110 likes | 187 Vues
Endocrine System. A transmitter of chemical “messengers”. Consists of :. GLANDS that release “chemical messengers” called HORMONES. Hormones are carried by blood and affect distal target cells. . Pineal gland- melatonin for rhythmic activities ( sleep-wake). Glands. Hypothalamus
E N D
Endocrine System A transmitter of chemical “messengers”
Consists of : • GLANDS that release “chemical messengers” called HORMONES. • Hormones are carried by blood and affect distal target cells.
Pineal gland- melatonin forrhythmic activities ( sleep-wake) Glands Hypothalamus - Controls pituitary gland Pituitary gland- regulate other glands Thyroid – thyroxine for metabolism Pancreas – insulin forglucose levels Parathyroid glands- regulates level of calcium in blood Ovary- estrogen forfemale eggs, sex characteristics; progesterone to prepare uterus for a fertilized egg Thymus- T cell development, immunity Testis – testosterone for sperm development and male sex characteristics Adrenal glands - respond to stress
Pituitary gland • Master gland of body • Located in the depression of sphenoid bone • Produces many hormones that affect other glands • thyroid stimulating hormone • Somatotropin- growth hormone • Lutenizing (LH)- causes ovulation • ICSH- causes testes to secrete testosterone • Melanocyte stimulating- distribution of melanin in skin • ADH- antidiuretic hormone ( slows down water removal from blood)
Giantism- oversecretion of growth hormone ( GH) before puberty • Dwarfism- undersecretion of GH. Cause: tumor, injury, infection, genetics
Thyroid Gland • Produces hormones that control metabolism and calcium in blood. • hyperthyroidism ( when too much thyroxine)- results in weight loss, increased blood pressure, elevated body temp. • hypothyroidism ( too little thyroxine)- results in low metabolic rates, low body temp, lack of energy, weight gain. Iodine- for normal thyroxine production
Adrenal Glands • Sit on top of kidneys; • Help the body prepare for and deal with stress; • Has two structural parts: adrenal cortex ( involved in metabolism) and adrenal medulla ( “fight or flight” response);
Pancreas • -Help break down food • Secrete hormones “insulin” and “ glucagon” ; Both help to keep the levels of glucose in the blood stable. • - When pancreas fail to produce or use insulin, diabetes occurs.
2 Groups of Hormones: STEROID and NONSTEROID They need a specific receptor on a specific cell to do their job
Control of the Endocrine System • Regulated by feedback mechanism that function to maintain homeostasis ( increase in substance “ feeds back” to stop the process that produced the substance) Example: Hypothalamus TRH Anterior Pituitary Thyroid TSH Thyroxine
Growth Waterbalance Reproduction Metabolism Calciumand glucoselevels Responseto stress Pituitary Testes Thyroid Pancreas Adrenals Ovaries Parathyroids The Endocrine System regulates by meansof the by meansof the by meansof the by meansof the by meansof the by meansof the