Hormones

Question 1

Define

Hormones

Answer 1

A chemical substance produced in minute quantities by an endocrine gland where it is transported in the bloodstream to target organ(s) where it exerts its effects

Question 2

Features of hormones

4 features

Answer 2

1. Produced by endocrine glands
2. Transported by blood to target organs
3. Alter the activity of one or more target organs
4. Destroyed by the liver after use and excreted by the kidneys

Question 3

What is the difference between endocrine and exocrine glands?

Answer 3

Endocrine glands: Ductless and transport secretions through the bloodstream

Exocrine glands: Ducts present to transport secretions to target organ(s)

Question 4

Is the pancreas a endocrine or exocrine gland?

Answer 4

Both. Islets of Langerhans are endocrine and Acinar cells are exocrine

Question 5

What are the effects of hormones?

2 effects

Answer 5

1. Control or influence various functions of organs and muscles in the body
2. Contol or coordinate body activities such as growth and development

Question 6

Why and how is hormone production controlled?

Answer 6

• Production must be very carefully controlled to prevent disastrous results
• Some endrocrine glands are controlled by the nervous system (adrenal gland)
• Some are controlled by chemicals from other endocrine glands (piturary gland)

Question 7

Where is insulin produced and what are its effects?

Answer 7

Produced in the beta cells of the Islets of Langerhans when blood glucose conc. are higher than normal

Effects:
1. Promote the utilisation of glucose by cells
2. Increase permeability of cell membranes to glucose, increasing rate of glucose uptake
3. Stimulates the conversion of glucose to glycogen in the liver and muscles

Question 8

Where is glucagon produced and what are its effects?

Answer 8

Produced in the alpha cells of the Islets of Langerhans when blood glucose conc. drops below normal

Effects:
1. Increases blood glucose level by stimulating conversion of glycogen to glucose, fats and amino acids to glucose, and lactic acid to glucose