Endocrine system (JW).ppt

The Endocrine System What is the endocrine system? The function of the endocrine system is the production and regulation of chemical substances called hormones. The endocrine system regulates all biological processes in the body from conception through adulthood and into old age What makes up the en...

The Endocrine System What is the endocrine system? The function of the endocrine system is the production and regulation of chemical substances called hormones. The endocrine system regulates all biological processes in the body from conception through adulthood and into old age What makes up the endocrine system? GLANDS and HORMONES Endocrine Glands The primary endocrine glands are the pituitary (the master gland), pineal, thyroid, parathyroid, adrenals, ovaries in the female and testes in the male. Hormones….. A hormone is a chemical transmitter. It is released in small amounts from glands, and is transported in the bloodstream to target organs or other cells. Hormones are chemical messengers, transferring information and instructions from one set of cells to another. Hormones…. regulate growth and development, mood, tissue function, metabolism, and sexual function. Hormones…. Hormones act slower than nervous impulses but cause longer-lasting effects Hormones are used to stabilize the body’s internal environment (homeostasis) Hormones…. Things can go wrong with the production of hormones Hormones…. "Hormone" means to "excite" or "spur on" and that's exactly what hormones do. They cause other things to start happening. It's as if they were keys which not only unlock the doors to other activities, but also regulate those other activities that they've initiated. Hormones…. The endocrine system and nervous system work together to help maintain homeostasis…Balance The hypothalamus in the brain is the primary link between the two systems. It produces chemicals that either stimulate or suppress hormone secretions of the pituitary gland. How communication happens? Hormones follow a complex path to reach their target. Generally a releasing hormone is released from the hypothalamus. This releasing hormone acts on cells in the pituitary gland to release a stimulating hormone which then acts on the endocrine gland or organ. If there is a break anywhere in the path it can cause disorder or disease. The Main Glands and their hormones. Hypothalamus Pituitary Gland Pineal Gland The pineal gland is a small, peashaped gland in the brain. Its function isn't fully understood. Researchers do know that it produces and regulates some hormones, including melatonin. Melatonin is best known for the role it plays in regulating sleep patterns. Thyroid Produces the hormone thyroxine:  Regulates rate of metabolism.  Excess causes hyperactivity.  Deficiency causes weight gain and sluggishness. Parathyroid Gland These glands, located behind the thyroid at the bottom of your neck, are about the size of a grain of rice. The parathyroid hormone produced by the thyroid glands helps maintain the right balance of calcium in the bloodstream Adrenal Gland ‘Fight’ or ‘Flight’ The "fight or flight response" is our body's primitive, automatic, inborn response that prepares the body to "fight" or "flee" from perceived attack, harm or threat to our survival. ‘Fight’ or ‘Flight’ The release of adrenaline and norepinephrine from the adrenal glands to the respiratory centres, heart, and blood vessels is triggered by the production and release of the hormone acetylcholine from the nerves. These hormones are responsible for the constriction of blood vessels, the increase in breathing and the heart rate, the tightening of muscles. They work during times of real or perceived danger. Pancreas Produces the hormone glucagon:  Converts of glycogen back to glucose in the liver. Produces the hormone insulin:  Controls the conversion of blood glucose to glycogen, which is stored in the liver. Reproductive organs Reproductive Organs