{"id":1535,"date":"2016-12-14T18:13:24","date_gmt":"2016-12-15T01:13:24","guid":{"rendered":"http:\/\/anatomycorner.com\/main\/?p=1535"},"modified":"2016-12-14T18:22:48","modified_gmt":"2016-12-15T01:22:48","slug":"heart-systole-and-diastole","status":"publish","type":"post","link":"https:\/\/anatomycorner.com\/main\/2016\/12\/14\/heart-systole-and-diastole\/","title":{"rendered":"Heart &#8211; Systole and Diastole"},"content":{"rendered":"<p>During the cardiac cycle, two contractions occur. \u00a0<strong>Systole<\/strong> occurs when the muscles contract and <strong>diastole<\/strong> occurs when the muscles relax. \u00a0 Atrial systole occurs when the atria contract and push blood into the lower ventricles. \u00a0During this point, the aortic valve is closed. \u00a0 Ventricular contraction then occurs when the much larger muscles of the ventricles contract and push blood out of the aorta and the pulmonary arteries. \u00a0 The left ventricle is much larger and provides enough thrust for blood to leave the heart and travel through the body via the <strong>aorta<\/strong>. \u00a0The right ventricle only needs to push blood to the lungs and back via the <strong>pulmonary arteries<\/strong> and veins. \u00a0This is why the left side of the heart is more muscular than the right and why we tend to feel our heartbeat on the left side of our chest.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1536\" src=\"http:\/\/anatomycorner.com\/main\/wp-content\/images\/CG_Heart.gif\" alt=\"animated heart\" width=\"800\" height=\"600\" \/>When listening to heart sounds with a stethoscope, the characteristic &#8220;lub-dub&#8221; noises occur when the valves snap shut. \u00a0 The atrioventricular valves open during atrial systole so that blood moves into the ventricles. \u00a0These valves then close during ventricular systole when the aortic valve opens to allow blood to leave the heart. \u00a0 Leaking valves are often heard as a &#8220;psshh&#8221; sound at the hind end of the lub-dub.<\/p>\n<p>The <a href=\"http:\/\/depts.washington.edu\/physdx\/heart\/demo.html\" target=\"_blank\">University of Washington<\/a> has an excellent page that displays heart sounds and common disorders, such as an atrial septal defect, or a heart murmur.<\/p>\n<p><a href=\"http:\/\/anatomycorner.com\/main\/wp-content\/images\/heart-sounds.png\" target=\"_blank\" rel=\"http:\/\/depts.washington.edu\/physdx\/heart\/demo.html\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-1538 size-full\" src=\"http:\/\/anatomycorner.com\/main\/wp-content\/images\/heart-sounds.png\" alt=\"heart sounds\" width=\"341\" height=\"229\" srcset=\"https:\/\/anatomycorner.com\/main\/wp-content\/images\/heart-sounds.png 341w, https:\/\/anatomycorner.com\/main\/wp-content\/images\/heart-sounds-250x168.png 250w, https:\/\/anatomycorner.com\/main\/wp-content\/images\/heart-sounds-300x200.png 300w\" sizes=\"auto, (max-width: 341px) 100vw, 341px\" \/><\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>During the cardiac cycle, two contractions occur. \u00a0Systole occurs when the muscles contract and diastole occurs when the muscles relax. \u00a0 Atrial systole occurs when the atria contract and push blood into the lower ventricles. \u00a0During this point, the aortic valve is closed. \u00a0 Ventricular contraction then occurs when the much larger muscles of the ventricles contract and push blood out of the aorta and the pulmonary arteries. \u00a0 The left ventricle is much larger and provides enough thrust for blood to leave the heart and travel through the body via the aorta. \u00a0The right ventricle only needs to push <\/p>\n","protected":false},"author":1,"featured_media":1536,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[21,352,90,351,349,95,350,348,76],"class_list":["post-1535","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-anatomical","tag-aorta","tag-atrial","tag-circulatory","tag-contract","tag-diastole","tag-pulmonary","tag-relax","tag-systole","tag-ventricle","has_thumb"],"_links":{"self":[{"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/posts\/1535","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/comments?post=1535"}],"version-history":[{"count":3,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/posts\/1535\/revisions"}],"predecessor-version":[{"id":1540,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/posts\/1535\/revisions\/1540"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/media\/1536"}],"wp:attachment":[{"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/media?parent=1535"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/categories?post=1535"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/anatomycorner.com\/main\/wp-json\/wp\/v2\/tags?post=1535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}