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42 Cards in this Set
- Front
- Back
What is the basic anatomy of the heart |
Blood enters through two large veins --> empty oxygen-poor blood to atrium --> tricuspid valve allows flow into right ventricle -->pulmonic valve allows blood to lungs --> left atrium --> mitral valve opens to allow blood into left ventrical. It shuts and pumps to aorta |
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Where does electrical signal originate from in the heart? |
sinoatrial node located in the atrium of the right atrium |
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Where is the endocardium found? |
Lines the atria and ventricles. Innermost layer. lines ventricle cavity and arium cavity
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Where is the myocardium found? |
next layer out from the endocardium. Where cardiac muscle is that leads to contraction |
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Where is epicardium? |
outermost layer along the surface of the heart |
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What is found in the endocardium? |
Endothelium Subendothelium Subendocardium |
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What is the function of endothelium? |
simple squamous epithelium with a thin continuous basal lamina
Is in physical contact with the blood in the chambers of the heart
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What is the function of the subendothelium? |
loos connective tissue layer with abundant elsatic fibers and some smooth muscle bundles
Similar to lamina propria |
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Subendocardium |
Layer of loose connective tissue with small vessels, nerves, bundle branches, and Purkinje fibers
Connects to myocardium |
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What molecules are extremely rich in the endocardium as a whole? how will these appear? |
Collagen and elastin. Collagen = pink fuzzy lines, |
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What is the blue what is the group of red that the big arrow is pointing to? |
Blue = collagen Red group = smooth muscle bundle |
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What makes up the myocardium? |
cardiac muscle fibers, parts of the cardiac skeleton, the impulse conductions ystem
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What surrounds each cardiac muscle cells and what bundles these cells? |
Each muscle cell is surrounded by endomysium
Groups of cardiac cells (fascicles) are held in place by perimysium t |
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What fibers make up atrial cardiac muscle? |
overlapping network of woven fibers with collagen and elastin interspersed |
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What do atrial cells look like compared to ventricle cells |
They are smaller and more granular |
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What leads to the more granular appearance of atrial cells? |
they have an endocronine fuction |
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What electrically distinguishes atrial cardiac muscle from ventrical cardiac muscle |
It conducts impulses faster and contract more rhythmically due to more gap junctions than ventricular cardiac cells |
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What does the ratio of endocardium to myocardium look like in the artial cardiac muscle? |
Thicker endocardium and thinner myocardium |
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What histologically identifies ventricular cardiac muscle from atrial muscle cell? |
Thicker myocardium than atria Large cardiac myocytes, less granular
Cell layers whind helically around cavity to aid in "wringing out" of heart during contraction
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What is a general feature of all cardiac skeleton? |
Dense connective tissue scaffolding into which cardiac muscle fibers insert and from which cardiac valves extend |
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What are the commponents of the cardiac skeleton |
- annuli fibrosae -trigona fibrosae -septum membranaceum
All of these are subject to calcification with age or dz |
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What does annuli fibrosae consist of? |
Dense CT rings that surround and reinforce valve openings
All four rings associated with the 4 major valves |
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Trigona fibrosae |
two triangular dense CT masses lying between the two groups of annuli fibrosae |
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What is the septum membranaceum? |
Dense fibrous plate forming the top of the mascular interventricular septum |
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What are cardiac valves made up of> |
Folds of endocardium enclosing a core of dene fibrous CT (rich in collagen and elastin)
Bases are anchored to the strong fibrous rings of the annuli fibrosae |
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Where is the mitral/bicuspid valve? |
located between left atrium and left ventricle
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What is the structure of the bicuspid? |
2 cusps or flaps each anchored to papillary muscles |
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What are the chordae tendinae |
Chordae tendinae |
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What are the chordate tendinae made up of? |
loosely arranged collagen and elstin fibers on the outside, central core of longitudinally arranged collagen fibers
Elastic fibers on the outside and collagen in the middle |
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What are the papillary muscles and what is their function? |
They prevent valves from collapsing The chordae insert on the fibrous cap (In blue) |
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what are the structural features of the tricuspid valve/av valve? |
Located between right atrium and ventricle
3 cusps
Free edge of each cusp is anchored to the papillary muscles in the floor of the right ventricle by chordae tendinae
Fibrous connective tissue core |
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Which valves are the semilunar valves? What is unique about them |
The aortic valve (left ventricle and aorta), pulmonary valve (between right ventricle and pulmonary artery)
3 cusps each No chordae tendinae
Each cusp has a thickened nodule at the center of its free edge |
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What are the three distinct layers of the aortic cusp? |
Fibrosa: densley packed collagen Spongiosum: proteoglycan and GAG matrix with loosely arranged collagen Ventricularis: abundant elastic fibers |
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How does the current spread through the heart. |
SA node --> AV node --> AV bundle --? bundle branches --? purkinje fibers |
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What does the SA node consist of> |
Small mass of specialized cell found in the right atrium median wall adjacent to the opening of the superior vena cava within the terminal groove
Fastest intrinsic rhythm of contraction |
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What does the SA node have lots of? |
collagen and elastin SA node |
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What do purkinje fibers look like |
Larger and paler than typical cardiac myocytes with 1-2 central nuclei, intercalated disk and sparse myofilaments |
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What do purkinje fibers look like |
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What happens during myocardial infarction |
1. acute/ischemia. you lose intracellular striations. Nuclei and pyknotic are irregularly shaped 2. Three days later you will see a great deal of nutrophils everywhere 3. A few weeks later you will get wavy tissue/elastic type fibers 4. Eventually you get fibrosis and scarring and the replacement of the area with dense connective tissue |