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Feedback mechanisms. Are used to either maintain or amplify (to increase) chemical systems in the body. Note: To determine the type of mechanism you must be able to determine the stimulus and response. Feedback Mechanisms. Identify a Stimulus and Response.
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Feedback mechanisms • Are used to either maintain or amplify (to increase) chemical systems in the body. • Note: To determine the type of mechanism you must be able to determine the stimulus and response.
Identify a Stimulus and Response Your dog chases the ball and you say “Good Boy!” • Stimulus: __________________ • Response:__________________ Your dog pees on the rug and you say “Bad Dog!” • Stimulus:____________________ • Response:____________________
Feedback Mechanisms Negative Feedback The response will increase the stimulus Does not return to homeostasis but will cause more of the stimulus to happen. The response will decrease the stimulus or return the system back to homeostasis. Positive Feedback
Feedback Mechanisms ? The dog pees on the rug and you say “Bad Dog!” Is this Positive or Negative Feedback? The dog chases the ball and you say “Good Boy!” Is this positive or Negative Feedback? ?
You have your head phones in listening to your favorite songs. Negative Feedback What would be an example? What would be an example? Positive Feedback
Functions • To transport oxygen to the cells of the body so cells can continue Cell Respiration • To Transport nutrients to the cells of the body
Parts • Heart • Blood Vessels • Blood
Components of Blood • Red blood cells • White blood cells • Platelets • Plasma
What are Red Blood Cells? • Also called erythrocytes • Transport oxygen • Contain Hemoglobin • An iron containing protein that binds to oxygen • Gives blood a red color
What are White Blood Cells? • Also called leukocytes • Can live for days, months or even years • Guard against infection, fight parasites, and attack bacteria • Can leave the circulatory system and go into the immune system fighting infection
What are two kinds of White Blood Cells? • Phagocytes (eating cells) • Engulf and digest bacteria and other disease causing bacteria • Lymphocytes • Produce antibodies that are proteins to help destroy pathogens
What are platelets? • Cell fragments needed for clotting • Clotting process • Platelet comes in contact with edges of broken blood vessel and becomes sticky • A cluster of platelets gathers around the wound forming a clot (scab)
What is plasma? • Fluid part of blood (mostly made of water) • Straw colored • Transport fatty acids, hormones and vitamins • Regulate osmotic pressure and blood volume • Fight viral and bacterial infections • Aid in blood clotting
What are blood vessels? • Types of blood vessels • Arteries (largest) • Capillaries (smallest) • Veins
What are arteries? • Large, thick walled blood vessels • Carry blood from the heart to the cells • All arteries except the pulmonary artery carry oxygen rich blood
What are capillaries? • Tiny blood vessels with walls that are only one cell thick • Oxygen and nutrient absorption take place in the capillaries • Also carbon dioxide and waste products move into the blood through the capillaries • Diffusion of Oxygen and Carbon Dioxide occurs here in the lungs.
What are veins? • Smaller than arteries but larger than capillaries • Return blood to the heart • Contain valves to keep blood flowing towards the heart
Parts of the Heart Aorta Pulmonary Artery Pulmonary Vein Superior Vena Cava Left Atrium Right Atrium Left Ventricle Right Ventricle Septum Inferior Vena Cava
Blood Flow Through the Heart • Oxygen poor- 1.) Superior and inferior vena cava 2.) Right Atrium 3.) Right Ventricle 4.) Lungs • Oxygen rich- 5.) Left Atrium 6.) Left Ventricle 7.) Aorta 8.) Body
Blood Flow Through the Body • Pulmonary circulation • Right side of the heart pumps blood from the heart to the lungs • Systemic circulation • Left side of the heart receives blood from the lungs and pumps it to the rest of the body
Feedback Mechanisms in the Circulatory System When human tissue, such as skin is torn or cut, all the cells near the damage send out a signal that activates the platelets in that area. A the platelets begin to form a plug, they send out chemical signals calling for more platelets in order to stop the bleeding. Stimulus:__________ Response:_________ Feedback:_________
Feedback Mechanisms in the Circulatory System • When muscle cells are active they need more ENERGY (ATP). In cellular respiration, the Mitochondria uses Oxygen to make ATP. After you are done exercising, your breathing returns to a normal rate because the amount of Oxygen required by your cells has decreased. • Stimulus: ______________ • Response:______________ • Feedback:_______________