Chapter 9 The Endocrine System. Functions – regulate growth – regulate reproduction – utilization of nutrients – salt and fluid balance – regulation of.

Chapter 9

The Endocrine System

The Endocrine System• Functions

– regulate growth– regulate reproduction– utilization of nutrients– salt and fluid balance– regulation of metabolic rate– adaptation to stress

• Control w/ Hormone– chemical messengers– responses may last– target tissues can be specific– entire body can be target– many have multiple effects

Structure that Secrete Hormones

• Endocrine Gland– “ductless”– hormones– pituitary, thyroid, parathyroid,

adrenals, pineal, thymus– organs• pancreas & gonads

• Other Tissue & Organs– wall of digestion organs– placenta & kidneys

Chemistry of Hormones• Steroid Hormone– derived from cholesterol– sex glands & adrenal cortex

• Amino Acid Base– simplest hormones–many types (I.e. epinephrine)

• Prostaglandins– from fatty acids

How Hormones Work• Receptors in the target cells

– hormones chemically bond w/ receptors• Mechanisms

– alter activity of cells– change permeability– synthesize proteins– activate/deactivate enzymes– stimulate mitosis

• Onset & Duration– <1 min ---> 30 minutes

Hormone Regulation of Secretion

• Hormonal• Humoral– blood levels

• Neural

Gigantism

Goiter

Graves Disease

Cushings Disease