The document discusses the endocrine system, which regulates processes in the body through hormones. It describes the major endocrine glands - the hypothalamus, pituitary gland, thyroid gland, parathyroid glands, adrenal glands, pancreas, gonads, pineal gland, thymus - and the hormones they secrete. The endocrine system maintains homeostasis through feedback loops between the hypothalamus and pituitary gland and target organs. Disorders can arise from hormone deficiencies, excesses, or insensitivities.

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