Chapter 1 Physiology is the science of biological function Relate physiological processes and structures at various scales molecule cell tissue organ organ system and the human organism Homeostasis Homeostasis refers to maintenance of a constant internal environment despite external changes As oxygen increases so does carbon dioxide Heart beats faster breaths get faster and deeper and more oxygenated blood is able to move through the muscles because the blood vessels expand If you re in an area with low oxygen for a longer time your body creates more oxygen carrying RBC s 3 more homeostatic mechanisms maintenance of body temperature maintenance of blood glucose concentration and maintenance of blood and cellular proton concentration pH Explain the importance of understanding both normal physiology and pathophysiology External causes such as infection or internal causes such as genetic mutations Describe benefits of biomedical research for individuals family and society Improving medical practice reducing death rates for diseases ultimately lowering the financial toll on the individuals and society Chapter 2 Blood is part of the circulatory cardiovascular system Major cellular components of blood Blood can be considered a type of connective tissue Pumped through blood vessels delivering oxygen and nutrients to cells throughout our body and transporting biochemical wastes to be removed by the kidneys liver and lungs Most connective tissues provide mechanical connections such as a tendon Blood is a connective tissue because it connects cells throughout our body with its continuous circulation within blood vessels Circulating blood transports molecules such as oxygen or carbon dioxide from one organ to another and chemical signals such as hormones between cells within different regions of the body Blood major component is water but it s a complex fluid Cells most are red and a clear fluid in which the cells are suspended Made of RBC s WBC s plasma and platelets Red Blood cells are specialized for transporting oxygen They have a biconcave shape due to protein structures that make up the cytoskeleton Platelets Smaller fragments of cells Blood Proteins Plasma the clear fluid in which cells are suspended Plasma is mostly water but contains electrolytes sodium chloride bicarbonate Major cellular components of plasma potassium calcium and more Plasma contains dissolved gasses O2 CO2 and N2 Describe general features of cells Describe physiological significance of hematocrit The cell is surrounded by a membrane composed of lipids arranged in a bilayer structure Cell membranes contain proteins The membrane separates the inside of the cell from the outside Inside the cell is cytoplasm Cytoskeleton provides structural support in the cell RBC The biconcave shape of RBC s allows O2 concentration to reach equilibrium much faster than a spherical shape because the diffusion distance is shorter No nucleus and no DNA so they cannot divide and reproduce which frees up space for hemoglobin oxygen binding protein to have more oxygen WBC Also called leukocytes part of our immune system responsible for defending us against infections Do not produce hemoglobin and have a cell nucleus Hematocrit of someone s blood that is RBC s 45 M 40 F Can increase due to low atmospheric O2 May decrease due to loss of blood either externally or internally Diffusion Explain transport in molecules and blood to maintain homeostasis O2 molecules move into and out of RBC s by diffusion the net movement of molecules from regions of high concentration to regions of low concentration by the random motion of molecules colliding Each respiratory gas O2 and CO2 is transported in more than one form with hemoglobin and carbonic anhydrase in RBC s O2 Each molecule of hemoglobin is made of 4 parts consisting of a protein portion and an iron containing heme group essential for O2 binding Heme group carbon oxygen hydrogen and nitrogen atoms surrounding a single iron atom Each hemoglobin molecule can bind 4 molecules of O2 CO2 Transports CO2 from tissues where it is produced to the lungs where it is exhaled CO2 dissolves in plasma is generated by our cells and must be removed Carbonic anhydrase enzyme essential for CO2 transport Carbonic anhydrase combines a molecule of water with CO2 to form carbonic acid H2CO3 Nutrients and metabolic wastes Chemical signals hormones Blood carries chemical signals hormones from endocrine glands to cells in other parts of the body Hormones are a chemically diverse group of molecules and production typically occurs in response to a stimulus For example low blood oxygen triggers EPO production by the kidney High blood sugar triggers insulin release by the pancreas Heat and regulation of body temp Blood circulates throughout our body transporting and redistributing heat with the cells Our bodies have integrated mechanisms that maintain temperature despite external Clotting Coagulation Fighting infections immune function climate If we are exercising or in high heat our blood transports excess heat to the skin On cold days heat loss is minimized by reduction in blood flow to the skin s surface Shivering muscle contractions can increase heat generation Antibodies are protein components of the immune system that circulate in the plasma They are said to recognize a foreign agent such as a flu by binding to specific parts of the virus preventing it from infecting cells by blocking its ability to latch onto the cell surface Bound antibodies signal that the particle needs to be removed and destroyed by WBC s Clotting is important for limiting blood loss from small wounds and it is an initial step toward healing Insufficient clotting caused by disease or diet can result in excessive blood loss But abnormal clotting within blood vessels can be harmful because clots can be transported to organs such as the heart or brain limiting blood flow to cells At the site of a cut platelets are activated to form a seal blocking blood flow from broken blood vessels Plasma protein fibrinogen and platelets are necessary for clotting and are circulating in the blood at all times First when a cut happens formation of a platelet plug and activation of platelets occurs Next formation of fibrin strands that strengthen the platelet plug come in Humans generate new blood cells from stem cells located in the red marrow of bone Erythropoiesis process of forming new RBC s controlled by Erythropoietin EPO a hormone that is produced by the
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