4. 4
Objectives:-
At the end of the presentation
studentswill beable todescribe
What is endocrine system
What is exocrine system
What is its function and role in our
body
Theglands which work under
endocrine system
What are their hormones and their
role
5. Definition :
Theendocrine system is thecollection of glands
that produce hormones that regulate metabolism,
growth and development, tissue function,
•The endocrine system is made up of the pituitary gland,
thyroid gland, parathyroid glands, adrenal glands,
pancreas, ovaries (in females) and testicles (in males).
•The word endocrine derives from the Greek words
"endo," meaning within, and "crinis," meaning to secrete
• Endocrinesystem uses hormones as messenger
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6. Special Features:-
6
•Special features of endocrine glands are, in
general, theirductless nature, theirvascularity,
and commonly the presence of intracellular
vacuoles orgranules thatstore their hormones.
•In contrast, exocrine glands, such as salivary
glands, sweatglands, and glands within the
gastrointestinal tract, tend to be much less vascular
and haveductsora hollow lumen.
7. Functions of Endocrine system
7
Controls the processes involved in
movementand physiological equilibrium
Includes all tissues orglands thatsecrete
hormones into the blood
Secretion of most hormones is regulated by a
negative feedback system
The numberof receptors fora specific
hormonecan be altered to meet the body’s demand
13. Hypothalamus:-
13
Location:
The hypothalamus is located below the thalamus,
just above the brainstem and is part of the limbicsystem.
Anatomy:
The hypothalamus is a region of the brain
composed of many small nuclei with diverse functions.
Physiology:
The hypothalamus is a small area in the ventral
diencephalon of the forebrain, in the floor of the third
ventricle, and is a functional link between
the nervous and endocrinesystems.
14. Hypothalamus produces many hormones, someof
which are given below
• ADH ( vasopressin)
• DA (dopamine)
• CRH (corticotrophin releasing hormone)
ADH:
Increases water permeability in the distal
convoluted tubule and collecting ductof nephrons, thus
promoting water reabsorption and increasing blood
volume
14
15. DA(Dopamine):
Inhibit prolactin released from anterior pituitary.
Prolactin (PRL), also known as luteotropic hormone
or luteotropin, is a protein that in humans is best
known for its role in enabling female mammals to
produce milk.
CRH (corticotrophin releasing hormone):
Stimulate adrenocorticotropic hormone
(ACTH)release from anterior pituitary.
The principal effects of ACTH are increased
production and release of cortisol by the cortex of
theadrenal gland.
15
18. Thyroid Gland:-
18
Location:
Thyroid Gland located at the baseof the neck and wrapped
around the lateral sides of the trachea.
Anatomy:
The thyroid gland is a butterfly-shaped gland
Physiology:
The thyroid gland produces 3 major hormones:
Calcitonin:
Stimulatesosteoblastsand thus boneconstruction
Inhibits Ca2+ release from bone, therebyreducing
blood Ca2+
19. Tri iodothyronine (T3)
is a thyroid hormone. It affects almost
every physiological process in the body, including growth and
development , metabolism, body temperature, and heart rate.
Thyroxin (T4)
(Acts as a prohormone to triiodothyronine )
Stimulates bodyoxygen and energy consumption, thereby
increasing the basal metabolic rate
Stimulates RNA polymerase I and II, thereby promoting
protein synthesis
19
22. Parathyroid Gland:-
22
Location:
Parathyroid gland found on the posteriorside of the
thyroid gland.
Anatomy :
The parathyroid gland are 4 small massesof glandular
tissue
Physiology:
The parathyroid gland produces parathyroid hormone.
23. Parathyroid Hormone:
Parathyroid hormone which is involved in the calcium ion
homeostasis
23
Parathyroid hormone (PTH), parathormone or parathyrin,
is secreted by thechief cells of the parathyroid glands as
a polypeptidecontaining 84 aminoacids, While PTH acts to
increase theconcentration of ioniccalcium (Ca2+) in the blood,
Stimulators:
• Decreased serum [Ca2+].
• Mild decreases in serum [Mg2+].
26. Adrenal Gland:-
26
Location:
Adrenal gland found immediatelysuperior to the kidneys.
Anatomy:
The Adrenal glands area pairof roughly triangularglands.
Physiology:
Theadrenal glands areeach madeof 2 distinct layers, each
with theirown unique functions:
the outeradrenal cortex
and inneradrenal medulla
27. Adrenal cortex produces many cortical
hormones in 3 classes i.e.
Glucocorticiods
Minralocoticoids
Androgens
Adrenal Medulla produces
hormones i.e.
Epinephrine
Norepinephrine 27
30. Pituitary Gland:-
30
Location:
Pituitarygland is connected to the inferiorportion of
the hypothalamus of the brain.
Anatomy:
The Pituitary gland, also known as the hypophysis, is
a small pea-sized lumpof tissue
Physiology:
Many Blood vessels surround the pituitarygland to
carry the hormones it releases throughout the body. Itconsists
of 2 separate parts i.e.
Posteriorpituitary
Anteriorpituitary
31. Posteriorpituitary
31
produces two hormones i.e.
• Oxytocin induces laborpain
• Antidiuretic hormone (ADH)
Increases water permeability in the distal convoluted tubule and
collecting ductof nephrons ,thus promoting water reabsorption and
increasing blood volume
Anteriorpituitary produces many hormones i.e.
•TSH Stimulates thyroxine (T4) and triiodothyronine(T3)
synthesisand release from thyroid gland
Stimulates iodineabsorption by thyroid gland
etc
32. •Adrenocorticotrophic Hormone(ACTH)
•Stimulates corticosteroid (glucocorticoid and
mineralcorticoid) and androgen synthesisand release from
adrenocortical cells
•
•Folliclestimulating Hormone(FSH)
32
• In females: Stimulates maturationof ovarian follicles in
ovary.
In males: Stimulates maturationof seminiferous tubules
•Luteinizing Hormone(LH)
In females: Stimulatesovulation
In females: Stimulates formation of corpus luteum
In males: Stimulates testosterone synthesis from Leydig
cells (interstitial cells)
35. Pancreas:-
35
Location:
Pancreas is located in theabdominal cavity just inferiorand
posteriorto the stomach .
Anatomy:
The pancreas isa large gland
Physiology:
The pancreas is considered as heterocrine gland as it
contains both endocrine and exocrine tissues . Two typesof cells are
present i.e.
Alphaand
Betacells
36. Alphacells
produce hormone Glucagon which is responsible for
raising blood glucose level .
Betacells
produces hormone Insulin which is responsible for
lowering blood glucose level after meal
36
39. Ovaries:-
39
The ovary (From Latin: ovarium, literally "egg" or "nut") is
an ovum-producing reproductiveorgan.
Location:
Ovaries found in pairs at the lower back of the femaleas
partof thevertebrate femalereproductivesystem.
Anatomy:
Theyarealmond-shaped and about 3.5 cm (1.5 inches) long.
Physiology:
Theovaries have 2 main functions. They produce mature
eggs. They also make the female sex hormones, which control
reproduction and sexual development
40. It mainly produces two hormones;
40
Estrogen:
is responsible forthedevelopment of secondary sex
characteristics, such as thegrowth of breasts.
Progesterone:
prepares the body forconception bycausing the buildup
of the uterine lining (endometrium) and otherchanges.
43. Anatomy:
Like the ovaries to which they are homologous, testes
are components of both the reproductive system and the endocrine
system.
43
Physiology:
The primary functions of the testes are to produce
• sperm(spermatogenesis) and to produce
• androgens, primarilytestosterone.
44. Testosterone:
44
•Testosterone is a steroid hormone from theandrogen group
and is found in humans and othervertebrates.
•In humans and other mammals, testosterone is secreted
primarily by the testicles of males and, to a lesser extent,
theovaries of females.
•Small amounts arealso secreted by theadrenal glands. It is the
principal malesex hormone and an anabolic steroid.
45. In men, testosterone plays a key role in thedevelopment of
male reproductive tissues such as
• the testis and
• Prostate
As well as promoting secondary sexual characteristics such as
increased
• muscle,
• bone mass, and
• thegrowth of body hair
In addition, testosterone is essential for health and well-
being as well as the prevention of osteoporosis.
45
48. Pineal Gland:-
48
Location:
The pineal gland is located in acentral depression
between the thalami and thecorporaquadrigemina (colliculi)
Anatomy:
It is a small ovoid or fufiform mass which is found deep
within the brain also known as “third eye” as it response to the
lightand day length
Physiology:
It secretes melatonin which influence thesexual
maturityand the seasonalityof breeding and hibernation
51. 51
Thymus Gland :-
Location:
It is situated in theanterior mediactinal space of the thoracic
cavity.
Anatomy:
It is aductless gland which has close resemblance to the
lymphoid tissue
Physiology:
Its main function is to providean area For the T
LYMPHOCYTE maturationand isvital in protecting against
autoimmunity.
The stock of the T lymphocyte is built up in early life, so the
function of the thymusgland isdiminished in adult.
It is largely degenerated in elderly adults and is barely
identifiable.
54. 54
Liver:-
Location :
It isalways located immediatelycaudal to thediaphragm
And tends to be located on the rightside .
Anatomy:
The liver is the largestgland of the bodyand is 1-2 % of the
total bodyweight .
Physiology:
itsecrets two hormones
• Insulin likegrowth factor (GF) :
Insulin likeeffect
Regulatecell growth and development
• Angiotensiogen And Angiotension:
vasoconstriction
releaseof aldosterone from adrenal cortex
57. Kidney:
57
Location:
It usually lieventral to the first three lambar transverse
processes; against thedorsal wall of he abdominal cavity.
Anatomy:
The kidneyarea pairof excretoryorgans and isa bean
shaped
Physiology:
It secrets following hormones
•Erythropoietin
Stimulateserythrocyte production
•Thrombopoietin:
stimulates megakaryotes to produce platelets
60. Heart:
60
Location:
It is situated in the middle mediastinumand is enclosed
within the pericardium
Anatomy:
It isaconical hollow muscularorgan That pumps blood
Physiology:
It secrets following hormones
• Atrial –natriuetic
Peptide(ANP) Reduce blood
pressure
Increase Na+ excretion by kidney
•Brain-natriuretic peptide:(BNP)
Reduce blood pressure to minordegree Than ANP
62. Definition:-
Exocrine system includes Exocrineglands areglands that produce
and secrete substances onto an epithelial surface bywayof aduct.
Examplesof exocrine glands include
• sweat
• salivary
Parotid
submandibular
sublingual
• lacrimal sebaceous .
• Pyloric gland
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63. Classification:-
Bystructure:
Exocrine glands contain aglandularportion and aduct
portion, the structuresof which can be used toclassify thegland.
• Theduct portion may be branched (called compound) or
unbranched (called simple).
• Theglandular portion may be tubularoracinar, or may bea mix
of the two (called tubuloacinar). If the glandular portion
branches, then thegland is called a branched gland.
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64. By method of excretion:-
Exocrine glands are named apocrine glands, holocrine
glands, or merocrine glands based on how their products are
excreted.
• Merocrine secretion – cells excrete theirsubstances
by exocytosis; forexample, pancreaticacinarcells.
• Apocrine secretion – a portion of thecell membrane that
contains theexcretion buds off.
• Holocrine secretion – theentirecell disintegrates toexcrete its
substance; forexample, sebaceous glands of the skin and nose.
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65. By productexcreted:-
• Serouscells excrete proteins, often enzymes. Examples
includegastricchief cells and Paneth cells
• Mucous cells excrete mucus. Examples include Brunner‘s
glands, esophageal glands, and pyloricglands
• Mixed glands excrete both protein and mucus. Examples include
the salivary glands, although the parotid gland is predominantly
serous, the sublingual gland
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67. Name(s) Location Product Structure
Parotid Gland mouth serous tubulo-alveolar
Parotid Gland:-
Its production rises to 50 % during stimulation
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68. Name(s) Location Product Structure
Submandibular
gland
mouth mixed (M+S) tubulo-alveolar
Submandibular gland:-
They contribute some 60–67% of unstimulated saliva
secretion; on stimulation their contribution decreases in
proportion as the parotid secretion rises to 50%.
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69. Name(s) Location Product Structure
Sublingual gland,
Rivini's gland
mouth mucus (primarily) tubulo-alveolar
Sublingual gland:-
They provideonly 3-5% of the total salivaryvolume
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70. Name(s) Location Product Structure
Sebaceous gland skin sebum acinar branched
Sebaceous gland:-
It secrete an oily or waxy matter, called sebum, to lubricate and
waterproof the skin and hair of mammals.
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71. Name(s) Location Product Structure
Pyloric glands stomach mucous
simple branched
tubular
Pyloric Gland:-
The pyloricglands are located in theantrum of the pylorus.
Theysecrete gastrin produced by their G cells
Gastrin isa peptide hormone thatstimulates
secretionof gastric acid (HCl)
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