Introduction: The Heart
The heart is a muscular, cone shaped, hollow organ that is only the size of our fist when we are adults (Farley, McLafferty & Hendry, 2012). The heart is located in between the lungs in the thoracic cavity with the esophagus and other structures (Farley et al., 2012). In our body the heart is facing with the cone shaped end, called the apex, to the left with the flat end (base) lying opposite (Farley et al., 2012). The heart is divided into three tissue layers: the outer layer called the pericardium, the middle layer called the myocardium and the innermost layer of tissue named the endocardium (Farley et al., 2012).
External Anatomy of the Heart
Pericardium
The pericardium is a sac that surrounds and protects the heart. It is doubled layered with an outer layer composed of fibrous connective tissue and an inner layer composed of simple squamous epithelium (Farley, McLafferty & Hendry, 2012). The fibrous portion of the pericardium ensures that the heart is anchored in place and prevents over distension (Farley et al., 2012). The inner layer named the serous membrane is further divided into two sections: the parietal and visceral
…show more content…
Ventricles are larger because they have to pump the blood longer distances than the atriums. Blood flows through the heart in one direction; the valves that are created by the endocardium maintain this one directional flow. There are two sets of valves present in the heart, atrioventricular (AV) valves, and semilunar valves (Mahadeven, 2015). The AV valves are located between the top portion of the heart called atriums, and the lower portion of the heart called ventricles and the semilunar valves are located between the ventricles and the major arteries inside the heart- the pulmonary artery and the aorta (Mahadeven,
In this figure, SN = sinus node; AVN = AV node; RA = right atrium; LA
The normal Mitral Valve controls blood flow between the upper (left atrium) and lower chamber (left ventricle) of the left side of the heart. The mitral valve allows blood to flow from the left atrium into the left ventricle, but not flow the other way. With each heartbeat, the atria contract and push blood into the ventricles. The flaps of the mitral and tricuspid valves open to let blood through. Then, the ventricles contract to pump the blood out of the heart. The flaps of the mitral and tricuspid valves close and form a tight seal that prevents blood from flowing back into the atria (nhlbi.nih.gov).
Cardiomyopathy, by definition, means the weakening of the heart muscle. The heart is operated by a striated muscle that relies on the autonomic nervous system to function. Cardiomyopathy is diagnosed in four different ways based on what caused the illness and exactly what part of the heart is weakened. The four main types of cardiomyopathy are dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, and arrhythmogenic right ventricular dysplasia. One other category of cardiomyopathy that is diagnosed is “unclassified cardiomyopathy.” Unclassified cardiomyopathy is the weakening of the heart that does not fit into the main four categories.
of the heart: one chamber is on the top and one chamber is on the
Furthermore, Aristotle and Galen’s theories contributed to the Renaissance revival of heart anatomy. This reawakening made it possible for physicians to indicate the basic arrangement of the heart. It became commonly accepted that the heart was divided into four parts: two ventricles (lower chambers that pump blood out) and two auricles (upper chamber that r...
The cardiovascular system is divided into two systems a pulmonary and a systemic. Pulmonary division- blood flows from the heart to alveolar capillaries and back to the heart. Systemic division- blood flows from heart to every capillary “except alveolar” and back to heart.
As the left atrium contracts, the mitral valve opens, which releases stored oxygen rich blood into the left ventricle. The left ventricle fills with this blood then it contracts forcefully and the aortic valve opens. The left ventricle pushes the blood through the aortic valve to the aorta where it leaves the heart and is distributed throughout the body. For this reason the left ventricle is a major part of the systemic circulation process.
The pattern of blood flow starts in the left atrium to right atrium, then into the left ventricle and right ventricle. During its course, blood flows through the mitral and tricuspid valves. Simultaneously, the right atrium is granted blood from the veins through the superior and inferior vena cava. The job of the superior vena cava is to transport de-oxygenated blood to the right atrium. When your heart beats, the first beat represents the AV valves closing to prevent the backflow of blood into the atrium.
The heart serves as a powerful function in the human body through two main jobs. It pumps oxygen-rich blood throughout the body and “blood vessels called coronary arteries that carry oxygenated blood straight into the heart muscle” (Katzenstein and Pinã, 2). There are four chambers and valves inside the heart that “help regulate the flow of blood as it travels through the heart’s chambers and out to the lungs and body” (Katzenstein Pinã, 2). Within the heart there is the upper chamber known as the atrium (atria) and the lower chamber known as the ventricles. “The atrium receive blood from the lu...
(Slide 2) What is Cardiomyopathy? If we break down the word we can see “Cardio” which means of the heart, “myo” which means muscle, and “pathy” which means disease, therefore cardiomyopathies are diseases of the heart muscle. (Slide 3) There are 3 main types of cardiomyopathies; hypertrophic, dilated, and restrictive. I will only be discussing dilated cardiomyopathy, which is characterized by the enlargement of the hearts chambers with impaired systolic function. It is estimated that as many as 1 of 500 adults may have this condition. Dilated cardiomyopathy is more common in blacks than in whites and in males than in females. It is the most common form of cardiomyopathy in children and it can occur at any age (CDC).
The heart is two sided and has four chambers and is mostly made up of muscle. The heart’s muscles are different from other muscles in the body because the heart’s muscles cannot become tired, so the muscle is always expanding and contacting. The heart usually beats between 60 and 100 beats per minute. In the right side of the heart, there is low pressure and its job is to send red blood cells. Blood enters the right heart through a chamber which is called right atrium. The right atrium is another word for entry room. Since the atrium is located above the right ventricle, a mixture of gravity and a squeeze pushes tricuspid valve into the right ventricle. The tricuspid is made up of three things that allow blood to travel from top to bottom in the heart but closes to prevent the blood from backing up in the right atrium.
From there the impulse travels along the left and right bundle branches in the septum of the heart all the way to the Purkinje fibers. At this point, the blood has flowed from the atria to the ventricles. The impulse signal in the Purkinje fibers is allowing the apex of the heart to contract. Allowing the apex to contract first allows for the heart to work more efficiently. As soon as the apex contracts, the AV valves close and the walls of the heart begin to contract which pull the papillary muscles. The papillary muscles have chordae tendineae that attach themselves to the atrioventricular valves. These chordae tendineae work to try and prevent AV valve prolapse. When the pressure is great enough in the ventricles to overcome the resting blood on the other side of the arteries, the blood will be pushed out of the ventricles and will be passed through the semilunar valves. The right ventricle pushed blood through the pulmonary semilunar valve, and the left ventricle will push blood through the aortic semilunar valve. When the ventricles have expelled as much blood as they can and the pressure returns to a lower level the heart will begin to relax allowing the semilunar valves to close. Excess blood that does not get pushed along the arteries will remain on the artery side of the semilunar
the aortic valve, between the left ventricle and the aorta. heart_chambers.jpg Each valve has a set of "flaps" (also called leaflets or cusps). The mitral valve normally has two flaps; the others have three flaps. Dark bluish blood, low in oxygen, flows back to the heart after circulating through the body. It returns to the heart through veins and enters the right atrium.
The heart is the organ that pumps the blood throughout the body. It has three chambers: the atria, the ventricles, and the septum. It also contains two main valves: the tricuspid and the bicuspid (the atrioventricular valves). It has two sections that carry the different types of blood (oxygenated and deoxygenated). The oxygen depleted blood goes through the right atrium to the right ventricle. From the right ventricle the blood goes out of the pulmonary artery to the lungs; which is referred to as the pulmonary circuits. The oxygen rich blood goes from the lungs to the left ventricle. From the left atrium, it travels to the left ventricle and out through the aorta to the different parts of the body; referred to as the systemic
5) A mammal’s heart consists of four chambers; two atria and two ventricles. The left and right side of the heart is separated by septum thus, deoxygenated and oxygenated bloods are not combined. This is regard as the most efficient system. The right atrium receives deoxygenated blood from the body which consist low amount of oxygen in the red blood cells through both the inferior and superior vena cava. The blood then travels to the right ventricle where it is pumped through the pulmonary arteries to the lungs and hence, becomes oxygenated. It makes its way back to the left atrium via pulmonary vein. This oxygen-rich blood then travels to the left ventricle and is pumped out from the heart through the aorta to the entire body which is needed for cellular respiration. The aorta is the largest artery and has an enormous amount of stretch and elasticity to withstand the pressure created by the pumping ventricle. The four-chambered heart fortifies the facilitation of repetitious muscle contractions by ensuring the tissues of the body are constantly supplied with oxygen-saturated