{"id":181041,"date":"2025-01-09T13:01:41","date_gmt":"2025-01-09T13:01:41","guid":{"rendered":"https:\/\/learnexams.com\/blog\/?p=181041"},"modified":"2025-01-09T13:01:43","modified_gmt":"2025-01-09T13:01:43","slug":"which-characteristic-or-component-is-shared-by-skeletal-muscle-and-smooth-muscle","status":"publish","type":"post","link":"https:\/\/www.learnexams.com\/blog\/2025\/01\/09\/which-characteristic-or-component-is-shared-by-skeletal-muscle-and-smooth-muscle\/","title":{"rendered":"Which characteristic or component is shared by skeletal muscle and smooth muscle"},"content":{"rendered":"\n<p>Which characteristic or component is shared by skeletal muscle and smooth muscle? (A) Thick and thin filaments arranged in sarcomeres (B) Troponin (C) Elevation of intracellular [Ca2+] for excitation\u2013contraction coupling (D) Spontaneous depolarization of the membrane potential (E) High degree of electrical coupling between cells<\/p>\n\n\n\n<p><mark style=\"background-color:rgba(0, 0, 0, 0)\" class=\"has-inline-color has-ast-global-color-6-color\"><strong>The Correct Answer and Explanation is :<\/strong><\/mark><\/p>\n\n\n\n<p>The correct answer is <strong>(C) Elevation of intracellular [Ca2+] for excitation\u2013contraction coupling<\/strong>.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Explanation:<\/h3>\n\n\n\n<p>Both <strong>skeletal muscle<\/strong> and <strong>smooth muscle<\/strong> share the fundamental process of excitation-contraction coupling, where an increase in intracellular calcium ion concentration ([Ca\u00b2\u207a]) triggers muscle contraction. However, the mechanisms involved in this process differ between the two muscle types.<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Skeletal Muscle<\/strong>:<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Skeletal muscle contraction is primarily controlled by the <strong>neuromuscular junction<\/strong>, where motor neurons release acetylcholine. This leads to an action potential in the muscle fiber, which travels along the <strong>sarcolemma<\/strong> and into the <strong>T-tubules<\/strong>.<\/li>\n\n\n\n<li>The action potential then triggers the release of calcium ions from the <strong>sarcoplasmic reticulum (SR)<\/strong>, which binds to <strong>troponin<\/strong>. This binding leads to a conformational change that moves tropomyosin, exposing binding sites on the actin filaments and allowing cross-bridge formation between actin and myosin, resulting in muscle contraction.<\/li>\n<\/ul>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Smooth Muscle<\/strong>:<\/li>\n<\/ol>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Smooth muscle contraction is regulated by <strong>intracellular calcium levels<\/strong>, but it doesn&#8217;t rely on a neuromuscular junction or troponin for its contraction. Instead, calcium binds to <strong>calmodulin<\/strong>, which activates <strong>myosin light-chain kinase (MLCK)<\/strong>. This enzyme phosphorylates the myosin light chain, allowing myosin to interact with actin, thus facilitating contraction.<\/li>\n\n\n\n<li>Calcium in smooth muscle can enter the cell through <strong>voltage-gated channels<\/strong> or be released from the sarcoplasmic reticulum.<\/li>\n<\/ul>\n\n\n\n<p>Although the exact mechanisms differ, both skeletal and smooth muscle rely on the elevation of intracellular calcium to initiate the contraction process, which is a shared characteristic.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Other Options:<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>(A) Thick and thin filaments arranged in sarcomeres<\/strong>: This is specific to skeletal and cardiac muscle. Smooth muscle does not have sarcomeres.<\/li>\n\n\n\n<li><strong>(B) Troponin<\/strong>: Troponin is specific to skeletal and cardiac muscles and is not found in smooth muscle.<\/li>\n\n\n\n<li><strong>(D) Spontaneous depolarization of the membrane potential<\/strong>: This is more characteristic of smooth muscle, especially in the case of certain smooth muscles like those in the gastrointestinal tract. Skeletal muscle does not typically exhibit spontaneous depolarization.<\/li>\n\n\n\n<li><strong>(E) High degree of electrical coupling between cells<\/strong>: This is more characteristic of smooth muscle, especially in multi-unit and single-unit smooth muscles, where gap junctions provide electrical coupling between cells. It is not a typical feature of skeletal muscle, which has discrete motor units.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Which characteristic or component is shared by skeletal muscle and smooth muscle? (A) Thick and thin filaments arranged in sarcomeres (B) Troponin (C) Elevation of intracellular [Ca2+] for excitation\u2013contraction coupling (D) Spontaneous depolarization of the membrane potential (E) High degree of electrical coupling between cells The Correct Answer and Explanation is : The correct answer [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[25],"tags":[],"class_list":["post-181041","post","type-post","status-publish","format-standard","hentry","category-exams-certification"],"_links":{"self":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/181041","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/comments?post=181041"}],"version-history":[{"count":0,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/posts\/181041\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/media?parent=181041"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/categories?post=181041"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.learnexams.com\/blog\/wp-json\/wp\/v2\/tags?post=181041"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}