. The layers of the heart wall include epicardium, myocardium, and endocardium. Epicardium is the surface of the wall and it’s also called visceral pericardium. It contains serous membrane covering the heart. Myocardium is in the middle of the two layers it’s described as having a thick muscular layer of the heart. It serves as having contractions of the heart as well in containing fibrous skeleton in networking of collagenous and elastic fibers. Some of the functions are providing structural support, attachment for cardiac muscle, and having electrical insulation. Endocardium is the inner lining that is smooth and contains epithelial. There is also the pericardial sac which allows the heart to beat without friction and the heart having room to expand and resist excessive expansion. It has three layers which include parietal pericardium the tough outer layer, pericardial cavity is filled with pericardial fluid, and visceral pericardium which is thin, smooth, and serous layer covering the heart surface.
2. Three reasons why dynamic or parallel blood flow through the systemic circuit is important is because it supplies blood to all organs of the body, it’s catered to the body’s needs, and it diffuses CO2 from blood.
3. The heart is located in the
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They all compare in having depolarization in a form of action potential and channels that open or close. The differences is that skeletal and non-nodal have a stable resting membrane while nodal doesn’t have a stable resting membrane potential. Skeletal resting membrane is about -90 mV, non-nodal is -90 mV, while nodal doesn’t have a resting membrane is gradual depolarizes from -60 mV. Sodium opens in the non-nodal and skeletal action potential while there is a leak of sodium in the nodal. Nodal depolarizes by calcium channels opening in the non-nodal and skeletal the sodium is the depolarizing. In nodal and skeletal the repolarizing phase the potassium channels close but in the non-nodal the potassium channels
According to Stephen B. Bright, many of the men, women, and children sent to prison in the United States everyday, are processed through courts without legal representation that is indispensable to a fair trial, a reliable verdict and a just sentence. We see many examples of this everyday. “A poor person arrested by police may languish in jail for days, weeks or months before seeing a lawyer for the first time” (Bright 6). Once convicted a poor person can face years in prison, or even be executed without ever having a lawyer present. The concepts of crime can be defined differently in different societies and can be classified according to race ethnic, gender, sexuality class, and religious identifications (Bright 6). Common targets of this “poverty-to-prison” cycle can be seen in When a Heart Turns Solid Rock by Timothy Black. The book shows how schools, jobs, the streets, and prisons have shaped the lives and choices of poor Puerto Rican boys at the turn of the twenty- first century. Rather than using a model of urban poverty that blame the poor for their poverty, Black instead focuses, through ethnography, on the social forces that affect the individual lives of three urban Puerto Rican brothers: Julio, Fausto, and Sammy. As viewed in the book, many targets for the prison system are poor African American and Latino men. People that come from poor neighborhoods are at a higher risks of being incarcerated.
In this figure, SN = sinus node; AVN = AV node; RA = right atrium; LA
•Tunica Media - the middle layer of the walls of arteries and veins. It is composed of smooth muscle and elastic fibres. This layer is thicker in arteries than in veins. Its function is to help in the increasing and decreasing in calibre of the artery.
The cardiovascular system - The cardiovascular system is responsible for transporting nutrients and removing gaseous waste from the body. It consists of the heart, which powers the whole process, the veins, arteries, and capillaries, which deliver oxygen to tissue at the cellular level. The cardiovascular system carries blood that is low in oxygen away from the heart to the lungs via arteries, where oxygen levels are restored through the air once oxygenated, this blood is then carried throughout the body via arteries, keeping our organs and tissue alive. The cardiovascular system is the workhorse of the body, continuously moving to push blood to the cells. If this important system ceases its work, the body dies.
The walls of arteries are made up of three layers same as veins. Its inner endothelium is composed of epithelial cells which is very smooth. This layer helps minimise the friction. The tunica media provides strength and elasticity. It contains smooth muscles, collagen and large amount of elastic fibres.
The four tissue layers are the mucosa, submucosa, muscularis externa, and the serosa. The mucosa is the inner most layer which also composes of its own; the epithelial, lamina propia, and muscularis mucosa. The mucosa secretes hormones, digestive enzymes and also mucus as well. The submucosa is composed of areolar connective tissue, which contains a rich blood supply, nerve fibers and lymphatic vessels and follicles. The muscularis external is the layer that is responsible for the function of segmentation and peristalsis. It contains an inner circular layer and also an outer longitudinal layer both of smooth muscle cells. The serosa is the layer that is the outermost. It is also called the visceral peritoneum and it is areolar connective tissue that is covered with mesothelium.
The behavior of the narrator in The Tell-Tale heart demonstrate characteristic that are associated with people with obsessive-compulsive disorder and paranoid schizophrenia . When Poe wrote this story in 1843 obsessive-compulsive disorder and paranoia had not been discovered. However in modern times the characteristics demonstrated by the narrator leads people to believe that he has a mental illness. Poe’s narrator demonstrates classic signs throughout the story leading the reader to believe that this character is mad
The myocardium is the middle layer and is the biggest of all. Myocardial Infarction is a disease later read about in this report. The pericardium is a fibrous sac with a very smooth lining. In the space between the pericardium and epicardium is a small amount of fluid. This fluid makes the movement of the heart muscle smooth.
The Tell-Tale Heart: An Analysis In Edgar Allan Poe’s short-story, “The Tell-Tale Heart,” the storyteller tries to convince the reader that he is not mad. At the very beginning of the story, he asks, "...why will you say I am mad? " When the storyteller tells his story, it's obvious why. He attempts to tell his story in a calm manner, but occasionally jumps into a frenzied rant.
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...
Just as breast cancer is killing our African American women, heart disease is also one of the major diseases killing our women. Heart disease is one of the nation’s leading causes of death in both woman and men. About 600,000 people die of heart disease in the United States (Americas heart disease burden, 2013). Some facts about heart disease are every year about 935,000 Americans have a heart attack. Of these, 610,000 are a first heart attack victim. 325,000 happen in people who have already had a heart attack. Also coronary heart disease alone costs the United States $108.9 billion each year. This total includes the cost of health care services, medications, and loss of productivity. Deaths of heart disease in the United States back in 2008 killed about 24.5% of African Americans.
The circulatory system and respiratory system share a highly important relationship that is crucial to maintaining the life of an organism. In order for bodily processes to be performed, energy to be created, and homeostasis to be maintained, the exchange of oxygen from the external environment to the intracellular environment is performed by the relationship of these two systems. Starting at the heart, deoxygenated/carbon-dioxide (CO2)-rich blood is moved in through the superior and inferior vena cava into the right atrium, then into the right ventricle when the heart is relaxed. As the heart contracts, the deoxygenated blood is pumped through the pulmonary arteries to capillaries in the lungs. As the organism breathes and intakes oxygenated air, oxygen is exchanged with CO2 in the blood at the capillaries. As the organism breathes out, it expels the CO2 into the external environment. For the blood in the capillaries, it is then moved into pulmonary veins and make
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...