Endocrine System Page 586 Textbook 2 nd edition

Endocrine System Page 586 Textbook – 2 nd edition Amerman book Page 3 Coursepack

Controlling Systems of the Body • Nervous System – Faster – Uses neurotransmitters • Endocrine System – Slower – Uses hormones

How are hormones different from neurotransmitters?

How Do Exocrine Glands Differ from Endocrine Glands? Exocrine Gland (Sweat Gland) Endocrine Gland (Thyroid Gland)

Major Endocrine Glands

What are hormones? Hormones are chemical messengers that travel through the blood stream to target areas.

Two Chemical Classifications of Hormones • Amino acid-based (protein) • Steroids (lipid)

Review of Plasma Membrane Structure

How do Hormones Arouse their Target Cells? Target cells must have a receptor for the hormone Two methods: • Secondary messenger system (proteins) • Direct gene activation (lipids)

Secondary Messenger System – Protein-based Hormones

Direct Gene Activation – Steroid-based Hormones

Hormone Interactions • Permissiveness • Synergism • Antagonism

Control of Hormone Release • Humoral stimuli • Ion or nutrient concentration (in blood) stimulates hormone release • Neural stimuli • ANS stimulates hormone release from nerves • Hormonal stimuli • One hormone stimulates the release of another hormone

Hypothalamus – Makes and Releases Releasing hormones (RH) & Inhibiting hormones (IH) To target the Anterior Pituitary Gland

Hypothalamus Hormones • • Growth Hormone Releasing Hormone (GHRH) Growth Hormone Inhibiting Hormone (GHIH) Thyroid Releasing Hormone (TRH) Corticotropic Releasing Hormone (CRH) Gonadotropic Releasing Hormone (Gn. RH) Prolactin Releasing Hormone (PRH) Prolactin Inhibiting Hormone (PIH)

RULE #1 Releasing hormones (RH) and inhibiting hormones (IH) made by the hypothalamus will target the anterior pituitary

Hypothalamus • Makes and releases releasing (-RH) and inhibiting hormones (-IH) to target the anterior pituitary • Makes OXY and ADH • Stores these hormones in axon terminals in the posterior pituitary until they are released • The posterior pituitary is responsible for releasing OXY and ADH

Hypothalamus & Pituitary Gland Relationship & Location

Anterior Pituitary Hormones (–SH and –TH hormones) • • Growth Hormone Thyroid Stimulating Hormone (TSH) Adrenocorticotropic Hormone (ACTH) Gonadotropins – Follicle Stimulating Hormone (FSH) – Luteinizing Hormone (LH) • Prolactin (PRL)

RULE #2 Stimulating hormones (SH) & some tropic hormones (TH) are made by the anterior pituitary gland

Tropic Hormones • Tropic hormones stimulate other glands of the body to produce hormones • Some tropic hormones are produced by the anterior pituitary gland – Thyroid stimulating hormone (TSH) is a tropic hormone because it stimulates the thyroid gland to produce a hormone called thyroxine

Anterior Pituitary Hormones are Proteins

Growth Hormone (GH) • Target: all cells of the body, especially bones, skeletal muscles, and liver • Functions: – Increase size of body cells – Growth of muscle and bone tissue (and liver) • Did you know? Levels increase when we sleep

Flow Chart for Growth Hormone Hypothalamus produces GHRH targets the anterior pituitary Anterior pituitary produces GH GH targets the body’s cells Body cells grow (enlarge in size)

Control of GH secretion • Growth hormone-releasing hormone (GHRH) promotes GH release • Growth hormone-inhibiting hormone (GHIH or somatostatin) inhibits GH release

Cell Cycle and Growth Hormone

Growth Hormone Disorders • Gigantism / Giantism – excess or hypersecretion of GH (child) • Acromegaly – excess or hypersecretion of GH (adult) • Pituitary Dwarfism – too little or hyposecretion of GH (child)

Gigantism Normal Pituitary Dwarfism

Andre the Giant Had Both Gigantism And Acromegaly

Sandy Allen-was the tallest woman until her death in 2008

• Yao Ming • 7’ 6”

• Robert Wadlow 8’ 11” Tallest man in recorded history

• 1918 -1940 Died from a blister caused by his leg brace!

Acromegaly

More acromegaly

Far Left: Cretinism, hypothyroidism (notice disproportionate body) Next two, Pituitary Dwarfs (notice proportions are correct) Next two could be achondroplasic dwarfs (notice disproportionate size of extremities)

Quick Review! • Hormones that have the same effect when working together are exemplifying: A. B. C. D. E. Synergism Permissiveness Antagonism Both Synergism and Permissiveness Both Synergism and Antagonism

Quick Review! • Calcitonin and PTH perform opposite actions from one another while regulating blood calcium levels. They are: A. B. C. D. E. Synergists Antagonists Permissive Responding to hormonal stimuli Responding to neural stimuli

Quick Review! • A hormone that uses the secondary messenger system is (select all that apply): ____Assembled from cholesterol ____Composed of amino acids ____Activating protein kinases via c. AMP ____Able to diffuse across the plasma membrane ____Docking with an intracellular receptor ____Promoting protein synthesis within the cell

On a piece of paper… 1. Outline how the secondary messenger system operates 2. Explain how the hypothalamus controls the release of hormones from the anterior pituitary gland.