Types of circulatory system Humans and other vertebrates

Types of circulatory system Humans and other vertebrates have a closed circulatory system in which the blood stays in the circulatory system as it circulates, and chemicals are exchanged by diffusion. By contrast, arthropods, such as insects andspiders, have an open circulatory system, in which the blood is pumped forward by the heart, but then flows through the body cavity, directly bathing the internal organs.

Open Circulatory Systems Arthropods and mollusks have an open circulatory system. Insects can get by with this type system because they have numerous openings in their bodies (spiracles) that allow the "blood" to come into contact with air.

Closed Circulatory Systems The closed circulatory system of some mollusks and all higher invertebrates and the vertebrates is a much more efficient system. Here blood is pumped through a closed system of arteries, veins, and capillaries. Capillaries surround the organs, making sure that all cells have an equal opportunity for nourishment and removal of their waste products. However, even closed circulatory systems differ as we move further up the evolutionary tree.

One of the simplest types of closed circulatory systems is found in annelids such as the earthworm.

The circulatory system is an organ system that moves nutrients, gases, and wastes to and from cells to help fight diseases and help stabilize body temperature and p. H to maintain homeostasis. This system may be seen strictly as a blood distribution network, but some consider the circulatory system as composed of the cardiovascular system, which distributes blood, and the lymphatic system, which distributes lymph.

While humans, as well as other vertebrates, have a closed cardiovascular system (meaning that the blood never leaves the network of arteries, veins and capillaries), some invertebrate groups have an open cardiovascular system. The most primitive animal phyla lack circulatory system. The lymphatic system, on the other hand, is an open system.

Heart The heart is a four chambered muscle that pumps blood through out the body. It delivers oxygen and vital nutrients to all of the other systems cells (its own included). The heart beats within the pericardium- a three layered sac that completly encloses it. The conducting system is what causes the heart to beat on its own without aid from the nervous system. The electrical impulse starts in the Sinoatrial (SA) node, where it travels to the atrioventricular (AV)node.

The signal then goes to the AV bundle (aka Bundle of His) where it then splits into teh bundle branches. One branch leads to the purkinje fibers in the right ventrical and the other branch leads to the purkinje fibers in the left ventrical. as the electrical impluse reaches the muscle of the heart it causes them to contract. First the atrium contract then the ventricals, when the muscle is in a resting state the valves slam shut, giving off the familiar lub dub sound.

Blood Flow Unoxynigated blood enters the right atruium of the heart from the superior vena cava. The right atrium contracts and pushes the blood through the tricuspid valve into the right ventrical then contracts forcing the blood through the Pulmonary semilunar valve, through the pulmanary arteries, and into the lungs where the blood cells pick up oxygen.

Blood Flow from the lungs the blood enters the pulmanary vein and travels into the left atrium. The left atrium contracts and pushes the blood through the Mitral valve and into the left ventrical, which then contracts and pushes the oxygenated blood to the aorta through the Aortic semilunar valve, and then travels to the rest of the body

การไหลเวยนของเลอด ขอมลจากภาพเสนเลอด 1. Right ventricle 2. Pulmonary trunk (to pulmonary arteries) 3. Lungs 4. Left Atrium 5. Left Ventricle 6. Aorta 7. Head and neck 8. Lower body 9. Superior Vena cava 10. Inferior Vena cava 11. Right atrium

Pulse and blood pressure Pulse refers to the rhythmic expansion of an artery that is caused by ejection of blood from the ventricle. It can be felt where an artery is close to the surface and rests on something firm.

Pulse and blood pressure In common usage, the term blood pressure refers to arterial blood pressure, the pressure in the aorta and its branches. Systolic pressure is due to ventricular contraction. Diastolic pressure occurs during cardiac relaxation.

Pulse and blood pressure Pulse pressure is the difference between systolic pressure and diastolic pressure. Blood pressure is measured with a sphygmomanometer and is recorded as the systolic pressure over the diastolic pressure. Four major factors interact to affect blood pressure: cardiac output, blood volume, peripheral resistance, and viscosity. When these factors increase, blood pressure also increases.

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