Ch 1 Overview What is Physiology Physiology the science of biological function Molecules cells tissues organs organ systems human organism Homeostasis maintenance of a constant environment ex temperature regulation regulation of oxygen use while exercising maintaining blood glucose levels throughout the day maintaining blood and cellular proton concentration Pathophysiology changes in physiology associated with disease It is important to understand both physiology and pathophysiology through biomedical research because it will help us to know more about the human body and how diseases come about and can be treated Ch 2 Blood Blood is part of the cardiovascular system and circulatory system Blood can be considered a type of connective tissue even though it is a fluid because it connects cells throughout the body much like tissue connects muscle to bone etc Major components of blood o red blood cells which transport oxygen and carbon dioxide Oxygen binds to hemoglobin a molecule within the red blood cell CO2 is converted to bicarbonate and carbonic acid and back to CO2 againwith an enzyme in the red blood cell called carbonic anhydrase o white blood cells which help to fight diseases part of the immune system o platelets cell fragments which help with blood clotting o plasma which is mostly water electrolytes proteins and hormones Cells are the basic units of life Hemocrit is the percentage of red blood cells in your body by volume For example if your hemocrit level is 42 then red blood cells make up 42 of your blood volume the other 58 is made up of plasma Transport of gases between plasma and the cytoplasm of red blood cells is done by diffusion the net movement of molecules from regions of high concentration to regions of low concentration Blood cells can also transport heat throughout the body to help regulate body temperature Platelets help control blood loss by clotting and coagulating Coagulation happens when platelets change size and shape to partially block a small broken blood tube in order to attempt to stop the bleeding As more and more platelets begin to coagulate they eventually form a clot which stops the bleeding from that particular broken tube Blood cells and platelets are formed in the bone marrow Sickle cell disease is a genetic disease in which the hemoglobin molecules within a red blood cell stick together and stretch the cell membrane This makes it easier for the cell to get caught within the walls of small tubes and block blood flow Cancers that affect blood cells are leukemias Leukemias involve abnormally high numbers of white blood cells Metastasis is when a cancer cell leaves the tumor and travels through the blood and forms a new tumor in another tissue Blood and lymph are closely related but one is not the other Lymph is transported through the lymphatic system and eventually mixes with blood in the cardiovascular system Ch 3 Cardiovascular Physiology The Heart and Vasculature The main job of the cardiovascular system is to circulate blood Structure of the human heart o Divided into two sides vertically left and right o Divided into two halves horizontally atria top half and ventricle bottom half Ventricles mainly the left ventricle are the main generators of pressure that drives blood flow through the cardiovascular system o Valves that open and close to ensure that blood moves in one direction o Sinoatrial node the heart s pacemaker in the right atrium sends electrical signals to begin the cardiac cycle o Atrioventricular node the central structure responsible for the transmission of the electrical signal between atria and ventricles An electrocardiogram ECG or EKG shows the activity of the cardiac cycle when measured using electrodes on the body s surface The major features are the P wave electrical activity in the atria the QRS complex electrical activity in the ventricles and the T wave a wave formed when the ventricles are recovering from the electrical signal After the electrical cycle started by the SA node the mechanical cycle begins The mechanical cycle is the actual physical pumping of the heart There are two phases of this systole when the heart contracts and blood is pumped and diastole when the heart is relaxed and fills with blood ready to be pumped Cardiac output is the volume of blood pumped by the heart in a minute Components stroke volume volume of blood pumped by one heartbeat and heart rate number of beats per minute CO SV HR Nerochemicals in the brain can influence the rate of contraction heart rate and therefore either raise or lower your cardiac output Types of blood vessels o Arteries carry blood away from the heart towards capillaries throughout the body Arteries are the largest of the blood vessels They contain smooth muscle connective tissue and endothelium a thin coating on the inside walls of the arteries o Veins receive blood from capillaries and return it to the atria of the heart Veins have the same components as arteries but are not as thick o Capillaries the smallest blood vessels Capillaries are where gasses are exchanged between the blood and the tissue the capillary is connected to They are made up of one very thin layer of endothelium in order to make it easy for the diffusion of molecules in and out Common cardiovascular diseases o Atherosclerosis the blockage of arteries due to the buildup of fats such as cholesterol LDL particles platelets and blood cells This can lead to increased blood pressure ahead of the blockage and very low blood pressure after it o Myocardial Infarction Heart Attack and Stroke Myocardial Infarction happens when blood vessels to the heart become fully blocked Stroke happens when blood vessels to the brain become completely blocked Since no oxygen is getting to the heart or brain the cells in the heart brain will begin to die o Heart Failure a result of a non fatal yet still serious heart attack In heart failure the heart is not able to pump as it used to Heart tissue damaged by a heart attack cannot repair itself so the damaged parts won t contribute like they used to Ch 4 Respiratory Physiology Gas Exchange in the Lungs Mucus is a moist sticky fluid that is produced by goblet cells It traps particles in the air and prevents them from moving deep into the lungs Cilia are small protruding structures that faice the airway and mucus lining Cilia help transport the mucus and particles stuck to it out of the lungs Alveoli are the functional units of the lungs They are the surface where CO2
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