HOME

TheInfoList




A ventricle is one of two large chambers toward the bottom of the
heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste ...

heart
that collect and expel
blood Blood is a body fluid Body fluids, bodily fluids, or biofluids are liquid A liquid is a nearly incompressible In fluid mechanics or more generally continuum mechanics, incompressible flow (isochoric process, isochoric flow) refers t ...

blood
received from an atrium towards the peripheral beds within the body and lungs. The atrium (an adjacent/upper heart chamber that is smaller than a ventricle) primes the pump. In a four-chambered heart, such as that in
human Humans (''Homo sapiens'') are the most abundant and widespread species In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes ...

human
s, there are two ventricles that operate in a
double circulatory system
double circulatory system
: the right ventricle pumps blood into the
pulmonary circulation The mammalian heart is divided between the systemic and the pulmonary circulation, generally agreed upon as left and right sided circuits. The right circuit is the portion of the circulatory system The circulatory system, also called the ca ...
to the
lung The lungs are the primary organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many organs that co-exist in organ systems. A given organ's tissues can be broadly categorized as parenchyma ...

lung
s, and the left ventricle pumps blood into the
systemic circulation The circulatory system, also called the cardiovascular system or the vascular system, is an organ system An organ system is a group of organs An organ is a group of tissues with similar functions. Plant life and animal life rely on many o ...
through the
aorta The aorta ( ) is the main and largest in the , originating from the of the and extending down to the , where it into two smaller arteries (the ). The aorta distributes blood to all parts of the body through the . Structure Sections In a ...

aorta
. The term "interventricular" means between the ventricles (for example the
interventricular septum The interventricular septum (IVS, or ventricular septum, or during development septum inferius) is the stout wall separating the ventricles, the lower chambers of the heart The heart is a muscle, muscular Organ (anatomy), organ in most ani ...
), while "intraventricular" means within one ventricle (for example an intraventricular block).


Structure

Ventricles have thicker walls than atria and generate higher
blood pressure Blood pressure (BP) is the pressure Pressure (symbol: ''p'' or ''P'') is the force In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motio ...

blood pressure
s. The physiological load on the ventricles requiring pumping of blood throughout the body and lungs is much greater than the pressure generated by the atria to fill the ventricles. Further, the left ventricle has thicker walls than the right because it needs to pump blood to most of the body while the right ventricle fills only the lungs. On the inner walls of the ventricles are irregular muscular columns called
trabeculae carneae The trabeculae carneae (columnae carneae, or meaty ridges), are rounded or irregular muscular columns which project from the inner surface of the right and left ventricle of the heart The heart is a cardiac muscle, muscular Organ (biology), ...
which cover all of the inner ventricular surfaces except that of the
conus arteriosus The infundibulum (also known as conus arteriosus) is a conical pouch formed from the upper and left angle of the right ventricle in the chordate heart, from which the pulmonary trunk arises. It develops from the bulbus cordis. Typically, the infundi ...
, in the right ventricle. There are three types of these muscles. The third type, the
papillary muscle The papillary muscles are muscles located in the ventricles of the heart. They attach to the cusps of the atrioventricular valves (also known as the mitral and tricuspid valves) via the chordae tendineae The chordae tendineae (tendinous cords ...
s, give origin at their apices to the
chordae tendinae The chordae tendineae (tendinous cords), colloquially known as the heart strings, are tendon A tendon or sinew is a tough band of fibrous connective tissue that connects muscle to bone A bone is a Stiffness, rigid tissue (anatomy), tissu ...
which attach to the cusps of the
tricuspid valve The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle A ventricle is one of two large chambers toward the bottom of the heart The heart i ...
and to the
mitral valve The mitral valve (), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valve A heart valve is a that allows in one direction through the chambers of the . Four valves are usually present in a mammalian h ...

mitral valve
. The mass of the left ventricle, as estimated by
magnetic resonance imaging Magnetic resonance imaging (MRI) is a medical imaging Medical imaging is the technique and process of imaging Imaging is the representation or reproduction of an object's form; especially a visual representation (i.e., the formation of a ...
, averages 143 g ± 38.4 g, with a range of 87––224 g. The right ventricle is equal in size to the left ventricle and contains roughly 85 millilitres (3 imp fl oz; 3 US fl oz) in the adult. Its upper front surface is circled and convex, and forms much of the
sternocostal The sternocostal joints also known as sternochondral joints (or costosternal articulations), are synovial joint, synovial plane joints of the costal cartilages of the rib, true ribs with the sternum. The only exception is the first rib, which has a ...
surface of the heart. Its under surface is flattened, forming part of the diaphragmatic surface of the heart that rests upon the diaphragm. Its posterior wall is formed by the
ventricular septum The interventricular septum (IVS, or ventricular septum, or during development septum inferius) is the stout wall separating the ventricles, the lower chambers of the heart The heart is a muscle, muscular Organ (anatomy), organ in most ani ...
, which bulges into the right ventricle, so that a transverse section of the cavity presents a semilunar outline. Its upper and left angle forms a conical pouch, the
conus arteriosus The infundibulum (also known as conus arteriosus) is a conical pouch formed from the upper and left angle of the right ventricle in the chordate heart, from which the pulmonary trunk arises. It develops from the bulbus cordis. Typically, the infundi ...
, from which the pulmonary artery arises. A tendinous band, called the tendon of the conus arteriosus, extends upward from the right atrioventricular fibrous ring and connects the posterior surface of the conus arteriosus to the aorta.


Shape

The left ventricle is longer and more conical in shape than the right, and on transverse section its concavity presents an oval or nearly circular outline. It forms a small part of the sternocostal surface and a considerable part of the diaphragmatic surface of the heart; it also forms the apex of the heart. The left ventricle is thicker and more muscular than the right ventricle because it pumps blood at a higher pressure. The right ventricle is triangular in shape and extends from the tricuspid valve in the right atrium to near the
apex of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as ...
. Its wall is thickest at the apex and thins towards its base at the atrium. When viewed via cross section however, the right ventricle seems to be crescent shaped. The right ventricle is made of two components: the sinus and the conus. The Sinus is the inflow which flows away from the tricuspid valve. Three bands made from muscle, separate the right ventricle: the parietal, the septal, and the moderator band. The moderator band connects from the base of the anterior papillary muscle to the ventricular septum.


Development

By early maturity, the walls of the left ventricle have thickened from three to six times greater than that of the right ventricle. This reflects the typical five times greater pressure workload this chamber performs while accepting blood returning from the pulmonary veins at ~80mmHg pressure (equivalent to around 11 kPa) and pushing it forward to the typical ~120mmHg pressure (around 16.3 kPa) in the aorta during each heartbeat. (The pressures stated are resting values and stated as relative to surrounding atmospheric which is the typical "0" reference pressure used in medicine.)


Function

During
systole The systole ( ) is the part of the during which some chambers of the contract after refilling with blood. The term originates, via , from (''sustolē''), from (''sustéllein'' 'to contract'; from ''sun'' 'together' + ''stéllein'' 'to se ...
, the ventricles contract, pumping blood through the body. During
diastole Image:Heart diastole.png, upright=1.5, Heart performance during ventricular diastole: early diastole is a suction mechanism that draws blood 'down' from the left atrium (pink) and right atrium (blue) into each of the two ventricles. Then, in late ve ...
, the ventricles relax and fill with blood again. The left ventricle receives oxygenated blood from the
left atrium The atrium (Latin ātrium, “entry hall”) is the upper chamber through which blood enters the Ventricle (heart), ventricles of the heart. There are two atria in the human heart – the left atrium receives blood from the pulmonary (lung) circula ...
via the
mitral valve The mitral valve (), also known as the bicuspid valve or left atrioventricular valve, is one of the four heart valve A heart valve is a that allows in one direction through the chambers of the . Four valves are usually present in a mammalian h ...

mitral valve
and pumps it through the
aorta The aorta ( ) is the main and largest in the , originating from the of the and extending down to the , where it into two smaller arteries (the ). The aorta distributes blood to all parts of the body through the . Structure Sections In a ...

aorta
via the
aortic valve The aortic valve is a Heart valve, valve in the Heart, human heart between the Ventricle (heart), left ventricle and the aorta. It is one of the two Heart valve#Semilunar valves, semilunar valves of the heart, the other being the pulmonary valve. ...

aortic valve
, into the systemic circulation. The left ventricular muscle must relax and contract quickly and be able to increase or lower its pumping capacity under the control of the nervous system. In the diastolic phase, it has to relax very quickly after each contraction so as to quickly fill with the oxygenated blood flowing from the
pulmonary vein The pulmonary veins are the vein Veins are blood vessels in humans, and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary vein, pulmonary a ...
s. Likewise in the systolic phase, the left ventricle must contract rapidly and forcibly to pump this blood into the aorta, overcoming the much higher aortic pressure. The extra pressure exerted is also needed to stretch the aorta and other arteries to accommodate the increase in blood volume. The right ventricle receives deoxygenated blood from the right atrium via the
tricuspid valve The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle A ventricle is one of two large chambers toward the bottom of the heart The heart i ...
and pumps it into the pulmonary artery via the
pulmonary valve The pulmonary valve (sometimes referred to as the pulmonic valve) is a valve of the heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood vessels of the circulatory system ...
, into the pulmonary circulation.


Pumping volume

The typical healthy adult heart pumping volume is ~5 liters/min, resting. Maximum capacity pumping volume extends from ~25 liters/min for non-athletes to as high as ~45 liters/min for Olympic level athletes.


Volumes

In
cardiology Cardiology (from Ancient Greek, Greek ''kardiā'', "heart" and ''wikt:-logia, -logia'', "study") is a branch of medicine that deals with the disorders of the heart as well as some parts of the circulatory system. The field includes medical dia ...
, the performance of the ventricles are measured with several volumetric parameters, including
end-diastolic volume In cardiovascular physiologyCardiovascular physiology is the study of the cardiovascular system, specifically addressing the physiology of the heart ("cardio") and blood vessels ("vascular"). These subjects are sometimes addressed separately, unde ...
(EDV), end-systolic volume (ESV),
stroke volume In cardiovascular physiologyCardiovascular physiology is the study of the cardiovascular system, specifically addressing the physiology of the heart ("cardio") and blood vessels ("vascular"). These subjects are sometimes addressed separately, unde ...
(SV) and
ejection fraction An ejection fraction (EF) is the volumetric fraction A fraction (from Latin ', "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certa ...
(Ef).


Pressures

Ventricular pressure is a measure of
blood pressure Blood pressure (BP) is the pressure Pressure (symbol: ''p'' or ''P'') is the force In physics Physics is the natural science that studies matter, its Elementary particle, fundamental constituents, its Motion (physics), motio ...

blood pressure
within the ventricles of the
heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste ...

heart
.


Left

During most of the
cardiac cycle The cardiac cycle is the performance of the human heart The heart is a cardiac muscle, muscular Organ (biology), organ in most animals, which pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxy ...
, ventricular pressure is less than the pressure in the
aorta The aorta ( ) is the main and largest in the , originating from the of the and extending down to the , where it into two smaller arteries (the ). The aorta distributes blood to all parts of the body through the . Structure Sections In a ...

aorta
, but during
systole The systole ( ) is the part of the during which some chambers of the contract after refilling with blood. The term originates, via , from (''sustolē''), from (''sustéllein'' 'to contract'; from ''sun'' 'together' + ''stéllein'' 'to se ...
, the ventricular pressure rapidly increases, and the two pressures become equal to each other (represented by the junction of the blue and red lines on the diagram on this page), the
aortic valve The aortic valve is a Heart valve, valve in the Heart, human heart between the Ventricle (heart), left ventricle and the aorta. It is one of the two Heart valve#Semilunar valves, semilunar valves of the heart, the other being the pulmonary valve. ...

aortic valve
opens, and blood is pumped to the body. Elevated left ventricular end-diastolic pressure has been described as a risk factor in cardiac surgery. Noninvasive approximations have been described. An elevated pressure difference between the aortic pressure and the left ventricular pressure may be indicative of
aortic stenosis Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pumps blood through the blood vessels of the circulatory system. T ...

aortic stenosis
.


Right

Right ventricular pressure demonstrates a different pressure-volume loop than left ventricular pressure.


Dimensions

The heart and its performance are also commonly measured in terms of ''dimensions'', which in this case means
one-dimensional In physics Physics (from grc, φυσική (ἐπιστήμη), physikḗ (epistḗmē), knowledge of nature, from ''phýsis'' 'nature'), , is the natural science that studies matter, its Motion (physics), motion and behavior through S ...
distances, usually measured in millimeters. This is not as informative as volumes but may be much easier to estimate with (e.g.,
M-Mode echocardiography Medical ultrasound (also known as diagnostic sonography or ultrasonography) is a diagnostic imaging technique, or therapeutic application of ultrasound Ultrasound is sound waves with frequency, frequencies higher than the upper audible ...
or with
sonomicrometry Sonomicrometry is a technique of measuring the distance Distance is a numerical measurement of how far apart objects or points are. In physics or everyday usage, distance may refer to a physical length or an estimation based on other criteria ...
, which is mostly used for animal model research). Optimally, it is specified with which plane the distance is measured in, e.g. the dimension of the longitudinal plane. Fractional shortening (FS) is the
fraction A fraction (from Latin ', "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths ...
of any diastolic dimension that is lost in systole. When referring to endocardial luminal distances, it is EDD minus ESD divided by EDD (times 100 when measured in percentage). Normal values may differ somewhat dependent on which
anatomical plane An anatomical plane is a hypothetical plane Plane or planes may refer to: * Airplane An airplane or aeroplane (informally plane) is a fixed-wing aircraft A fixed-wing aircraft is a heavier-than-air flying machine Early flyi ...
is used to measure the distances. Normal range is 25–45%, Mild is 20–25%, Moderate is 15–20%, and Severe is <15%. Cardiology Diagnostic Tests Midwall fractional shortening may also be used to measure diastolic/systolic changes for inter-ventricular septal dimensions and posterior wall dimensions. However, both endocardial and midwall fractional shortening are dependent on myocardial wall thickness, and thereby dependent on long-axis function. By comparison, a measure of short-axis function termed epicardial volume change (EVC) is independent of myocardial wall thickness and represents isolated short-axis function.


Clinical significance

Cardiac dysrhythmia Arrhythmia, also known as cardiac arrhythmia or heart arrhythmia, is a group of conditions in which the heartbeat Heartbeat or heartbeats may refer to: Physiology *Cardiac cycle, of the heart *Contraction of the cardiac muscle, muscles of the ...
is an
irregular heartbeat Arrhythmia, also known as cardiac arrhythmia or heart arrhythmia, is a group of conditions in which the heartbeat is irregular, too fast, or too slow. The heart rateHeart rate is the speed of the heartbeat measured by the number of contraction ...
that can occur in the ventricles or atria. Normally the heartbeat is initiated in the
SA node The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is a group of cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Closed spaces * Monastic cell, a small ...
of the atrium but initiation can also occur in the Purkinje fibres of the ventricles, giving rise to premature ventricular contractions, also called ventricular extra beats. When these beats become grouped the condition is known as
ventricular tachycardia Ventricular tachycardia (V-tach or VT) is a type of regular, fast heart rate that arises from improper electrical activity in the ventricles of the heart The heart is a muscle, muscular Organ (anatomy), organ in most animals, which pump ...
. Another form of arrhythmia is that of the
ventricular escape beat: starting from the sinoatrial node, an electrical impulse spreads across the Atrium (heart), atria, then passes through the atrioventricular node (AV node) and conducts on via the bundle branches towards the ventricle (heart), ventricles. In cardio ...
. This can happen as a compensatory mechanism when there is a problem in the conduction system from the SA node. The most severe form of arrhythmia is
ventricular fibrillation Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the Ventricle (heart), ventricles of the heart Fibrillation, quiver. It is due to disorganized electrical conduction system of the heart, electrical activity. Ventricular ...

ventricular fibrillation
which is the most common cause of
cardiac arrest Cardiac arrest is a sudden loss of blood flow Hemodynamics American and British English spelling differences#ae and oe, or haemodynamics are the Fluid dynamics, dynamics of blood flow. The circulatory system is controlled by homeostasis, homeost ...
and subsequent sudden death. *
Ventricular septal defect A ventricular septal defect (VSD) is a defect in the ventricular septum The interventricular septum (IVS, or ventricular septum, or during development septum inferius) is the stout wall separating the ventricles, the lower chambers of the hear ...

Ventricular septal defect
*
Atrioventricular septal defect Atrioventricular septal defect (AVSD) or atrioventricular canal defect (AVCD), also known as "common atrioventricular canal" (CAVC) or " endocardial cushion defect" (ECD), is characterized by a deficiency of the atrioventricular septum of the hear ...


See also

*
Wiggers diagram A Wiggers diagram, named after its developer, Carl Wiggers, is a standard diagram that is used in teaching cardiovascular physiology, cardiac physiology. In the Wiggers diagram, the X-axis is used to plot time, while the Y-axis contains all of the ...

Wiggers diagram


References


External links


Photo of dissection at uc.edu

Left Ventricle - Cell Centered Database
* {{DEFAULTSORT:Ventricle (Heart) Cardiac anatomy Cardiovascular physiology