Chapter 45: Hormones and The Endocrine System

Question 1

What does the endocrine system do? How does it work?

Answer 1

• it’s responsible for communication
• works with the nervous system
• specialized cells receive messages and response by decreasing hormones

Question 2

What is endocrine signaling?

Answer 2

• When endocrine cells secrete hormones that travel long distances in the blood stream

Question 3

What is paracrine signaling?

Answer 3

• Secreting hormones to neighboring cells (no touchy)

Question 4

What is autocrine signaling?

Answer 4

When a cell secretes hormones and binds to its own receptors outside of the cell

Question 5

What is neuroendocrine signaling?

Answer 5

When the axon directly transfer hormones into the blood stream

Question 6

The endocrine system uses two types of signaling molecules. What are they?

Answer 6

1) Local regulators
- small, nonpolar/hydrophobic
2) Hormone regulators
- polypeptides
- steroids
- amines

Question 7

There are two types of hormone signals, what are they and what makes them different?

Answer 7

1) Water-soluble (philic)
- Starts off in a vesicle
- Released into the blood stream
- Released and attached to receptor protein of target cell

2) Lipid-soluble (phobic)
- Starts off in the cytoplasm
- Released into the blood
- Transport proteins surround it so it doesn’t clump up the blood
- Dropped through the membrane into the target cell (no receptors needed)

Question 8

What are 3 examples of water-soluble hormone signaling?

Answer 8

• G Protein-Coupled Receptors
• Tyrosine Kinase Receptors
• Ion Channel Receptors

Question 9

Why can the same hormone produce different effects in different target cells?

Answer 9

• the target cells have different receptors

- each target cell has a different structure and function

Question 10

Two different receptors bind with the same hormone. Why?

Answer 10

They have identical binding sites

Question 11

What is negative feedback?

Answer 11

A response to a stimulus.

Negative feedback will reduce this stimulus.

Question 12

What is positive feedback?

Answer 12

Response to a stimulus.

Positive feedback will encourage this stimulus to continue.

Question 13

What are examples of negative feedback?

Answer 13

• Photosynthesis (Calvin cycle)

- Respiration (Citric Acid Cycle)

Question 14

What’s an example of positive feedback?

Answer 14

Breastfeeding

Question 15

How do you turn signaling off in positive feedback?

Answer 15

There needs to be a loss of the original stimulus (baby stops suckling)

Question 16

What is Homeostasis?

Answer 16

The ability to maintain a constant internal environment even if there’s environmental changes.

Question 17

Hormones help maintain ______.

Answer 17

Homeostasis

Question 18

________ feedback loops are common in maintaining homeostasis.

Answer 18

Negative

E.g., just ate, blood glucose is high

1) pancreas secretes insulin
2) insulin encourages transport/storage of glucose
3) blood glucose lowers

Question 19

What are endocrine disruptors?

Answer 19

Molecules that disrupt hormone signaling (they look similar to molecules in our own bodies and could act like a competitive inhibitor)

Question 20

Why don’t people want to drink milk?

Answer 20

Could have endocrine disruptors (hormones from cows) that could bind to our receptors