The cardiac cycle is vital in all organisms with a heart, to pump blood round the body. There are phases of the cardiac cycle; systole (contraction) and diastole (relaxation). The heart consists of 4 chambers, 2 being the atria at the top of the heart and the other 2 being the ventricles at the bottom of the heart. Systole occurs separately in the atria and ventricles and diastole occurs simultaneously in all 4 chambers. The cardiac cycle is controlled by electrical waves that spread throughout the heart.
The serous membrane secretes serous fluid into the space between the visceral and parietal layers that allows smooth movement between the layers, when the heart beats. The Myocardium: The myocardium is the middle layer of the heart and is composed of specialised muscle tissue called as the cardiac muscle, on which the circulation of blood depends. It varies in thickness, being thickest in the left ventricle, thinner in the right ventricle and thinnest in the artrium. The Endocardium: The endocardium forms the inner linging of the heart is a thin, smooth, glistening membrane consisting of flattened epithelial cells which is continuous with the valves and with the lining of the blood
This pumping action of blood flow is controlled by electrical impulses in the heart. It begins at the Sinoatrial node (SA node), located in the right atrium. When the blood fills in the right atrium, the electrical signal sends an impulse across the left and right atria, which cause the atria to contract. The P wave on an EKG marks the contraction of the atria. The signal then arrives from the SA node to the Atrioventricular node
Lastly the blood is then given back to hearts left side. And on the right side, the left atrium gets blood and gives it back to ventricle, this also happens when the heart relaxes. The blood then is pushed through aorta and given to rest of the
Restate your predictions that were correct and give data from your experiment that support them. Restate your predictions that were not correct and correct them, giving supporting data from your experiment that supports your corrections. During exercise HR, SV, and CO will all increase due to the increased demand of oxygen needed throughout the body as well as the increased pumping action of the heart having to work faster to get blood to the tissues during exercise Application 1. We measured the stroke volume of the left ventricle. What was the average stroke volume of the right ventricle at rest and
When your blood gets to your lungs, the oxygen from your lungs gets put into your bloodstream. Then it goes back to the heart, with the oxygen-enriched blood being delivered to all parts of your
Chapter 18 Practice Quiz 2 1. Heart valves function to A. pump the blood B. prevent clots from entering the heart C. direct the blood flow through the heart D. measure the blood pressure 2. The right and left atrioventricluar valves open when the A. atria contract B. papillary muscles contract C. atria relax D. ventricles contract 3. During atrial systole, the upper chambers contract and open the AV valves so that blood can be pumped into the A. ventricles B. veins C. atria D. arteries 4. Blood flows past the aortic semilunar valve when the contracts.
They tend to enlarge following vigorous exercise, a phenomenon called muscular hypertrophy and are located around the body. Conversely, cardiac muscle is confined only to the heart, its main role being to distribute blood. Its myogenic nature means contractions are under involuntary control and cause prevention from fatigue. The natural beating rhythm is adjusted via sympathetic and parasympathetic neurons of the CNS to suit physiological conditions. The function of these muscles is closely related to their structure and any differences in structure allow these two types of muscle to be identified.
The arteries carry nutrients and oxygenated blood to the body’s tissues. The veins return de-oxygenated blood to the heart, where the cycle repeats itself continuously. However the blood vessels have a closed type of cardiovascular system in which blood doesn’t come in direct contact with the body tissues. Instead the blood flows in restricted pathways called blood vessels. The blood vessels are pathways of blood flow in the body.
The myocardium is the middle layer and comprised of cardiac muscle tissue, makes up the majority of the cardiac wall and is responsible for its pumping action. The thickness of the myocardium mirrors the load to which each specific region of the heart is subject. The endocardium is the inner layer and is a thin layer of endothelium overlying a thin layer of connective tissue. It provides a smooth lining for the chambers of the heart and covers the valves. The endocardium is continuous with the endothelial lining of the large blood vessels attached to the heart.