Chapter 45: Hormones and The Endocrine System Flashcards Preview

Bio 93: Exam 2 > Chapter 45: Hormones and The Endocrine System > Flashcards

Flashcards in Chapter 45: Hormones and The Endocrine System Deck (20)
Loading flashcards...
1

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

- it's responsible for communication
- works with the nervous system

- specialized cells receive messages and response by decreasing hormones

2

What is endocrine signaling?

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

3

What is paracrine signaling?

- Secreting hormones to neighboring cells (no touchy)

4

What is autocrine signaling?

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

5

What is neuroendocrine signaling?

When the axon directly transfer hormones into the blood stream

6

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

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

7

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

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)

8

What are 3 examples of water-soluble hormone signaling?

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

9

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

- the target cells have different receptors
- each target cell has a different structure and function

10

Two different receptors bind with the same hormone. Why?

They have identical binding sites

11

What is negative feedback?

A response to a stimulus.
Negative feedback will reduce this stimulus.

12

What is positive feedback?

Response to a stimulus.
Positive feedback will encourage this stimulus to continue.

13

What are examples of negative feedback?

- Photosynthesis (Calvin cycle)
- Respiration (Citric Acid Cycle)

14

What's an example of positive feedback?

Breastfeeding

15

How do you turn signaling off in positive feedback?

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

16

What is Homeostasis?

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

17

Hormones help maintain ______.

Homeostasis

18

________ feedback loops are common in maintaining homeostasis.

Negative

E.g., just ate, blood glucose is high
1) pancreas secretes insulin
2) insulin encourages transport/storage of glucose
3) blood glucose lowers

19

What are endocrine disruptors?

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

20

Why don't people want to drink milk?

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