Chapter 35

Question 1

Which two systems coordinate communication throughout the body?

Answer 1

Endocrine and Nervous

Question 2

Endocrine System

Answer 2

• Secretes hormones into the blood
• Slower response
• More prolonged response

Question 3

Nervous System

Answer 3

• Transmits nerve impulses
• Faster response
• Less prolonged response

Question 4

What are hormones?

Answer 4

Chemicals that reach target cells through the bloodstream, results in regulation, secretion, and homeostasis.

Question 5

Autocrine Signaling

Answer 5

Signals are produced by and act on the same cell.

Examples: estrogens, ovaries, maturation of ovarian follicles before ovulation

Question 6

Paracrine Signaling

Answer 6

Signals diffuse locally and act on nearby cells. Example: chemical transmitted from nerve to muscle that causes the muscle to contract

Question 7

Endocrine Signaling

Answer 7

Endocrine cells release hormones that are transported to the target cells by the blood.
Examples: Hypothalamus, pituitary, thyroid, parathyroid, adrenals, pineal body, pancreas, ovaries and testes

Question 8

Neuroendocrine Signaling

Answer 8

Neurons release neurohormones which are transported to the target cells by the blood
Examples: Adrenal medulla releases adrenaline to the blood

Question 9

Pheromones

Answer 9

chemical signals that are released from the body into the environment, used to communicate with other individuals in the same species

Question 10

Function of Pheromones

Answer 10

• Mark trails to food sources
• Defining territories
• Warn of Predators
• Attract potential mates

Question 11

When the steroid estrogen is released, it travels through the circulation to signal responses from other cells to facilitate development and maintenance of the female reproductive system. This is an example of which of the following?

Answer 11

Endocrine signaling

Question 12

Polypeptides

Answer 12

chain of amino acids linked by peptide bonds

Question 13

Amines

Answer 13

derived from a single amino acid precursor

Question 14

Steroids

Answer 14

family of lipids derived from cholesterol

Question 15

Water soluble hormones (hydrophilic)

Answer 15

Molecules do not readily cross the plasma membrane. Cannot pass through the hydrophobic middle portion of the phospholipid bilayer.

Question 16

Lipid soluble hormones (hydrophobic)

Answer 16

Molecules can easily enter cells through plasma membrane.

Question 17

Where would you find water soluble hormones?

Answer 17

Water soluble hormones bind to receptors on the surface of target cell

Question 18

Where would you find lipid soluble hormones?

Answer 18

Lipid soluble hormones bind to receptors inside target cells

Question 19

What are the three key events involved in hormone signaling?

Answer 19

Reception - Signal Transduction - Response

Question 20

Cellular Response Pathway for Water Soluble Hormones

Answer 20

• Glycoproteins, Peptide Hormones Composed of Polypeptides, and Thyroid stimulating hormones
• Doesn’t diffuse across cell membranes
• Secreted by exocytosis
• Circulates freely in the bloodstream
• Binds to receptor on the cell membrane, forming the hormone receptor complex

Question 21

Water soluble hormones activate what?

Answer 21

Enzymes, which produce 2nd messengers within the cell

Question 22

Cellular Response Pathway for Lipid Soluble Hormones

Answer 22

• Steroids
• Diffuse across the cell membranes
• Travel in the bloodstream bound to transport proteins
• Dissociate from transport protein at target cells
• Diffuse through the membrane
• Bind to intracellular receptors (cytoplasm or nucleus

Question 23

Lipid soluble hormones induce what change?

Answer 23

A change in gene expression

Question 24

A single hormone can have different effects due to:

Answer 24

• Different receptors for the hormones

- Different signal transduction pathways

Question 25

Epinephrine

Answer 25

- a chemical that narrows blood vessels and opens airways in the lungs

Question 26

The second messenger cAMP forms from what?

Answer 26

ATP

Question 27

cAMP function

Answer 27

- used for intracellular signal transduction - the enzyme that catalyzes the formation of cAMP from ATP is located on cytoplasmic side of plasma membrane and is called adenylyl cyclase or adenylate cyclase

Question 28

MAPK pathway

Answer 28

-activated within protein kinase cascades that regulate cell proliferation, cell differentiation, and cell death in eukaryotes from yeast to humans

Question 29

Steroid Hormones (lipid)

Answer 29

- Diffuse through cell membrane - transported by proteins in blood - Intracellular receptors - Slow acting, Long lasting - Typically derived from cholesterol

Question 30

Protein Hormones (peptide)

Answer 30

- Do not diffuse through cell membrane - circulates freely in blood - cell surface receptors - Fast acting, short lasting - Typically derived from amino acids

Question 31

What is the difference between an autocrine and a paracrine?

Answer 31

Autocrine hormones bind to receptors on the cell and affects the cell that produces it, while Paracrine hormones are released from cells and bind to receptor on nearby cells and affects their function

Question 32

What would happen if the chemical messengers are destroyed?

Answer 32

They would not respond with appropriate actions

Question 33

True or False: Steroid hormones are lipid soluble.

Answer 33

True

Question 34

True or False: Water soluble hormones easily pass through the plasma membrane on their own.

Answer 34

False, they must bind to a surface cell membrane receptor

Question 35

Interaction with a membrane bound receptor will transduce the hormonal message via _____.

Answer 35

a second messenger

Question 36

Cytokines

Answer 36

small proteins that are important in cell signaling

Question 37

Growth Factors

Answer 37

Stimulate cell proliferation, grow, divide, develop

Question 38

Gas Nitric Oxide

Answer 38

- Decrease blood O2 - Release NO - Result in vasodilation in smooth muscle cells - Improves blood flow to tissue

Question 39

Simple endocrine pathway

Answer 39

- hormones are assembled into simple endocrine pathways regulated by negative feedback - Respond directly to an internal or environmental stimulus

Question 40

Pancreatic Hormones

Answer 40

- relies on sets of simple endocrine pathways with coordinated activity - insulin and glucagon secreted by the pancreas help to maintain glucose homeostasis

Question 41

What homeostatic imbalance involves glucose regulation?

Answer 41

Diabetes Mellitus

Question 42

Diabetes Mellitus

Answer 42

- group of diseases that affect how your body used blood glucose - glucose is excreted in urine, as it exceeds the maximum which the kidneys can reabsorb back into the blood

Question 43

Type I Diabetes

Answer 43

- an autoimmune disorder that destroys pancreatic beta cells - insulin deficiency - requires daily injection of insulin