Lecture 8

Question 1

3 Main types of Hormones

Answer 1

1. Peptide/Protein
2. Steroid
3. Amine

Question 2

2 classifications of hormones

Answer 2

1. Hydrophilic
2. Hydrophobic

Question 3

Hydrophilic Hormones

Answer 3

• Water soluble, plasma soluble
• Lipid insoluble (lipophobic)
• Unable to cross through plasma membranes

Question 4

Hydrophobic hormones

Answer 4

• Water insoluble, plasma insoluble
• Lipid soluble (lipophilic)
• Rapidly crosses the plasma membrane

Question 5

What are peptide/protein hormones derived from?

Answer 5

3 or more amino acids

Question 6

What are steroid hormones derived from?

Answer 6

cholesterol

Question 7

What are amine hormones derived from?

Answer 7

single amino acids

Question 8

Melatonin

Answer 8

• Secreted at night (sleep)
• Made in the pineal gland (also gi tract, leukocytes and other brain regions)

Question 9

Amine Hormones

Answer 9

Synthesized only from tryptophan or tyrosine

Question 10

Tryptophan derivative

Answer 10

melatonin (behaves like peptides or steroids)

Question 11

Tyrosine derivatives

Answer 11

• catecholamines (behave like peptides)
• Thyroid hormones (behave like steroids)

Question 12

Control of hormone release

Answer 12

endocrine cells directly sense stimuli, then secrete the hormone

Question 13

Synergistic Effects

Answer 13

• Multiple hormones act together for greater effect
• Synergism between FSH and testosterone on sperm production

Question 14

Permissive Effects

Answer 14

• One hormone enhances the target organ’s response to a second later hormone
• Estrogen prepares the uterus for action of progesterone

Question 15

Antagonistic Effects

Answer 15

• One hormone opposes the action of another
• Insulin lowers blood glucose and glucagon raises it

Question 16

Where do protein hormones act?

Answer 16

react with receptors on the surface of the cell, and the sequence of events that results in hormone action is relatively rapid

Question 17

Where do steroid hormones act?

Answer 17

The complex is broken down inside the lysosome, and free steroid hormone diffuses into the cell, where it subsequently exerts its action at the genomic level or undergoes metabolism