Heart (Cardiac Muscle) Cells
Question 1: Briefly describe, in 500 words or less, the normal structure and function of your chosen cell type. In your answer, discuss specific features in your chosen cell type, including cell organelles.
Throughout the heart, Cardiac Muscle cells are connected together to form a large network from one end to the other. These cells form a shape such that each individual cell always remains in-contact with 3 others cells at all times.
The cells are held together by regions known as intercalated disks. These overlapping, finger-like extensions of the cell membrane contain gap junctions and desmosomes. Gap junctions are protein-lined tunnels which allow currents to travel from cell to cell to ensure the cells contract in unison. Desmosomes are known for holding the Heart Cells together during a contraction. This is induced by the sliding of the cardiac
This may include metabolic changes, structural changes, etc.
Hypertrophic Cardiomyopathy, also known as HCM, is a type of heart disease that affects the Cardiac Muscles and Cardiac Muscle cells. This disease occurs if the Cardiac Muscle cells enlarge, which causes the wall of the heart’s ventricles (most often the left ventricle) to thicken. It can also cause stiffness in the ventricles, as well as mitral valve and cellular changes.
On a cellular lever, HCM can cause the cells to become disorganised and lost. Under a microscope, a normal Cardiac Muscle cell appears parallel and organised, while a cell affected by HCM will appear irregular and disorganised. This disorganisation can create changes and altercations in the signals sent and received through the lower chambers of the heart, which in turn can lead to an abnormal heart rhythm, known as ventricular
The building of the grocery store is like the cell membrane, because it gives it structure and keeps everything inside safe. The security guard of the front door in the grocery store is like the cell membrane, because it says what can come in and out of the cell. The boss of the store is like the nucleus, because they tell the employes what to do and what needs to be done. The floors of the grocery store is like the cytoplasm, because it hold everything in it place, where it need to be. The illes in the store is
When a muscle contracts and relaxes without receiving signals from nerves it is known as myogenic. In the human body, the cardiac muscle is myogenic as this configuration of contractions controls the heartbeat. Within the wall of the right atrium is the sino-atrial node (SAN), which is where the process of the heartbeat begins. It directs consistent waves of electrical activity to the atrial walls, instigating the right and the left atria to contract at the same time. During this stage, the non conducting collagen tissue within the heart prevents the waves of electrical activity from being passed directly from the atria to the ventricles because if this were to happen, it would cause a backflow. Due to this barrier, The waves of electrical energy are directed from the SAN to the atrioventricular node (AVN) which is responsible for transferring the energy to the purkyne fibres in the right and left ventricle walls. Following this, there is a pause before the wave is passed on in order to assure the atria has emptied. After this delay, the walls of the right and left ventricles contract
“Hypoplastic left heart syndrome accounts for 9% of all critically ill newborns with congenital cardiac disease, causing the largest number of cardiac deaths in the first year of life.(2) ” HLHS is a severe heart defect that is present at birth. HLHS combines different defects that result in an underdeveloped left side of the heart. This syndrome is one of the most challenging and difficult to manage of all of the congenital heart defects. Multiple portions on the left side of the heart are affected including the left ventricle, the mitral and aortic valve, and the ascending aorta. These structures are greatly reduced in size, or completely nonexistent causing the functionality of the left heart to be reduced, or non-functional all together.
The thickening of the muscle cells do not necessarily have to change the size of the ventricles, but can narrow the blood vessels inside the heart. Hypertrophic cardiomyopathy can be grouped into two categories: obstructive HCM and non-obstructive HCM. With obstructive HCM, the septum (the wall that divides the left and right sides of the heart) becomes thickened and blocks the blood flow out of the left ventricle. Overall, HCM usually starts in the left ventricle. HCM can also cause blood to leak backward through the mitral valve causing even more problems. The walls of the ventricles can also become stiff since it cannot hold a normal amount of blood. This stiffening causes the ventricle to not relax and entirely fill with
Capture Myopathy? Not very often a diagnosis is termed liked this, especially in the field of human medicine, especially n the field of cardiology the where the term myopathy is revered as Cardiomyopathy. Myopathy is a disease that affects the muscles and causes weakness due to dysfunction of muscle fibers (1); Cardiomyopathy is of the same circumstance but deals primarily with the heart. Capture Myopathy is relative to many animals, especially mammals and provides a definitive correlation to humans and their potential medical prognosis of Cardiomyopathy. Capture Myopathy is a syndrome that that occurs within captive animals and causes rapid death through excessive adrenaline within the bloodstreams. (3) Capture Myopathy is quite often referred to as white muscle disease, the muscle when used causes a change of metabolism from using oxygen to using the stored energy within the muscle. The change up allows for lactic acid to build up and make its way into the bloodstream where it changes the homeostasis of the body: the body pH and the heart output. In essence, if the heart is inefficiently pumping the correct oxygen to the muscle, the muscle will begin to deteriorate and ultimately lead to damages to the kidney and the effector organs. (2) Animal Capture Myopathy is very relatable to human Takotsubo Cardiomyopathy, and thus this paper will aim to trace how animals are very relatable to humans even through the Cardiovascular System based on normal physiology and stress. (WHAT SHOULD I TALK ABOUT?)
The cells of a cardiac muscle are shaped and wider and shorted than a skeletal muscle however they are stripped like skeletal
The skeletal and ultimate cardiac muscle fibers are affected by DMD. The disease starts by affecting the lower port...
Congestive Heart Failure is when the heart's pumping power is weaker than normal. It does not mean the heart has stopped working. The blood moves through the heart and body at a slower rate, and pressure in the heart increases. This means; the heart cannot pump enough oxygen and nutrients to meet the body's needs. The chambers of the heart respond by stretching to hold more blood to pump through the body or by becoming more stiff and thickened. This only keeps the blood moving for a short while. The heart muscle walls weaken and are unable to pump as strongly. This makes the kidneys respond by causing the body to retain fluid and sodium. When the body builds up with fluids, it becomes congested. Many conditions can cause heart failure, and they are Coronary artery disease, Heart attack, Cardiomyopathy, and conditions that overwork the heart.
Hypertrophic cardiomyopathy is an inherited disease that affects the cardiac muscle of the heart, causing the walls of the heart to thicken and become stiff. [1] On a cellular level, the sarcomere increase in size. As a result, the cardiac muscles become abnormally thick, making it difficult for the cells to contract and the heart to pump. A genetic mutation causes the myocytes to form chaotic intersecting bundles. A pathognomonic abnormality called myocardial fiber disarray. [2,12] How the hypertrophy is distributed throughout the heart is varied. Though, in most cases, the left ventricle is always affected. [3] The heart muscle can thicken in four different patterns. The most common being asymmetrical septal hypertrophy without obstruction. Here the intraventricular septum becomes thick, but the mitral valve is not affected. Asymmetrical septal hypertrophy with obstruction causes the mitral valve to touch the septal wall during contraction. (Left ventricle outflow tract obstruction.) The obstruction of the mitral valve allows for blood to slowly flow from the left ventricle back into the left atrium (Mitral regurgitation). Symmetrical hypertrophy is the thickening of the entire left ven...
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...
8. Becker W. M, Hardin J, Kleinsmith L.J an Bertoni G (2010) Becker’s World of the Cell, 8th edition, San Francisco, Pearson Education Inc- Accessed 23/11/2013.
Most often the disease starts in the left ventricle, and then often spreads to both the atrium and right ventricle as well. Usually there will also be mitral and tricuspid regurgitation, due to the dilation of the annuli. This regurgitation will continue to make problems worse by adding excessive volume and pressure to the atria, which is what then causes them to dilate. Once the atria become dilated it often leads to atrial fibrillation. As the volume load increases the ventricles become more dilated and over time the myocytes become weakened and cannot contract as they should. As you might have guessed with the progressive myocyte degeneration, there is a reduction in cardiac output which then may present as signs of heart failure (Lily).
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.
The heart is a pump with four chambers made of their own special muscle called cardiac muscle. Its interwoven muscle fibers enable the heart to contract or squeeze together automatically (Colombo 7). It’s about the same size of a fist and weighs some where around two hundred fifty to three hundred fifty grams (Marieb 432). The size of the heart depends on a person’s height and size. The heart wall is enclosed in three layers: superficial epicardium, middle epicardium, and deep epicardium. It is then enclosed in a double-walled sac called the Pericardium. The terms Systole and Diastole refer respectively and literally to the contraction and relaxation periods of heart activity (Marieb 432). While the doctor is taking a patient’s blood pressure, he listens for the contractions and relaxations of the heart. He also listens for them to make sure that they are going in a single rhythm, to make sure that there are no arrhythmias or complications. The heart muscle does not depend on the nervous system. If the nervous s...
"The general idea is an old one, that any two cells or systems of cells that are repeatedly active at the same time will tend to become 'associated', so that activity in one facilita...