BSC1005 Biology for Non Majors Dr P Bryant Chase Unit 1 Movement and Physiology Physiology is the Science of Biological Function How does your body deliver oxygen and nutrients to all of your cells How does your body remove wastes such as carbon dioxide How do your muscles work allowing you to move and your heart to pump How does your body continue functioning normally and adapt when conditions change Topics Circulatory system blood and cardiovascular system Respiratory system Musculoskeletal system Why learn about physiology know how our physiological systems work develop better understanding of our physical selves o applies to ourselves and other people o helps us understand similarities and unique adaptations of other animals and organisms Homeostasis maintaining a constant internal environment with changes in activity our bodies are adapted and can change to move and perform in a remarkably broad range of conditions and circumstances o example increasing blood supply and oxygen to muscle during exercise maintains energy needed for muscle contraction o limit if not enough oxygen is supplied muscles produce lactic acid in this case where buffers would keep the muscle from becoming too acidic o Another example maintaining body temperature in cold hot environments o Mechanisms reduce heat loss by reducing blood flow to skin the blood vessels in the skin become smaller so that less blood flows through them increase heat production by shivering muscle contractions when it s hot blood vessels relax and dilate to get rid of heat and you sweat as heat it loss with the water that is evaporated Pathophysiology Changes in physiology associated with diseases genetic mutations infections environmental factors etc Learning about pathophysiology o Understand diseases mechanism o Understand our body s response to disease o Find treatments and cures o Be more understanding of and helpful to people we know Biomedical research is helping us to understand normal and pathophysiology with benefits for individuals families and society Chapter 2 Blood connects tissues and cells in the body 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 some are proteins and others are bound to proteins includes gases oxygen and CD food molecules and metabolic wastes Hematocrit of blood volume Red Blood Cells RBCs in a blood sample Determines oxygen carrying capacity of blood in normal individuals there s usually red blood cells on the bottom 40 then white cells and platelets 10 and then plasma on top of that 50 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 Erythocytes RBCs are specialized to transport oxygen Biconcave shape o Short diffusion distance of oxygen to get into and out of red blood cell o Cytoskeleton protein spectrin maintains shape Like the frame of a building Oxygen transport in blood o Dissolved in plasma and cytoplasm of blood cells o Bound to hemoglobin Hb RBCs are filled with LOTS of Hb protein Myoglobin one quarter of hemoglobin and Hemoglobin Hb are oxygen binding proteins in muscle and blood Myoglobin binds one oxygen molecule and hemoglobin will bind 4 oxygen molecules binding 1 oxygen increases the binding of the next Red Blood Cells also participate in carbon dioxide transport co2 transport in blood o dissolved in plasma and cytoplasm of blood cells o bound to Hb after it has released o2 o converted to carbonioc acid H2CO3 by an enzyme enzyme carbonic anhydrase in RBCs o carbonic acid comes apart bicarbonate HC03 H proton co2 and hco3 can easily leave and re enter RBCs bicarbonate can be very useful and act as a homeostatic mechanism Most CO2 is transported in blood converted to bicarbonate HCO3 1 Hemoglobin Hb is a protein in RBCs that has four binding sites to cooperatively bind iClicker question blood a water b oxygen c d calcium ions carbonic anhydrase Erythropoiesis the process by which new RBCs are made in the red marrow of the bone an individual RBC circulates in blood for only 3 4 months new RBCs come from stem cells that divide replicate and specialize differentiate into RBCs o occurs in red marrow of bone o maturation process takes about 1 week o note RBC loses nucleus during maturation more room for Hb which means more oxygen RBC production is primarily controlled by a hormone erythropoietin EPO EPO stimulates RBC production EPO produced by the kidneys Example of homeostasis moving to live in the mountains o Less atmospheric o2 at elevation o Less o2 in blood especially during activity o Kidneys produce more EPO o More RBCs are produced o Hematocrit increases higher of more red blood cells in your blood o More o2 in blood o Sickle cell disease hemoglobin stick to each other to form a rod in the clay model green and orange not green and red loose ones Molecular origin of sickle cell disease a single mutation in an Hb gene New white blood cells WBCs come from red marrow of bone new WBCs come from stem cells that divide replicate and specialize differenciate into WBCs which occurs in red marrow of bone WBCs exist in blood and other parts of the body like the immune system to help protect against infections Platelets thrombocytes are cell fragments produced by megakaryocytes platelets are involved in blood clotting New Platelets come from red marrow of bone also new platelets come from cells called megakaryocytes iClicker question All of the following are cellular components of blood except a Hb b Platelet c WBC d RBC Blood Plasma Composition water Electrolytes ions Small molecules o Dissolved gasses o2 co2 and also n2 o Food molecules and metabolic wastes Proteins Chemical signals hormones o Some are proteins and others are bound to proteins Major proteins in blood plasma albimins Globulins includes antibodies Fibrinogen o Blood clotting with platelets Lipoprotein assemblies o Apolipoproteins lipids including cholesterol o High density lipoprotein HDL good cholesterol o Low density lipoprotein LDL bad cholesterol Protein hormones RBCs o Note Hb and carbonic anhydrase are not included in plasms theyre only in Blood clotting coagulation involves both platelets and fibrinogen stops bleeding from damaged blood vessels Antibodies are blood proteins globulins that help protect against infections a protein component of the immune system Vaccination primes the
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