Endocrine System Ready let’s go….
Endocrine Glands Endocrine glands- secrete hormones directly into the bloodstream They are ductless
Exocrine Glands Secrete substances through a duct : Sweat, salivary Lacrimal, pancreas
Functions of the Endocrine System To secrete hormones Hormones are: Chemical messengers that coordinate and direct target cells and organs
Hormonal Control Negative feedback-Drop in hormone level triggers a chain reaction to increase secretion, for example: Blood level of hormone falls Brain gets message and sends out hormone to stimulate more hormone Gland stimulates more hormone When blood levels of hormone increase, the brain hormones stop.
Nervous Control In some cases, sympathetic nervous system causes direct release of hormone from gland (for example, when stress causes the adrenal medulla to secrete adrenalin
Pituitary Gland Tiny structure the size of a grape Located at the base of the brain Connected to the hypothalamus Divided into anterior and posterior lobes The “Master Gland”
Anterior Pituitary Gland LH ACTH FSH
Anterior Pituitary Gland GH TSH
Posterior Pituitary Gland Vasopressin Converts to ADH (antidiuretic hormone) in the bloodstream, acts on kidney to concentrate urine and preserve H2O in the body Oxytocin Released during childbirth causing contractions of the uterus.
Thyroid Gland Butterfly-shaped mass of tissue On either side of larynx, over trachea H-shaped Main hormone THYROXINE is controlled by the secretion of TSH Thyroxine controls the rate of metabolism CALCITONIN controls calcium ion concentration in the body, prevents hypercalcemia
Parathyroid Glands Parathyroid gland is located in the neck. Four glands, each the size of a grain of rice Attached to posterior thyroid Produce PARATHORMONE which helps control blood calcium level, prevents hypocalcemia
Thymus Endocrine gland and lymphatic organ Located behind the sternum, in the thoracic cavity above and in front of the heart Begins to disappear at puberty
Adrenal Glands Located on top of each kidney Adrenal cortex secretes corticoids (anti-inflammatory hormones) and sex hormones Androgens are male sex hormones Adrenalin hormone form adrenal medulla powerful cardiac “fight or flight” hormone (stress hormone)
Gonads Ovary in female located in the pelvic cavity. Testes for male Estrogen- development of female reproductive organs, secondary sex characteristics Progesterone-plays a part in the menstrual cycle Testosterone- male reproductive organs and secondary sex characteristics
Pancreas Located behind the stomach Endocrine and exocrine functions Endocrine portion of the pancreasI is by ISLETS OF LANERHANS which produces insulin Insulin- promotes utilization of glucose by the cells Prostaglandin's- tissue hormones Insulin lowers blood sugar levels
Hormones are classified as: The endocrine gland that is located in front of the trachea is the: The chemical substances that secreted by endocrine glands are: The pancreas is located in the cavity. Which endocrine gland is located in the cranial cavity? Which endocrine glands are located above the kidneys? The parathyroid glands are located: The endocrine portion of the pancreas is the: What endocrine gland is normally found in the pelvic cavity? Test Your Grey matter chemicals adrenals Thyroid gland In the neck hormones Islets of Langerhans abdominal Ovary pituitary
The endocrine gland located in the thoracic cavity is the: The hormone FSH stimulates growth of the graafian follicle to grow in the: The function of the thyroid hormones is to: Which endocrine gland produces a response to stress: Body cells that react to a particular hormone are called: When released from endocrine cells in the pancreas, insulin acts to: During what time of day would the pancreas normally secrete the most insulin? thymus Target organ cells Ovaries Lower blood sugar levels Stimulate cellular metabolism After meals Adrenals
Parathyroid hormone tends to increase the concentration of : Prolactin stimulates milk secretion after the delivery of a baby. Prolactin is produced by the: TSH is secreted by the pituitary and acts on the: Which two pituitary hormones act on the ovaries and testes? Thyroid gland Calcium in the blood Pituitary gland FSH and LH