Lecture 1

Question 1

Explain Exocrine glands

Answer 1

Secrete material into ducts which lead outside of body

Question 2

Paracrine glands

Answer 2

Secretion of a chemical messenger from a specialized cell that only acts on neighboring cells

Question 3

Neurocrine Gland

Answer 3

Secretion of a chemical messenger from a neuron directly into the bloodstream

Question 4

Example of exocrine

Answer 4

Sweat

Pancreatic enzymes

Pepsin

Question 5

2 examples of paracrine

Answer 5

Histamine

Nitric Oxide

Question 6

Example of neurocrine?

Answer 6

Norepinephrine

Question 7

What is the main point of the endocrine system?

Answer 7

Help maintain homeostasis

Question 8

3 ways endocrine system and nervous system are similar

Answer 8

1. Both require a sensor cell that detect some change in the environment
2. Both have a cell that actually transmits the information
3. Both have target cells/organs

Question 9

What are the 3 general classifcations of hormones?

Answer 9

Peptides/ Proteins

Amines (derivatives of the a.a. tyrosine)

Steroids

Question 10

Why is hormone structure important?

Answer 10

Small differences in chemical composition has a big change in effect

If we know the structure we can synthesize exogenous hormone

Question 11

Which type of hormones are generally water-soluble?

Answer 11

Peptides

Proteins

Catecholamines

Question 12

What 6 characteristics will be influenced by a hormone’s solubility?

Answer 12

How/where it is synthesized in the cell

Where in the cell it is stored

How it is transported in the blood

Where its target cell receptors are located

How it exerts its effects

Duration of time in the circulation

Question 13

How are peptide/protein hormones produced?

Answer 13

Like any other protein

• ribosomes on the ER

Question 14

From what are steroid hormones derived from?

Answer 14

Cholesterol

Question 15

Are steroid hormones ususally stored?

Answer 15

NO

-secretion is controlled by rate of synthesis

Question 16

How are the following hormones transported?

Peptide/protein hormones

Answer 16

Travel freely in the bloodstream (hydrophilic)

Question 17

How are the following hormones transported?

Catecholamines

Answer 17

Half free/ Half protein bound

Question 18

How are the following hormones transported?

Thyroid hormone and steroids?

Answer 18

Mostly protein bound - (hydrophobic)

Question 19

4 Reasons why we care how a hormone is transported in blood?

Answer 19

1. Only free hormone is active
2. Bound fraction acts as a reserve hormone in bloodstream
3. Bound fraction is likely to metabolized and eliminated more slowly than free hormones
4. Changes in plasma protein concentrations may affect hormone transport

Question 20

4 reasons why receptor theory helps explain why hormone concentration and effect may not have a linear relationship

Answer 20

1. Threshold of hormone-receptor complexes (amount, % saturated and time) before physiological effect can occur
2. Saturation of receptors at high hormone levels
3. Effect of other compounds on receptors
4. Up or down regulation of receptors

Question 21

Where are hydrophilic hormone receptors found?

Answer 21

Surface of cell - hormones cannot easily penetrate membrane

Question 22

2 effects that a hydrophilic hormone may have on its receptor

Answer 22

1. Open an ion channel on the membrane surface
2. Signal transduction and 2nd messenger activation

Question 23

Where are lipophilic hormone receptors found?

Answer 23

Inside cell or nucleus

Question 24

What do lipophilic hormone receptors tend to be?

Answer 24

Transcription factors

Question 25

What do transcription factors do?

Answer 25

Change the rate of transcription of DNA into mRNA, which changes the rate and types of cellular protein production

Question 26

what are the 3 general factors which determine hormonal effects?

Answer 26

1. Quantity of hormone secreted from the gland 2. Rate of hormone distribution, metabolism and excretion 3. Number of hormone receptors on the target cell - Not all of these factors are easily regulated

Question 27

What are 3 things which affect the rate of secretion?

Answer 27

1. Neuroendocrine control 2. Diurnal (circadian) rhythms 3. Negative feedback loops

Question 28

What is the most common way of regulating rate of secretion

Answer 28

Negative feedback loops

Question 29

What is a tropic hormone?

Answer 29

Regulates the release of other hormone

Question 30

What is primary hyposecretion?

Answer 30

Problem with gland itself - not enough precursor molecule to make the hormone - defect in cellular enzymes needed in hormone production - chemical or immune-mediated damage to endocrine gland - damage to endocrine gland (invasive tumor)

Question 31

What is secondary hyposecretion?

Answer 31

Not enough tropic hormone release to stimulate secondary hormone

Question 32

2 reasons for hypersecretion

Answer 32

1. Functional tumor within gland 2. Idiopathic - we dont know whats going on

Question 33

What could alter hormone transport in the body?

Answer 33

Hypoproteinemia - Results in more unbound (active) hormones being transported

Question 34

How does hormone metabolism affect its functions?

Answer 34

May be required to activate hormone May be required to inactivate hormone

Question 35

What is an example of an effect on quantity of receptors of target cell?

Answer 35

Non-insulin dependent diabetes mellitus