Hormones

Question 1

What are hormones?

Answer 1

Molecules released by endocrine glands directly into the blood, carrying a signal to a specific target.

Question 2

What is an endocrine gland?

Answer 2

A gland that secretes hormones directly into the blood without ducts.

Examples include adrenal glands, pancreas, and pituitary gland.

Question 3

What is the endocrine system?

Answer 3

A communication system that uses hormones transported through the blood.

Question 4

What is an exocrine gland?

Answer 4

A gland that secretes molecules into a duct that carries them to where they are used.

Example: saliva from the salivary gland.

Question 5

What are peptide hormones?
Name 3 examples.

Answer 5

Hormones made of proteins or amino acids, such as adrenaline, insulin, and glucagon.

Question 6

What are steroid hormones?
Name 3 examples.

Answer 6

Hormones made of cholesterol, such as sex hormones, estrogen, and testosterone.

Question 7

What is adrenaline?

Answer 7

A hormone released from the adrenal gland that stimulates the body to prepare for fight or flight.

Question 8

What is diabetes mellitus?

Answer 8

A condition in which blood glucose cannot be controlled effectively.

Question 9

Describe peptide hormone action.

Answer 9

• Hormone (first messenger) binds to complementary receptor on the cell surface membrane
• G protein is activated by turning on effector molecule called adenyl cyclase
• Adenyl cyclase converts ATP to cAMP (second messenger)
• cAMP may act on protein channels or initiates a cascade of enzyme controlled reactions

Question 10

Describe steroid hormone action.

Answer 10

• Soluble in phospholipid bilayer, so passes through phospholipid bilayer
• Binds to steroid receptor to form a hormone receptor complex
• This complex enters nucleus of target cell and binds to another receptor on chromosome
• This stimulates the production of mRNA and codes for proteins

Question 11

Effects of adrenaline.

Answer 11

Relaxes smooth muscle in bronchioles
Increases stroke volume
Increases heart rate
Vasoconstriction to increase blood pressure
Conversion of glycogen to glucose
Increases ventilation rate
Pupil dilation
Causes hairs to erect
Increasing mental awareness
Inhibiting action of gut

Question 12

Zona reticularis

Answer 12

Precursor for sex hormones

Question 13

Zona fasiculata

Answer 13

Glucorticoids; cortisol

Question 14

Zona glomerulosa

Answer 14

Mineralcorticoids; aldestorone

Question 15

Describe the pancreas exocrine function

Answer 15

• acini synthesise and release digestive enzymes
• amylase, tripase, trypsinogen