Chapter 9 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 – 30 minutes

Hormone Regulation of Secretion Hormonal Humoral – blood levels Neural

Gigantism

Goiter Graves Disease

Cushings Disease