Chemical Control Chapter 7-2 p 237

3D Brain - animation Endocrine System - interactive

Endocrine system page 237 Hormones - chemical substances that act as messengers in the body - slow acting and long term effects - unlike nerves which are fast acting. Endocrine glands - glands that produce hormones - also known as 'ductless' glands. Endocrine system - all the endocrine glands of the body. Pituitary gland - the endocrine gland that controls the activities of other endocrine glands; it is often called the "master gland" – because it controls the ovaries, the testes and thyroid gland Hypothalamus - a portion of the brain that constantly checks the internal environment of the body - links the neural and hormonal functions of the body.

Some Endocrine Glands page 238 Thymus a ductless glandular organ at the base of the neck that produces lymphocytes and aids in producing immunity Pancreas located partially behind the stomach in the abdomen, and it functions as both an endocrine and exocrine gland. It produces digestive enzymes as well as insulin and glucagon Adrenal gland one of a pair of ductless glands, located above the kidneys, which produce adrenaline (epinephrine) Ovaries The female sex glands that store the ova and produce female sex hormones Testes The male gonads, which produce sperm and secrete male sex hormones. ADH Anti-diuretic hormone is secreted by the Pituitary Gland - regulates fluid levels in the body by targeting the Kidneys

How Hormones work – p238 Travel via the bloodstream Act on specific TARGET cells Hormones have unique shapes

Controlling the internal environment page 238 Homeostasis the process of maintaining a constant internal environment eg 37 degrees body temp - requires set point, a receptor and an effector to control the system using negative feedback - through the integration of Hormones and Neural control. Page 238 has an AV clip.

Controlling Body Temperature page 237 Metabolism all the chemical reactions occurring in the cells – including digestion, respiration, thinking, growth, repair and the manufacture of hormones. Endothermic able to maintain a constant body temperature - mammals Exothermic require energy (heat) from the environment to help them maintain body processes - lizard. CREATE (draw) a Negative feedback loop for temperature control – read Hormonal control of temperature p 239 and refer to diagram 7.2.4 page 238

Controlling Body Temperature page 237

Controlling Body Temperature page 237

Controlling Fluid Balance page 240 Kidneys control fluid balance and blood pressure. ADH – Anti-diuretic hormone (Hypothalamus via the Pituitary gland) regulates fluid levels. If the fluid volume increases then more urine is excreted, if dehydrated, then less urine is excreted and it is is more concentrated.

Controlling Fluid Balance page 240

Controlling Fluid Balance page 240

Controlling Fluid Balance page 240

Controlling Blood sugar levels page 241 Blood Sugar Level (BSL) – all cells in the body require sugar for energy and it is transported via the blood. Too much sugar in the blood and the blood becomes thick and damages the capillaries. Too little sugar and you feel weak and dizzy. Pancreas controls BSL Insulin causes sugar to move into the cells thereby reducing BSL – forms glycogen which is stored in the liver and muscle cells. Glucagon releases sugar from storage into the blood – raises BSL to make more sugar available for the active cells. Diabetes is characterized by an inability to maintain control of BSL. Type 1 Diabetes is genetic and fairly rare. Type 2 Diabetes is generally associated with a high sugar diet and low exercise.

Responding to Stress page 241 Stress causes messages to be sent to your Adrenal Glands (on top of your kidneys) and they release the hormone Epinephrine/Adrenaline.