Chapter 45

Question 1

What are the chemical classes of hormones?

Answer 1

• Polypeptides
• Amines derived from amino acids
• Steroid hormones

Question 2

Lipid-soluble hormones

Answer 2

Pass through cell membranes

Question 3

Water-soluble hormones

Answer 3

Cannot pass through cell membrane

Question 4

Insulin is what type of hormone? Therefore…

Answer 4

Water-soluble, so its receptor is on cell membrane

Question 5

Steroids are what type of hormone?

Answer 5

Lipid-soluble

Question 6

What is the pathway of a water-soluble hormone?

Answer 6

• Secretion from cell (exocytosis)
• Free travel through bloodstream
• Bind to cell-surface receptor

Question 7

What is the pathway of a lipid-soluble hormone?

Answer 7

• Diffuse across membrane
• Travel through bloodstream bound to transport proteins
• Diffuse through membrane of target cell

Question 8

The hormone epinephrine is a _____-soluble hormone and is secreted by ________

Answer 8

• water-soluble

- adrenal glands

Question 9

What are the 2 responses to epinephrine?

Answer 9

• Inhibition of glycogen synthesis

- Promotion of glycogen breakdown

Question 10

What is the typical response to a lipid-soluble hormone

Answer 10

Change in gene expression

Question 11

How can the same hormone have different effects on target cells?

Answer 11

Target cells have

• Different receptors
• Different pathway
• Different proteins for carrying out response

Question 12

What are animal hormones?

Answer 12

Chemical signals secreted into circulatory system that communicate regulatory messages within body

Question 13

Endocrine system vs nervous system

Answer 13

• Endocrine: secretes hormones that communicate longer-acting and slower responses (reproduction, development, growth)
• Nervous: secretes high-speed hormones along specialized cells called neurons to regulate other cells

Question 14

Function of hormones

Answer 14

Mediate responses to environmental stimuli and regulate growth, development, reproduction (endocrine)

Question 15

Function of local regulators

Answer 15

Chemical signals that travel short distances by diffusion and regulate blood pressure, help nervous system function, and reproduction (endocrine)

Question 16

Types of local regulators?

Answer 16

• Paracrine signals act on cells nearby

- Autocrine signals act on own cell

Question 17

Function of neurons

Answer 17

Contact target cells at synapses (nervous)

Question 18

What happens as synapses?

Answer 18

Neurons secrete neurotransmitters that diffuse a short distance to bind to receptors on target cell

Question 19

Function of neurohormones

Answer 19

Originating from neurons in the brain, these hormones diffuse through bloodstream to target cells (nervous)

Question 20

Function of pheromones

Answer 20

Released from body through exocrine glands and used to communicate with other individuals

Question 21

Paracrine vs autocrine

Answer 21

Both local regulators secreted by endocrine system

• Paracrine acts on nearby cells
• Autocrine acts on own cell

Question 22

How does nitric oxide help erectile disfunction?

Answer 22

-NO is neurotransmitter/local regulator from nervous system

Activates enzyme that relaxes nearby muscle cells, increasing blood flow in tissues

Question 23

How do prostaglandins contribute to menstrual cramps?

Answer 23

-Local regulators

Stimulate muscle cells of uterine walls to trigger muscle contractions

Question 24

Function of endocrine signals

Answer 24

Secreted into extracellular fluids and travel via bloodstream (endocrine)

Question 25

Endocrine vs exocrine glands

Answer 25

- Endocrine glands are ductless and secrete hormones into surrounding fluid - Exocrine glands have ducts and carry substances to outside the body (pheromones use this)

Question 26

What happens in a negative feedback loop of a pathway?

Answer 26

Inhibits response by reducing initial stimulus

Question 27

The pancreas has what two cells used for homeostasis of blood glucose level? What does each cell release?

Answer 27

- Beta cells release insulin | - Alpha cells release glucagon

Question 28

What situation would cause insulin to be released?

Answer 28

If blood glucose level rises

Question 29

What situation would cause glucagon to be released?

Answer 29

If blood glucose level falls

Question 30

How does insulin reduce blood glucose levels?

Answer 30

- Promoting uptake of glucose into glycogen - Slowing glycogen breakdown in liver - Promoting fat storage

Question 31

How does glucagon raise blood glucose levels?

Answer 31

- Stimulating conversion of glycogen to glucose in liver | - Stimulating breakdown of fat/protein into glucose

Question 32

Difference between type I and type II diabetes

Answer 32

- Type I: immune system destroys pancreatic beta cells (which secrete insulin) - Type II: insulin deficiency or reduced response of target cells due to change in insulin receptors