APII Notes Home Page

Endocrine Glands & Hormones

I). Hypothalamus

Location in the diencephelon

capillary bed forms the hypophyseal portal vein

1). Growth Hormone Releasing Hormone (GHRH)

Stimulates: Growth hormone

Controlled by: level of GH

2). Somatostatin (SS)

Inhibits: GH & Thyroid Stimulating Hormone

Controlled by: level of GH

3). Thyrotropin Releasing Hormone (TRH)

Stimulates: TSH

Controlled by: Thyroid Hormone

4). Corticotropin Releasing Hormone (CRH)

Stimulates: ACTH

Controlled by: glucocorticoids

5). Gonadotropin Releasing Hormone (GnRH)

Stimulates: FSH & LH

Controlled by: gonadal hormones

6). Prolactin Releasing Hormone (PRH)

Stimulates: (PRL)

Controlled by: estrogen

7). Prolactin Inhibiting Hormone (PIH)

Inhibits: (PRL)

Controlled by: estrogen

B). Storage in : Posterior Pituitary

1). Oxytocin

Stimulates:

Uterine Contractions

Mammary Glands

Controlled by: oxytocin

2). Antidiuretic Hormone (ADH)

Stimulates: kidney tubules

Controlled by: solute concentration

II). Pituitary Gland ---- Hypophysis

Pituatary glands

A). Anatomy

1). Anterior Pituitary (adenohypophysis)

2). Posterior Pituitary (neurohypophysis)

B). Anterior Pituitary (adenohypophysis)

1). Growth Hormone (GH) or Somatotropin

i). Stimulates:

Cell growth

Movement of amino acids

Protein synthesis

ii). Primary Targets:

muscle

epiphyseal plate

iii). assisted by

insulin-like growth factors

iv). Controlled by hypothalamus

GHRH
Somatostatin (SS)
GH

v). Growth Hormone Imbalance

Too much:

Gigantism:

Acromegaly:

Too little:

Progeria:

Pituitary dwarfism:

2). Thyroid Stimulating Hormone (TSH)

i). Targets & Stimulates: thyroid gland

ii). Controlled by:

Stimulated by: TRH

Inhibited by: SS & TSH

iii). TSH imbalance

Too much:

goiter

3). Adrenocorticotropic Hormone (ACTH)

i). Targets & Stimulates

Adrenal cortex

ii). Controlled by

Stimulated by: CRH

Inhibited by: glucocorticoids

4). Gonadotropins

Follicle-stimulating hormone (FSH)

Luteinizing hormone (LH)

i). Targets & Stimulates: ovaries and testes

FSH: production of sperm & eggs.

LH: gonadal hormones.

ii). Controlled by:

Stimulated by: GnRH

Inhibited by: Gonadal Hormones & Age:

5). Prolactin (PRL)

PROlactin stimulates the mammary glands to PROduce milk.

i). Targets & Stimulates:

Mammary glands

Testes

ii). Controlled by:

stimulated by: PRH

inhibited by: PIH

Feedback control

Low estrogen Þ PIH

High estrogen Þ PRH

Infant suckling Þ PRH

iii). Imbalance

Too much:

Too little:

6). Melanocyte-Stimulating Hormone

Stimulates:

Darkening of the skin

Functions as neurotransmitter

C). Posterior Pituitary (neurohypophysis)

Hormones produced in the hypothalamus and stored in the posterior pituitary.

1). Oxytocin

i). Stimulates:

Uterine contractions

Milk

Nurturing behavior

Sexual arousal

ii). Targets

Uterus

Reproductive organs

Mammary glands

iii). Controlled by:

oxytocin levels.

2). Antidiuretic Hormone (ADH)

i). Stimulates

Water reabsorption preventing urine formation.

ii). Targets:

iii). Controlled by:

solute concentration

Inhibited by Alcohol & caffeine

III). Thyroid Gland

Anatomy of the thyroid gland

A). Anatomy

anterior trachea connected by an isthmus

Composed of hollow follicles that produce the hormone precursor thyroglobulin.

B). Thyroid Hormone (TH)

i). produced in the follicles (amine hormone)

ii). Types:

Thyroxine (T4)
Triiodothyronine (T3)

iii). Targets & Stimulates:

Everything except the brain, some gonads, spleen & thyroid gland.
Stimulates enzymes for glucose oxidation.

Normal development of the nervous system, skeleton, and reproductive capabilities.

iv). Controlled by:

Stimulated by:

thyroxine levels;

TSH

C). Calcitonin

i). Produced in parafollicular cells.

ii). Targets & Stimulates Skeletal system; lowers blood Ca++ levels.

Antagonist to Parathyroid Hormone

Inhibits osteoclast activity and stimulates calcium uptake

iii). Controlled by: Ca++ blood levels

IV). Parathyroid

A). Anatomy

Posterior of the thyroid gland.; hidden between the thyroid and the esophagus.

B). Parathyroid Hormone (protein hormone)

i). Stimulates

Increases blood calcium levels.

Antagonist to calcitonin

ii). Targets

Skeleton:

Kidneys:

Intestine:

iii). Controlled by: blood calcium levels

iv). Imbalance:

Hyperparathyroidism:

Hypoparathyroidism:

V). Adrenal (Suprarenal) Gland

A). Anatomy

superior on the external kidney.

It is divided into:

capsule

adrenal cortex

adrenal medulla

The cortex divides into 3 zones called the:

zona glomerulosa

zona fasciculata

zona reticularis

B). Adrenal Cortex

Produces corticosteroids;

In the zona glomerulosa

1). Mineralocorticoids

i). Aldosterone

ii). Stimulates:

Reabsorption of Na+ to regulate electrolyte (Na+ & K+) levels.

Water follows sodium.

iii). Targets:

Kidney tubules

Anywhere that Na+ can be secreted:

iv). Imbalance:

Hypersecretion:

v). Mechanisms of control:

a). Renin-Angiotensin Mechanism:

Renin-Angiotensin

Specialized cells in the kidneys become excited when blood volume is low.

Release renin ®

cleaves blood protein angiotensinogen ®

releases angiotension I®

in the lungs converts to angiotensin II®

when reaches adrenal cortex stimulate aldosterone release.

There are also mechanisms that involve:

Direct stimulation from the plasma concentration

ACTH

Atrial natriuretic peptide (ANP)

In the zona fasciculata

2). Glucocorticoids

i). Cortisol, (cortisone, & corticosterone)

ii). control blood sugar level.

iii). Targets & Stimulates

Gluconeogenesis:

iv). Controlled by:

Corticotropin-releasing hormone (CRH) from the hypothalamus®

Adrenocorticotropic Hormone (ACTH) from the anterior pituitary®

cortisol high levels inhibit CRH & ACTH

v). Imbalance

Cushing’s disease .

Addison’s disease

In the zona reticularis

3). Gonadocorticoids (sex hormones)

i). Androgens (Estrogen & Testosterone)

ii). Stimulates: onset of puberty & the formation of secondary sex characteristics

iii). Controlled by:

iv). Imbalance:

C). Adrenal Medulla middle layer of the adrenal gland

1). Epinephrine & Norepinephrine (adrenalin)

i). Target: Heart & peripheral vascular system

ii). Stimulates:

Metabolism,

Heart rate

Blood pressure

inhibits blood flow to digestive system)

iii). Controlled by:

Sympathetic nervous system

Hypothalamus

VI). Pancreas

A). Anatomy

Part of the digestive system in the abdomen

Exocrine: Acinar cells produce pancreatic juice

Endocrine anatomy: Pancreatic Islets (Isles of Langerhan)

alpha a cells & beta b cells

B). Glucagon: alpha a cells

i). Target: Liver

ii). Stimulates:

Breakdown of glycogen

Synthesis of glucose from noncarbohydrates

Release of glucose from the liver

iii). function: Raise blood sugar levels

iv). Controlled by:

sugar level

amino acid levels

Somatostatin

B). Insulin: beta b cells

INsulin gets sugar INto cells

i). Target: Cell membranes of muscle & fat & other tissue

ii). Stimulates:

membrane transport of glucose.

enzymatic breakdown of glucose.

converts glucose to fat

protein synthesis

iii). Inhibits: Breakdown of fat and amino acids

iv). Main function: To lower glucose levels

v). Controlled by:

blood glucose levels

inhibited by: low glucose levels

vi). Antagonist for glucagon

vii) Imbalance:

Diabetes mellitus:

Polyuria:

Polydipsia:

Polyphagia:

Type I diabetes:

Type II diabetes:

Hypoglycemia: Low glucose (low glycogen)

VII). Gonads: (produce steroids)

A). Anatomy & Hormone

Female: Ovaries: estrogen & progesterone

Male: Testes: testosterone

B). Stimulate:

The production of eggs and sperm

Secondary sex characteristics

C). Controlled by:

Gonadotropic hormones: FSH & LH

Gonadal hormones

Placental hormones

VIII). Pineal Gland

A). Anatomy

Attached to the diencephalon.

B). Melatonin

Diurnal cycle

biological clock:

May inhibit early sexual maturity

IX). Thymus

A). Anatomy

Deep in the sternum and inferior to the thyroid.

B). Thymopoietins & Thymosins

Function in the production (T cells)

X). Heart

A). Produces: atrial natriuretic peptide (ANP)

B). Targets: Kidneys and adrenal cortex

C). Affects:

Blood pressure & volume

Na+ concentration

Lowers aldosterone

XI). Gastrointestinal tract

A). Produces: peptides for digestion

B). Targets: Act as local hormones

XII). Placenta:

A). Produces:

Estrogen

Progesterone

Human Chronic Gonadotropin

B). Functions: maintain pregnancy

XIII). Kidney

A). Produces: erythropoietin

B). Target: Red bone marrow

C). Stimulates: Production of red blood cells

XIV). Skin

A). Produces: chlolecalciferol

B). Function: precursor to vitamin D

C). Target:

Liver:

Kidney:

Small intestine:

XV). Adipose tissue

A). Produces: leptin

B). Target: Central Nervous System

C). Functions: Produces sensation of satiety

	Low estrogen Þ PIH
	High estrogen Þ PRH
	Infant suckling Þ PRH

	Everything except the brain, some gonads, spleen & thyroid gland.
	Stimulates enzymes for glucose oxidation.
	Normal development of the nervous system, skeleton, and reproductive capabilities.

	Reabsorption of Na+ to regulate electrolyte (Na+ & K+) levels.
	Water follows sodium.

	Direct stimulation from the plasma concentration
	ACTH
	Atrial natriuretic peptide (ANP)

	Metabolism,
	Heart rate
	Blood pressure
	inhibits blood flow to digestive system)

	Breakdown of glycogen
	Synthesis of glucose from noncarbohydrates
	Release of glucose from the liver

	membrane transport of glucose.
	enzymatic breakdown of glucose.
	converts glucose to fat
	protein synthesis

	Diabetes mellitus:
	Polyuria:
	Polydipsia:
	Polyphagia:

	Female: Ovaries: estrogen & progesterone
	Male: Testes: testosterone

	Gonadotropic hormones: FSH & LH
	Gonadal hormones
	Placental hormones