the endocrine system. endocrine system the endocrine system consists of an organization of glands,...
TRANSCRIPT
Endocrine System
• The Endocrine System consists of an organization of glands, each that secrete different kinds of hormones into the bloodstream that serves the purpose to maintain homeostasis.
• A hormone is a chemical signal that circulates through body fluids and affects distant target cells.
• These chemical signals allow animals to manage the activities of cells through the body.– In charge for maintaining trillions of cells
Discovery
• In the early 1900s, research of animal hormones began after the discovery of secretin.
• Researchers added a small amount of HCl to the small intestine to emulate the arrival of acidic material from the stomach.
• It was confirmed that the pancreas secreted compounds that neutralized the acid in the small intestine.
Structure
• Hormones are characterized into three different major classes.– Polypeptides – chains of amino acids linked by
peptide bonds– Amino Acid Derivatives – molecules that are made
by an original amino acids. (Tyrosine
epinephrine)– Steroids – family of lipids differentiated by a four-
ring structure
Endocrine System: glands
• Organs that secrete a hormone into the bloodstream are considered endocrine glands.
• The types major glands that have endocrine functions are:– Hypothalamus - Kidneys– Pituitary gland - Adrenal glands– Thyroid gland - Pancreas– Parathyroid glands - Testes– Pineal gland - Ovaries
Hypothalamus
• Part of the brain that maintains homeostasis• Hormones found in the Hypothalamus:– Oxycotin• Induces labor and milk production in females
– Dopamine– Antidiuretic hormone (ADH)• Promotes reabsorption of H2O by kidneys
– Corticotropin-releasing hormone (CRH)
Pituitary Gland
• Found at the protrusion off the bottom of the hypothalamus.
• Hormones found in the hypothalamus– Growth hormone– Thyroid-stimulation hormone (TSH)– Adrenocorticotropic hormone (ACTH)– Follicle-stimulating hormone (FSH)– Luteinizing hormone – Prolactin– Melanocytes stimuli
Parathyroid glands
• Located on the rear surface of the thyroid gland about the size of a grain of rice.
• Produces the parathyroid hormone:– Control the amount of calcium in the blood and
within the bones
Adrenal Gland
• Endocrine glands that sit right above the kidneys.
• Hormones involved:– Epinephrine (many effects related to short term
stress response)– Cortisol (many effects related to short term and
long term stress responses)– Aldosterone (increases reabsorption of Sodium
ions by kidneys)
Kidneys
• They are essential in the urinary system and also serve homeostatic functions such as the regulation of acid-base levels.
• Also regulating salt-water balance.• Hormones:– Erythropoietin (EPO)• Increases synthesis of red blood cells.
Pancreas
• The pancreas produced several important hormones, including insulin and glucagon.
• It is also a digestive organ that secretes pancreatic juice, which contains digestive enzymes to assist the absorption of nutrients.
• Hormones: – Somatostatin– Insulin (decreases blood glucose)– Glucagon (increases blood glucose)
Ovaries
• Estradiol – regulates development and maintenance of secondary sex characteristics in females– Secondary sex characteristic: features that
distinguish two sexes of a species