RileyDillonCardiovascularsystem (heart (microscopic anatomy of the…
fibrous pericardium: opaque, surrounds the heart, very tough outer most layer
parietal pericardium: on the body wall
Pericardial cavity: filled with serous fluid to reduce friction
layers of the heart
epicardium/ visceral pericardium: on the surface of the heart, simple squamous epithelium
endocardium: lines the heart, and covers the valves, areolar connective tissue
microscopic anatomy of the myocardium
intercalated discs: strong connections between cells
Fascia Adherens: desmosome like structures, keep cardiac muscle together like zippers
Gap junctions: pass electrical signals back and fourth, movement of ions
myofibrals: branch and attach to each other
right and left atriventricular valves: great the first heart sound "lub" when they snap shut
aortic and pulmonary semilunar valves: make the second heart sound "dub" when they snap shut
conduction of heart
SA node: Sinoatrial node, pacemaker of the heart, intrinsic electrical signal innervation from nervous system. Generates electrical signals that spread through the myocardium of the atria.
AV bundle: atrioventricuar bundle, gets the electrical signals from the AV node, then passes it through the interventricular septum.
right and left bundle branches: receives the signals from the AV bundle, then passes it along to the purkinje fibers
elastic/ conducting arteries: most proximal to the heart, many elastic fibers, move blood away from the heart, largest arteries are the aorta, brachiocepahlic, and subclavian arteries. stretch and recoil to propel blood forward.
muscular/ distributing arteries: sends blood to organs and organ parts, contains the most muscle relative to its size, constrict and dilate based on blood flow needs, examples: heptic artery, renal artery
arterioles: smallest of the arteries, 1-2 layers of smooth muscle, constrict and dilate vessels.
venules: smallest of the veins, much like capillaries, sometimes gas exchange happens here, 1-2 layers of smooth muscle
veins: large and medium sizes, contain less elastic fibers than arteries.
continuous: most common, intercellular clefts make them somewhat leaky. location: lungs, skin, and smooth and skeletal muscle
fenestrated: capillaries with windows/ large pores, found in places with a high rate of gas exchange like small intestine, kidneys, and choroid plexus.
sinusoid: contain the biggest clefts in the vessel and basement membrane, large or whole proteins and cells can be exchanged here. location : bone marrow, liver, spleen
erythrocyte: have a bi-concave shaped to increase the surface area that simplifies taking in and giving out oxygen. contain hemoglobin which binds with oxygen
leukoctyes: play a role in immunity, fight pathogens and viruses
basophils, eosinophils, neutrophils, monocytes, leukoctyes
thrombocytes: aka plasma, not blood cells at all they are pieces of cytoplasm from megakarocytes, they are involved in blood clotting