The Heart Of Cardiac Muscle Essay

“Racism is man’s gravest threat to man- the maximum of hatred for a minimum of reason.” (Abraham J. Heschel, Jewish philosopher). Richard Beynon’s ‘The Shifting Heart’ was first published in 1960, and insightfully explores the impact of racism. It is based on the lives of the Bianchis, an Italian family living in the suburb of Collingwood, during the post World War II immigration boom. As a literary device, symbolism is the representation of a concept through underlying meanings of objects. Beynon portrays the message, ‘racism is a result of intolerance, not the specific races alone,’ through the use of symbolism as well as the various racial attitudes of characters. The set

Thesis: In The Shifting Heart, the playwright Richard Beynon conveys ideas and representations of Australian identity through the use of narrative techniques, especially dialogue and characterisation. Each character represents an aspect of Australian society in the 1950 's that Beynon perceives to be true. 1st published in 1960. Set in 1956. NUTSHELL-

Resting heart contractions were recorded for thirty seconds until the heart rate was less than 60 beats per minute. A stimulator electrode to be used was set to the following states: Amplitude of 4.00 Volts, a stimulus delay of 50ms, stimulus duration of 10ms, a frequency of 1.0Hz, and a pulse number of 30. The electrode was then placed in direct contact with the heart for 30 seconds at which time the data was observed and recorded.

The Myocardium is made up of specialised cardiac muscle, only found in the heart and is not under voluntary control.

Composed of the heart, blood vessels, and blood, the cardiovascular system is the body system that carries out the tasks of pumping and transporting blood, oxygen, nutrients, and waste products, and other substances throughout the body.

The effect of Acetylcholine had on the frog’s heart. The heart flatlined, and the spikes seen after the rinsing of the chest cavity in hopes that the heart will beat again.

In cardiac muscle, a single nucleus is located in the middle of each fibre. The brain tissue also has a nucleus which is located in the middle of cell body. The cardiac muscle and brain tissue don’t have the exact same function. The cardiac muscle and the brain tissue don’t work together because the cardiac muscle doesn’t takes any instructions from the brain tissue (Neurones). This means that the cardiac muscle contracts automatically.

Oxygen and nutrients the body requires for function are pumped around this complex network of blood vessels by the heart. At roughly the size of a human fist, the heart is a four-chambered muscle and performs two functions of circulation simultaneously and continuously. Systemic and pulmonary circulation. The heart is made up from three separate layers of cardiac tissue; the outer layer called the pericardium, which is a double sac-like outer covering with serous fluid inside to keep the middle layer, the myocardium from adhering to the outer layer. This middle layer of the heart is the heart muscle which is thicker on the left side, to aid with the pressure needed to sustain systemic circulation. The inner layer of the heart is the endocardium. It’s lining is smooth to help prevent the blood which circulates around the inside of the heart from clotting. The heart is the human body’s in-built pacemaker, and the electrical signals sent through the it cause the heart to contract and relax. This process is triggered by the autonomic nervous system and the contraction and relaxing cycle is

The heart serves an important purpose within the body, pumping blood throughout the circulatory system to supply all parts of the body with vital nutrients and molecules. It pumps oxygen and nutrient rich blood to be exchanged for carbon dioxide, which is then pumped to the lungs and eliminated from the body. The movement of blood throughout the body is due to the heart’s ability to push blood along the circulatory system at a steady, unfaltering rate. This rate, known as heart rate, is regulated and can be altered at a moment’s notice by signaling within the body and heart itself. In vertebrates, the autonomic nervous system controls and regulates heart rate. The autonomic nervous system is divided into two subunits, the sympathetic nervous system and parasympathetic nervous system. The parasympathetic nerve that innervates the heart is the vagus nerve. In this laboratory experiment, the regulation of heart rate was observed by studying a certain breed of turtle, the Red-eared Slider (Trachemys scripta elegans). Both chemical and electric signaling can influence the components of the nervous

has to work harder pumping blood to the rest of the body. Blood in our

The cardiac cycle describes the coordinated and rhythmic series of muscular contractions associated with the normal heart beat.

9. When the heart is externally stimulated just after the start of the contraction cycle, why does this have no affect on heart rate?

6. Automaticity – ability of heart to beat spontaneously and repetitively without external neurohormonal control. The heart is capable of beating outside the body, given proper laboratory conditions. Automaticity is evidently linked to fluid and electrolyte balance rather than to nervous system control.

From the very first time the heart starts pounding until the time of death, it may beat more than 3.5 billion times. The center of the circulatory system is the heart. The average heart beats 100,000 times each day, pushing around 2,000 gallons of blood throughout your body. With a life span of 70-90, the heart will beat two to three billion times and circulate 50-65 million gallons of blood.

While contraction in skeletal muscle is triggered by motor neurons under central control, certain cardiac muscle variants exhibit autorhythmicity. This means that that they are capable of producing their own depolarizing electrical potential. The cardiomyocytes that are capable of producing their own electrical potentials are found in what is referred to as the electrical condition system of the heart. This system is comprised of specializes cardiomyocytes that are autorhythmic and are able to conduct electrical potentials rapidly. These specialized structures include the sinoatrial node, atrioventricular node and bundle, and Purkinje fibers.