BMS 231: 2015/2016 ENDOCRINE SYSTEM DR SOBIA IKRAM DR AQEELA BANO

Objectives When you finish this lesson, you should be able to Identify the Major Organs of the Endocrine System. Identify the Anatomy of the Hypothalamus and Pituitary gland. 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.Hypothalamus 2.Pituitary gland 3.Pineal gland 4.Thymus 5.Thyroid gland 6.Parathyroid gland 7.Pancreas 8.Adrenal 9.Gonads (ovaries and testis)

Pineal gland Pituitary gland Hypothalamus Thyroid gland Thymus Adrenal gland Pancreas Gonads: Ovary (female) Testis (male) Trachea Posterior view Parathyroid glands

Hypothalamus Regulates –water balance –thermoregulation –Reproductive function Many of its functions carried out by pituitary gland 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.

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 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 Pineal Gland

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 –Butterfly-shaped gland –Present in front of trachea –Has two lobes and central connecting portion called isthmus Inferior thyroid vein Isthmus Thyroid cartilage Thyroid gland Trachea Superior thyroid artery and vein.

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

In cross section adrenal gland shows  outer portion called cortex  inner portion called medulla Adrenal glands

Pancreas 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 is the gland that has both exocrine and endocrine portion

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 Pancreas

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.

Testis In humans the testes occur as a pair of oval-shaped organs. They are contained within the scrotal sac. The Gonads

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