads to growth of facial hair, deepening of voice, and development of muscles.
These hormones are produced at higher levels during puberty and are controlled by signals from the pituitary gland.
The changes make their bodies ready for adulthood and reproduction.
This shows how hormones control the timing and pattern of puberty.

Answer:

The child is likely suffering from an iodine deficiency, leading to under-functioning of the thyroid gland (hypothyroidism).
Symptoms like stunted growth and poor mental development occur due to less production of thyroxine, and the swollen neck indicates goitre.
Iodine is essential to form thyroxine; without it, the thyroid gland swells as it tries to work harder.
The solution is to include iodized salt in the child's diet to provide enough iodine.
Regular use of iodized salt can prevent such hormonal and developmental problems.
Awareness about nutrition is key in such villages.

Answer:

During stress, adrenal glands produce more cortisol, known as the "stress hormone".
Cortisol helps the body manage stress by changing energy supply and suppression of some immune functions.
If stress is constant, high cortisol levels over a long time weaken the immune system.
This makes it easier for germs to attack the body, resulting in frequent sicknesses or infections.
Thus, long-term hormonal imbalance can adversely affect health.
Managing stress through relaxation and good habits helps keep hormones in balance.

Answer:

The pancreas makes insulin and glucagon to control blood sugar levels.
If the pancreas is removed, the body cannot make insulin, causing uncontrolled high blood sugar (diabetes mellitus).
Without insulin, glucose remains in the blood and is not used for energy, leading to tiredness, weight loss, and eventually more serious problems in eyes, kidneys, or nerves.
The person would need to take insulin injections for life to survive.
The pancreas also makes juices to help digest food, so they might need enzyme supplements as well.
Thus, the pancreas is vital for both digestion and sugar control.

Answer:

Short-term (immediate) responses: Certain hormones act quickly during emergencies.
- Example 1: Adrenaline increases heart rate and energy during moments of fear or stress ("fight or flight" response).
- Example 2: Insulin quickly lowers blood sugar right after a meal.
Long-term (developmental) changes: Some hormones guide slow and steady changes over years.
- Example 1: Growth hormone from the pituitary controls a child's height and size over many years.
- Example 2: Sex hormones (testosterone in boys, estrogen/progesterone in girls) drive puberty and body development over a period of several years.
Thus, hormones can affect the body both instantly and over long periods, ensuring health and growth.