ENDOCRINE SYSTEM
BMS 231:
2015/2016
DR SOBIA IKRAM
DR AQEELA BANO
DR SADIA FARHAN
Table of Contents
1. Objectives for this lesson
2. Functions of the Endocrine System and the Components
involved.
3. Specific features of the Endocrine Glands and the Major
Endocrine organs involved.
4. Functions of the Hypothalamus and Pituitary
5. Control of the Pituitary Feedback from Target organ
(Negative and Positive )
6. Anatomy and Functions of the other major Organs of the
Endocrine System.
Objectives
When you finish this lesson, you should be able to
• Describe the Functions and Components of the Endocrine System.
• Identify the Major Organs of the Endocrine System.
• Identify the Anatomy of the Hypothalamus and Pituitary and Explain the
Negative and Positive Feedback from Target organs.
• Understand the Anatomy and Functions of the Pineal gland, Thyroid ,
Parathyroid, Thymus, Pancreas, Adrenals And Gonads.
Endocrine System
The Endocrine System regulates body activities by releasing
hormones into the blood stream, where they are carried
throughout the entire body.
Endocrine System
Components of endocrine system are glands, tissues, and
cells that secrete hormones
Endocrine Glands – organs that produce hormones
Hormones - chemical messengers transported by the
bloodstream to stimulate responses in another tissue or organ,
often far away
Specific features of Endocrine Glands
1. No ducts
2. Contain dense capillary networks to allow easy
uptake of hormones by the bloodstream
3. Effects on the target cells (as metabolic alteration
occurs)
Major Endocrine Organs
1.
2.
3.
4.
5.
6.
7.
8.
9.
Hypothalamus
Pituitary gland
Pineal gland
Thymus
Thyroid gland
Parathyroid gland
Pancreas
Adrenal
Gonads (ovaries and testis)
Pineal gland
Hypothalamus
Pituitary gland
Thyroid gland
Thymus
Adrenal gland
Pancreas
Parathyroid
glands
Trachea
Posterior view
Gonads:
Ovary (female)
Testis (male)
Hypothalamus
The hypothalamus is a funnel shaped
gland in the brain located just above the
brain stem
It is a small cone-shaped structure that
projects downward from the brain, and
connects to pituitary gland by a stalk.
• Regulates
– water balance
– thermoregulation
– Reproductive function
• Many of its functions carried
out by pituitary gland
Pituitary Gland
• Also called Hypophysis
• Suspended from
hypothalamus by a stalk
• Composed of two
portions;
– Adenohypophysis
(anterior pituitary)
– Neurohypophysis
(posterior pituitary)
Pineal Gland
• Pineal gland also known as the pineal body is located in the
center of the brain, between two cerebral hemispheres .
Pineal Gland
Pineal gland is associated with
– 24-hour circardian rhythms of daylight and
darkness
– Regulation of timing of puberty in humans
– Seasonal effects on body as body changes in
winters
Thymus
• Plays a role in two systems: endocrine, lymphatic.
• Bilobed gland in the mediastinum anterior and superior to
the heart.
• Secretes hormones that affect immune activity
Thyroid Gland Anatomy
.
Superior thyroid
artery and vein
Thyroid
cartilage
Thyroid
gland
Isthmus
Inferior thyroid vein
Trachea
– Butterfly-shaped
gland
– Present in front of
trachea
– Has two lobes and
central connecting
portion called
isthmus
Parathyroid Glands
Four pea shaped glands
•
•
Embedded in the
posterior surface of
thyroid glands
•
Concerned with calcium
metabolism
Adrenal glands
• The suprarenal glands, also known as adrenal glands, belong
to the endocrine system.
• They are a pair of triangular-shaped glands, each about 2 in.
long and 1 in. wide, that sit on top of the kidneys
Adrenal glands
• In cross section adrenal
gland shows
 outer portion called
cortex
 inner portion called
medulla
Pancreas
Pancreas is the gland that has both exocrine and
endocrine portion
1. The pancreas lies specifically in the
upper left abdomen, in oblique
transverse direction.
2. It is found behind the stomach with the
head of the pancreas surrounded by the
duodenum.
3. The pancreas is about 15 cm (6 in) long
Pancreas
Pancreas has two main ducts
1. Main pancreatic duct
2. Accessory pancreatic duct
These drain enzymes into the duodenum.
Pancreas
Anatomically pancreas has five parts
1. Head
2. Neck
3. Body
4. Tail
5. Uncinate process
The Gonads
Gonads are the reproductive organs in the human beings.
In females ovaries (estrogen and progesterone)
In males
testes (testosterone)
ovaries
• They are two nodular bodies, situated on each side of the uterus.
The Gonads
Testis
In humans the testes occur as a pair of oval-shaped
organs. They are contained within the scrotal sac.
Thank you