Explain the significance of the thickness of the left ventricular wall. The left ventricle works harder as it pumps blood to the systemic circuit, not just to the pulmonary portions as the right ventricular does. Therefore, the left ventricular walls are thicker, to support the hard work that it has to do throughout the body (Martini & Nath,2014 p.685)
The major coronary vessels are on the surface of the heart. What is the advantage of that location? The heart has its own blood supply from the Coronary arteries. The two main coronary arteries are connected were the aorta and left ventricle come together. These arteries pump to all areas of the body like the brain, pulmonary cavities, and etc. Coronary vessels as well circulate the blood throughout the heart as well, as the heart doesn’t receive oxygen from the blood that it is pumping out the body. The heart needs to get oxygen someway and the circulation of the coronary vessels is what provides the nutrition of oxygen to the heart. It is located on the surface of the heart where it improves efficiency so there are no problems throughout the job of the heart (Martini & Nath,2014 p.695-696). “The great cardiac vein begins on the anterior surface of the ventricles, along the interventricular sulcus. This vein drains blood from the region supplied by the anterior interventricular artery, a branch of the left coronary artery. The great cardiac vein reaches the level of the atria and then curves around the left side of the heart within the coronary sulcus. The vein empties into the coronary sinus, which lies in the posterior portion of the coronary sulcus. The coronary sinus opens into the right atrium near the base of the inferior vena cava” (Martini & Nath,2014 p.696). Since the SA node is at the top of the atrial mass, the atria contract from the top down. How does this increase the efficiency of atrial contraction? Do the ventricles have a similar arrangement? If so, how does it work? The cardiac cycle is the blood pressure that occurs when the beginning of one heartbeat goes to the beginning of the next heartbeat. Atrial systole is the contraction of the myocardia on the left and right atria. The heart is made up of two different areas the promote impulses, the sinoatrial node, and the atrioventricular node. Purkinje fibers are fibers in the muscle that conduct impulses. The impulses move five times faster than other cells that surround the myocardia. They also form a pathway for job of the impulse (Martini & Nath,2014 p.700). The location of the SA Node is in the wall of the right atrium, where the junction of the atrium and the superior vena cava are nearly placed. This area of the cardiac muscle contracts 80-100 times per minute. When the rest of the muscle contracts it will only contract 40 times per minute on its own. Then the ventricles contract on own about 20 + times per minute. Since the cells in the SA node contract the most times per minute, the SA node is what makes it the pacemaker of the heart (Martini & Nath,2014 p.700). “The rate of spontaneous depolarization differs in various parts of the conducting system. It is fastest at the SA node. Without …show more content…
The location of the myocardium is in the middle layer of the heart. It is made up of striated muscle fibers that pump blood throughout the body. Where they are placed in irregular intervals within the muscle. The Cardiac muscle is also known as the myocardium. The movement of the muscle is automatic and constant rhythmic movements that won’t stop. It contractions of the heart consist of the heart taking blood out of the heart and then relaxes to fill the heart back up with blood (Martini & Nath,2014 p.689-692).
Each cardiac muscle fiber is made up of a single nucleus that has the appearance of striated or striped. The appearance is light and dark bands. Dark bands are made up of thick protein filaments that are produced by myosin proteins. These bands do not let light pass through. The light bands are between the dark bands, they are made up of actin protein and let light pass through them (Martini & Nath,2014
The major coronary vessels are on the surface of the heart. What is the advantage of that location? The heart has its own blood supply from the Coronary arteries. The two main coronary arteries are connected were the aorta and left ventricle come together. These arteries pump to all areas of the body like the brain, pulmonary cavities, and etc. Coronary vessels as well circulate the blood throughout the heart as well, as the heart doesn’t receive oxygen from the blood that it is pumping out the body. The heart needs to get oxygen someway and the circulation of the coronary vessels is what provides the nutrition of oxygen to the heart. It is located on the surface of the heart where it improves efficiency so there are no problems throughout the job of the heart (Martini & Nath,2014 p.695-696). “The great cardiac vein begins on the anterior surface of the ventricles, along the interventricular sulcus. This vein drains blood from the region supplied by the anterior interventricular artery, a branch of the left coronary artery. The great cardiac vein reaches the level of the atria and then curves around the left side of the heart within the coronary sulcus. The vein empties into the coronary sinus, which lies in the posterior portion of the coronary sulcus. The coronary sinus opens into the right atrium near the base of the inferior vena cava” (Martini & Nath,2014 p.696). Since the SA node is at the top of the atrial mass, the atria contract from the top down. How does this increase the efficiency of atrial contraction? Do the ventricles have a similar arrangement? If so, how does it work? The cardiac cycle is the blood pressure that occurs when the beginning of one heartbeat goes to the beginning of the next heartbeat. Atrial systole is the contraction of the myocardia on the left and right atria. The heart is made up of two different areas the promote impulses, the sinoatrial node, and the atrioventricular node. Purkinje fibers are fibers in the muscle that conduct impulses. The impulses move five times faster than other cells that surround the myocardia. They also form a pathway for job of the impulse (Martini & Nath,2014 p.700). The location of the SA Node is in the wall of the right atrium, where the junction of the atrium and the superior vena cava are nearly placed. This area of the cardiac muscle contracts 80-100 times per minute. When the rest of the muscle contracts it will only contract 40 times per minute on its own. Then the ventricles contract on own about 20 + times per minute. Since the cells in the SA node contract the most times per minute, the SA node is what makes it the pacemaker of the heart (Martini & Nath,2014 p.700). “The rate of spontaneous depolarization differs in various parts of the conducting system. It is fastest at the SA node. Without …show more content…
The location of the myocardium is in the middle layer of the heart. It is made up of striated muscle fibers that pump blood throughout the body. Where they are placed in irregular intervals within the muscle. The Cardiac muscle is also known as the myocardium. The movement of the muscle is automatic and constant rhythmic movements that won’t stop. It contractions of the heart consist of the heart taking blood out of the heart and then relaxes to fill the heart back up with blood (Martini & Nath,2014 p.689-692).
Each cardiac muscle fiber is made up of a single nucleus that has the appearance of striated or striped. The appearance is light and dark bands. Dark bands are made up of thick protein filaments that are produced by myosin proteins. These bands do not let light pass through. The light bands are between the dark bands, they are made up of actin protein and let light pass through them (Martini & Nath,2014