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Endocrine System Introduction

A). Endocrine System:

B). Hormone:

Steroidal or amino acid based molecules released to the blood that act as chemical messengers to regulate specific body functions by influencing the metabolic activities of cells.

Tropic hormones:

C). Endocrine Glands:

1. Amino Acid

2.  Peptides

3.  Proteins

4.  glycoproteins (proteins with sugar)

B).  Steroids

C).  prostaglandins 

III). Summary of Hormonal Effects

A). Alters membrane permeability

B). Stimulates proteins.

C). Activates/deactivates enzymes

D). Secretory activity

E).  Mitosis

 

IV). Hormone Specificity

A). Definitions

i). Target Cells:

ii). Receptor:

B). Are hormones directional?

i). Hormones are not directed to any specific tissue

ii). Hormones are released through out the body.

iii). Some receptors can be found in only certain glands and organs.

C). Factors that affect hormone-receptor interaction

i). Blood levels of the hormone.

ii). Relative number of receptors

iii). The affinity or strength of the bond

V).  Control of Hormone Levels

A).  Duration

 

B).  Hormone release

 

1).  Hormonal Stimuli

 

2).  Humoral Stimuli

 

3) Neural Stimuli

 

C).  Feed back loops

        receptor

        control

        effector

1).  negative feedback loop

Release of product prevents the release of more product

 

2).  positive feedback loop

Release of product increases the release of more product