Anatomy of the Endocrine System

1. Mother Patern College of Health Sciences
UN Drive/RandallStreet,Monrovia-Liberia
HumanAnatomy (Zoology 411)
Presentation
Mr.Abraham G. Dayklee
Presenter

2. • Includes all the glands of the body and the hormones produced by those glands

3. The Endocrine System:
 Secrete their products into body fluids directly
rather than ducts as in the exocrine glands.
 The study and treatment of the endocrine system
is called ENDOCRINOLOGY

4.  Cellular metabolism
 Reproduction
 Sexual reproduction
 Heart rate
 Digestion
 Plus other processes regulated
by reactions of hormones
Generally they regulate metabolic
processes or regulated by
hormones action.

5. Characterized by:
 Ductless nature
 Vascularity
 Presence of intercellular vacuoles
of granules for hormone storage
 It has an unusually high density of
blood capillaries (fenestrated
capillaries)

6.  Are chemical messengers that are secreted into the bloodstream and
stimulate responses in distant organs
 They affect only their targeted cells with specific receptor.
 Classified into two (2) base on the chemical makeup and solubility:
 Lipid Soluble Hormones (Steroid Hormones)
 Water Soluble Hormones (Non-steroid Hormones)

8.  The hypothalamus, shaped like a flattened funnel
 The hypothalamus is located superior and anterior to the brain stem and inferior to the
thalamus.

9. Thyrotropin-releasing hormones (TRH)
Corticotropin-releasing hormone (CRH)
Gonadotropin-releasing hormone (GnRH)
Growth hormone-releasing hormone (GHRH)
Growth hormone-inhibiting hormone (GHIH)
Prolactin-inhibiting hormone (PIH)

10.  It is attached to the hypothalamus by a stalk ( Infundibulum) and is enclosed
in the saddle-like, Sella turcica of the sphenoid bone
 It is an ovoid gland about 1.3 cm wide but
grows 50% larger during pregnancy
 it is composed of two structures:
• Adenohypophysis
• Neurohypophysis

12. The adenohypophysis is the anterior three-quarters of the pituitary.
• It has two parts:
• Anterior lobe
• Pars tuberalis
 Three classes of cells:
• Acidophils
• Basophils
• Chromophobes

13. It is the posterior one-quarter of the pituitary
And it has three parts:
• Posterior lobe (pars nervosa)
• Stalk (infundibulum)
• Median eminence

14. The anterior lobe of the pituitary gland synthesizes and secretes six principal hormones.
The first two, are called GONADOTROPINS
• Follicle-stimulating hormone (FSH).
• Luteinizing hormone (LH).
The four others are called TROPIC OR TROPHIC
• Thyroid stimulating hormone (TSH)
• Adrenocorticotropic hormone
• Prolactin (PRL).
• Growth hormone (GH)

15. The two posterior lobe hormones, namely:
 Antidiuretic Hormone (ADH)
 Oxytocin (OT)

17. Also called (epiphysis cerebri) – a small pinecone-shaped
 It is posterior to the thalamus of
the brain and beneath the
posterior end of the CORPUS CALLOSUM.
 The pineal gland produces
the hormone MELATONIN .

18. • The thymus plays a role in three systems:
Endocrine, Lymphatic, Immune Systems
• Is a bilobed gland in the mediastinum
superior to the heart, behind the
sternal manubrium.
• It weighs about 20 g up to age 60.
It secretes several hormones
• Thymopoietin
• Thymosin
• Thymulin

19. • The largest in adults, weighing 20 to 25
• Composed of two lobes that wrap
Like a butterfly around the trachea,
Immediately below the larynx.
• It is named for the nearby,
Shield-like thyroid cartilage
Of the larynx

20. Are small ovoid glands in the neck measuring about 3 to 8 mm long and 2 to 5 mm wide.
• They adhere to the posterior side of the thyroid gland.

21. Also known as Suprarenal gland is
attached to the superior to medial aspect
of each kidney. Include 2 types:
• The right adrenal gland is more or less
triangular and rests on the superior pole
of the kidney.
• The left adrenal gland is more crescent-
shaped and extends from the medial
indentation (hilum) of the kidney to its
superior pols.
• Like the kidneys, the adrenal glands are
retroperitoneal, lying side the peritoneal
cavity between the peritoneum and post
body wall.
• In adults, is measures about 5 cm high, 3
cm wide and 1 cm from anterior to
posterior. It weighs 7 to 10 g.

22. It contains two parts, namely;
ADRENAL MEDULLA and ADRENAL CORTEX
• Adrenal medulla - which is the inner core
and is about 10% to 20% of the gland.
• Adrenal cortex - the thicker portion
constituting 80% to 90% of the mass
THE ADRENAL MEDULLA
 It has a dual nature, acting as both an
endocrine gland and a ganglion of the
sympathetic nervous system
 They secrete a mixture of EPINEPHRINE,
NOREPINEPHRINE, and DOPAMINE

24.  An elongated, spongy gland located below
and behind the stomach, mostly superficial
to the peritoneum.
 It is approximately 15 cm long and 2.5 cm
thick
 There are about 1 to 2 million endocrine cell
clusters called the Pancreatic Islets
(ISLETS OF LANGERHANS)
 There are about 1 to 2 million
endocrine cell clusters called the
pancreatic islets (islets of
Langerhans)
 The major effect of these
hormones is to regulate
GLYECMIA, the concentration of
glucose in the blood.

26. • Islets contain from a few to 3,000 cells, belonging to five classes:

27. Gonads (reproductive glands)
 Ovaries is a pair of almond-shaped
located in pelvic cavity lateral
and superior to the uterus
• Hormones secreted are ESTROGEN,
PROGESTERONE and GONADOTROPIN
 Testes is a pair of ellipsoid organs
• Located in the strotum
• Hormone secreted is testosterone

28.  The skin produces CHOLECALCIFEROL.
 The liver involved in the production of at
least five hormones.
 The kidneys secrete most (85%) of the
body’s erythropoietin.
 The heart secretes NATRIURETIC
PEPTIDES.
 Adipose tissue secrete LEPTIN.
 Placenta secrets
ESTROGEN, PROGESTERONE, and other
hormones.

29.  Most disorders of the endocrine system revolve around three causes:
• Hormone deficiency, or HYPOSECRETION
• Hormone excess, or HYPERSECRETION
• Hormone insensitivity

30. For more Information:
abrahamdaylee25@gmail.com
adayklee@yahoo.com
Contact: 0880760020/0776782278