1. Pineal Glands

2.Pituitary Gland

3.Thyroid Gland

4.Parathyroid Gland

5.Thymus

6.Adrenal Gland

7.Pancreas

8.Gonads - ovary and testes

9.Special secretory cells of the GI tract

1.Secretion of hormones

2.Ductless glands

3.Very Vascular

4.Target tissue

5.Slow but long lasting

1.Negative feedback mechanism.

2.Neural Control.

↓in Hormone level in Blood → ↑in secretion of Hormone → ↑in Hormone level in Blood → Result: Gland stops secreting Hormone (Works in a cycle!!)

Example:

↑in Glucose in Blood → ↑in secretion of Insulin → ↓in Blood Glucose level → Result: Pancreas stop secreting insulin.

The release of hormones is controlled by the Hypothalamus of the brain which secretes substances called releasing factors. This stimulates glands to secrete their specific hormones. 

Example: Growth Hormone Releasing Factor (GHRF) causes the pituitary to release growth hormones.  

Endocrine Glands:

1.Pituitary Gland

(Hypophysis)

-Location

Inferior surface of brain

Attached to Hypothalamus

Surrounded by the circle of Willis

Two Distinct Lobes:

1.Adenohypophysis

2.Neurohypophysis

Anterior lobe.

Glandular Portion.

Produces and secretes six major hormones:

1.Growth Hormone(GH)

2.Thyroid-stimulating Hormone(STH)

3.Adrenocroticotropic Hormone(ACTH)

4.Follicle-stimulating Hormone(FSH)

5.Luteinizing Hormone(LH)

6.Prolactin

1.Increase protein synthesis and mitosis.

2.Regulates growth of most cells of the body.

1.Plays a role in ovulation.

2.Stimulates secretion of sex hormones.

-Estrogen and Testosterone

1.Stimulates follicle(ova) develpoment in the ovary and sperm in the testes.

2.Also stimulates sex hormone secretion.

Posterior Lobe.

Nervouos Portion.

Stores and releases 2 hormones produced by the Hypothalamus.

1.Oxytocin

2.Antidiuretic hormone (ADH)

1.Stimulates uterine contractions.

2.Promotes milk ejections from breast.

1.Affects permeability of the kidney tubules to reduce the excretion of water H₂O.

2.Vasopressin: controls BP; constricts Blood Vessels.

1."Master Glands" of the body.

2.Regulates many body activities through it's influence on other endocrine glands.

3.It does this by releasing specific hormones which affect the activity of these glands(eg. cause them to secrete the hormones they produce.)

Thyroid Gland

-Location

Anterior neck inferior to larynx.

Surrounds anterior and lateral aspects of the TRACHEA.

Structure

(Gross)

Two lobes connected by an Isthmus.

May contain a pyramidal lobe (superior extension)

Structure

(Microscopic) 

1.Cuboidal Cells: hormone production

2.Follicles: store hormones

1.Thyroxine(T₄)

2.Triiodothyromine(T₃)

3.Calcitonin

Thyroxine(T₄)

Triiodothyromine(T₃)

-Site of Action

-Effect

-Both found in most cells of the body

-Regulates Basal Metabolic Rate

Calcitonin

-Site of Action

-Effect

-Bone

-Regulates osteoclasts activity and therefore the amount of Ca which leaves bone → this lowers blood Ca level.

Parathyroid Gland

-Location

Parathyroid Hormone

-Site of Action

-Effect

-Osteoclast in bone, kidney, intestine

-Increase blood calcium levels 

Adrenal Glands

-Location

-Paired glands

-Located on superior poles of the kidneys.

1.Medulla

2.Cortex

Medulla

-Structure

-Hormone

-Inner portion

-activated by stress

-Prepares body for "Flight or Fight" reponse (ANS)

-Epinephrine

Epinephrine(catecholamines)

-Site of Action

-Effect

-Many organs and tissues

-Reinforces and prolongs Sympathetic ANS respons thus causes:

↑in Heart Rate!! and ↑in Respiration!!

Cortex

-Structure

-Hormone

-outer portion

-produces cortico hormones

-responds to ACTH(Adrenocorticotropic hormone)

-hormones:

1.Aldosterone

2.Cortisol/Hydrocortisone

3.Androgens

Aldosterone

-General Info

-Site of Action

-Effect

(Primary and Secondary)

-a mineralocorticoid

-kidney tubules

-Primary effect: regulates Na and K levels

-Secondary effect: to reabsorb water into tubules

Androgens

(Estrogen and Progesterone)

-Site of Action

-Effect

-Various tissues

-supplement gonadal hormones; promote development of secondary sex characteristics.

Pancreas

-General Info

-Location

-Pancreas are both exocrine as well as endocrine

-In the upper abdomen, posterior inferior to stomach

What is the duct of the exocrine pancreas called?

and

What is the function of exocrine pancreas?

-Duodenal Papilla

drains into the stomach

-containscells and ducts that produce and secrete digestive enzymes into the duodenum of the stomach. 

Structure of Endocrine Pancreas

Hormones

-Islets of Langerhans contain endocrine cells.

-Hormones:

1.Insulin

2.Glucagon

Insulin

-General Info(what cells produce insulin?)

-Site of Action

-Effect

-Beta Cells produce insulin

-all body cells

-regulates transport of glucose into cells.

Glucagon

-Genral Info(What cells produce this hormone?)

-Site of Action

-Effect

-Alpha cells produce glucagon

-Liver

-promotes conversions of glucagon into glucose

Gonads

Types

-Ovary

-Testes

Ovary

-Structure

-Hormones

-corpus luteum and follicle

-Estrogen and Progesterone

Estrogen and Progesterone

-Site of Action

-Effect

-female reproductive organs esp. uterus

-development and regulation of female reproductive organs and secondary sex characteristics 

Testes

-Structure

-Hormones

-Interstitial cells of leydig

-Testosterone

Testosterone

-Site of Action

-Effect

-Male reproductive organs

-Development and regulation of male reproductive organs and secondary sex characteristics.

Pineal Gland

-Location

Structure

Hormones

-Glandular structure of epithelial cells.

-Melatonin

-Receives and responds to input from visual pathway

-Highest level at night, may affect wake-sleep cycle(circardian rhythm)

-Inhibits hypothalamus stimulation of hormones which stimulate gonads. Delays sex maturation