Presentation on theme: "Regulation The Endocrine System Regulation: The Endocrine System."— Presentation transcript:
Regulation The Endocrine System Regulation: The Endocrine System
Endocrine System Function Coordinate body functions using chemical messages (Hormones) Works with the nervous system to provide homeostasis Slower to respond than Nervous System Effect lasts longer than Nervous System
Endocrine System Example: Glucagon from the pancreas (hormone) and the liver hepatocytes (targets) Endocrine glands: Secrete hormones into bloodstream Ductless Target Cells: Cells with appropriate receptors that respond to the hormone
ENDOCRINE SYSTEM: Major Organs
Hypothalamus and Pituitary gland Hypothalamus (part of CNS) –controls the hormonal secretions of the pituitary gland. Pituitary gland – The Master Gland –secretes hormones that regulate other endocrine glands. –For example: Follicle-Stimulating Hormone (FSH): Causes reproductive organs (ovaries, testes) to produce gametes & hormones.
Hypothalamus and Pituitary
ENDOCRINE SYSTEM: Major Organs Adrenal gland : Epinephrine [formerly adrenalin] Mobilizes body for action: –increases heart rate, blood pressure, and breathing rate Pancreas : Insulin - Causes cells to take up glucose from blood Glucagon – Causes liver to release glucose to blood
ENDOCRINE SYSTEM: Major Organs Thyroid: Thyroxin Increases overall metabolic rates Needs iodine to make thyroxin
ENDOCRINE SYSTEM: Major Organs Gonads (Sex Cell Organs) Ovary Estrogen - Promotes development of female sex organs & secondary sexual characteristics. Progesterone - causes uterus to thicken & become vascularized [once every menstrual cycle] Testis Testosterone - Promotes development of male sex organs & secondary sexual characteristics.
Endocrine System Control Feedback loop systems The level of a hormone controls its release Example: Hypothalamus tells pituitary to send out TSH when thyroxin levels are low TSH tells the thyroid to release thyroxin High levels of thyroxin reduces the amount of TSH released
Control of Blood Sugar After a meal, blood glucose levels are high Pancreas secretes insulin to lower it Glucose is stored as glycogen in the liver and muscles Before a meal, blood glucose levels are low Pancreas secretes glucagon to raise it Glucose is released from the liver