Physiology Overview Physiology study of biological function from molecules cells tissues organs systems organism Focus here movement systems muscles heart blood lungs Structure is key to understanding function Homeostasis Homeostasis keeping internal conditions stable despite external internal changes Examples O2 CO2 balance increases during exercise long term adaptations at high altitude Temperature blood glucose pH tightly regulated Involves short term adjustments minutes hours and long term adaptations days weeks Disease Pathophysiology how diseases disrupt normal function Causes external infection toxins or internal genes Studying disease helps improve health treatment and understanding of normal physiology Blood Plasma Sodium is the most abundant molecule in blood plasma Blood Parts Two main components of Blood Cells RBCs carry O WBCs fight infections Platelets clotting Plasma Mainly water salts proteins albumin globulins fibrinogen nutrients hormones important role in maintaining homeostasis and overall health electrolytes like sodium chloride and bicarbonate Plasma also contains dissolved gases like oxygen and carbon dioxide which are essential for respiration also contains transport proteins called lipoproteins RBCs the enzyme carbonic anhydrase within red blood cells is crucial for the efficient transport of CO2 Mos abundant cell in blood Carry oxygen and remove CO as bicarbonate Shape biconcave no nucleus This shape allows for efficient O2 diffusion Contains hemoglobin oxygen binding protein binds 4 O Lifespan 3 4 months made in bone marrow EPO hormone from kidneys Hematocrit Men 45 Women 40 Sickle cell crescent shaped blocks vessels causes anemia WBCs mature leukocytes not only in the blood but also in other parts of the body extending the protective functions of the immune system beyond the blood macrophages and dendritic cells are subtypes of leukocytes derived from monocytes hematopoiesis the formation of blood cells and platelets in bone marrow includes the formation of all types of WBCs Fight infections have nucleus no hemoglobin Types Neutrophils Eosinophils Basophils Lymphocytes B T NK Monocytes macrophages dendritic cells High count infection Low count risk of illness Platelets don t have nuclei protect against blood loss by forming a seal at the site of a cut blocking blood flow from broken blood vessels Cell fragments from bone marrow clot formation Platelets stick fibrin forms strong mesh Plasma Proteins Albumin keeps water in blood carries substances Globulins antibodies Fibrinogen fibrin for clot Lipoproteins LDL bad HDL good transport fats and cholesterol Heat Regulation Transporting heat to the skin surface for dissipation is primary way heat is lost from the body Blood moves heat around body Hot vasodilation skin blood flow surface blood flow is increased enhancing heat loss panting Cold vasoconstriction keep heat in Shivering helps body stay warm which increases metabolism through muscle contractions surface blood flow is reduced is how to reduce heat loss Shivering brown fat generate heat Hormones modulate cellular metabolism and heat generation Cancer Blood Cancer uncontrolled cell growth tumors Leukemia abnormal WBC growth weak immunity may affect RBCs platelets Cancer can spread metastasis via blood Chemotherapy may lower WBC infection risk Lymphatic System helps rid the body of toxins waste and other unwanted materials Lymph nodes are key components of the immune system because they contain large numbers of leukocytes particularly lymphocytes B cells and T cells and macrophages These cells help filter the lymph and identify foreign invaders Interstitial fluid is the fluid between cells in tissues Lymph fluid from tissues lymph nodes blood Contains B T cells macrophages Functions return fluid filter pathogens fight infections Moves via muscles valves one way flow Heart Blood Vessels Atrium Ventricle Artery Blood enters the atrium then moves into the ventricle on the same side and from the ventricle blood moves into a major artery Systole is the phase of the cardiac cycle when the heart muscle contracts and pumps blood while diastole is the phase when the heart muscle is relaxed and the chambers fill with blood The SA node initiates the electrical impulse which travels to the AV node The AV node then delays the impulse slightly before passing it to the bundle branches which conduct it down to the ventricles causing them to contract Heart 4 chambers RA RV lungs LA LV body Valves AV tricuspid mitral Semilunar pulmonary aortic Electrical SA node AV node bundle branches ventricles Cardiac cycle Diastole fill Systole pump Cardiac output CO Stroke Volume Heart Rate Vessels Arteries thick high pressure Capillaries gas nutrient exchange Veins valves prevent backflow Common Problems Atherosclerosis involves the thickening of the arterial wall due to the buildup of fats including cholesterol leading to reduced elasticity This condition is also known as hardening of the arteries due to the reduced ability of the arteries to stretch and recoil with each heartbeat Atherosclerosis plaques narrow arteries Heart attack MI blocked artery tissue dies Stroke blocked brain blood flow Heart failure weak heart less blood pumped Treatment of heart failure often includes management of excess fluid buildup Respiratory System Cilia are small finger like projections that line the airways They work in conjunction with mucus which is produced by goblet cells to trap and remove foreign particles and pathogens from the lungs The coordinated movement of cilia propels the mucus layer upward towards the pharynx where it can be swallowed or expelled Air nose pharynx larynx trachea bronchi bronchioles alveoli Alveoli tiny sacs for gas exchange surfactant prevents collapse Pulmonary surfactant is a lipoprotein that s essential for the structure and function of the alveoli It helps alveoli to remain partially filled with air which allows them to expand more easily during inhalation and prevents them from collapsing upon exhalation It also reduces the effort required for breathing Pulmonary circulation RV lungs LA O binds hemoglobin CO mostly as bicarbonate Breathing muscles diaphragm intercostals Lung volumes Tidal Vital Residual Total Breathing control brainstem sensors detect O CO pH changes Diseases Asthma Cystic Fibrosis Lung Cancer Muscles Contraction Type Striated Control Location Skeletal Yes Cardiac Yes Smooth No Voluntary Bones Involuntary Heart Involuntary Organs vessels
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