The Endocrine System PDF

The Endocrine System  Types of glands Exocrine glands The secretions released into ducts ( i.e has duct), secret enzymes e.g salivary gland ,sweat gland.lacrimal gland ,part of pancreas. Endocrine glands The secretions released directly into the bloodstream (ductless), secret ho...

The Endocrine System  Types of glands Exocrine glands The secretions released into ducts ( i.e has duct), secret enzymes e.g salivary gland ,sweat gland.lacrimal gland ,part of pancreas. Endocrine glands The secretions released directly into the bloodstream (ductless), secret hormones. Hormones : is chemical substance secret from endocrine gland that control the activates of other organ. Each hormones bind to specific tissue called target organ or tissue. The endocrine glands are: hypothalamus pituitary Thyroid parathyroids pancreas adrenal pineal body ovaries and testes Hypothalamus : Lies in the lower part of the brain. Control the pituitary gland. Release releasing and inhibitory hormones Pituitary Gland (Hypophysis) It’s the master endocrine gland lies inferior to the hypothalamus. Connected to the hypothalamus by the infundibulum. This gland housed within the hypophyseal fossa or sella turcica of the sphenoid bone. Divided into an anterior lobe and a posterior lobe The anterior secret hormones but the posterior store the hormones of the hypothalmus. The secretion of the pituitary gland is controlled by the hypothalamus Names of major hormones Growth hormone (GH) Anterior pituitary gland 8  Posterior pituitary gland Names of storage hormones Oxytocin (OT) 9 10 11  12 Fig 19.4 Pituitary Hormones and Their Targets Thyroid Gland Its largest endocrine gland is located in the anterior neck. has and right & left lobes, which are connected by isthmus. hormones of the thyroid gland : T3 & T4 control the metabolic rate regulator the growth and development Calcitonin Decrease the level of calcium in the blood. 14 Parathyroid Glands located on the posterior surface of the thyroid gland. four small glands Its hormones: parathyroid hormone (PTH) which increase the level of the calcium in the blood. 16 Adrenal Glands (suprarenal) located on the upper pole of the kidney. Consist of the outer cortex and an inner medulla. secrete different types of hormones Adrenal Cortex Secrete the : Glucocorticoids ,like cortisol regulate the CHO metabolism 19 Adrenal Medulla : is modified sympathetic ganglion Secrete the epinephrine and nor epinephrine or adrenaline and nor adrenaline for fight and flight. Pancreas situated between the duodenum and the spleen Mix gland exocrine and endocrine. Exocrine part because secret pancreatic juice share in digestion the lipids. Endocrine part secret hormones: insulin: decrease the glucose level in the blood. glucagon: increase the glucose level in the blood. 22 Pineal Gland attached to the posterior region of the diencephalon. Secretes melatonin. helps regulate a circadian rhythm (24-hour body clock) Endocrine Tissue of the Reproductive System Testis: secret testosterone for secondary sex characteristic in male and hair growth for female. Ovaries: secret estrogen & progesterone For secondary sex characteristic in female and preapre uterus for pregnancy,breast for lactation.