Lymphatic system summary

Summary – Circulatory System
Types of circulation :
* Systemic circulation: the general circulation of the blood through the body, as opposed to the circulation of the blood from the heart to the lungs and back to the heart.
* Pulmonary circulation: the circulation of blood through the lungs for the purpose of oxygenation and the release of carbondioxide. Also known as lesser circulation.
* Coronary circulation: consists of the blood vessels that supply blood to, and remove blood from, the heart. The vessels that supply blood high in oxygen to the heart are known as coronary arteries. The vessels that remove the deoxygenated blood from the heart are known as cardiac veins.


Function:It is in charge of the transport of different substances needed and discarded by the body. For example: nutrients like glucose, amino acids, vitamins, minerals; gases like oxygen and carbon dioxide; also wastes, hormones, water, hydrogen ions and chemical substances all over the body for their uniform distribution. It also transmits heat, regulates body temperature, and fights off diseases andinfections.



Components
1. Heart: The human heart is a two-sided, 4
chambered structure with muscular walls that works like a pump. It has the size of your clenched fist. Layers of the heart are: endocardium, myocardium, and pericardium.
The chambers and other related structures are: Atria: located at theupper part of the heart, in charge of receiving blood. Right one receives blood from the cava vein; left one from the pulmonary vein.
Ventricles: located at the lower part of the heart, in charge of pumping blood out. The right one pumps blood out to the lungs through the pulmonary artery. The left one is thicker and more muscular because it pumps blood at a higher pressure. It pumpsblood out to the head and rest of the body through the aorta. Septum: division of the left and right side of the heart.
Valves: An atrio-ventricular valve separates each atrium from ventricle, the mitral valve and the tricuspid valve. They let blood flow from the atria to the ventricles. A semilunar (also known as arterial) valve separates each ventricle from its connecting artery;the aortic valve and pulmonary valve, and they are in charge of controlling the flow as the blood leaves the heart. These valves all work to keep the blood flowing forward. They open up to let the blood move ahead, and then they close quickly to keep the blood from flowing backward.
1The cardiac cycle consists of two parts: systole (contraction of the heart muscle) and diastole(relaxation of the heart muscle/filling of the ventricles with blood). Atria contract while ventricles relax. Ventricular systole opens the semilunar valves, forcing blood out of the ventricles through the pulmonary artery or aorta. The sound of the heart contracting and the valves opening and closing produces a characteristic "lub-dub" sound. “Lub” is associated with closure of the atrioventricularvalves; “dub” is the closing of the semilunar valves. The pulse is a wave of contraction transmitted along the arteries. Valves in the heart open and close during the cardiac cycle. Heart muscle contraction is due to the presence of nodal tissue in two regions of the heart. The sinoatrial node initiates heartbeat (near the right atrium). The atrioventricular node causes ventricles to contract. Theatrioventricular node is sometimes called the pacemaker since it keeps heartbeat regular. Heartbeat is also controlled by the autonomic nervous system.
2.Blood vessels Arteries, arterioles: they are thicker and except for the pulmonary arteries they carry oxygenated blood away from the heart. The aorta artery is the largest vessel. Veins, venules: they are thinner, have valves and...