anatomy and physiology of gland

1. H U M A N G L A N D A N D I T S F U N C T I O N
E X O C R I N E A N D E N D O C R I N E G L A N D S
P R E S E N T E D B Y
J I J I . V
P R O F E S S O R

2.  What is gland ?
 A gland is an organ which produces and
releases substances that perform a specific
function in the body.
 There are two types of gland.
 Exocrine
 Endocrine

3. Endocrine glands Exocrine gland
1.Ductless glands .
2. Release the
substances that they
make (hormones)
directly into the
bloodstream.
Duct gland
Do not produce
hormones and they
release their product
through a duct Into
cavities inside the
body or its outer
surface (exocrine
gland)

4. What is Exocrine glands?
 Exocrine glands release their secretions onto an epithelial
surface via a duct.
Exocrine glands consist of two main parts,
 A secretory unit
 A duct.
 The secretory unit consists of a group of epithelial cells,
which release their secretions into a lumen.
 A duct is lined with epithelium and is involved in
transporting the secretions from the secretory unit to an
epithelium-lined surface.

6.  Pancreas gland

7.  Classification by shape
 Exocrine glands can be classified into a
variety of categories
 In terms of their structure and Shape of
their secretory unit.
 Duct

8.  Classification by shape

10. Classification according to function

11.  Classification according to function

12.  Classification summarise

13. Structure and
shape
Function Secretion mechanism
1. Tube shape are
referred to
as tubular.
2. Spherical units
are referred to
as alveolar or a
cinar
3. Duct is
branched or
not.
• An unbranched
duct is referred
to as a simple
gland, e.g sweat
gland
• Branched duct
is known as
a compound
gland.
1. Serous glands :
Serous fluid contains
enzyme.
2…Mucous glands:
The production of
mucus, a viscid
(sticky)
glycoprotein.
3. Mixed glands
Comprised of both
serous and mucous
glands and secrete a
mixed substance
containing both
serous fluid and
mucus.
1. Merocine glands
Secretory products of these
glands are usually proteins.
2.Apocrine glands
Release their secretory products
contained within membrane-
bound vesicles. This type of
secretion is rare and these
glands are found in
the breast and constitute
some sweat glands
3.Holocrine glands
Release whole secretory cells,
which later disintegrate to
release the secretory
products. This type of
secretion is seen in
sebaceous glands associated

14.  Types of exocrine glands and their functions-
• Salivary gland:
 In the buccal cavity secrete saliva.
 This saliva has many functions. .
• Sweat glands:
 Secrete sweat which acts to regulate body
temperature and also excretion.
• Sebaceous gland:
 Secrete sebum in the skin and the ear. •
Lachrymal glands: In eye secrete water to
moisten the eye.

16.  Lacrimal gland
 Produces tears that help to bath the eyes, thereby
serving as a lubricant and it contains antibacterial
property.
 The pancreas
 This is both an exocrine and an endocrine gland.
 The exocrine portions secrete digestive enzymes
that are carried by ducts to the duodenum of the
small intestine .
 The endocrine portions of the pancreas called
pancreatic islets or islets of Langerhans, secrete
two hormones: insulin and glucagon directly into
the blood that help in the regulation of blood
glucose.

18.  WHAT IS ENDOCRINE SYSTEM?
 The endocrine system is made up of glands
that produce And secrete hormones,
Chemical substances produced in the body
That regulate the activity of cells or organs.

19.  Continues………..
 These hormones Regulate the body's
growth,
 Metabolism (the physical and chemical
processes of the body),
 And sexual development and function.

20.  WHAT IS HORMONES?
 Hormones are
 Chemical messengers created by the body.
 They transfer information from one set of
cells to another to coordinate the functions
of different parts of the body.

21.  The major glands of the endocrine system are
 Hypothalamus,
 Pituitary,
 Thyroid,
 Parathyroids,
 Adrenals,
 Pineal body, and
 The reproductive organs (ovaries and testes).
 The pancreas is also a part of this system; it
has a role in hormone production as well as in
digestion.

23. FUNCTION OF ENDOCRINE SYSTEM
 The endocrine system
 Is regulated by feedback mechanism
 A signal is sent from
 The hypothalamus to the Pituitary gland in the form of a
"releasing hormone,"
 which stimulates the Pituitary to secrete a "stimulating
hormone" into the circulation.
 The stimulating hormone then signals the target gland
to secrete its hormone.
 As the level of this hormone rises in the circulation,
 the hypothalamus and the pituitary gland shut down
secretion of the releasing hormone and the stimulating
hormone,
 which in turn slows the secretion by the target gland.
 This system results in stable blood concentrations of the
hormones that are regulated by the pituitary gland.

24. HYPOTHALAMUS
STIMULATE
PITUTARY GLAND
SECREATE STIMULATING HORMONE
TARGET GLANDS (OTHER GLANDS)
GLAND SECREATE HORMONE
INTO BLOOD
SHUT DOWN THE SECREATION OF
STIMULATING HORMONE BY HYPO AND
PITUTARY

25.  Hypothalamus

26.  Hypothalamus
 The hypothalamus is located in the lower
central part of the brain.
 This part of the brain is important in
regulation of satiety, metabolism, and body
temperature.
 In aHypothalamus releasing hormones
signal secretion of stimulating hormones.

27.  The hypothalamus is a part of the brain that
secretes hormones that regulate body
temperature and metabolism.
 The hypothalamus also secretes a hormone
called somatostatin, which causes the
pituitary gland to stop the release of growth
hormone.

28.  PITUTATY

29.  The pituitary gland
 Is located at the base of the brain beneath
the hypothalamus and
 Is no larger than a pea.
 It is often considered the most important
part of the endocrine system
 Because it produces hormones that control
many functions of other endocrine glands

30.  The pituitary gland is divided into two parts:
 Anterior lobe
 Posterior lobe.
 Anterior lobe
 The anterior lobe produces the following
hormones, which are regulated by the
hypothalamus:
 Growth hormone: Stimulates growth of bone and
tissue (Growth hormone deficiency results in
growth failure. Growth hormone deficiency in
adults results in problems in maintaining proper
amounts of body fat and muscle and bone mass. It
is also involved in emotional well-being.)

31.  Thyroid-stimulating hormone (TSH): Stimulates
the thyroid gland to produce thyroid hormones (A lack
of thyroid hormones either because of a defect in the
pituitary or the thyroid itself is called hypothyroidism.)
 Adrenocorticotropin hormone
(ACTH): Stimulates the adrenal gland to produce
several related steroid hormones
 Luteinizing hormone (LH) and follicle-
stimulating hormone (FSH): Hormones that
control sexual function and production of the
sex steroids, estrogen and progesterone in females or
testosterone in males
 Prolactin: Hormone that stimulates milk production
in females

32.  The posterior lobe
 Produces the following hormones, which are not
regulated by the hypothalamus:
 Antidiuretic hormone
(vasopressin): Controls water loss by the kidneys
 Oxytocin: Contracts the uterus during childbirth
and stimulates milk production

33.  THYROID

34.  Thyroid Gland
 The brain's growth and development is
controlled by the thyroid gland.
 The thyroid gland is located in the lower front
part of the neck.
 It produces thyroid hormones that regulate the
body's metabolism.
 It also plays a role in bone growth and
development of the brain and nervous
system in children.
 The pituitary gland controls the release of
thyroid hormones.
 Thyroid hormones also help maintain
normal blood pressure, heart rate, digestion,
muscle tone, and reproductive functions.

36.  Parathyroid Glands
 The parathyroid glands are two pairs of
small glands.
 Embedded in the surface of the thyroid
gland, one pair on each side.
Functions
 They release parathyroid hormone,
 which plays a role in regulating calcium
levels in the blood
 And bone metabolism.

37. Adrenal gland
Adrenal glands regulate your body's
metabolism, immune system, and sexual
functions

38. Adrenal Glands
 The two adrenal glands are triangular-shaped glands.
Location
 Top of each kidney.
The adrenal glands are made up of two parts.
1.The outer part is called the adrenal cortex,
2.and the inner part is called the adrenal medulla.
1.The outer part produces hormones called corticosteroids,
which regulate the body's metabolism,
 The balance of salt and water in the body,
 The immune system, and sexual function.

39. 2.The inner part, or adrenal medulla,
 Produces hormones called catecholamines
(for example, adrenaline).
Function
 These hormones help the body cope with
physical and emotional stress by increasing
the heart rate and blood pressure.

40. Pancreas

41.  PANCREAS
 The pancreas is an organ comprised of both exocrine
and endocrine glands.
 The majority of the pancreas has an exocrine function
and secretes an enzyme-rich alkaline fluid into
the pancreatic duct, which joins the common bile duct
before emptying into the duodenum.
The exocrine glands secrete the proteolytic enzymes
 Trypsinogen and chymo trypsinogen, which are
activated to trypsin and chymotrypsin in the duodenum
and aid in digestion.
 The exocrine pancreas also secretes bicarbonate ions,
which neutralise the acidic chyme as it reaches the
duodenum.

42.  There are also clusters of endocrine
glands located within the exocrine tissue
and these are referred to as islets of
Langerhans.
The two main hormones released from
the endocrine glands of the Pancreas
 Insulin
 Glucagon.

43.  Reproductive gland

44.  Anatomy of the ovaries
 A woman's 2 ovaries are located on each side of the
uterus, just below the opening of the fallopian
tubes (tubes that extend from the uterus to near
the ovaries).

45.  Function of the ovaries
 The ovaries contain the egg cells needed for
reproduction.
 They also make estrogen and progesterone.
 These affect many of the female
characteristics and reproductive functions.
 Estrogens also play an important role in
bone health and strength.
 The levels of estrogen and progesterone are
controlled by certain hormones made by
the pituitary gland.

46.  Testes
Anatomy of the testes
The 2 testes are oval-shaped organs that hang
suspended in a pouch of skin (scrotum) outside the
male body.

47. Function of testes
•The testes are the site of sperm
production.
•They also make testosterone and other
hormones.
•These affect many of the male
characteristics and support sperm
production.
•Testosterone also plays an important
role in bone health and strength.

49.  Anatomical Structure and Position
 The pineal gland is small glandular body,
approximately 6mm long. It is shaped like a pine
cone, from which its name is derived.
 There are two types of cells present within the
gland:
 Pinealocytes – hormone secreting cells.
 Glial cells – supporting cells.
 In middle age, the gland commonly becomes
calcified, and can be subsequently identified on
radiographs and CT scans of the head.

50.  Anatomical Position
 The pineal gland is a midline structure, located
between the two cerebral hemispheres. It is
attached by a stalk to the posterior wall of third
ventricle.
 In close proximity to the gland are the superior
colliculi of the midbrain – paired structures that
play an important role in vision.

51.  The pineal gland it has direct access to the bloodstream
via fenestrated capillaries.
 The most important function of the pineal gland is to
gather information about the state of the day-night cycle
from the outside environment and use this information
to modulate its production and release of melatonin. .
 Its main secretion is melatonin, which regulates the
circadian rhythm of the body.
 The hormones of the pineal gland have a highly
regulatory importance in which they influence the
activity of other endocrine glands, namely the pituitary
gland
, endocrine pancreas
, adrenal gland
, parathyroid
gland and the gonads.
 The effects of the pineal gland on these glands are
mostly inhibitory, by reducing the synthesis and release
of the hormones produced by these glands

52.  Functions of Glands in the Human body
 The function of all glands is basically secretion of substances;
but the individual functions of each gland depends on the
substances secreted and the target areas or organs.
 Specific Functions of some glands in the human body
 Salivary glands produces saliva that contains some enzymes
for digestion of food and makes food palatable. Saliva also
contains some antibacterial proteins.
 Lacrimal gland produces tears that help to bath the eyes,
thereby serving as a lubricant and it contains antibacterial
property.


53.  Mammary gland responsible for the
production of breast milk especially in
females.
 Prostate gland produces some substances
that help to add secretions to the sperm
before release
 Sebaceous gland produces sebum that helps
to oil the hair and skin making them moist,
 Sweat gland (also called Sudoriferous or
sudoriparousglands) produces sweat that
helps to cool off the body and therefore
helps in regulation of body temperature
through the process of perspiration

54.  The pancreas this is both an exocrine and
an endocrine gland.
 The exocrine portions secrete digestive
enzymes that are carried by ducts to the
duodenum of the small intestine
 while the endocrine portions of the
pancreas called pancreatic islets or islets of
Langerhans, secrete two
hormones: insulin and glucagon directly
into the blood that help in the regulation of
blood glucose.
 .

55.  Adrenal glands located above the kidneys
and produces hormones: adrenaline and
noradrenaline whose functions are in
regulating the response of the body to
threats and this can be in different forms
 Such as increasing the blood pressure via
vasoconstriction,
 Can also increase heart rate and
 Also increase glucose level of blood and so
much more.
 It is called the fight and flight hormone.

56.  Pineal gland
 This is a small, pea-shaped gland located in
the human brain that produces and
regulates some hormones such
as melatonin which in turn regulates sleep
patterns.
 Thyroid gland
 Secretes thyroxine and helps in regulation
of the body metabolism.
 Gastric glands
Secrete gastric juice whose function is to aid
in digestion.

57.  Pituitary gland (also known as the Hypophysis
or Master gland it controls many other glands)
produces several releasing hormones that further
controls many of bodys functions such as growth,
blood pressure, uterine contractions, breast milk
production, thyroid gland function, water and
osmolarity regulation in the body, water balance
via the control of reabsorption of water by the
kidneys, temperature regulation and pain relief
 Parathyroid glands (four tiny glands located in
the neck) produces parathyroid hormone which
controls the level of calcium in the blood and
bones.

58.  Ceruminous glands
 These are sebaceous glands and modified apocrine
sweat glands found in the outer third of the
cartilaginous portion of the human ear canal and
are responsible for the production of Earwax (also
known medically as Cerumen). Cerumen plays a
vital role in the human ear canal by assisting in
cleaning and lubrication of the ear as well as
protection from bacteria, fungus, and insects.
 Bulbourethral glands (also known asCowper
glands) add fluid to semen

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