Copy of Block 6 MicroAna LOs PDF

1. Understand the basic concepts regarding fetal cardiac development 2. Recognize the following structures and terminology: cardiogenic field, cardiac tube, loop formation, internal division of the cardiac tube, truncus arteriosus, bulbus cordis, foramen ovale, fossa ovalis, aortic arches....

1. Understand the basic concepts regarding fetal cardiac development 2. Recognize the following structures and terminology: cardiogenic field, cardiac tube, loop formation, internal division of the cardiac tube, truncus arteriosus, bulbus cordis, foramen ovale, fossa ovalis, aortic arches. a. Cardiogenic field - blood forming cavities in a “U” shape cranial to the neural plate b. Cardiac tube - tubes formed from cardiogenic fields c. Loop formation - folding of the cardiac tube d. Internal division of cardiac tube - i. Primitive atrium -> left and right atria ii. Primitive ventricle -> left ventricle iii. Bulbus cordis -> right ventricle iv. Truncus arteriosus -> aorta and pulmonary trunk e. Truncus arteriosus - see above f. Bulbus cordis - see above g. Foramen ovale - passage through the right to left atria h. Fossa ovalis - once the foramen ovale closes and fuses shut i. Aortic arches - forms from the truncus arteriosus through a spiral aorticopulmonary septum  3. Understand fetal circulation from placenta to all bypasses (shunts) and back to the placenta. the oneygffudhffffff.comthatofanadultisthatlungsare actusarteriosusthe aorta between connection pulmonary and artery the sothePlacentadoesthejobofgasexnange t orliverneed functionalsoneitherlung much us Y has umbilicalarteriesandone cord plaienta 2 ovale openinginatrial oramen is umymijiy.la fm II left fix wbloodtoreach atrium has artery ympgy.at deoxygenated veinhasoxygenate blood umbilical plaientaisthe why the that'soxygenating one theveina bloodso mi fiiii iiiiii iii iiiiiiiii Iiii iiiiii ii iii iiiiii i ii iiiiiii.EE 4. Explain functional versus anatomical closure of the foramen ovale and ductus arteriosus. a. Foramen ovale i. Functional closure - the primary and secondary septum get physically pushed together, closing the gap ii. Anatomical closure - when the primary and secondary septum fuse together and the foramen ovale becomes the fossa ovalis b. Ductus arteriosus i. Functional closure ii. Anatomical closure 5. Trace the flow of blood through the neonatal heart and compare it with the blood flow through the fetal heart. a. Fetal flow i. Right atrium -> left atrium of right ventricle -> little to lungs or through ductus arteriosus to body -> left ventricle -> out to body b. Neonate flow i. Into right atrium -> right ventricle -> lungs -> left atrium -> left ventricle -> to the body 6. List the different types of vessels, their cellular structure and their morphologic characteristics used for differentiation. a. 3 major layers in most all vessels i. Tunica intima 1. Innermost layer 2. Vascular endothelium (modulates homeostasis and perfusion), internal elastic membrane, subendothelial connective tissue ii. Tunica media 1. Middle layer 2. Smooth muscle (circumferentially arranged, dilation and constriction), elastic lamellae/ fibers iii. Tunica adventitia 1. Outermost layer 2. Collagen, may contain blood vessels (vasa vasorum), nerves (nervi vasorum), and lymphatics b. Artery i. Elastic - ex: aorta 1. Tunica intima - endothelium and loose connective tissue 2. Tunica media - mostly elastic lamellae 3. Tunica adventitia - vasa vasorum present ii. Muscular - ex: femoral artery 1. Tunica intima - endothelium and loose connective tissue 2. Tunica media - mostly smooth muscle - thickest layer 3. Tunica adventitia - vasa vasorum present c. Arterioles - have the greatest effect on blood pressure i. Tunica intima - nuclei of endothelium bulge into the lumen, NO internal elastic membrane in smaller ones ii. Tunica media - 1-2 cell layers thick of smooth muscle d. Metarterioles - arterioles that have sphincters that regulate blood flow into the capillaries e. Capillary i. Of mesenchymal origin ii. One cell (simple squamous) thick walls rolled into a tube formation iii. Nutrient and gas exchange to surrounding tissues and organs 1. O2, CO2 2. Ions 3. H2O 4. Glucose 5. Amino acids  6. Fatty acids 7. Vitamins 8. Hormones 9. Proteins and blood cells - ONLY in sinusoid iv. 3 types - see #7 for description f. Venules i. Also known as postcapillary venules ii. NO smooth muscle iii. Very “leaky” iv. Leukocyte diapedesis (white blood cell perfusion) can occur here g. Veins i. 3 layers 1. Tunica intima a. endothelium b. Valves present - endothelial cells with an elastic fiber core c. Subendothelial layer 2. Tunica media a. Smooth muscle in irregular orientation, somewhat circular 3. Tunica adventitia a. Loose connective tissue, ONLY a few nerves in larger vessels and vasa vasorum b. Thickest part in veins h. Lymphatic i. Endothelial lining with thin layer of smooth muscle, and adventitia that binds the vessels to the surrounding tissue ii. Valves present iii. Transport lymph iv. NO blood cells 7. List the different types of capillaries and correlate their structure with their specific function. Give examples on where in the body specific types of capillaries can be found. a. Continuous i. Most common ii. Where at? - brain, bone, lungs b. Fenestrated i. Allow fluid exchange ii. Where at? - intestinal villi, choroid plexus, glomerular capillaries (renal) c. Sinusoid i. Lumen is enlarged and irregular, endothelium is discontinuous and fenestrated, basal lamina discontinuous ii. Larger molecules are able to exit/enter iii. Where at? - spleen, liver 8. Describe the following cardiac structures: endocardium, myocardium, epicardium, Purkinje cells, intercalated discs and cross striations within the sarcoplasm of cardiomyocytes. a. Endocardium i. Tunica intima of heart ii. Inner linings and valves of the heart iii. In direct contact with blood iv. Contains part of the conduction system and purkinje cells v. Covers the surface of the valves vi. 3 layers  1. Endothelium 2. Basal lamina 3. Subendothelial thin layer of connective tissue b. Myocardium i. Cardiac muscle 1. Single central nucleus 2. Have intercalated discs (gap junctions and desmosomes) 3. Many mitochondria, sarcoplasmic reticulum present, may have lipofusion (wear and tear of cells) 4. Involuntary contractions 5. Striated muscle ii. Left ventricle ~2-4 times thicker than the right c. Epicardium i. Outermost surface of the heart - visceral pericardium ii. Surface is mesothelium that secretes serous fluid for lubrication during pumping movement -> dense connective tissue and a variable thickness of adipose tissue with coronary arteries and veins (arteries and veins for the heart tissues) d. Purkinje cells i. Also known as fibers ii. A modified cardiomyocyte that aids in the function of conduction e. Intercalated discs i. Include gap junctions (passage of ions between cells) and desmosomes (strength to keep cells together) f. Striated cardiac muscle g. Pericytes i. Also known as Roujet cells ii. Contractile cells that wrap around the endothelium of capillaries and venules iii. Communicate by physical contact and paracrine signaling iv. Important for homeostasis 1. Stem cell source 2. Proliferate after injury 3. Vital for angiogenesis (new blood vessel formation) h. Podocytes i. Located in the nephrons ii. Help prevent large molecules from being filtered by increasing that surface area of cells with its pedicals (foot processes)