Pulmonary circulation
Overview
 
Pulmonary circulation is the half portion of the cardiovascular system which carries Oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

-depleted Blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 away from the heart, to the Lungs, and returns oxygenated (oxygen rich) blood back to the heart. Encyclopedic description and discovery of the pulmonary circulation is widely attributed to Doctor Ibn al-Nafis (1213-1288). The term pulmonary circulation is readily paired and contrasted with the systemic circulation
Systemic circulation
Systemic circulation is the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. This physiologic theory of circulation was first described by William Harvey...

.
A separate system known as the bronchial circulation supplies blood to the tissue of the larger airways of the lung.
Pulmonary circulation is the movement of blood from the heart, to the lungs, and back to the heart again.
Encyclopedia
Pulmonary circulation is the half portion of the cardiovascular system which carries Oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

-depleted Blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....

 away from the heart, to the Lungs, and returns oxygenated (oxygen rich) blood back to the heart. Encyclopedic description and discovery of the pulmonary circulation is widely attributed to Doctor Ibn al-Nafis (1213-1288). The term pulmonary circulation is readily paired and contrasted with the systemic circulation
Systemic circulation
Systemic circulation is the part of the cardiovascular system which carries oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. This physiologic theory of circulation was first described by William Harvey...

.
A separate system known as the bronchial circulation supplies blood to the tissue of the larger airways of the lung.

Course

Pulmonary circulation is the movement of blood from the heart, to the lungs, and back to the heart again. De-oxygenated blood leaves the heart, goes to the lungs, and then re-enters the heart; oxygen poor blood leaves through the right ventricle through the pulmonary artery, the only artery in the body that carries oxygen-poor blood, to the capillaries where carbon dioxide diffuses out of the blood cell into the alveoli, and oxygen diffuses out of the alveoli into the blood. Blood leaves the capillaries to the pulmonary vein, the only vein in the body that carries oxygen-rich blood in the body, to the heart, where it re-enters at the left atrium.

Right heart

Oxygen-depleted blood from the body
Body
With regard to living things, a body is the physical body of an individual. "Body" often is used in connection with appearance, health issues and death...

 leaves the systemic circulation when it enters the right heart
Right heart
Right heart is a term used to refer collectively to the right atrium and right ventricle of the heart; occasionally, this term is intended to reference the right atrium, right ventricle, and the pulmonary trunk collectively....

, more specifically the right atrium
Right atrium
The right atrium is one of four chambers in the hearts of mammals and archosaurs...

 through the superior (upper) vena cava
Superior vena cava
The superior vena cava is truly superior, a large diameter, yet short, vein that carries deoxygenated blood from the upper half of the body to the heart's right atrium...

 and inferior (lower) vena cava
Inferior vena cava
The inferior vena cava , also known as the posterior vena cava, is the large vein that carries de-oxygenated blood from the lower half of the body into the right atrium of the heart....

. The blood is then pumped through the tricuspid valve
Tricuspid valve
The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, between the right atrium and the right ventricle. The normal tricuspid valve usually has three leaflets and three papillary muscles. They are connected to the papillary muscles by the chordae...

 (or right atrioventricular valve), into the right ventricle
Right ventricle
The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....

. Blood is then pumped through the semilunar valve and into the pulmonary artery
Pulmonary artery
The pulmonary arteries carry deoxygenated blood from the heart to the lungs. They are the only arteries that carry deoxygenated blood....

.

Arteries

From the right ventricle
Right ventricle
The right ventricle is one of four chambers in the human heart. It receives deoxygenated blood from the right atrium via the tricuspid valve, and pumps it into the pulmonary artery via the pulmonary valve and pulmonary trunk....

, blood is pumped through the pulmonary semilunar valve into the left and right pulmonary arteries (one for each lung) and travels through the lungs.

Lungs

The pulmonary arteries carry deoxygenated blood to the lungs, where it releases carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...

 and pick up oxygen during respiration
Respiration (physiology)
'In physiology, respiration is defined as the transport of oxygen from the outside air to the cells within tissues, and the transport of carbon dioxide in the opposite direction...

. Arteries are further divided in to very fine branches called the capillaries. In structure the capillaries are very thin walled. Their function is to carry blood to all cells of the body.

Veins

The oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart
Left heart
Left heart is a term used to refer collectively to the left atrium and left ventricle of the heart; occasionally, this term is intended to reference the left atrium, left ventricle, and the aorta collectively....

, completing the pulmonary cycle. This blood then enters the left atrium
Left atrium
The left atrium is one of the four chambers in the human heart. It receives oxygenated blood from the pulmonary veins, and pumps it into the left ventricle, via the mitral valve.-Foramen ovale:...

, which pumps it through the bicuspid valve, also called the mitral or left atrioventricular valve, into the left ventricle
Left ventricle
The left ventricle is one of four chambers in the human heart. It receives oxygenated blood from the left atrium via the mitral valve, and pumps it into the aorta via the aortic valve.-Shape:...

. The blood is then distributed to the body through the systemic circulation before returning again to the pulmonary circulation.

History

Pulmonary circulation was first discovered and published by Ibn al-Nafis in his Commentary on Anatomy in Avicenna's Canon (1242). It was later published by Michael Servetus
Michael Servetus
Michael Servetus was a Spanish theologian, physician, cartographer, and humanist. He was the first European to correctly describe the function of pulmonary circulation...

 in Christianismi Restitutio (1553).
Since it was a theology work condemned by most of the Christian factions of his time, the discovery remained mostly unknown until the dissections of William Harvey
William Harvey
William Harvey was an English physician who was the first person to describe completely and in detail the systemic circulation and properties of blood being pumped to the body by the heart...

 in 1616.

Embryonic

The pulmonary circulation loop is virtually bypassed in fetal circulation
Fetal circulation
The fetal circulation is the circulatory system of a human fetus, often encompassing the entire fetoplacental circulation that also includes the umbilical cord and the blood vessels within the placenta that carry fetal blood....

. The fetal lungs are collapsed, and blood passes from the right atrium directly into the left atrium through the foramen ovale
Foramen ovale (heart)
In the fetal heart, the foramen ovale , also ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus...

, an open passage between the two atria. When the lungs expand at birth, the pulmonary pressure drops and blood is drawn from the right atrium into the right ventricle and through the pulmonary circuit. Over the course of several months, the foramen ovale
Foramen ovale (heart)
In the fetal heart, the foramen ovale , also ostium secundum of Born or falx septi, allows blood to enter the left atrium from the right atrium. It is one of two fetal cardiac shunts, the other being the ductus arteriosus...

 closes, leaving a shallow depression known as the fossa ovalis
Fossa ovalis (heart)
Found in the right atrium of the heart, the fossa ovalis is an embryonic remnant of the foramen ovale, which normally closes shortly after birth.In a heart specimen of a neonate, the fossa ovalis is translucent, but later in life the membrane thickens...

in the adult heart.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK