Intro

Question 1

The endocrine system Coordinates hormone signaling pathways that regulate: ?

Answer 1

1. Metabolism
2. Growth & development
3. Water & electrolyte balance
4. Reproduction

Question 2

What other system does the endocrine system work closely with?

Answer 2

Nervous system

Question 3

Compare the endocrine and nervous systems

Answer 3

1. Endocrine System
A. Secretes hormones that travel through bloodstream
B. Action relatively slow
C. Effects are prolonged
D. More general effetcs
2. Nervous System
A. Electrochemical impulses via neurons 
   with neurotransmitters
B. Rapid response
C. Effects are brief and specific

Question 4

What does the heart secrete?

Answer 4

ANP & BNP

Important in sodium and water balance

Question 5

What does the kidney secrete?

Answer 5

Secretes erythropoietin

Hormone essential for production of red blood cells

Question 6

Define hormones

Answer 6

1. Chemical substances that regulate activity of certain cells
2. Hormones react with specific receptors
3. Organs, tissues, or cells lacking the specific receptor do not respond to its stimulating effects

Question 7

How are hormones secreted? What are the characteristics of each method?

Answer 7

A. Diffusion
1. Continuous release
2. Steroid hormones
B. Pulsatile
1. Peak & ebb relative to: 
-Circadian rhythm
-Response to meals
-Hormone releasing factors

Question 8

What is the action of a hormone?

Answer 8

1. Once secreted by endocrine organs, hormones travel to their target tissue
   A. Bind to specific receptors
   B. Initiate chain of events
   -Physiologic effects of hormone

Question 9

Which type of glands have ducts?

Answer 9

Exocrine

Question 10

Which type of glands do not have ducts?

Answer 10

Endocrine

Question 11

How are hormones transported?

Answer 11

1. Circulate bound to carrier proteins or free
   A. Free = active hormone
   B. Bound = reservoir to prolong half life

Question 12

What are circulating levels of hormones regulated by?

Answer 12

1. Rate of secretion
2. Nature of secretion
3. Hormone degradation and/or uptake
4. Receptor binding
5. Receptor availability
6. Affinity of hormones for plasma carriers

Question 13

What is the action and source of thyroid hormone?

Answer 13

1. Thyroid

2. Controls basal metabolism

Question 14

What is the action and source of cortisol?

Answer 14

1. Adrenal cortex

2. Energy metabolism; basis for sex hormones

Question 15

What is the action and source of mineralcorticoids?

Answer 15

1. Adrenal cortex

2. Regulates plasma volume via effects on serum electrolytes

Question 16

What is the action and source of vasopressin?

Answer 16

1. Post pit

2. Regulates plasma osmolality via effects on water excretion

Question 17

What is the action and source of PTH?

Answer 17

1. Parathyroid glands

2. Regulates Ca & PO4

Question 18

What is the action and source of insulin?

Answer 18

1. Pancreas

2. Regulates glucose concentration

Question 19

What are the classes of hormones?

Answer 19

1. Peptides
2. Steroids
3. Biogenic amines

Question 20

What are the characteristics of peptide hormones?

Answer 20

1. Formed from chains of amino acids
2. Longer chains are called protein hormones
3. Example: growth hormone

Question 21

What are the characteristics of steroid hormones?

Answer 21

1. Type of lipid derived from cholesterol

2. Example: aldosterone, testosterone

Question 22

What are the characteristics of biogenic amines?

Answer 22

1. Small molecules produced by altering the structure of tyrosine
2. Example: thyroid hormone

Question 23

Where are cell surface hormone receptors located?

Answer 23

Cell membrane

Question 24

What are the classes of hormones that bind to cell surface receptors?

Answer 24

Proteins and Amines

Question 25

What is the moa of protein and amine hormone/receptor binding?

Answer 25

1. Hormone binds to receptor (first messenger); stimulates chemical response via a second messenger 2. Second messengers alter activity of enzymes within the cell 3. Receptor binding increases adenylate cycalse activity -> ATP converted to cyclic AMP -> stimulates changes in cell processes (activate enzymes, alter cell membrane permeability, stimulates protein synthesis, stimulates secretion)

Question 26

Where are intracellular hormone receptors located?

Answer 26

Located in cytoplasm or nucleus

Question 27

What are the classes of hormones that bind to intercellular receptors?

Answer 27

Steroid and thyroid hormones

Question 28

What is the moa of steroid and thyroid hormone/receptor binding?

Answer 28

1. Alters transcriptional activity of genes | 2. Causes synthesis of proteins in target cells via translation

Question 29

define negative feedback regulation

Answer 29

1. Responsiveness of target cells to hormonal action -> Feeds back to control secretion 2. Inhibition of initial hormone release mechanism

Question 30

define positive feedback regulation

Answer 30

Continued stimulation of the original hormone release mechanism ex. Prolactin and oxytocin

Question 31

What is the function of the hypothalamus?

Answer 31

1. Secretes regulatory hormones that control endocrine cells in anterior pituitary gland 2. Synthesizes & releases hormones from posterior pituitary gland. Hormones affect adrenal, thyroid, and gonadal glands

Question 32

What can hormone deficiency result from? What are some examples?

Answer 32

1. Results from destruction of glandular structure A. Hashimoto’s thyroiditis B. Diabetes mellitus Type I

Question 33

What can hormone resistance result from? What is an example?

Answer 33

1. Adequate levels of hormone synthesized and released 2. Target tissues are resistant to hormone’s effects A. Diabetes Mellitus Type II

Question 34

What can hormone excess result from? What is an example?

Answer 34

1. Hormones produced in excessive and uncontrollable manner A. Acromegaly or gigantism B. Graves Disease