BIOLOGY NOTES 1 9 15 MOVEMENT PHYSIOLOGY Physiology is the science of biological function How does your body deliver O2 and nutrients to all of your cells How does your body remove wastes such as CO2 How do your muscles work Etc Carbon atoms essential for life HOMEOSTASIS Maintaining a constant internal environment with changes in activity Bodies are adapted and can change to move and perform in a remarkably broad range Ex Increasing blood supply and O2 to muscle during exercise maintains energy needed of conditions and circumstances for muscle contractions Limit If not enough O2 is supplied muscles produce lactic acid Ex Maintaining body temperature in cold environments Limit Reduce heat loss by reducing blood flow to skin increase heat production by shivering muscle contraction PATHOPHYSIOLOGY Changes in physiology associated with diseases genetic mutations infections environmental factors etc o Learning about pathophysiology o Understand disease mechanisms o Understand our body s responses to disease o Find treatments and cures Bio medical research is helping us to understand normal and pathophysiology with benefits to individuals families and society BLOOD CHAPTER 2 BLOOD COMPOSITION Cells Plasma o Red blood cells o White blood cells o Platelets cell fragments o Water o Electrolytes ions and small molecules o Proteins o Chemical signals hormones Includes gasses O2 and CO2 food molecules and metabolic wastes HEMATOCRIT Some are proteins others are bound to proteins Percent of blood volume RBCs red blood cells Determines O2 carrying capacity of blood in normal individuals CELLULAR COMPONENTS OF BLOOD Red Blood Cells RBCs o Erythrocytes White Blood Cells WBCs o Leukocytes Platelets o Thrombocytes o Cell fragments RED BLOOD CELLS ERYTHROCYTES Red blood cells are specialized to transport O2 o Bi concave shape o O2 transport in blood Short diffusion distance for O2 Cytoskeleton protein spectrin maintains shapes Like the frame of a building Dissolved in plasma and cytoplasm of blood cells Bound to hemoglobin Hb RBCs are filled with lots of Hb Myoglobin and Hemoglobin Hb are O2 binding proteins in muscle and blood o Myoglobin will bind 1 oxygen molecule o Hemoglobin will bind 4 oxygen molecules Binding 1 O2 increases the binding of the next Sir A V Hill BIOLOGY NOTES 1 12 Red blood cells also participate in carbon dioxide CO2 transport o CO2 transport in blood Dissolved in plasma and cytoplasm of blood cells Bound to Hb after it has released O2 Converted to carbonic acid H2CO3 by an enzyme Enzyme Carbonic anhydrase enzyme acts as a catalyst changes something without changing itself In RBCS Carbonic acid comes apart biocarbonate HCO3 H proton CO2 and HCO3 Becomes part of homeostasis can easily leave and re enter RBCs Most carbon dioxide is transported in blood converted to bicarbonate ERYTHROPOIESIS New RBCs come from red marrow of bone IMPORTANT o An individual RBC circulates in blood for only approx 3 4 months IMPORTANT o New RBCs come from stem cells that divide replicate and specialize differentiate into RBCs Occurs in red marrow of bone Maturation takes about one week IMPORTANT Note RBC loses nucleus during maturation more room for Hb RBC production is primarily controlled by a hormone erythropoietin EPO o EPO stimulates RBC production o EPO produced by kidneys o Examples of homeostasis moving to live in the mountains Less atmospheric O2 at elevation Less O2 in blood especially during activity Kidneys produce more EPO More RBCs and produced Hematocrit inreases More O2 in blood Molecular origin of sickle cell disease o A single mutation in an HB gene o Normal Hb GC AT GC Sickle Cell GC TA GC make Hb clump together to form a rod to make sickle cell WHITE BLOOD CELLS LEUKOCYTES WBCs New white blood cells WBCs come from red marrow of bone o New WBCs come from stem cells that divide replicate and specialize differentiate into WBCs Occurs in red marrow of bone o WBCs in blood and other parts of body help prevent infections PLATELETS THROMBOCYTES Cell fragments Platelets thrombocytes are cell fragments produced by megakaryocytes Platelets are involved in blood clotting New platelets come from red marrow of bone BLOOD PLASMA COMPOSTION Water Electrolytes ions Small molecules o Dissolved gasses O2 and CO2 and N2 o Food molecules and metabolic wastes Proteins Chemical signals hormones o Some are proteins and others are bound to proteins o Ex Steroid hormones MAJOR PROTEINS IN PLASMA Albumins Globulins Fibrinogen o Includes antibodies o Blood clotting with platelets Lipoprotein assemblies o Apolipoproteins lipids including cholesterol o High density lipoprotein HDL good cholesterol o Low density lipoproteins LDL bad cholesterol Protein hormones NOTE Hb and carbonic anhydrase are within RBCs Not plasma proteins Blood clotting coagulation involves both platelets and fibrinogen o Stops bleeding from damaged blood vessels o Fibrinogen becomes fibrin which form protein strands Antibodies are blood proteins globulins that help protect against infections o A protein component of the immune system o Vaccination primes the immune system to produce antibodies against infections Benefits individuals and society Heat transport by blood and role in regulation of body temperature o Cold days blood vessels constrict vasoconstriction resulting in heat conservation o Hot days blood vessels dilate vasodilation resulting in increased heat loss SEE BOOK FOR MISSED INFO ABOUT BLOOD Q Food molecules glucose amino acids etc are distributed through the body in the blood along with O2 and CO2 Cancer and Blood White Blood Cell Cancers in US o Second only to cardiovascular diseases as leading cause of death o Cancer occurs when cells multiply at an abnormally high rate o Leukemias abnormally high numbers of white blood cells o White blood cells produced faster than normal when control is o Cancer cells do not function normally leading to abnormal o Some treatments may lead to low WBC counts lost over some part of hematopoiesis aspects of blood function Metastasis cancer Lymph blood related ones o Blood can play significant role in many types of cancers not just o Cancer cells can enter bloodstream and be transported o If cancer cell leaves blood invades another tissue and begins forming a new tumor then it has spread through metastasis o Likelihood of metastasis varies throughout different types of throughout the body becomes a lymph o Lymph is not blood but is very closely related o Fluid between cells is called
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