Exam Anatomy Heart B and T cells are adaptive Punching holes is inate Dendritic Cell Antigen Presenting Cell Gulf the bacteria and when pass through lymph node they show the bacteria to roll to infection site Cardiovascular System Heart and Blood Vessels Arteries carry oxygenated blood from heart via systemic circulation to cells THICK always away from heart and carry DEoxygenated blood from heart to lungs Endothelium continuous cell layer that lines inner walls of heart and blood vessels Smooth muscle involuntary muscle layer contracts to vasoconstrict or relaxes to vasodilate vessels Connective tissue collagen strength elastin elasticity Arterioles major source of resistance blood pressure not capillaries Veins Carry deoxygenated blood back to heart THIN veins always carry blood heart and carry oxygenated blood from lungs to heart Venules small veins that drain from capillaries into larger veins Capillaries Microscopic highly branched network of blood vessels smallest vessels Pacemaker potential heartbeat electrical signaling and is automatic repeating depolarization and repolarization of nodal regions of heart which send electrical signal to cardiac muscle cells to contract SA node sinoatrial upper wall of right atrium normal Pacemaker sends action potential every 0 85 seconds to contract atria AV node atrioventricular base of right atrium Transmits AP signal from atria to ventricles via Bundle of His to Purkinje fibers Purkinje fibers rapidly spread electrical signal to ventricles to contract Medulla oblongata cardiac control center in CNS SymNs stimulate heart ParaSymNs slow heart rate Hormones epinephrine and norepinephrine released by adrenal glad to stimulate heart rate Pulse rhythmic expansion and recoil of arterial walls Blood pressure pressure of blood against inner wall of vessel Systolic pressure highest arterial pressure Diastolic pressure lowest arterial pressure Aneurysm ballooning and bursting of blood vessel Thrombus stationary clot that forms near atherosclerotic plaques Embolus liberated clot moving in blood Stroke bursting or blockage of small cranial arteriole lack of oxygen to brain Key Concepts Thick walled arteries and arterioles transport blood to the tissues under high pressure Capillaries allow fluid exchange between blood and interstitial fluid Large thin walled veins store most of the blood and return it to the heart Heart pumps blood through one way valves and coordinated muscle contraction Arterial blood pressure is held fairly constant by homeostatic control mechanisms Blood vessels transport blood As blood leaves the heart its pumped into large arteries Thick because they have to withstand high pressure Three layers of a vessel wall thin inner is endothelium then smooth muscle w elastic fibers the connective tissue Reaches smallest arteries called arterioles Right where an arteriole joins a capillary is a band of smooth muscles called precapillary sphincter gates Vasconstriction vs vasodialiton on cold day they would constrict to keep heat near organs and on hot day dilation so increase blood flow to help cool you off Capillaries are where blood exchanges substances with tissues Allow for exchange of oxygen carbon dioxide nutrients and waste with tissue cells Small amount of filtered fluid remains in the interstitial space as excess fluid so its picked up by lymphatic capillaries Veins return blood to the heart as blood moves through the system the pressure becomes lower and lower Since lower pressure the walls don t have to be as big and they can stretch like balloons Three mechanics that help blood flow back to heart 1 Contraction of skeletal muscles 2 One way valves in veins 3 Movements associated with breathing Heart Enclosed in tough fibrous sac called the pericardium between heart and pericardium is the pericardial cavity Layers go from outside to inside as epicardium myocardium endocardium Septum separates the left side of the heart from the right side Blood returning to the heart from the tissues enters RIGHT ATRIUM then goes into the RIGHT VENTRICLE Then goes into PULMONARY TRUNK and gets oxygen in lungs From the lungs it goes into the LEFT ATRIUM and then the LEFT VENTRICLE Finally it passes up through the AORTA to the arteries arterioles capillaries venules and veins Blood flow happens when flows into atria and ventricles then the atria contracts and finally the ventricles contract Systole period of contraction and Diastole period of relaxation Atrial systole Ventricular systole diastole Stimulus that starts a heart beat begins in the sinoatrial SA node then atrioventricular AV node AV bundle and lastly the Purkinje fibers Blood Pressure BP is the force that blood exerts on the wall of a blood vessel as a result of the pumping action of the heart Not the same in all vessels highest is systolic pressure and lowest is diastolic pressure Want to be in homeostasis by maintaining a constant arterial blood pressure Heartbeat is electrical signaling called pacemaker potential repolarizing and depolarizing Medulla oblongata is the cardiac control center in the CNS Sym NS stimutates and ParaSYm Ns slows Hormones like epinephrine and norepinephrine released by adrenal glad to stimulate heart rate Hypertension elevated arterial blood pressure 140 90 Atherosclerosis plaque devo inside walls of blood vessels narrowed vessels Aneurysm ballooning and bursting of blood vessel Myocardial infarction heart attack portion of heart muscle dies from lack of oxygen Heart failure faulty heart pumping action Thrombus stationary clot that forms near atherosclerotic plaques Embolus liberated clot moving in blood Thromboembolism clot lodges into smaller blood vessel and blocks blood flow Stroke bursting or blockage of small cranial arteriole lack of oxygen to brain Blood Plasma Liquid component of blood mostly water has salts proteins vitamins sugars Plasma Proteins Mostly produced by liver maintain homeostasis e g can bind H ions Albumin contributes to osmotic balance in blood Globulins alpha and beta carry hormones cholesterol and iron while gamma ones are antibodies Fibrinogen cleaver into active fibrin to clot blood Osmotic pressure Exerted on water due to concentrations of salts and plasma proteins in blood and prevents water loss from blood Red Blood Cells contain many molecules of hemoglobin which are O2 carrying proteins but it has no nucleus and no mitochondria Hemoglobin Hb 4 peptides 2 alpha and 2 beta contains heme group iron binds O2 reversibly but