ENDOCRINE SYSTEM

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I. OVERVIEW

A. Exocrine glands-

B. Endocrine glands-

1. Hypothalamus (neuroendocrine organ)
2. Pituitary gland (hypophysis)
3. Thyroid gland
4. Parathyroid glands
5. Adrenal glands
6. Pancreas
7. Pineal body (gland)
8. Thymus gland
9. Gonads (testes, ovaries)
10. Tissues that secrete hormones found in stomach, intestines, kidney, heart

C. Processes Controlled and Integrated by Hormones (i.e. their functions):

1. Reproduction
2. Growth/development
3. Cellular metabolism and energy
4. Maintains water, electrolyte balance
5. Nutrient balance of blood

II. Chemistry of Hormones

A. Types of hormones:

1. Amino acid-based hormones
2. Peptide hormones
3. Steroid hormones (lipid-based)

B. Hormone-Target Cell Specificity

1. Protein receptors
2. Up-regulation > target cells are able to form more receptors in response to hormonal release
3. Down-regulation > decrease in receptor formation so that responses do not continue

C. Two Major Mechanisms of Hormone Action

1. Second-Messenger Systems:

2. Direct Gene Activation:

D. Control of Hormone Release

1. Negative feedback system/inhibition

2. Nervous system modulation

a. Hypothalamus - can stimulate the release of E and NE from the adrenal medulla
b. Sympathetic nervous system

III. Major Endocrine Organs

A. Hypothalamic-Pituitary Relationship

1. Hormones produced by the Hypothalamus affecting the Anterior Pituitary

a. Releasing hormones (ex: Growth Hormone-Releasing Hormone GH-RH)

b. Inhibiting hormones (ex: GH-IH or Somatostatin)

c. Hypophyseal-Portal System

2. Hormones produced by the Hypothalamus and stored in the Posterior Pituitary

a. Oxytocin

b. Antidiuretic hormone (ADH)

1. Function:

2. Target =

Neurogenic Diabetes Insipidus

Nephrogenic Diabetes Insipidus

Cause:

Symptoms:

Treatment:

B. Pituitary Gland (Hypophysis)

1. Location and Anatomy

a. Sella turcica
b. Infundibulum -
c. Adenohypophysis = anterior pituitary
d. Neurohypophysis = posterior pituitary

2. Anterior Pituitary Hormones (6 hormones, a - f)

a. Growth Hormone (GH)

1. Function:

2. Target =

3. Gigantism -

"Andre the Giant"; "My Giant"

4. Acromegaly -

5. Pituitary dwarfism -

b. Thyroid-stimulating hormone (TSH) or Thyrotropin

1. Function:

2. Target=

c. Adrenocorticotropic Hormone (ACTH) or Corticotropin

1. Function:

2. Target =

d. Follicle-stimulating hormone (FSH)

1. Function:

2. Target =

e. Luteinizing hormone (Interstitial cell-stimulating hormone [ICSH] in males)

1. Function:

2. Target =

f. Prolactin (PRL)

1. Function:

2. Target =

C. Thyroid Gland

1. Location and structure

a. Follicles -

b. Parafollicular cells (C-cells) -

1. Calcitonin function:

2. Calcitonin targets:

2. Thyroid hormones (TH) -

a. Thyroxine (T4) and Triiodothyronine (T3)

b. Target =

c. Calorigenic effect:

1. Increase glucose metabolism
2. Increase heat production
3. Normal skeletal & nervous system development
4. Mobilization of lipids

3. Synthesis of Thyroid Hormone

a. Colloid

b. Iodine

c. Tyrosine

d. Enzymes attach iodine to tyrosine

4. Disorders of the Thyroid gland (Hypothyroidism, Hyperthyroidism)

a. Simple Goiter
   -Cause:
    -Symptoms:

b. Cretinism
    -Cause:
    -Symptoms:

D. Parathyroid Glands
1. Parathyroid hormone (parathormone, PTH):

a. Stimulates:

b. Actions:

2. Target of the Parathyroid =

E. Adrenal (Suprarenal) Glands

1. Adrenal Cortex Hormones:

Hormone Class	Hormone example	Hormone Target	Action of Hormone
*Mineralocorticoids*	*Aldosterone*
*Glucocorticoids*	*Cortisol*		a. Inhibits protein synthesis (raises blood amino acid levels) b. Promotes fatty acid metabolism c. Stimulates gluconeogenesis (liver) and raises blood glucose levels d. Antiinflammatory properties e. Prevents lysosomes from releasing enzymes f. Inhibits prostaglandin synthesis
*Gonadocorticoids*	*Androgens*

2. Renin-angiotensin mechanism and its tie to aldosterone release

What are "ACE inhibitors?"

3. Atrial natriuretic peptide (ANP) - produced by heart

-Action:

4. Addison's disease -

-Cause:

-Symptoms

2. Adrenal Medulla

a. Epinephrine 80%

b. Norepinephrine 20%

F. Pancreas

1. Islets of Langerhans

a. Alpha cells -

b. Beta cells -

c. Diabetes mellitus (DM):

Type I (IDDM)

Type II (NIDDM)

Cause:

Cardinal Signs:

a. Polyuria
b. Polydipsia
c. Polyphagia

Treatment:

Complications:

G. The Gonads

1. Estrogen
2. Progesterone
3. Testosterone

H. Pineal Gland

1. Melatonin - influenced by light levels

2. Daily (circadian) rhythms

3. Seasonal Affective Disorder (SAD)

I. Thymus Gland

1. Thymosins
2. Maturation of immune system

IV. Other Organs with Hormone-producing Tissues

A. Heart

1. Atrial natriuretic peptide (ANP)
2. Lowers blood pressure

B. Kidney

1. Erythropoietin
2. Stimulates erythrocyte production

Last Updated 05/26/06

BIO 1007 Lecture Outlines | BIO 1007 Resources | Mrs. Caley Opsal's Home | IVCC Home | Contact Us