Question

2. Name the three layers that make up the heart wall. 3. Of the two ventricles, which is more muscular? How does this difference correlate with its function? 57

Answer 1

2.The heart wall is divided into three layers: epicardium, myocardium, and endocardium.

Epicardium— outer protective layer of the heart.

Myocardium—muscular middle layer wall of the heart.

Endocardium—inner layer of the heart

3. Left ventricle of heart is more muscular than right ventricle because left ventricle has to pump blood a longer distance than the right ventricle.

4.Tricuspid valve

Right ventricle

Pulmonary semilunar valve

Pulmonary trunk

Pulmonary arteries

Pulmonary vein

Left atrium

Bicuspid valve

Left ventricle

Aortic semilunar valve

Aorta

5.The cardiac conduction system (CCS) consists of distinctive components that initiate and conduct the electrical impulse required for the coordinated contraction of the cardiac chambers.

The various components of the CCS are composed of a distinct set of cardiomyocytes that generate and propagate the electrical impulse required for contraction of the cardiac chambers. The sinoatrial node, which is located at the junction of the superior caval vein and right atrium, generates the impulse that then travels to the atrioventricular node, which delays the signal. The atrioventricular bundle forms the only myocardial connection between atria and ventricles through the non-myocardial atrioventricular junction. Propagation through the left and right bundle branches and the peripheral ventricular conduction system leads to activation of contraction of the ventricles. LA, left atrium; LV, left ventricle; RA, right atrium; RV, right ventricle.

SA Node

Atrial wall

AV Node

AV Bundle

Bundle branches

Purkinje fibres

Ventricular wall

6.Pericarditis refers to inflammation of the pericardium, two thin layers of a sac-like tissue that surround the heart, hold it in place and help it work. A small amount of fluid keeps the layers separate so that there’s no friction between them.

A common symptom of pericarditis is chest pain, caused by the sac’s layers becoming inflamed and possibly rubbing against the heart. It may feel like pain from a heart attack.

Mitral valve prolapse is a condition in which the two valve flaps of the mitralvalve do not close smoothly or evenly, but instead bulge (prolapse) upward into the left atrium. Mitral valve prolapse is also known as click-murmur syndrome orBarlow's syndrome or floppy valve syndrome.

Myocardial ischemia occurs when blood flow to your heart is reduced, preventing it from receiving enough oxygen. The reduced blood flow is usually the result of a partial or complete blockage of your heart's arteries.

Acute myocardial infarction is the medical name for a heart attack. A heart attack is a life-threatening condition that occurs when blood flow to the heart muscle is abruptly cut off, causing tissue damage. This is usually the result of a blockage in one or more of the coronary arteries.

Acute myocardial infarction is the medical name for a heart attack. A heart attack is a life-threatening condition that occurs when blood flow to the heart muscle is abruptly cut off, causing tissue damage. This is usually the result of a blockage in one or more of the coronary arteries.

Coronary artery disease (CAD) is the most common type of heart disease.. CAD happens when the arteries that supply blood to heart muscle become hardened and narrowed.

B. C 1. Normal heart rate is between 60-100 bpm

Anterior View Posterior View Arch of eorta Ascending aorta orta Superior vena cava terioaum Left pulmanary Auricle of right atrium LEFT Pulmonary tunk ATRIUM atrium LEFT NTRICLE Conus RIGHT VENTRICLE ROGHT VEN Fat in coronary nterior Fat in anterior interventricutar sukcus Anterior

2. Heart rate increases after doing exercises

When exercising many muscles will all require nutrients and elimination of waste products constantly at the same time. To meet this demand the heart must rapidly increase therate at which it beats and pushes blood through the body. This is why the heart beatssignificantly faster during exercise.

3.The “ lub” is the first heart sound, commonly termed S1, and is causedby turbulence caused by the closure of mitral and tricuspid valves at the start of systole. The second sound,” dub” or S2, is caused by the closure of aortic and pulmonic valves, marking the end of systole.

1. Typical reating heart rate : 60 to 100 beats per minute

Tachycardia :Tachycardia refers to a heart rate that’s too fast. The heart rate will be more that 100bpm

Bradycardia: Bradicardia refers to a heart rate that's too slow. The heart rate will be less than 50 bpm

2. Heart murmur : Heart murmurs are sounds during your heartbeat cycle — such as whooshing or swishing — made by turbulent blood in or near your heart. These sounds can be heard with a stethoscope

Valvular insufficiency. Also called regurgitation, incompetence, or "leaky valve," this occurs when a valve does not close tightly. If the valves do not seal, some blood will leak backwards across the valve

Valvular stenosis: Here the tissues forming the valve leaflets become stiffer, narrowing the valve opening and reducing the amount of blood that can flow through it.

3.Rheumatic fever is caused by a bacterium called group A Streptococcus. This bacterium causes strep throat or, in a small percentage of people, scarlet fever. It’s an inflammatory disorder.

In some cases rheumatic fever causes long-term damage to theheart and its valves. This is called rheumatic heart disease.Untreated strep throat or other infections with strep bacteria that progress to rheumatic fever can cause heart valve disease. When the body tries to fight the strep infection, one or more heart valves may be damaged or scarred in the process. The aortic and mitral valves most often are affected.

4.Atrial fibrillation is an irregular heartbeat that increases the risk of stroke and heart disease. Signs include dizziness, weakness, and fatigue. Treatment involves medication and lifestyle changes, and sometimes procedures such as cardioversion, ablation, pacemakers, or surgery.

Atrial fibrillation can lead to serious complications, some far more frequent than sudden cardiac death — for instance, it is a leading cause of stroke and heart disease. But in most cases, if you are properly treated and closely monitored by your doctor, atrial fibrillation is not a life-threatening condition.

5. Foramen ovale : Hole in the interatrial septum to shunt oxygenated blood from right to left atria. More elaborate answer: The foramen ovale is an anatomic adaptation in the fetus to allow oxygenated blood coming from the umbilical vein via the inferior vena cava to bypass the pulmonary circulation.

If the foramen ovale does not close all the way, it is called a patent foramen ovale (PFO).

PFO can cause some problems. For example:

If you have pulmonary hypertension, PFO may make shortness of breath much worse.

The ductus arteriosus is a short blood vessel that connects the pulmonary artery to the aorta in the developing fetus. It is normally open only in a developing fetus. During development, the ductus arteriosus allows for oxygenated blood to bypass the pulmonary circulation (since breathing is not yet possible) and enter directly into the systemic circulation. After birth, the ductus arteriosus closes and becomes the ligamentum arteriosum

If this doesn't close after birth it leads to a condition called patent ductus arteriosus.

When the ductus arteriosus stays open, oxygen-rich blood passes from the aorta to the pulmonary artery, mixing with the oxygen-poor blood already flowing to the lungs. The blood vessels in the lungs have to handle a larger amount of blood than normal