Ch. 35 - The Endocrine System

Question 1

What are exocrine glands?

Answer 1

Exocrine glands release their product into ducts or tubes.

Question 2

What are endocrine glands?

Answer 2

Endocrine glands are ductless and they produce hormones that are released directly into the bloodstream.

Question 3

What is a hormone?

Answer 3

A hormone is a chemical messenger produced by an endocrine gland, carried by the bloodstream to an organ where it has an effect.

Question 4

State the location and hormones of the pituitary gland.

Answer 4

The pituitary gland is located at the base of the brain. It produces FSH, LH and GH (growth hormone).

Question 5

State the location and hormones of the hypothalamus.

Answer 5

The hypothalamus is in the ventral brain. It produces ADH, which causes water to be reabsorbed and is responsible for osmoregulation.

Question 6

State the location and hormones of the pineal gland.

Answer 6

The pineal gland is located in the brain. It produces melatonin.

Question 7

State the location and hormones of the thyroid.

Answer 7

The thyroid is a H-shaped gland located on the trachea in the neck. It produces thyroxine, which controls metabolism.

Question 8

What are the symptoms of thyroxine deficiency?

Answer 8

It causes cretinism in children and manifests as retarded mental and physical development. In adults, it is seen as lack of energy and weight gain. It is called myxoedema.

Question 9

What are some corrective measures for thyroxine deficiency?

Answer 9

The heel test is used for newborns. Thyroxine can be administered. Iodine tablets help prevent myxoedema.

Question 10

What are the symptoms of excess thyroxine?

Answer 10

Excess thyroxine causes Graves’ disease. Bulging eyes, hunger, weight loss, irritability and anxiety is seen.

Question 11

What are some corrective measures for excess thyroxine?

Answer 11

Graves’ disease is cured by removing part of the thyroid or killing part of the gland using radioactive iodine.

Question 12

State the location and hormones of the parathyroid.

Answer 12

There are 4 parathyroids embedded in the thyroid gland. They make parathormone, stimulating the release of Ca from bones into the blood.

Question 13

State the location and hormones of the thymus.

Answer 13

The 2 lobes of the thymus are located behind the breastbone in the upper chest. It produces thymosin, causing lymphocytes to mature and activate.

Question 14

State the location and hormones of the adrenals.

Answer 14

The 2 adrenal glands are located on top of the kidneys. They produce adrenaline, the fight or flight hormone.

Question 15

What is the exocrine function of the pancreas?

Answer 15

The pancreas produces enzymes such as amylase.

Question 16

What is the endocrine function of the pancreas?

Answer 16

The pancreas is located in the upper abdomen. The islets of Langerhans produce insulin. Insulin regulates blood glucose levels.

Question 17

What are 2 uses of hormone supplements?

Answer 17

Insulin injections are used to treat diabetes. Anabolic steroid injections are used in sports.

Question 18

Describe in detail how thyroxine level is controlled.

Answer 18

Thyroxine is controlled using negative feedback. When thyroxine concentration is normal, it inhibits the pituitary gland from producing TSH (thyroid stimulating hormone). When thyroxine concentration is low, the pituitary gland produces TSH. TSH causes more thyroxine to be made by the thyroid, until thyroxine is at normal levels again.