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Objectives 1. Review anatomy - endocrine glands of body.

2. Understand how hypothalamus Controls the endocrine system by controlling the pituitary gland.

Controls the sympathetic (fight/flight) response.

3. Learn anterior pituitary hormones & their effects on other glands of body.

4. Understand some common endocrine disorders.

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Ch 14. Endocrine Physiology

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Endocrine glands of body: Pituitary = master endocrine gland Pineal gland = located in posterior diencephalon Adrenal glands = located above kidneys Thyroid = located on anterior trachea Parathyroid glands = located on posterior thyroid Gonads = ovaries & testes Pancreas GI tract

**Most of these glands controlled by hypothalamus!

Endocrine System = system involving regulation of body functions through use secretory glands & chemical messengers (hormones)

1. Endocrine Glands of the Body

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Controls endocrine system 3 ways: Pg 267 Wiki text 1. Hypothalamic nuclei secrete neuro-hormones through posterior pituitary. Supraoptic nucleus secretes ADH

Paraventricular nucleus secretes oxytocin 2. Hypothalamus secretes Releasing hormones (RH) or Inhibiting hormones (IH)

which control anterior pituitary.

3. Hypothalamus controls autonomic sympathetic

secretion of epinephrine by the

Adrenal medulla

Oxytocin ADH

AP

PP

Hypothalamus controls the pituitary gland and sympathetic response

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AP PP

Hypothalamus Directs Anterior Pituitary Secretions

Know hypothalamic hormone (acronym) and what it causes

anterior pituitary to secrete! Pg 267 Hypothalamus secretes: 1. CRH (corticotropin releasing hormone)

2. TRH (thyrotropin releasing hormone)

3. PRH (prolacting releasing hormone)

4. GHRH (growth hormone releasing hormone)

5. GnRH (gonadotropin releasing hormone)

6. PIH (prolactin inhibitin hormone)

7. GHIH (growth hormone inhibiting hormone)

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AP PP

Anterior Pituitary Secretions (in response to hypothalamus) Pg 267

Anterior Pituitary Response (use acronym): 1. .

2. .

3. .

4. .

5. .

6. .

7. .

CRH

TRH

PRH

GHRH

GnRH

PIH

GHIH

ACTH (adrenocorticotropin hormone) secreted

TSH (thyroid stimulating hormone) secreted

Prolactin secretion

GH (growth hormone) secretion

LH (luteinizing hormone) and FSH (follicle stimulating hormone) secreted

Prolactin secretion inhibited

Growth hormone secretion inhibited

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Anterior Pituitary secretions & their effects on target organs or glands:

Effects: Effects:

Stimulates mammary glands to make milk (lactation)

Stimulates body tissues to grow!

Produce T3 & T4 to regulate metabolism

Produce - Sex steroids - Cortisol

- Mature eggs & sperm - ovulation, make estrogen & progesterone, testosterone

Prolactin

ACTH

TSH

GH FSH

LH

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At A Glance – the whole system

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PRH (prolactin releasing hormone

PIH (prolactin inhibiting hormone

GHRH

GHIH

Hypothalamus

Anterior Pituitary

Target organ responses

Cortisol Thyroid hormones

LH – estrogen & ovulation

FSH – mature sperm

LH - testosterone FSH – mature eggs

Click HERE for Endocrine Blank Flow Chart! Click HERE for KEY

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How hypothalamus & neg. feedback regulates anterior pituitary secretions:

QUES: 1. If the hypothalamus “senses” GH in blood is too high what does it do? What happens to anterior pituitary secretions of GH? 2. If GH in blood is too low, hypothalamus does what? What does pituitary then do? 3. If hypothalamus “senses” high estrogen or testosterone in blood it: What does pituitary then do? **This is how hormonal birth control works! 4. If hypothalamus “senses: low thyroid hormones in blood it: What does pituitary then do?

Stops GHRH secretion decreases

Increase GHRH

Increase GH secretion

stops GnRH Stops LH and FSH secretion

increases TRH Increase TSH secretion

Review • Hypothalamic controls endocrine system

– Nuclei secrete ADH & oxytocin

– 4 Releasing hormones (CRH, GnRH, TRH, GHRH)

– 2 Inhibiting hormones (PIH, GHIH)

– Controls adrenal medulla secretion of epinephrine

• Anterior pituitary secretions & their target organs

– ACTH, TSH, GH, FSH, LH, PRL

• Endocrine glands of body

– Pituitary, adrenals, thyroid, parathyroids, gonads, pineal gland, pancreas, GI tract

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Pituitary Disorders: ONLINE

1. Insufficient GH = insufficient body growth > Pituitary dwarfism 2. Excessive GH – excessive body growth > Gigantism – when onset in childhood > Acromegaly – when onset in adulthood

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Adrenal Gland Hormones: Pgs 272-274

Epinephrine

1. Sex steroids Ex. - estrogen, testosterone, progesterone

2. Mineralcorticoids

Ex. - Aldosterone (tells kidney tubules to increase salt, & then water retention)

3. Glucocorticoids

Ex. - cortisol

Sympathetic response

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Clinical App Pg 209 & ONLINE Exogenous glucocorticoids and negative feedback on adrenal cortex

Adrenal Cortex Disorders: A. Cushing’s Disease (“hypercortisolism”) – Excess Cortisol

Clinical View Pg 206 & ONLINE Causes: - Excess hypothalamic CRH or pituitary ACTH - Adrenal gland tumor Clinical Presentation: - Hyperglycemia = - Hyperlipidema= - Hypervolemia = (“moon face”) - Hypertension =

High blood glucose

High blood lipids (triglycerides and fatty acids)

High blood volume

High blood pressure

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Adrenal Cortex Disorders: B) Addison’s Disease – Insufficient Aldosterone & Cortisol

Bronzing of skin

Clinical View Pg 206 & ONLINE Causes: - ↓hypothalamic CRH or pituitary ACTH. - Adrenal cortex tumor or autoimmune disorder. Clinical Presentation: Na+ retention by kidneys, excess K+ retention

- Hyponatremia =

- Hyperkalemia =

- Hypovolemia =

- Polyuria =

- Hypotension =

- Anorexia = usually loss of body water

- Hypoglycemia =

- Skin bronzing (overstimulation of melanocytes)

Low blood sodium (Na+) – peeing salt out

High blood potassium (K+)

Low blood volume (water follows salt out in urine)

Low blood pressure (from losing body water)

Low blood glucose (from low cortisol)

High urine (GFR) output (water follows salt our in urine)

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Adrenal Cortex Disorders: C) Conn’s syndrome (hyperaldosteronism) Causes: - usually adrenal cortex tumor Clinical Presentation: Na+ retention by kidneys, excess K+ excretion in urine

- Hypernatremia =

- Hypokalemia =

- Hypervolemia =

- Hypertension =

- weight gain = usually retaining body water

High blood sodium (Na+), retained it

Low blood potassium (K+), pee it out

High blood volume (water follows salt back into blood)

High blood presure

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Adrenal Medulla Disorders: Pheochromocytoma = excessive norepinephrine/epinephrine

Clinical App ONLINE Causes: - adrenal medulla tumor Clinical Presentation: “fight or flight” symptoms

- Tachycardia = - Hypertension = - Hyperventilation = - Hyperglycemia = - Hyperlipidema = - Nervousness, sweating

High heart rate

High blood pressure

Rapid breathing

High blood glucose (from fight/flight response)

High blood lipids

Thyroid Gland pg 269

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Produces: 1. T3 (tri-iodothyronine) 2. T4 (thyroxine) 3. Calcitonin - ↓ blood Ca+2 by decreasing intestinal absorption, and blocking pull of Ca+2 from bones.

Increase body metabolism

Parathyroid Glands

Anterior View

PosteriorView

Produce: Parathyroid hormone - ↑blood Ca+2 by increasing intestinal absorption of it, and increasing pull of Ca+2 from bones.

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Thyroid gland disorders – Clinical App ONLINE A. Hyperthyroidism = excessive thyroid hormones Causes: - thyroid tumor - Graves disease = autoimmune attack, over-stimulates thyroid receptors. Clinical presentation: - High metabolism & anxiety - Intolerant to heat (sweating) - Tachycardia - Hypertension -↑ fluid behind eyes (“exopthalmos”)

B. Hypothyroidism = insufficient thyroid hormones

Causes: thyroid tumor, goiter, insufficient dietary iodine. Clinical presentation: - Low metabolism, depression - Intolerance to cold, dry skin, - Enlarged thyroid gland - When in children called “cretanism”

“Goiter” = thyroid can’t make thyroid hormones, it over-grows (swells)

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Gonads Pg 276-277

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Testes Ovaries

Response to LH = Response to FSH =

Response to LH = Response to FSH =

Secrete testosterone

Mature sperm

Secrete estrogen, make corpus luteum, and cause ovulation

Mature an egg each month

A. Kallmann Syndrome (Hypogonadism) = insufficient hypothalamic GnRH production. Results in less pituitary LH & FSH. Causes ↓testes growth and ↓ testosterone and estrogen production. In male child – can interfere with development of penis, testes, sperm production, and other masculine traits.

Sex Steroid Disorders:

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B. Androgen Insensitivity Syndrome (AIS)

= in male fetus, failure of tissues to respond to testosterone. Causes feminization. Partial AIS - Micropenis or enlarged clitoris, partial or no closure of scrotum.

Complete AIS – Clitoris rather than penis, hip & breast development at puberty. No female repro structures inside. Testes retained in abdomen (must be removed!)

Partial AIS – partial fusion of scrotal skin, micropenis or enlarged clitoris

Complete AIS

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Pineal gland (Pg 277)

Pancreas (Pg 274- 276)

- Makes melatonin at night - helps regulate circadian rhythm

- Makes insulin and glucagon

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GI Tract 1. Gastrin (stomach) = stimulates HCL production (by parietal cells) 2. Secretin (sm. intestine) = stimulate water and bicarbonate secretion from pancreas 3. Cholecystokinin (sm. intestine) - stimulates gallbladder contraction (get bile into duodenum) - stimulates pancreatic enzyme secretion 4. Gastric inhibitory peptide (sm. intestine) = - slows gastric motility (slow down) - stimulates pancreatic insulin.

Review

• Endocrine glands of body – Pituitary, adrenals, thyroid, parathyroids, gonads, pineal gland, pancreas, GI tract

• Endocrine disorders

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