The endocrine system SHANDONG UNIVERSITY Liu Zhiyu The

The endocrine system SHANDONG UNIVERSITY Liu Zhiyu

The endocrin system • The general description Composition endocrine glands (ductless glands) have no ducts, their secretions (hormone) release directly into circulation and trave to its target organs endocrine tissue The endocrine system is an important another regulating and intergrative system besides the nervous system.

endocrine glands The endocrine glands include : hypophysis thyroid gland parathyroid gland suprarenal gland pineal body thymus The endocrine tissues lie in the pancreas ( pancreatic islets)and the ovary and testis.

1、position： n situated in the hypophyseal fossa of the body of the sphenoid bone; n connected to the hypothalamus by the infundibulum. 2、 division: it is divided into two parts: Adenohypophysis neurohypophysis 一、 hypophysis

Pars distalis Adenohypophysis Pars tuberalis Pars intermedia Neurohypophysis Pars nervous Infundibular part Median eminence Anterior lobe Posterior lobe infundibulum

3、neighborhood Superior : Inferior ：sphenoid sinus diaphragma sellae Lateral side: optic chiasmatic cistern cavernous sinus and the strunctures passing through it

Connect with hypothalamus

Function of hypophysis Supraoptic nucleus (vasopressin) Paraventricular nucleus Paraventriculohypophyseal tract (oxytocin) Supraopticohypophyseal trac posterior lobe of hypophysis

1、division : right and left lobes Isthmus: the median narrow part , pyramidal lobe ： Sometimes present， extendes upwards from the isthmus. 二、thyroid gland

二、thyroid gland 2、position： • lies in the anterior neck region with one lobe on either side of lower larynx and upper part of the trachea. • The ishmus lies in front of the 2 -4 tracheal cartilages.

3、The coats of the thyroid glands Inner layer: fibrous capsule External layer: thyroid sheath Suspensory ligament of thyroid gland 4、relation: from superficial to deep: Skin Superficial fascia superficial layer of cervical fascia Infrahyoid muscles pretracheal fascia

三、parathyroid glands they are 4 small yellowish ovoid bodies. superior parathyroid glands: • lie at the junction of the middle and upper 1/3 of the posterior border of the thyroid gland ； between the two capsules. inferior parathyroid glands lie in the lower end of thyroid glands and close to the inferior thyroid artery

三、parathyroid glands Function: they regulate the metablism of the calcium and phosphate which are needed by all cells.

四、suprarenal galnd Position and shape: Position: lie on the medial part of the upper end of each kidney ； enclosed by the renal fascia. ； Shape: the right is crescent- like shape the left one is triangular. Division: • the suprarenal gland may be divided into two parts:

四、suprarenal galnd ncortex : secrets numbers of steroid hormones ，maintain the electrolytic balance and carbohydrorate metabolism. nmedulla ： epinephrine norepinephrine

五、 The pineal body lies on the supero-posterior to the dorsal thalamus； connect to the posterior of the roof of third ventricle.

六、thymus position: the thymus lies in the anterior part of the superior madiastinum, anterosuperior to the pericardium.

六、thymus function: the thymus is an important organ of the immune system and secrete a hormone, the lymphopoietin(胸腺素和促胸腺 生成素)，that stimulates the develoment of lymphocytes.

七、 pancreatic islets lie within the pancreas and is called islets of Langerhans , they secrete insulin regulate the blood sugar level. 八、 ovary The ovarian follicle and the corpus luteum are the endocrine tissue of the ovary. hormons: estrogen progesterone

九、testis the interstitial tissue of the testis produce the testosterone : responsible for the development of the male secondary sexual characteristics.