BIO100 Chptr 15 Cardiovascular System Flashcards
1
Q
angio-
A
angio-, vessel: angiotensin—substance that constricts blood vessels.
2
Q
ather-
A
ather-, porridge: atherosclerosis—deposits of plaque in arteries.
3
Q
brady-
A
brady-, slow: bradycardia—abnormally slow heartbeat.
4
Q
diastol-
A
diastol-, dilation: diastolic pressure—blood pressure when the ventricle of the heart is relaxed.
5
Q
edem-
A
edem-, swelling: edema—accumulation of fluids in the tissues that causes them to swell.
6
Q
-gram
A
-gram, something written: electrocardiogram —recording of the electrical changes in the myocardium during a cardiac cycle.
7
Q
lun-
A
lun-, moon: semilunar valve—valve with crescent-shaped flaps.
8
Q
myo-
A
myo-, muscle: myocardium—muscle tissue within the wall of the heart.
9
Q
papill-
A
papill-, nipple: papillary muscle—small mound of muscle projecting into a ventricle of the heart.
10
Q
phleb-
A
phleb-, vein: phlebitis—inflammation of a vein.
11
Q
scler-
A
scler-, hard: arteriosclerosis—loss of elasticity and hardening of a blood vessel wall.
12
Q
syn-
A
syn-, together: syncytium—mass of merging cells that act together.
13
Q
systol-
A
systol-, contraction: systolic pressure—blood pressure resulting from a single ventricular contraction.
14
Q
tachy-
A
tachy-, rapid: tachycardia—abnormally fast heartbeat.
15
Q
The term “cardiovascular” refers to
A
both the heart and the blood vessels.
.The pumping action of the heart moves blood through the body’s blood vessels. The blood vessels form two circuits. The pulmonary (pul′mo-ner″e) circuit sends oxygen-poor blood to the lungs to pick up oxygen and unload carbon dioxide. The systemic (sistem′ik) circuit sends oxygen-rich blood and nutrients to all body cells and removes wastes.
16
Q
pulmonary (pul′mo-ner″e) circuit
A
sends oxygen-poor blood to the lungs to pick up oxygen and unload carbon dioxide.
17
Q
systemic (sistem′ik) circuit
A
systemic (sistem′ik) circuit sends oxygen-rich blood and nutrients to all body cells and removes wastes.
18
Q
The heart is
A
The heart is a hollow, cone-shaped, muscular pump. It is in the mediastinum of the thoracic cavity, superior to the diaphragm.
19
Q
Size and Location of the Heart
A
Heart size varies with body size. An average adult’s heart is generally about 14 centimeters long and 9 centimeters wide.
The heart is bordered laterally by the lungs, posteriorly by the vertebral column, and anteriorly by the sternum and reference plates 10, 16, 21, and 22. The base of the heart, which attaches to several large blood vessels, lies beneath the second rib. The heart’s inferior end extends downward and to the left, terminating as a bluntly pointed apex at the level of the fifth intercostal space. Because of the heart’s location, it is possible to detect the apical heartbeat by feeling or listening to the chest wall between the fifth and sixth ribs, about 7.5 centimeters to the left of the midline.
20
Q
Coverings of the Heart
A
pericardium (per″i-kar′de-um), or pericardial sac, is a covering that encloses the heart and the proximal ends of the large blood vessels to which it attaches. The pericardium consists of an outer fibrous bag, the fibrous pericardium, that surrounds a more delicate, double-layered serous membrane. The innermost layer of this serous membrane, the visceral pericardium (epicardium), covers the heart. At the base of the heart, the visceral pericardium turns back upon itself to become the parietal pericardium, which covers the inner surface of the fibrous pericardium
21
Q
Wall of the Heart
A
The wall of the heart is composed of three distinct layers: an outer epicardium, a middle myocardium, and an inner endocardium
22
Q
epicardium (ep″ĭ-kar′de-um)
A
which corresponds to the visceral pericardium, protects the heart by reducing friction. It is a serous membrane that consists of connective tissue covered by epithelium, and it includes capillaries and nerve fibers. The deeper portion of the epicardium typically contains adipose tissue, particularly along the paths of coronary arteries and cardiac veins that provide blood flow through the myocardium.
23
Q
myocardium (mi″okar′de-um),
A
middle layer of the heart wall, or myocardium (mi″okar′de-um), is thick and consists largely of the cardiac muscle tissue that pumps blood out of the heart chambers. The muscle fibers lie in planes that are separated by connective tissues richly supplied with blood capillaries, lymph capillaries, and nerve fibers.
24
Q
endocardium (en″dokar′de-um
A
The inner layer of the heart wall, or endocardium (en″dokar′de-um), consists of epithelium and underlying connective tissue that contains many elastic and collagen fibers. The endocardium also contains blood vessels and covers some specialized cardiac cells called Purkinje fibers, The Heart, Cardiac Conduction System.
The endocardium lines all of the heart chambers and covers the structures, such as the heart valves, that project into them. This inner lining is also continuous with the inner linings (endothelium) of the blood vessels attached to the heart and throughout the cardiovascular system.
25
Heart Chambers and Valves
Internally the heart is divided into four hollow chambers, two on the left and two on the right.
* The upper chambers, called atria
* The lower chambers, the ventricles
26
auricles
Small, earlike projections called auricles extend anteriorly from the atria, slightly increasing atrial volume.
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ventricles
The lower chambers, the ventricles, force the blood out of the heart into arteries.
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atria
The upper chambers, called atria (sing., atrium), have thin walls and receive blood returning to the heart.
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interatrial septum
separates the right from the left atrium
30
interventricular
septum separates the two ventricles
31
atrioventricular orifice
The atrium on each side communicates with its corresponding ventricle through an opening called the atrioventricular orifice (a″tre-o-ven-trik′u-lar ori-fis), which is guarded by an atrioventricular valve (AV valve).
32
atrioventricular (coronary) sulcus
of the heart demarcates the borders of the underlying atria from the ventricles. It is a continuous sulcus but it has been described as right and left parts in the following section for the purposes of description.
33
interventricular (anterior and posterior) sulci
mark the septum that separates the right and left ventricles
34
vena cavae, two large veins:
| the superior vena cava and the inferior vena cava.
vena cavae, two large veins: the superior vena cava and the inferior vena cava. These veins return blood, which is low in oxygen, from tissues. A smaller vein, the coronary sinus, also drains venous blood into the right atrium from the myocardium of the heart.
35
large tricuspid valve (right atrioventricular valve)
guards the atrioventricular orifice between the right atrium and the right ventricle. It is composed of three leaflets, or cusps, as its name implies. This valve permits the blood to move from the right atrium into the right ventricle and prevents it from moving in the opposite direction.
36
chordae tendineae
attach to the cusps of the tricuspid valve on the ventricular side. These strings originate from small mounds of cardiac muscle tissue, the papillary muscles (pap′ĭ-ler″e mus′elz), that project inward from the walls of the ventricle (see fig. 15.7). The papillary muscles contract when the right ventricle contracts. As the tricuspid valve closes, these muscles pull on the chordae tendineae and prevent the cusps from swinging back (prolapsing) into the right atrium.
37
pulmonary trunk
A vessel that arises from the right ventricle of the heart, extends upward, and divides into the right and left pulmonary arteries that convey unaerated blood to the lungs.
38
pulmonary valve (pulmonary semilunar valve), which consists of three cusps
the pulmonic valve prevents regurgitation of deoxygenated blood from the pulmonary artery back to the right ventricle. It is a semilunar valve with 3 cusps, and it is located anterior, superior, and slightly to the left of the aortic valve. An image depicting the pulmonary valve can be seen below.
39
four pulmonary veins—two from the right lung and two from the left lung.
The left atrium receives the blood from the lungs through four pulmonary veins—two from the right lung and two from the left lung. The blood passes from the left atrium into the left ventricle through the atrioventricular orifice, which a valve guards. This valve consists of two leaflets and is named the mitral valve (shaped like a mitre, a type of headpiece), also called the bicuspid valve or left atrioventricular valve. It prevents the blood from flowing back into the left atrium from the left ventricle when the ventricle contracts.
40
mitral valve (shaped like a mitre, a type of headpiece), also called the bicuspid valve or left atrioventricular valve.
mitral valve (shaped like a mitre, a type of headpiece), also called the bicuspid valve or left atrioventricular valve. It prevents the blood from flowing back into the left atrium from the left ventricle when the ventricle contracts. As with the tricuspid valve, the papillary muscles and the chordae tendineae prevent the cusps of the mitral valve from swinging back (prolapsing) into the left atrium.
41
Mitral valve prolapse (MVP)
Improper closure of the valve between the heart's upper and lower left chambers.
Mitral valve prolapse can develop at any age. It can run in families and may be linked to other conditions, such as infection and connective tissue disease.
Symptoms may include an irregular heartbeat, palpitations, and shortness of breath.
Most people don't require treatment, but some cases may need medication or surgery.
42
aorta
the main artery of the body, supplying oxygenated blood to the circulatory system. In humans it passes over the heart from the left ventricle and runs down in front of the backbone.
43
aortic valve (aortic semilunar valve)
At the base of the aorta is an aortic valve (aortic semilunar valve) which consists of three cusps. It opens and allows blood to leave the left ventricle as it contracts. When the ventricular muscles relax, this valve closes and prevents blood from backing up into the left ventricle.
44
skeleton of the heart
The cardiac skeleton consists of four bands of dense connective tissue, as collagen, that encircle the bases of the pulmonary trunk, aorta, and heart valves. While not a "true" skeleton, it does provide structure and support for the heart, as well as isolate the atria from the ventricles.
45
Blood Flow Through the Heart
Blood low in oxygen (oxygen-poor blood) and high in carbon dioxide enters the right atrium through the venae cavae and the coronary sinus. As the right atrial wall contracts, the blood passes through the right atrioventricular orifice and enters the chamber of the right ventricle
46
Blood Supply to the Heart
The first two branches of the aorta, called the right and left coronary arteries, supply blood to the tissues of the heart. Their openings lie just superior to the aortic valve
47
Blood Supply to the Heart - posterior interventricular artery
which travels along the posterior interventricular sulcus and supplies the posterior walls of both ventricles, and a right marginal branch, which passes along the lower border of the heart. The right marginal branch supplies the walls of the right atrium and the right ventricle
48
Blood Supply to the Heart - One branch of the left coronary artery, the circumflex branch
One branch of the left coronary artery, the circumflex branch, following the atrioventricular sulcus between the left atrium and the left ventricle encircles the heart and travels posteriorly. Its branches supply blood to the walls of the left atrium and the left ventricle. Another branch of the left coronary artery, the anterior interventricular artery (or left anterior descending artery), lies in the anterior interventricular sulcus. Its branches supply the walls of both ventricles
49
collateral circulation
is the alternate circulation around a blocked artery or vein via another path, such as nearby minor vessels.
50
anastomoses
An anastomosis is a connection or opening between two things that are normally diverging or branching, such as between blood vessels, leaf veins, or streams.
51
thrombus or embolus -
A thrombus or embolus that partially blocks or narrows a coronary artery branch causes a decrease in blood flow called ischemia. This deprives myocardial cells of oxygen, producing a painful condition called angina pectoris. The pain usually happens during physical activity, when oxygen demand exceeds supply. Pain lessens with rest. Emotional disturbance may also trigger angina pectoris.
52
angina pectoris
is the medical term for chest pain or discomfort due to coronary heart disease.
53
ischemia
an inadequate blood supply to an organ or part of the body, especially the heart muscles.
54
Profuse perspiration (diaphoresis)
refers to excessive sweating for no apparent reason. Often, an underlying medical condition or a natural life event, such as menopause, cause this type of sweating. Sweat is the body's natural way to control its temperature.
55
difficulty breathing (dyspnea)
Shortness of breath — known medically as dyspnea — is often described as an intense tightening in the chest, air hunger, difficulty breathing, breathlessness or a feeling of suffocation.
56
coronary thrombosis
is the formation of a blood clot inside a blood vessel of the heart. This blood clot restricts blood flow within the heart. It is associated with narrowing of blood vessels subsequent to clotting. The condition is considered as a type of ischaemic heart disease.
57
myocardial infarction (MI)
A blockage of blood flow to the heart muscle.
| Called a heart attack
58
cardiac veins
Branches of the cardiac veins drain blood that has passed through the capillaries of the myocardium. Their paths roughly parallel those of the coronary arteries, these veins join the coronary sinus.
59
coronary sinus
the coronary sinus, which is an enlarged vein on the posterior surface of the heart in the atrioventricular sulcus. The coronary sinus empties into the right atrium. - the path of blood that supplies the tissues of the heart.
60
Cardiac Cycle
is the performance of the human heart from the ending of one heartbeat to the beginning of the next. It consists of two periods: one during which the heart muscle relaxes and refills with blood, called diastole, following a period of robust contraction and pumping of blood, dubbed systole.
61
Heart Sounds
A heartbeat heard through a stethoscope sounds like “lubb-dupp.” These sounds are due to vibrations in the heart tissues produced as the blood flow is suddenly slowed with the contraction and relaxation of the heart chambers and with the closing of the valves.
- The first part of a heart sound (lubb) occurs during ventricular systole, when the AV valves close. The second part (dupp) occurs during ventricular diastole, when the pulmonary and aortic valves close.
62
Using a stethoscope, it is possible to hear sounds associated with the aortic and pulmonary valves
by listening from the second intercostal space on either side of the sternum. The aortic sound comes from the right, and the pulmonic sound from the left. The sound associated with the mitral valve can be heard from the fifth intercostal space at the nipple line on the left. The sound of the tricuspid valve can be heard at the fifth intercostal space just to the left of the sternum
63
endocarditis
is an infection of the endocardium, which is the inner lining of your heart chambers and heart valves. Endocarditis generally occurs when bacteria, fungi or other germs from another part of your body, such as your mouth, spread through your bloodstream and attach to damaged areas in your heart.
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murmur
A heart murmur is an unusual sound heard between heartbeats. Murmurs sometimes sound like a whooshing or swishing noise. Murmurs may be harmless, also called innocent, or abnormal.
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Cardiac Muscle Cells
Recall that cardiac muscle cells function like skeletal muscle cells, but the cardiac muscle cells connect in branching networks. The intercalated discs, which include gap junctions, join cardiac muscle cells, allowing action potentials to spread throughout a network of cells . As a result, cardiac muscle cells contract as a unit. They also have 1-2 nuclei
66
functional syncytium (funk′shun-al sin-sish′e-um).
A mass of merging cells that act as a unit - Two such structures are in the heart—in the atrial walls and in the ventricular walls. Portions of the heart’s fibrous skeleton separate these masses of cardiac muscle, except for a small area in the right atrial floor. In this region, specialized conduction fibers connect the atrial syncytium and the ventricular syncytium.
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autorhythmic
able to initiate contraction itself without external nervous stimulation
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cardiac conduction system
is a group of specialized cardiac muscle cells in the walls of the heart that send signals to the heart muscle causing it to contract. The main components of the cardiac conduction system are the SA node, AV node, bundle of His, bundle branches, and Purkinje fibers.
69
Purkinje fibers
are networks of fibers that receive conductive signals originating at the atrioventricular node (AVN), and simultaneously activate the left and right ventricles by directly stimulating the ventricular myocardium.
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SA node (sinoatrial node or sinuatrial node)
SA node (sinoatrial node or sinuatrial node), which is a small, elongated mass of specialized cardiac muscle tissue just beneath the epicardium. It is in the right atrium near the opening of the superior vena cava, and its cells are continuous with those of the atrial syncytium.
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an SA node reaches threshold and triggers an action potential on its own.
Action Potential at the SA Node. The prepotential is due to a slow influx of sodium ions until the threshold is reached followed by a rapid depolarization and repolarization. The prepotential accounts for the membrane reaching threshold and initiates the spontaneous depolarization and contraction of the cell.
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The SA node is also called the pacemaker because it initiates the heart’s rhythmic contractions
The SA node is the heart's natural pacemaker. The SA node consists of a cluster of cells that are situated in the upper part of the wall of the right atrium (the right upper chamber of the heart). The electrical impulses are generated there. The SA node is also called the sinus node.
73
internodal atrial muscle
It is a broad band of cardiac muscle that passes from the right atrium, between the superior vena cava and the ascending aorta. Bachmann's bundle is, during normal sinus rhythm, the preferential path for electrical activation of the left atrium.
74
junctional fibers
(conducting fiber of heart) Located in Atria, they distribute the AP throughout the atria, then carry AP to the AV NODE. Bundle of H.I.S (AV Bundle) (conducting fibers of heart) Located in interventricular septum, they connect to the AV Node.
*P Wave. The P wave represents the depolarization of the left and right atrium and also corresponds to atrial contraction.
75
AV node (atrioventricular node)
which controls the heart rate, is one of the major elements in the cardiac conduction system. The AV node serves as an electrical relay station, slowing the electrical current sent by the sinoatrial (SA) node before the signal is permitted to pass down through to the ventricles.
76
AV bundle (atrioventricular bundle or bundle of His)
is a continuation of the specialised tissue of the AV node, and serves to transmit the electrical impulse from the AV node to the Purkinje fibres of the ventricles. ... Left bundle branch - conducts the impulse to the Purkinje fibres of the left ventricle.
77
Electrocardiogram (ECG, EKG)
is a recording of the electrical changes in the myocardium during a cardiac cycle. (This pattern occurs as action potentials stimulate cardiac muscle cells to contract, but it is not the same as individual action potentials.) Because body fluids can conduct electrical currents, such changes can be detected on the surface of the body.
78
accelerator nerves
Sympathetic fibers reach the heart by means of the accelerator nerves, whose branches join the SA and AV nodes as well as other areas of the atrial and ventricular myocardium. The endings of these fibers secrete norepinephrine in response to series of action potentials. Norepinephrine increases the rate and force of myocardial contractions.
79
baroreceptor reflexes
The baroreflex or baroreceptor reflex is one of the body's homeostatic mechanisms that helps to maintain blood pressure at nearly constant levels.
80
cardioinhibitor reflex center
Cardioinhibitory syncope (CS) is a neurally mediated response causing bradycardia or asystole. This study reports on changes in blood pressure, heart rate variability (HRV), and ECG patterns before and after syncope with asystole.
81
cardioaccelerator reflex center.
stimulates cardiac function by regulating heart rate and stroke volume via sympathetic stimulation from the cardiac accelerator nerve. - Baroreceptors that detect stretch can also signal to the cardiovascular center to alter heart rate.
82
The most important ions that influence heart action are
potassium (K+) and calcium (Ca+2)
83
An excess of potassium ions in the blood (hyperkalemia)
An excess of potassium ions in the blood (hyperkalemia) decreases the rate and force of myocardial contractions. If the potassium ion concentration in the blood drops below normal (hypokalemia), the heart may develop a potentially life- threatening abnormal rhythm.
84
An excess of calcium ions in the blood (hypercalcemia)
An excess of calcium ions in the blood (hypercalcemia) increases heart action, which can result in dangerously extended heart contractions. Conversely, a low blood calcium concentration (hypocalcemia) depresses heart action. - arrhythmias, abnormal heart rhythms.
85
The blood vessels are organs of the cardiovascular system
They form a closed circuit of tubes that carries blood from the heart to the body cells and back again. These vessels include arteries, arterioles, capillaries, venules, and veins. The arteries and arterioles conduct blood away from the ventricles of the heart and lead to the capillaries, where substances are exchanged between blood and the body cells. Venules and veins return blood from the capillaries to the atria.
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Arteries
Arteries are strong, elastic vessels adapted for transporting blood away from the heart under relatively high pressure. These vessels subdivide into progressively thinner tubes and eventually give rise to the finer, branched arterioles.
87
arterioles
a small branch of an artery leading into capillaries.
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tunics - The wall of an artery consists of three distinct layers.
The wall of an artery consists of three distinct layers.
- The innermost tunic, tunica interna (intima), is composed of a layer of simple squamous epithelium, called endothelium, that rests on a connective tissue membrane rich in elastic and collagen fibers.
- The middle layer, tunica media, makes up the bulk of the arterial wall. It includes smooth muscle cells, which encircle the tube, and a thick layer of elastic connective tissue.
- The outer layer, tunica externa (adventitia), is relatively thin and chiefly consists of connective tissue with irregular elastic and collagen fibers.
89
platelets
a small colorless disk-shaped cell fragment without a nucleus, found in large numbers in blood and involved in clotting.
90
Arrhythmias
An arrhythmia is a problem with the rate or rhythm of your heartbeat. It means that your heart beats too quickly, too slowly, or with an irregular pattern. When the heart beats faster than normal, it is called tachycardia.
91
Altering **Angiogenesis**
Angiogenesis is the formation of new blood vessels, usually from the extension of preexisting vessels. Under the influence of vascular endothelial growth factor (VEGF), endothelial cells divide and assemble into the tubules that form capillaries as well as the innermost linings of larger blood vessels.
92
Vasomotor fibers
of, relating to, affecting, or being those nerves or the centers (as in the medulla and spinal cord) from which they arise that supply the muscle fibers of the walls of blood vessels, include sympathetic vasoconstrictors and parasympathetic vasodilators, and by their effect on vascular diameter regulate the amount of
93
vasoconstriction
is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles. The process is the opposite of vasodilation, the widening of blood vessels.
94
vasodilation
A widening of blood vessels, usually near the surface of skin, leading to increased blood flow with flushing or warmth.
95
metarterioles
is a short microvessel in the microcirculation that links arterioles and capillaries. Instead of a continuous tunica media, they have individual smooth muscle cells placed a short distance apart, each forming a precapillary sphincter that encircles the entrance to that capillary bed.
96
Capillaries
the smallest-diameter blood vessels, connect the smallest arterioles and the smallest venules. Capillaries are extensions of the inner linings of arterioles in that their walls are endothelium—a single layer of squamous epithelial cells (fig. 15.26a). These thin walls form the semipermeable layer through which substances in the blood are exchanged for substances in the tissue fluid surrounding body cells.
97
Capillary Permeability
Vascular permeability, often in the form of capillary permeability or microvascular permeability, characterizes the capacity of a blood vessel wall to allow for the flow of small molecules (drugs, nutrients, water, ions) or even whole cells (lymphocytes on their way to the site of inflammation) in and out of the vessel
98
Regulation of Capillary Blood Flow
beds is controlled by precapillary sphincters to increase and decrease flow depending on the body's needs and is directed by nerve and hormone signals. Lymph vessels take fluid that has leaked out of the blood to the lymph nodes where it is cleaned before returning to the heart.
99
precapillary sphincter
is a band of smooth muscle that adjusts blood flow into capillaries mainly in the mesenteric microcirculation. At the point where each of the capillaries originates from an arteriole, a smooth muscle fiber encircles the capillary. This is called the precapillary sphincter.
100
Exchanges in the Capillaries
The vital function of exchanging gases, nutrients, and metabolic byproducts between the blood and the tissue fluid surrounding the cells takes place in the capillaries. The biochemicals exchanged move through the capillary walls by diffusion, filtration, and osmosis.
101
Diffusion in the heart
-
Diffusion compartments
The diffusion of water in the myocardium occurs in the intravascular space, extracellular space and intracellular space. The measurement of diffusion in the myocardium with most sequences reflects the contribution of all three compartments and the composite microstructure of the heart.
102
filtration, hydrostatic pressure
In filtration, hydrostatic pressure forces molecules through a membrane. In the capillaries, the blood pressure generated when ventricle walls contract provides the force for filtration.
103
peripheral resistance
is the resistance of the arteries to blood flow. As the arteries constrict, the resistance increases and as they dilate, resistance decreases. Peripheral resistance is determined by three factors: Autonomic activity: sympathetic activity constricts peripheral arteries.
104
Plasma proteins - Blood proteins, also termed plasma proteins, are proteins present in blood plasma. They serve many different functions, including transport of lipids, hormones, vitamins and minerals in activity and functioning of the immune system.
The three major groups of plasma proteins are as follows:
1. Albumin is the most abundant of the plasma proteins.
2. The second most common plasma proteins are the globulins. ...
3. The least abundant plasma protein is fibrinogen.
105
venules
Venules (ven′ūlz) are the microscopic vessels that continue from the capillaries and merge to form veins (vānz). The smallest of the venules are similar to capillaries in terms of permeability.
106
Systemic veins also function as blood reservoirs
In addition to their primary function of returning blood to the heart, veins may be considered blood reservoirs, since systemic veins contain approximately 64 percent of the blood volume at any given time.
107
Blood Pressure
Blood pressure is the force the blood exerts against the inner walls of the blood vessels and that circulates the blood. Although this force is present throughout the vascular system, the term blood pressure most commonly refers to pressure in arteries supplied by branches of the aorta (systemic arteries). Pressure differences throughout the vascular system keep the blood moving from higher pressure to lower pressure.
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Arterial Blood Pressure
Arterial pressure results from the pressure exerted by the blood in the large arteries. Blood pressure depends on cardiac output and total peripheral resistance. Arterial pressure fluctuates with each heartbeat, according to the pumping of the heart.
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systolic pressure vs diastolic pressure
The top number refers to the amount of pressure in your arteries during the contraction of your heart muscle. This is called systolic pressure. The bottom number refers to your blood pressure when your heart muscle is between beats. This is called diastolic pressure.
Your blood pressure is recorded as two numbers:
- Systolic blood pressure (the first number) – indicates how much pressure your blood is exerting against your artery walls when the heartbeats.
- Diastolic blood pressure (the second number) – indicates how much pressure your blood is exerting against your artery walls while the heart is resting between beats.
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sphygmomanometer
an instrument for measuring blood pressure, typically consisting of an inflatable rubber cuff which is applied to the arm and connected to a column of mercury next to a graduated scale, enabling the determination of systolic and diastolic blood pressure by increasing and gradually releasing the pressure in the cuff.
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atherosclerosis
a disease of the arteries characterized by the deposition of plaques of fatty material on their inner walls.
112
pulse
a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips
113
Blood Volume
Blood volume equals the sum of the formed elements and plasma volumes in the vascular system. Although the blood volume varies somewhat with age, body size, and sex, it is usually about 5 liters for adults or 8% of body weight in kilograms (1 kilogram of water equals 1 liter).
114
atrial natriuretic peptide (ANP)
The atrial natriuretic hormone (ANP) is a cardiac hormone which gene and receptors are widely present in the body. Its main function is to lower blood pressure and to control electrolyte homeostasis.
115
ventricular natriuretic peptide (BNP)
Ventricular natriuretic peptide or brain natriuretic peptide (BNP), also known as B-type natriuretic peptide, is a hormone secreted by cardiomyocytes in the heart ventricles in response to stretching caused by increased ventricular blood volume.
116
Peripheral Resistance
Friction between the blood and the walls of the blood vessels produces a force called peripheral resistance , which impedes blood flow.
117
Viscosity
Viscosity is the difficulty with which the molecules of a fluid flow past one another. The greater the viscosity, the greater the resistance to flow.
118
Control of Blood Pressure
Blood pressure (BP) is determined by cardiac output (CO) and peripheral resistance (PR) according to this relationship: BP = CO × PR. Maintenance of normal blood pressure, therefore, requires regulation of these two factors
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end-diastolic volume (EDV)
In cardiovascular physiology, end-diastolic volume (EDV) is the volume of blood in the right and/or left ventricle at end load or filling in (diastole) or the amount of blood in the ventricles just before systole.
120
end-systolic volume (ESV)
End-systolic volume (ESV) is the volume of blood in a ventricle at the end of contraction, or systole, and the beginning of filling, or diastole. ESV is the lowest volume of blood in the ventricle at any point in the cardiac cycle.
121
venous return
Venous return is the rate of blood flow back to the heart. It normally limits cardiac output. Superposition of the cardiac function curve and venous return curve is used in one hemodynamic model.
122
hemodynamic model
This model essentially combines the Balloon model and a simple linear dynamical model of changes in regional cerebral blood flow (rCBF) caused by neuronal activity.
123
stroke volume (SV)
In cardiovascular physiology, stroke volume is the volume of blood pumped from the left ventricle per beat.
124
Frank-Starling law of the heart, or Starling’s law of the heart.
The law states that the stroke volume of the heart increases in response to an increase in the volume of blood in the ventricles, before contraction (the end diastolic volume), when all other factors remain constant.
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preload
is the initial stretching of the cardiac myocytes (muscle cells) prior to contraction. It is related to ventricular filling. Afterload is the force or load against which the heart has to contract to eject the blood.
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Contractility
* *Myocardial contractility represents the innate ability of the heart muscle to contract. The ability to produce changes in force during contraction result from incremental degrees of binding between different types of tissue, that is, between filaments of myosin and actin tissue.
* *Contractility is the inherent strength and vigour of the heart's contraction during systole. According to Starling's Law, the heart will eject a greater stroke volume at greater filling pressures. For any filling pressure (LAP), the stroke volume will be greater if the contractility of the heart is greater.
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afterload
is the pressure that the heart must work against to eject blood during systole (ventricular contraction). Afterload is proportional to the average arterial pressure. As aortic and pulmonary pressures increase, the afterload increases on the left and right ventricles respectively.
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Increased arterial pressure (hypertension)
High blood pressure can cause hardening and thickening of the arteries (atherosclerosis), which can lead to a heart attack, stroke or other complications. Aneurysm. Increased blood pressure can cause your blood vessels to weaken and bulge, forming an aneurysm. If an aneurysm ruptures, it can be life-threatening.
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Venous Blood Flow
Right side of the heart
Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.
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central venous pressure CVP
Central venous pressure CVP is the blood pressure in the venae cavae, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood back into the arterial system.
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pericardial effusion
A pericardial effusion is excess fluid between the heart and the sac surrounding the heart, known as the pericardium. Most are not harmful, but they sometimes can make the heart work poorly. The pericardium is a tough and layered sac.
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acute cardiac tamponade
Compression of the heart caused by fluid collecting in the sac surrounding the heart.
Cardiac tamponade puts pressure on the heart and keeps it from filling properly. The result is a dramatic drop in blood pressure that can be fatal.
Symptoms include low blood pressure, shortness of breath, and lightheadedness.
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Pulmonary Circuit
he pulmonary circulation is the portion of the circulatory system which carries deoxygenated blood away from the right ventricle, to the lungs, and returns oxygenated blood to the left atrium and ventricle of the heart. The term pulmonary circulation is readily paired and contrasted with the systemic circulation.
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lobar branches
The right and left main pulmonary arteries give off branches that roughly correspond to the lung lobes and can in such cases be termed lobar arteries. The lobar arteries branch into segmental arteries (roughly 1 for each lobe segment), which in turn branch into subsegmental pulmonary arteries.
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alveolar capillary
Alveolar refers to the alveoli, the millions of tiny air sacs that are scattered throughout the lungs. The capillaries are very tiny blood vessels that connect the alveoli to larger blood vessels. When a person breathes in air, oxygen travels to the lungs and into the alveoli.
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lymphatic capillaries
Lymph capillaries or lymphatic capillaries are tiny, thin-walled microvessels located in the spaces between cells (except in the central nervous system and non-vascular tissues) which serve to drain and process extracellular fluid.
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Pulmonary edema
is a condition caused by excess fluid in the lungs. This fluid collects in the numerous air sacs in the lungs, making it difficult to breathe. In most cases, heart problems cause pulmonary edema.
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Four pulmonary veins
There are typically four pulmonary veins, two draining each lung:
right superior: drains the right upper and middle lobes.
right inferior: drains the right lower lobe.
left superior: drains the left upper lobe.
left inferior: drains the left lower lobe.
This completes the vascular loop of the pulmonary circuit.
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Systemic Circuit
is that part of your circulatory system that carries blood away from your heart, delivers it to most of your organs and tissues, and returns it to your heart again. The systemic circuit is distinct from the pulmonary circuit, which only conducts blood between your heart and lungs.
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Arterial System
is the higher-pressure portion of the circulatory system, with pressure varying between the peak pressure during heart contraction ( systolic pressure ) and the minimum (diastolic) pressure between contractions when the heart expands and refills.
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What are the 5 vascular systems?
There are five classes of blood vessels: arteries and arterioles (the arterial system), veins and venules (the venous system), and capillaries (the smallest bloods vessels, linking arterioles and venules through networks within organs and tissues)
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aorta
the main artery of the body, supplying oxygenated blood to the circulatory system. In humans it passes over the heart from the left ventricle and runs down in front of the backbone.
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Principal Branches of the Aorta
The part of the aorta attached to the heart is called the aortic root. From there, the first part of the aorta is called the ascending aorta. At the root are the three cusps of the aortic valve, and opposite each cusp is a swelling in the aortic wall called an aortic sinus. The right and left coronary arteries arise from two of these aortic sinuses. The elastic recoil of the aortic wall following contraction of the left ventricle helps drive blood flow into these arteries.
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Three major arteries originate from the arch of the aorta (aortic arch).
They are the brachiocephalic artery, the left common carotid artery, and the left subclavian artery.
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The aortic arch has baroreceptors called aortic bodies -
that detect changes in blood pressure. Several small structures called aortic bodies lie in the epithelial lining of the aortic arch. The aortic bodies house chemoreceptors that sense blood pH and blood levels of oxygen and carbon dioxide.
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The brachiocephalic trunk of the aorta -
and carotid artery
and subclavian artery
supplies blood to the tissues of the upper limb and head, as its name suggests. It is the first branch from the aortic arch and rises through the mediastinum to a point near the junction of the sternum and the right clavicle.
There it divides, giving rise to the right common carotid artery, which transports blood to the right side of the neck and head,
and the right subclavian artery, which leads into the right arm. Branches of the subclavian artery also supply blood to parts of the shoulder, neck, and head.
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The left common carotid artery and the left subclavian artery are respectively the second and third branches of the aortic arch -
They supply blood to regions on the left side of the body corresponding to those supplied by their counterparts on the right
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The upper part of the descending aorta -
is left of the midline, but it gradually extends medially and lies directly anterior to the vertebral column at the level of the twelfth thoracic vertebra.
- The part of the descending aorta above the diaphragm is the thoracic aorta. It gives off many small branches to the thoracic wall and the thoracic viscera.
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abdominal aorta
Below the diaphragm, the descending aorta becomes the abdominal aorta, and it branches to the abdominal wall and several abdominal organs. These branches include the following:
* celiac artery
* phrenic arteries
* superior mesenteric artery
* suprarenal arteries
* renal arteries
* Gonadal arteries
* inferior mesenteric artery
* Three or four pairs of lumbar arteries
* middle sacral artery
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The celiac artery
gives rise to the left gastric, splenic, and hepatic arteries, which supply upper portions of the digestive tract, the spleen, and the liver, respectively. (Note: The hepatic artery supplies the liver with about one-third of its blood flow, and this blood is oxygen-rich. The remaining two-thirds of the liver’s blood flow arrives by means of the hepatic portal vein and is oxygen-poor.)
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The phrenic arteries
are paired arteries that supply blood to the diaphragm.
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The superior mesenteric artery
is a large, unpaired vessel that branches to many parts of the intestinal tract, including the jejunum, ileum, cecum, ascending colon, and transverse colon.
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The pair of suprarenal arteries
supplies blood to the adrenal glands.
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The renal arteries
pass laterally from the aorta into the kidneys. Each artery then divides into several lobar branches in the kidney tissues.
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Gonadal arteries
are in the female and male. In a female, paired ovarian arteries arise from the aorta and pass into the pelvis to supply the ovaries. In a male, spermatic arteries originate in similar locations. They course downward and pass through the body wall by way of the inguinal canal to supply the testes.
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branches of the inferior mesenteric artery
lead to the descending colon, the sigmoid colon, and the rectum.
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Three or four pairs of lumbar arteries
Three or four pairs of lumbar arteries arise from the posterior surface of the aorta in the region of the lumbar vertebrae. These arteries supply muscles of the skin and the posterior abdominal wall.
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The middle sacral artery
a small vessel, descends medially from the aorta along the anterior surfaces of the lower lumbar vertebrae. It transports blood to the sacrum and coccyx.
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The abdominal aorta
terminates near the brim of the pelvis, where it divides into right and left common iliac arteries. These vessels supply blood to lower regions of the abdominal wall, the pelvic organs, and the lower extremities
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Arteries to the Brain, Head, and Neck
Carotid Arteries · External Carotid Artery · Internal Carotid Artery
The internal carotid arteries carry blood directly to the front and middle parts of the brain while the external carotid artery carries blood to the face and scalp. Both of the subclavian arteries carry blood mainly to the arms, but they also carry blood to the brain.
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vertebral arteries
arise from the subclavian arteries in the base of the neck near the tips of the lungs. They pass upward through the foramina of the transverse processes of the cervical vertebrae and enter the skull by way of the foramen magnum. Along their paths, these vessels supply blood to the brainstem and spinal cord, and to the vertebrae and their associated ligaments and muscles.
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basilar artery
is part of the blood supply system for the brain and central nervous system. It is formed where the two vertebral arteries join at the base of the skull. The basilar artery carries oxygenated blood to the cerebellum, brainstem, and occipital lobes.
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cerebral arterial circle (circle of Willis)
The circle of Willis (also called Willis' circle, loop of Willis, cerebral arterial circle, and Willis polygon) is a circulatory anastomosis that supplies blood to the brain and surrounding structures. It is named after Thomas Willis (1621–1675), an English physician.
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thyrocervical arteries
are short vessels. These vessels branch at the thyrocervical axis to the thyroid gland, parathyroid glands, larynx, trachea, esophagus, and pharynx, as well as to various muscles in the neck, shoulder, and back.
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costocervical arteries
the third vessels to branch from the subclavian, carry blood to muscles in the neck, back, and thoracic wall.
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The left and right common carotid arteries
In anatomy, the left and right common carotid arteries (carotids) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.
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The external carotid artery courses upward on the side of the head, giving off branches to structures in the neck, face, jaw, scalp, and base of the skull. The main vessels that originate from this artery include the following:
superior thyroid artery to the hyoid bone, larynx, and thyroid gland
lingual artery to the tongue, muscles of the tongue, and salivary glands beneath the tongue
facial artery to the pharynx, palate, chin, lips, and nose
occipital artery to the scalp on the back of the skull, the meninges, the mastoid process, and various muscles in the neck
posterior auricular artery to the ear and the scalp over the ear
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The external carotid artery terminates by
dividing into the maxillary and superficial temporal arteries. The maxillary artery supplies blood to the teeth, gums, jaws, cheek, nasal cavity, eyelids, and meninges. The superficial temporal artery extends to the parotid salivary gland and to various surface regions of the face and scalp.
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The internal carotid artery begins lateral to the external carotid artery, then extends medially to follow a deep course upward along the pharynx to the base of the skull. Entering the cranial cavity, it provides the major blood supply to the brain. The major branches of the internal carotid artery include the following:
ophthalmic artery to the eyeball and to various muscles and accessory organs within the orbit
posterior communicating artery that forms part of the cerebral arterial circle
anterior choroid artery to the choroid plexus within the lateral ventricle of the brain and to nerve structures in the brain
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The internal carotid artery terminates by
dividing into the anterior and middle cerebral arteries. The middle cerebral artery passes through the lateral tissue and supplies the lateral surface of the cerebrum, including the primary motor and sensory areas of the face and upper limbs, the optic radiations, and the speech area. The anterior cerebral artery extends anteriorly between the cerebral hemispheres and supplies the medial surface of the brain.
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carotid sinus
Anatomical terminology. In human anatomy, the carotid sinus is a dilated area at the base of the internal carotid artery just superior to the bifurcation of the internal carotid and external carotid at the level of the superior border of thyroid cartilage.
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How can the carotid sinus cause sudden death
A loss of muscle tone at times due to a decrease in heartbeat and blood reaching the muscles; Carotid sinus reflex death is a result of vagus nerve impulses which may cause the heart to stop beating, i.e. cardiac arrest; this occurs during strangulation.
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bifurcation
the division of something into two branches or parts.
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Arteries to the Shoulder and Upper Limb
The subclavian artery, after giving off branches to the neck, continues into the arm. It passes between the clavicle and the first rib and becomes the axillary artery
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carotid bodies
a small mass of receptors in the carotid artery sensitive to chemical change in the blood.
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axillary artery
supplies branches to structures in the axilla and the chest wall, including the skin of the shoulder; part of the mammary gland; the upper end of the humerus; the shoulder joint; and muscles in the back, shoulder, and chest. As this vessel leaves the axilla, it becomes the brachial artery.
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brachial artery
courses along the humerus to the elbow. It gives rise to a deep brachial artery that curves posteriorly around the humerus and supplies the triceps brachii muscle. Shorter branches pass into the muscles on the anterior side of the arm, whereas others descend on each side to the elbow and connect with arteries in the forearm. The resulting arterial network allows blood to reach the forearm even if a portion of the distal brachial artery becomes obstructed.
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The radial artery
In the elbow, the brachial artery divides into an ulnar artery and a radial artery -
- radial artery, which is a continuation of the brachial artery, extends along the radial side of the forearm to the wrist. As it nears the wrist, it comes close to the surface and provides a convenient vessel for taking the pulse (radial pulse). Branches of the radial artery join the anastomosis of the elbow and supply the lateral muscles of the forearm.
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The ulnar artery
In the elbow, the brachial artery divides into an ulnar artery and a radial artery-
- The ulnar artery leads downward on the ulnar side of the forearm to the wrist. Some of its branches join the anastomosis around the elbow joint, whereas others supply blood to flexor and extensor muscles in the forearm.
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anastomosis
A circulatory anastomosis is a connection (an anastomosis) between two blood vessels, such as between arteries (arterio-arterial anastomosis), between veins (veno-venous anastomosis) or between an artery and a vein (arterio-venous anastomosis).
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internal thoracic artery
This vessel originates in the base of the neck and passes downward on the pleura and behind the cartilages of the upper six ribs. It gives off two anterior intercostal arteries to each of the upper six intercostal spaces; these two arteries supply the intercostal muscles, other intercostal tissues, and the mammary glands.
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pleura
each of a pair of serous membranes lining the thorax and enveloping the lungs in humans and other mammals.
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two anterior intercostal arteries
The first and second anterior intercostal arteries are found in the endothoracic fascia, traveling between the internal intercostal muscles and parietal pleura. The third to sixth anterior intercostal arteries are separated from the parietal pleura by the fibers of the transverse thoracic muscle.
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posterior intercostal arteries
arise from the thoracic aorta and enter the intercostal spaces between the third through the eleventh ribs. These arteries branch to supply the intercostal muscles, the vertebrae, the spinal cord, and deep muscles of the back.
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Branches of the internal thoracic and external iliac arteries
provide blood to the anterior abdominal wall. Paired vessels originating from the abdominal aorta, including the phrenic and lumbar arteries, supply blood to structures in the lateral and posterior abdominal wall.
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Common iliac arteries
at the level of the pelvic brim. These vessels provide blood to the pelvic organs, gluteal region, and lower limbs.
Each common iliac artery descends a short distance and divides into an internal (hypogastric) branch and an external branch.
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The internal iliac artery
- Common iliac arteries
gives off many branches to various pelvic muscles and visceral structures, as well as to the gluteal muscles and the external genitalia.
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iliolumbar artery
- Common iliac arteries
iliolumbar artery to the ilium and muscles of the back
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superior and inferior gluteal arteries
- Common iliac arteries
superior and inferior gluteal arteries to the gluteal muscles, pelvic muscles, and skin of the buttocks
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internal pudendal artery
- Common iliac arteries
internal pudendal artery to muscles in the distal portion of the alimentary canal, the external genitalia, and the hip joint
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superior (arising from the umbilical artery) and inferior vesical arteries
- Common iliac arteries
superior (arising from the umbilical artery) and inferior vesical arteries to the urinary bladder; in males, these vessels also supply the seminal vesicles and the prostate gland
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middle rectal artery
- Common iliac arteries
middle rectal artery to the rectum
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uterine artery
- Common iliac arteries
uterine artery to the uterus and vagina
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obturator artery
- Common iliac arteries
obturator artery to the adductor muscles of the thigh
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external iliac artery provides
external iliac artery provides: the main blood supply to the lower limbs. It passes downward along the brim of the pelvis and gives off two large branches—
an inferior epigastric artery and a deep circumflex iliac artery.
These vessels supply the muscles and skin in the lower abdominal wall. Midway between the pubic symphysis and the anterior superior iliac spine, the external iliac artery becomes the femoral artery.
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femoral artery
which passes fairly close to the anterior surface of the upper thigh, gives off many branches to muscles and superficial tissues of the thigh. These branches also supply the skin of the groin and the lower abdominal wall.
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superficial circumflex iliac artery
- femoral artery branches/subdivisions
superficial circumflex iliac artery to the lymph nodes and skin of the groin
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superficial epigastric artery
- femoral artery branches/subdivisions
superficial epigastric artery to the skin of the lower abdominal wall
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superficial and deep external pudendal arteries
- femoral artery branches/subdivisions
superficial and deep external pudendal arteries to the skin of the lower abdomen and external genitalia
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deep femoral artery
- femoral artery branches/subdivisions
deep femoral artery (the largest branch of the femoral artery) to the hip joint and muscles of the thigh
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deep genicular artery
- femoral artery branches/subdivisions
deep genicular artery to distal ends of thigh muscles and to an anastomosis around the knee joint
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popliteal artery
Branches of this artery supply blood to the knee joint and to certain muscles in the thigh and calf. Also, many of its branches join the anastomosis of the knee and help provide alternate pathways for blood in the case of arterial obstructions. At the lower border of the popliteal fossa, the popliteal artery divides into the anterior and posterior tibial arteries.
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anterior tibia artery
passes downward between the tibia and the fibula, giving off branches to the skin and muscles in the anterior and lateral regions of the leg. It also communicates with the anastomosis of the knee and with a network of arteries around the ankle. This vessel continues into the foot as the dorsalis pedis artery, which supplies blood to the instep and toes.
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dorsalis pedis artery
dorsalis pedis artery, which supplies blood to the instep and toes.
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posterior tibial artery
which is the larger of the two popliteal branches, descends beneath the calf muscles, giving off branches to the skin, muscles, and other tissues of the leg along the way. Some of these vessels join the anastomoses of the knee and ankle. As it passes between the medial malleolus and the heel, the posterior tibial artery divides into the medial and lateral plantar arteries.
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the posterior tibial artery divides into the medial and lateral plantar arteries.
the posterior tibial artery divides into the medial and lateral plantar arteries. Branches from these arteries supply blood to tissues of the heel, instep, and toes.
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fibular artery
The largest branch of the posterior tibial artery is the fibular artery, which extends downward along the fibula and contributes to the anastomosis of the ankle.
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Venous circulation
returns blood to the heart after gases, nutrients, and wastes are exchanged between the blood and body cells.
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- Veins from the Brain, Head, and Neck
external jugular veins
right and left subclavian veins
external jugular veins drain blood from the face, scalp, and superficial regions of the neck. These vessels descend on either side of the neck, passing over the sternocleidomastoid muscles and beneath the platysma. They empty into the right and left subclavian veins in the base of the neck
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- Veins from the Brain, Head, and Neck
internal jugular veins
large brachiocephalic veins
internal jugular veins, which are somewhat larger than the external jugular veins, arise from many veins and venous sinuses of the brain and from deep veins in parts of the face and neck. They descend through the neck beside the common carotid arteries and also join the subclavian veins. These unions of the internal jugular and subclavian veins form large brachiocephalic veins on each side. These vessels then merge in the mediastinum and give rise to the superior vena cava, which enters the right atrium.
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- Veins from the Upper Limb and Shoulder
A set of deep veins and a set of superficial ones drain the upper limb. The deep veins generally parallel the arteries in each region and have similar names.
The superficial veins connect in complex networks just beneath the skin. They also communicate with the deep vessels of the upper limb, providing many alternate pathways through which the blood can leave the tissues
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Deep - Veins from the Upper Limb and Shoulder
| *digital veins
Deep venous drainage of the upper limbs begins in the digital veins that drain into pairs of radial veins and ulnar veins, which merge to form a pair of brachial veins.
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- Veins from the Upper Limb
The major vessels of the superficial network are the basilic and cephalic veins. They arise from anastomoses in the palm and wrist on the ulnar and radial sides, respectively.
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- Veins from the Upper Limb and Shoulder
| * basilic vein
basilic vein passes along the back of the forearm on the ulnar side for a distance and then curves forward to the anterior surface below the elbow. It continues ascending on the medial side until it reaches the middle of the arm. There it deeply penetrates the tissues and joins the brachial vein. As the basilic and brachial veins merge, they form the axillary vein.
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- Veins from the Upper Limb and Shoulder
| * brachial vein
is a component of the deep venous system of the upper limb. After forming from the radial and ulnar veins1, the brachial vein travels from the cubital fossa superiorly to become the axillary vein.
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- Veins from the Upper Limb and Shoulder
| * axillary vein
is a large blood vessel that conveys blood from the lateral aspect of the thorax, axilla (armpit) and upper limb toward the heart. There is one axillary vein on each side of the body. Its origin is at the lower margin of the teres major muscle and a continuation of the brachial vein.
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- Veins from the Upper Limb and Shoulder
| * cephalic vein
courses upward on the lateral side of the upper limb from the hand to the shoulder. In the shoulder, it pierces the tissues and joins the axillary vein, which beyond the axilla becomes the subclavian vein.
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- Veins from the Upper Limb and Shoulder
| * subclavian vein
subclavian vein (Latin: vena subclavia) is a large blood vessel that arises from the axillary vein. It is one of the deep veins of the neck. The subclavian vein originates at the outer border of the first rib. It travels within the subclavian groove, then runs laterally to the medial border of the anterior scalene.
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- Veins from the Upper Limb and Shoulder
| * a median cubital vein
In the bend of the elbow, a median cubital vein ascends from the cephalic vein on the lateral side of the forearm to the basilic vein on the medial side. This large vein is usually visible beneath the skin. It is often used as a site for venipuncture, when it is necessary to remove a sample of blood for examination or to add fluids to the blood.
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- Veins from the Abdominal and Thoracic Walls
Tributaries of the brachiocephalic and azygos veins drain the abdominal and thoracic walls. For example, the brachiocephalic vein receives blood from the internal thoracic vein, which generally drains the tissues the internal thoracic artery supplies. Some intercostal veins also empty into the brachiocephalic vein
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- Veins from the Abdominal and Thoracic Walls
| * azygos vein
azygos vein originates in the dorsal abdominal wall and ascends through the mediastinum on the right side of the vertebral column to join the superior vena cava. It drains most of the muscular tissue in the abdominal and thoracic walls.
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- Veins from the Abdominal and Thoracic Walls
| * *Tributaries of the azygos vein include
Tributaries of the azygos vein include the posterior intercostal veins on the right side, which drain the intercostal spaces, and the superior and inferior hemiazygos veins, which receive blood from the posterior intercostal veins on the left. The right and left ascending lumbar veins, with tributaries that include vessels from the lumbar and sacral regions, also connect to the azygos system.
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- Veins from the Abdominal Viscera
Veins transport blood directly to the atria of the heart, except for portal veins, such as those that drain the abdominal viscera. They originate in the capillary networks of the stomach, intestines, pancreas, and spleen and transport blood from these organs through a hepatic portal (por′tal) vein to the liver. There the blood enters capillary-like hepatic sinusoids. This venous pathway is called the hepatic portal system, which allows blood to flow from the gastrointestinal organs to the liver before returning to the heart.
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- Veins from the Abdominal Viscera
| * *The tributaries of the hepatic portal vein include the following vessels:
right and left gastric veins from the stomach
superior mesenteric vein from the small intestine, ascending colon, and transverse colon
splenic vein from a convergence of several veins draining the spleen, the pancreas, and a portion of the stomach; as well as its largest tributary, the inferior mesenteric vein, from the descending colon, sigmoid colon, and rectum
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Veins from the Lower Limb and Pelvis
Veins that drain the blood from the lower limb can be divided into deep and superficial groups, as in the upper limb. The deep veins of the leg, such as the paired anterior and posterior tibial veins, have names that correspond to the arteries they accompany. At the level of the knee, these vessels form a single trunk, the popliteal vein. This vein continues upward through the thigh as the femoral vein, which, in turn, becomes the external iliac vein.
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The superficial veins of the foot, leg, and thigh
The superficial veins of the foot, leg, and thigh connect to form a complex network beneath the skin. These vessels drain into two major trunks: the small and great saphenous veins.
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- The superficial veins of the foot, leg, and thigh
| * small saphenous vein
small saphenous vein begins in the lateral portion of the foot and passes upward behind the lateral malleolus. It ascends along the back of the calf, behind the knee, and joins the popliteal vein.
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- The superficial veins of the foot, leg, and thigh
| * great saphenous vein
great saphenous vein, the longest vein in the body, originates on the medial side of the foot. It ascends in front of the medial malleolus and extends upward along the medial side of the leg and thigh. In the thigh just below the inguinal ligament, it deeply penetrates and joins the femoral vein. Near its termination, the great saphenous vein receives tributaries from a number of vessels that drain the upper thigh, groin, and lower abdominal wall.
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- The superficial veins of the foot, leg, and thigh
| * internal iliac veins
In the pelvic region, vessels leading to the internal iliac veins transport blood away from organs of the reproductive, urinary, and digestive systems. These veins are formed by tributaries corresponding to the branches of the internal iliac artery, such as the gluteal, pudendal, vesical, rectal, uterine, and vaginal veins. Typically, these veins have many connections and form complex networks (plexuses) in the regions of the rectum, urinary bladder, and prostate gland (in the male) or uterus and vagina (in the female).
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- The superficial veins of the foot, leg, and thigh
| * common iliac veins
The internal iliac veins originate deep within the pelvis and ascend to the pelvic brim. There they unite with the right and left external iliac veins to form the common iliac veins. These veins, in turn, merge to produce the inferior vena cava at the level of the fifth lumbar vertebra.
