NURS 215 Topic 8 Cardiovascular PDF

Chapters 18, 19, 20 (parts) in Textbook  Responsible for transporting blood throughout the body ▪ Blood transports oxygen, nutrients, wastes, hormones, etc.  System of blood vessels and a heart ▪ Heart is responsible for moving the blood ▪ Network of blood vessels approx...

Chapters 18, 19, 20 (parts) in Textbook  Responsible for transporting blood throughout the body ▪ Blood transports oxygen, nutrients, wastes, hormones, etc.  System of blood vessels and a heart ▪ Heart is responsible for moving the blood ▪ Network of blood vessels approx. 100,000 km long  Approximately the size of a fist  Right side receives oxygen-poor blood from tissues ▪ Pumps blood to lungs to get rid of CO2, pick up O2, via pulmonary circuit  Left side receives oxygenated blood from lungs ▪ Pumps blood to body tissues via systemic circuit  Receiving chambers of heart ▪ Right atrium ▪ Receives blood returning from systemic circuit ▪ Left atrium ▪ Receives blood returning from pulmonary circuit  Pumping chambers of heart ▪ Right ventricle ▪ Pumps blood through pulmonary circuit ▪ Left ventricle ▪ Pumps blood through systemic circuit ▪ Interventricular septum: RV & LV separation  Left of midline Deep to sternum Mediastinum Base Left atrium Superior border Great vessels and SVC Apex (tip of LV) Inferior border = Right ventricle  Pericardium ▪ Encloses the heart ▪ Restricts movement (allows slight amount)  Composed of two parts: ▪ Fibrous pericardium ▪ Serous pericardium ▪ Parietal and visceral (epicardium) layers: pericardial cavity between  Atria ▪ Auricles ▪ Muscular extension of atria  Coronary sulcus marks the boundary between the heart's upper chambers (the atria) and the lower chambers  Anterior (the ventricles). interventricular sulcus is a groove or depression on the front surface of the heart. It runs between the two lower chambers of the heart, called the ventricles. seperates ventricals  Posterior interventricular sulcus ▪ Between the right and left ventricles  Ensure unidirectional blood flow through heart  Open and close in response to pressure changes  No valves are found between major veins and atria: ▪ Inertia of incoming blood prevents backflow ▪ Heart contractions compress venous openings  Two major types of valves: ▪ Atrioventricular valves located between atria and ventricles ▪ Semilunar valves located between ventricles and major arteries  Chordae tendineae prevent the valves from flipping backward into the  Prevent backflow atria when the ventricles contract, ensuring proper blood flow. into atria  Chordae tendineae (attachment)  Papillary muscles attached to the chordae tendineae and help control the opening and closing of the atrioventricular (AV) valves  Tricuspid valve (right AV valve): between right atria and ventricle  Mitral valve (left AV valve, bicuspid valve): lies between left atria and ventricle  Two semilunar valves prevent backflow from major arteries back into ventricles ▪ Each valve has three cusps ▪ Pulmonary semilunar valve: between right ventricle and pulmonary trunk ▪ Aortic semilunar valve: between left ventricle and aorta  Incompetent valve: valve does not close tightly ▪ What would be the result of this?  Valvular stenosis: valves become hardened ▪ What would be the result of this?  Defective valves can be replaced by mechanical, animal or cadaver valves ▪ Superior vena cava (SVC), inferior vena cava (IVC), and coronary sinus vein located on the back of the heart that collects deoxygenated blood from the heart muscle ▪ Right atrium ▪ Tricuspid valve ▪ Right ventricle ▪ Pulmonary semilunar valve A cardiac cycle ▪ Pulmonary trunk Start of one heartbeat to initiation of the next ▪ Pulmonary arteries Contraction = systole ▪ Lungs Relaxation = diastole ▪ Four pulmonary veins ▪ Left atrium ▪ Mitral valve ▪ Left ventricle ▪ Aortic semilunar valve ▪ Aorta ▪ Systemic circulation Summary Video:  Equal volumes of blood are pumped to pulmonary and systemic circuits  Pulmonary circuit is short, low- pressure circulation  Systemic circuit is long, high-friction circulation  Left ventricle walls are 3x thicker than right ▪ Pumps with greater pressure  Functional blood supply to heart muscle itself  Delivered when heart is relaxed  Right and left coronary arteries (within coronary sulcus)  Myocardial infarction: results from a blockage in one of these vessels ▪ What is the result of this?  Coronary sinus: deoxygenated blood into right atrium  Why is the left ventricular wall thicker than the right?  What are the 2 parts of the serous pericardium?  Freshly oxygenated blood is first received by which part of the heart? Where is deoxygenated blood received?  What are the names and locations of the 4 heart valves?  The three classes of blood vessels ▪ Arteries, capillaries, and veins  Arteries  Veins  The arteries and veins entering and leaving the heart are great vessels  1. Tunica intima ▪ Endothelium lines lumen 2. Tunica media ▪ Smooth muscle 3. Tunica externa ▪ Connective tissue ▪ Anchor blood vessel to an organ  Larger blood vessels require their own The vasa vasorum are small blood blood supply vessels located in the tunica externa (the outer layer of larger blood vessels). ▪ Vasa vasorum These tiny vessels supply oxygen and nutrients to the cells of the blood vessel (tunica externa) walls, especially in larger arteries and veins where the walls are too thick for nutrients to diffuse  Three types: 1. Elastic arteries 2. Muscular arteries 3. Arterioles  Largest  Near heart: ▪ Eg. Aorta, pulmonary, brachiocephalic, common carotids, subclavians  Elastic fibers ▪ Why?  Branch into muscular arteries  Medium-sized  Elastic fibers in two concentric rings between the three tunics: 1. Internal elastic lamina 2. External elastic lamina distribution of elastic fibers  Muscular arteries have thicker tunica media  Smallest  Less than six cell layers of smooth muscle in tunica media  Sympathetic innervation to tunica media tunica nerve signals from the sympathetic nervous system control smooth muscle in media, sends signals through sympathetic nerves to the smooth muscle in the tunica media, causing the muscles to contract narrows the blood vessel ▪ Causes? vasoconstriction which increases blood pressure and reduces blood flow to certain areas.  Parasympathetic innervation to tunica media arasympathetic innervation to the tunica media involves nerve signals from the parasympathetic nervous system, which typically ▪ Causes? have the opposite effect of sympathetic signals. However, the parasympathetic nervous system has a minimal direct effect on the smooth muscle of the tunica media  Smallest blood vessels  Small diameter ▪ Erythrocyte travel  Wall is only tunica intima ▪ Single layer  Metabolic exchange occurs ▪ What leaves and what enters the capillary blood?  a metarteriole. The metarteriole is a vessel that connects an arteriole (a small artery) to the capillary bed and eventually leads into a venule (a small vein). The metarteriole acts as a gateway between the arteriole and the capillaries. It allows blood to flow into the capillaries for nutrient and gas exchange.  Some capillary beds fed by a metarteriole: larger vessel that connects the metarteriole to the venule ▪ A thoroughfare channel connects to venule ▪ Function?  Branches from metarteriole = capillaries ▪ Ring of smooth muscle on their walls are true capillaries  Precapillary sphincters can control blood flow entering bed  Continuous: Most common, complete lining  Fenestrated: Contain pores ▪ Fluid exchange  Sinusoids: Large gaps ▪ Cell, large molecule transport  *Where do you think you could find each of these?  Return blood to heart  Pressure lower ▪ Blood reservoirs  Smallest veins  Companion vessels with arterioles  Smallest are postcapillary venules ▪ Leukocytes may pass through  Venules form veins  Larger than venules ▪ Smaller/medium-sized travel with muscular arteries ▪ Large veins travel with elastic arteries  Most veins contain valves to prevent pooling ▪ Formed from tunica intima  Venous return  What are the 3 different layers of blood vessels?  Do all arteries carry oxygenated blood?  What are 3 different types of capillaries?  How is blood flow to capillary beds controlled?  We will look at some examples of major blood vessels ▪ *You only need to know the ones we cover in the notes  Naming tips: usually named after body region, organ served or nearby bone  Arteries and veins often side by side  Not all vessels same on right and left https://newatlas.com/blood-vessel-regrowth-u-texas/21520/ sides  Aorta: ascending and abdominal (descending)  Branching from ascending aorta: ▪ Brachiocephalic trunk: branches into subclavian(right) and common carotid (right) ▪ Common carotid (left) ▪ Subclavian (left)  *Purpose of these arteries ?  Subclavian becomes axillary artery  Brachial artery  Radial and ulnar arteries  Abdominal aorta branches into many arteries, supplying several abdominal organs (e.g. renal arteries) ▪ Also continues to lower limbs  Common iliac artery  External iliac artery  Femoral artery  Popliteal artery, branches into anterior and posterior tibial arteries  Veins of head primarily drain into internal and external jugular veins  Veins of upper limbs drain into subclavian veins  These drain into right and left brachiocephalic veins  Merging into the superior vena cava, into the right atrium  Blood from lower limbs eventually drain into great saphenous and femoral veins  Common iliac vein  Inferior vena cava (other veins from abdominal organs also drain into here, e.g. renal veins) ▪ Drains into right atrium  Please trace the pathway of blood from the heart to the hand, listing the major arteries along the way  Which veins bring blood back from the lower limbs to the inferior vena cava?  If there was a blockage of the brachiocephalic trunk, which major areas of the body would be affected?  Returns fluid which leaks out of blood vessels, includes: ▪ Lymph: fluid, approx. 3L circulates per day ▪ Lymphatics: a network of vessels ▪ Lymph nodes: cleanse lymph, contain immune cells ▪ Spleen, thymus, tonsils, other tissues also included  Highly-permeable, blind-ended vessels, weave between blood capillaries and tissue cells ▪ Absent in bone, tooth tissues  Loosely overlapping endothelial cells form minivalves ▪ Minivalves anchored to connective tissue, will open more with more fluid  Specialized lymphatic capillaries in intestine are called lacteals (help absorb fat)  Similar structure to veins, more valves  Lymph capillaries drain into larger collecting lymphatic vessels  Lymph drains into larger lymphatic trunks  Finally, drains one of 2 lymphatic ducts  2 Lymphatics ducts: ▪ Right lymphatic duct: drains right upper limb, right side of head and thorax into junction of right internal jugular and subclavian veins ▪ Thoracic duct: drains rest of body into junction of left internal jugular and subclavian veins  Lymphoid organ tissue mainly comprised of reticular connective tissue ▪ Mainly functions to house and allow for lymphocyte development  2 main types of lymphoid organs: ▪ Primary lymphoid organs: red bone marrow and thymus ▪ Allow for T and B cell maturation ▪ Secondary lymphoid organs: includes lymph nodes, spleen, mucosa- associated lymphoid tissue (MALT) ▪ Where mature lymphocytes become activated (by antigens)  Served by splenic artery and vein, enter through hilum  White pulp: site of lymphocyte storage/ proliferation  Red pulp: old red blood cells and pathogens are broken down ▪ Contains macrophages to engulf these  Hundreds throughout body (deep and near surface): ▪ Common body surface regions: cervical, axillary and inguinal  Functions: ▪ Cleansing lymph by removing debris, organisms using macrophages ▪ Area for lymphocyte activation  Surrounded by fibrous capsule ▪ Capsule extends inward into trabeculae, to divide node  2 regions: outer cortex and inner medulla  Lymph enters through afferent lymphatics vessels ▪ Travels through several sinuses  Lymph exits from efferent lymphatic vessels  Bi-lobed organ inferior to neck  T-cells mature (more in 230), most active in childhood  Immature T-cells kept from blood through blood-thymus barrier  Primarily epithelial cells instead of reticular connective tissue  Cortex: outer area, most lymphocytes  Medulla: inner area, fewer lymphocytes ▪ Site of special “regulatory t-cells”, which prevent autoimmunity  MALT: mucosa-associated lymphoid tissue  Protects body from pathogens entering though mucosal barrier  Includes: ▪ Tonsils: around pharynx (more in respiratory) ▪ Peyer’s patches: small clusters within small intestine ▪ Appendix: offshoot of large intestine  Please describe the pathway of lymphatic flow from a tissue, into the heart  What is meant by MALT? What role does this type of tissue play?  Why do you think lymph nodes under your arms sometimes swell after a vaccine?