The abdominal and thoracic viscera of a five months fetus. The large liver and large size if its left lobe at this age should be noted.

Abdomen of Fetus

The abdominal and thoracic viscera of a five months fetus. The large liver and large size if its left…

Diagram of the aortic arches in a mammal, showing transformations which give rise to the permanent arterial vessels. A, primitive arterial stem or aortic bulb, now divided into A, the ascending part of the aortic arch, and p, the pulmonary; a, a', right and left aortic roots; A', descending aorta; 1, 2, 3, 4, 5, the five primitive aortic or branchial arches; I, II, III, IV, the four branchial clefts which, for the sake of clearness, have been omitted on the right side. The permanent systemic vessels are deeply, the pulmonary arteries lightly, shaded; the parts of the primitive arches which are transitory are simply outlined; c, placed between the permanent common carotid arteries; c e, external carotid arteries; c i, internal carotid arteries; s, right subclavian, rising from the right aortic root beyond the fifth arch; v, right vertebral from the same, opposite the fourth arch; v' s', left vertebral and subclavian arteries rising together from the left, or permanent aortic root, opposite the forth arch; p, pulmonary arteries rising together from the left fifth arch, forming ductus arteriosus; p n, p n', right and left pneumogastric nerves descending in from of aortic arch, with their recurrent branches represented diagrammatically as passing behind, to illustrate the relations of these nerves respectively to the right subclavian artery (4) and the arch of the aorta and ductus arteriosus (d).

Aortic Arches in a Mammal

Diagram of the aortic arches in a mammal, showing transformations which give rise to the permanent arterial…

A portion of an artery.

Artery

A portion of an artery.

A perennial thistle with arching green leaves and edible flowers.

Artichoke

A perennial thistle with arching green leaves and edible flowers.

The right auricle (atrium) and ventricle of the heart opened, and a part of their right and anterior walls removed, so as to show their interior; 1/2, 1, superior vena cava; 2, inferior vena cava; 2', hepatic veins cut short; 3, right auricle; 3', placed in the fossa ovalis, below which is the Eustachian valve; 3", is placed close to the aperture of the coronary vein; +, +, placed n the auriculo-ventricular groove, where a narrow portion of the adjacent walls of the auricle and ventricle has been preserved; 4, 4, cavity of the right ventricle; the upper figure is immediately below the semilunar valves; 4', large columna carnea or musculus papillaris; 5, 5', 5", tricuspid valve; 6, placed in the interior o the pulmonary artery, a part of the anterior wall of that vessel having been removed, and a narrow portion of it preserved at its commencement where the semilunar valves are attached; 7, concavity of the aortic arch close to the cord of the ductus arteriosus; 8, ascending part of sinus of the arch covered at its commencement by the auricular appendix and pulmonary artery; 9, placed between the innominate and left carotid arteries; 10, appendix of the left auricle; 11, 11, the outside of the left ventricle, the lower figure near the apex.

Right Atrium and Ventricle of the Heart

The right auricle (atrium) and ventricle of the heart opened, and a part of their right and anterior…

The arrangement of the muscles of the auricles.

Auricles Muscles

The arrangement of the muscles of the auricles.

<em>L.A.</em>, left auricle; <em>R.A.</em>, right auricle; <em>A</em>, opening of the inferior vena cava; <em>B</em>, superior vena cava; <em>C</em>, cardiac vein of right auricle laid open; <em>D</em>, left pulmonary veins; <em>E</em>, eight pulmonary veins; <em>F</em>, muscular fibers surrounding the openings between the left auricle and left ventricle, and the right auricle and right ventricle; <em>G, H, K,</em> and <em>L</em>, muscular fibers surrounding the great veins of the heart." &mdash; Blaisedell, 1904

Muscular fibers of the auricle

L.A., left auricle; R.A., right auricle; A, opening of the inferior vena…

"A Block is a pulley or a system of pulleys rotating on a pintle mounted in its frame or shell with its band and strap. There are many kinds of blocks, as a pulley block, a fiddle block, a fish block, a fly block, a heart block, a hook block, etc. A block and tackle is the block and the rope rove through it, for hoisting or obtaining a purchase."&mdash;(Charles Leonard-Stuart, 1911)

Block and Tackle

"A Block is a pulley or a system of pulleys rotating on a pintle mounted in its frame or shell with…

Diagram showing the circulation of blood in the heart. Let <em>a</em> represent the right side of the heart, <em>c</em>the left side, <em>b</em> the lungs, and <em>d</em> the general system of the body. The arrows point in the direction in which the blood flows. In all the shaded part the blood is dark (oxygen-poor), and in the part that is not shaded it is red (oxygen-rich).

Blood Circulation in the Heart

Diagram showing the circulation of blood in the heart. Let a represent the right side of the…

Diagram of the rush of blood when the heart beats. The valves (v) open above are closed below while the valves (s) closed above are open below.

The Course of Blood in the Heart

Diagram of the rush of blood when the heart beats. The valves (v) open above are closed below while…

"Organs in the body cavity viewed from the front." &mdash;Davison, 1910

Organs of the body cavity

"Organs in the body cavity viewed from the front." —Davison, 1910

Branchi of the lungs, the heart, and blood vessels. Labels: 1, left auricle; 2, right auricle; 3, left ventricle; 5, pulmonary artery; 6, arch of the aorta; 7, superior vena cava; 8, arteria innominata; 9, left primitive carotid artery; 10, left subclavian artery; 11, trachea; 12, larynx; 13, upper lobe of right lung; 14, upper lobe of left lung; 15, trunk of right pulmonary artery; 16, lower lobes of the lungs.

Branchi and Blood Vessels

Branchi of the lungs, the heart, and blood vessels. Labels: 1, left auricle; 2, right auricle; 3, left…

View of the bronchia and veins of the lungs, exposed by dissection, as well as the relative position of the lungs to the heart.

Bronchia and Veins of the Lungs

View of the bronchia and veins of the lungs, exposed by dissection, as well as the relative position…

Capillaries. 1: Vein; 2: Artery; 3: Capillary.

Capillaries

Capillaries. 1: Vein; 2: Artery; 3: Capillary.

The constitution of the cardiac plexuses. Labels: Sy, cervical sympathetic cord; C.1, superior cervical ganglia; C.2, middle cervical ganglia; C.3, inferior cervical ganglia; Car.1, superior sympathetic branch; Car.2, middle sympathetic branch; Car.3, inferior cardiac sympathetic branch; Va, pneumogastric nerve; R.L, recurrent laryngeal nerve; s, superior cervical cardiact branch of vagus; i, inferior cardiac branch of vagus; D.C.P, deep cardiac plexus; S.C.P, superficial cardiac plexus, A.P.P, anterior pulmonary plexus; P.P.P, posterior pulmonary plexus; R.Car.P, right coronary plexus; L.Car.P, left coronary plexus; Art.Pul, pulmonary artery.

Cardiac Plexuses

The constitution of the cardiac plexuses. Labels: Sy, cervical sympathetic cord; C.1, superior cervical…

"<em>A</em>, a muscle which aids in pushing the food down the esophagus; <em>B</em>, esophagus; <em>C</em>, section of the right bronchus; <em>D</em>, two right pulmonary veins; <em>E</em>, great azygos vein crossing the esophagus to empty into the superior vena cava, <em>F</em>, thoracic duct; <em>H</em>, thoracic aorta; <em>K</em>, lower portion of the esophagus passing through the diaphragm; <em>L</em>, diaphragm as it appears in sectional view, enveloping the heart; <em>M</em>, inferior vena cava, passing through the diaphragm and emptying into the right auricle; <em>N</em>, right auricle; <em>O</em>, section of the right branch of the pulminary artery; <em>P</em>, aorta; <em>R</em>, superior vena cava; <em>S</em>, trachea." &mdash; Blaisedell, 1904

Lateral section of the chest

"A, a muscle which aids in pushing the food down the esophagus; B, esophagus; C,…

Transverse section of the chest.

Transverse Section of the Chest

Transverse section of the chest.

A diagram of the circulation of a fish. Labels: 1, The pericardium. 2, The single auricle. 3, The single ventricle. 4, The vessel that conveys the blood from the ventricle to the gills. 5, The vessel that conveys the blood from the body to the heart. The arrows show the direction of the blood.

Circulation of a Fish

A diagram of the circulation of a fish. Labels: 1, The pericardium. 2, The single auricle. 3, The single…

A diagram of the circulation of a frog. Labels: 1, The pericardium. 2, The single ventricle. 3, The right auricle. 4, The left auricle. The arrows indicate the direction of the blood.

Circulation of a Frog

A diagram of the circulation of a frog. Labels: 1, The pericardium. 2, The single ventricle. 3, The…

Insects have neither arteries nor veins. The circulation, such as it is, is animated by the action of a vessel called dorsal, which is situated above the digestive tube. Labels: 1, Dorsal vessels in which the blood flows. 2,The lateral currents. The arrows show the outward and the inward current.

Diagram of the Circulation of an Insect.

Insects have neither arteries nor veins. The circulation, such as it is, is animated by the action of…

A diagram illustrating the circulation of the blood. Labels: A, vena cava descending (superior); Z, vena cava ascending (inferior); C, right auricle; D, right ventricle; E, pulmonary artery; F, P, lungs and pulmonary veins; G, left auricle; H, left ventricle; I, K, aorta.

Circulation of Blood

A diagram illustrating the circulation of the blood. Labels: A, vena cava descending (superior); Z,…

"<em>R.A.</em>, right auricle; <em>L.A.</em>, left auricle; <em>R.V.</em>, right ventricle; <em>L.V.</em>, left ventricle; <em>P.A.</i., pulmonary artery; <em>A</em>, pulmonary artery and vein of right lung; <em>B</em>, pulmonary artery and vein of left lung; <em>C</em>, carotid artery to head, showing branch of left subclavian artery; <em>D</em>, portal vein; <em>F</em>, hepatic artery; <em>G</em>, superior vena cava, bringing blood from head and upper limbs to right auricle." &mdash; Blaisedell, 1904

Diagram of the circulation of the blood

"R.A., right auricle; L.A., left auricle; R.V., right ventricle; L.V.,…

The human circulatory organs.

The Circulatory Organs

The human circulatory organs.

The circulatory organs. Labels: 1, The left auricle. 2, The right auricle. 3, The left ventricle. 4, The right ventricle. 5, 6, The aorta. 7, The femoral (leg) artery. 8, The branchial (arm) arteries. 9, carotid arteries. 10, The jugular veins. 11, The branchial veins. 12, The femoral veins. 13, 14, The vena cavas. 15, The pulmonary artery. 16, The right and left pulmonary arteries. 17, The pulmonary veins. 18, The lacteals. 19, The thoracic duct. 20, The absorbents of the upper extremities. 22, The small intestine.

The Circulatory Organs

The circulatory organs. Labels: 1, The left auricle. 2, The right auricle. 3, The left ventricle. 4,…

Organs of the circulation system

Circulatory System

Organs of the circulation system

"Diagrammatic cross-section of Cray-fish in the thoracic region, to show relation of circulation and respiration. a, appendage; c, carapace; c.f., flap of carapace overhanging the gills; d, digestive tube; g, gill; h, heart; l, liver; m, body muscles; m', muscles of the appendages; n.c., nerve cord; p.s., paricardial sinus; r, reproductive glands; st, sternal artery; v.a., ventral artery; v.s., ventral blood sinus in which the nerve cord lies." &mdash; Galloway

Cray-fish

"Diagrammatic cross-section of Cray-fish in the thoracic region, to show relation of circulation and…

"Cast or mold of the interior of the left ventricle of the heart of a deer. Shows that the left ventricular cavity in conical and spiral in its nature."&mdash;Pettigrew, 1874

Heart of a Deer

"Cast or mold of the interior of the left ventricle of the heart of a deer. Shows that the left ventricular…

"Dissected fish. a, air bladder; b, urinary bladder; b, urinary bladder; br, brain; c, spinal cord; d and da, dorsal fins; dv, anal fin; e, body of the vertebra; g, gills receiving the blood from the ventral aorta leading out of the heart h; i, intestine; k, kidney; l, liver; m, spines of the vertebra; n, auricle of the heart; ov, ovary; ovd, oviduct; st, stomach; sp, spleen; u, ureter." &mdash;Davison, 1906

Dissected Fish

"Dissected fish. a, air bladder; b, urinary bladder; b, urinary bladder; br, brain; c, spinal cord;…

"Frog with the left side cut away and some of the organs pulled downward. a, aorta leading from the ventricle; b, bladder; c, spinal cord surrounded by the vertebral column of bone; d, small intestine; e, opening of the lungs into the pharynx; h, ventricle of the heart; k, kidney; l, lung; liv, liver; n, brain; ov, ovary; ovd, oviduct; p, pancreas; r, rectum; sp, spleen; st, stomach; t, tongue; si, small intestine; u, left auricle; ur, ureter; v, vena cava; vc, body of vertebra." &mdash;Davison, 1906

Dissected Frog

"Frog with the left side cut away and some of the organs pulled downward. a, aorta leading from the…

"Argent (silver), a heart gules (red), ensigned with a royal crown.In heraldry, to distinguish (a charge) by a mark or an ornament, as a crown, coronet, or miter." -Whitney, 1911

Ensign

"Argent (silver), a heart gules (red), ensigned with a royal crown. In heraldry, to distinguish (a charge)…

The heart and lungs of a frog. 1: Heart. 2: Arch of the aorta. 3: Pulmonary artery. 4: Pulmonary veins. 5: Aorta. 6: Vena cava.

Frog

The heart and lungs of a frog. 1: Heart. 2: Arch of the aorta. 3: Pulmonary artery. 4: Pulmonary veins.…

The heart is the organ that propels the blood and causes it to circulate through the arteries, veins, and capillaries.

Heart

The heart is the organ that propels the blood and causes it to circulate through the arteries, veins,…

That which resembles a heart in shape.

Heart

That which resembles a heart in shape.

"The heart and blood-vessels diagrammatically represented. L, lung; M, intestine; P, liver; dotted lines represent lymphatic vessels." &mdash;Martin, 1917

Heart

"The heart and blood-vessels diagrammatically represented. L, lung; M, intestine; P, liver; dotted lines…

"The heart and the great blood-vessel attached to it, seen from the side towards the sternum. The left cavities and the vessels connected with them are colored red; the right black. Atd, right auricle; Adx and As, the right and left auricular appendages; Vd, right ventricle; Vs, left ventricle; Aa, aorta; Ab, innominate artery; Cs, left common carotid artery; Ssi, left subclavian artery; P, main trunk of the pulmonary artery, and Pd and Ps, its branches to the right and left lungs; cs, superior vena cava; Ade and Asi, the right and left innominate veins; pd, ps, the right and left pulmonary veins; crd and crs, the right and left coronary arteries." &mdash;Martin, 1917

Heart

"The heart and the great blood-vessel attached to it, seen from the side towards the sternum. The left…

"The heart vied from its dorsal aspect. ci, inverior vena cava; Vc, coronary vein; Atd, right auricle; Adx and As, the right and left auricular appendages; Vd, right ventricle; Vs, left ventricle; Aa, aorta; Ab, innominate artery; Cs, left common carotid artery; Ssi, left subclavian artery; P, main trunk of the pulmonary artery, and Pd and Ps, its branches to the right and left lungs; cs, superior vena cava; Ade and Asi, the right and left innominate veins; pd, ps, the right and left pulmonary veins; crd and crs, the right and left coronary arteries." &mdash;Martin, 1917

Heart

"The heart vied from its dorsal aspect. ci, inverior vena cava; Vc, coronary vein; Atd, right auricle;…

External view of the Heart. 1: Right Auricle; 2: Left Auricle; 3: Right Ventricle; 4: Left Ventricle; 5: Systemic Veins; 6: Pulmonary Veins; 7: Aorta; 8: Pulmonary Artery; 9: Coronary Vein and Artery.

Heart

External view of the Heart. 1: Right Auricle; 2: Left Auricle; 3: Right Ventricle; 4: Left Ventricle;…

Heart of a stag-beetle, showing the wings and chambers.

Heart

Heart of a stag-beetle, showing the wings and chambers.

The interior of a chamber, showing the valves of the heart of a stag-beetle.

Heart

The interior of a chamber, showing the valves of the heart of a stag-beetle.

Front view of the heart and great vessels. The pulmonary artery has been cut short close to its origin. Labels: 1, right ventricle; 2, left ventricle; 3, root of the pulmonary artery; 4, 4', arch of the aorta; 4'', the descending thoracic aorta; 5, part of the right auricle; 6, part of the left auricle; 7, 7', innominate veins joining to form the vena cava superior; 8, inferior vena cava; 9, one of the large hepatic veins; X, placed in the right auriculo-ventricular groove, points to the right or posterior coronary artery; X, X, placed in the anterior interventricular groove, indicate the left or anterior coronary artery.

Heart

Front view of the heart and great vessels. The pulmonary artery has been cut short close to its origin.…

A diagram of the heart. Labels: 1. Left auricle. 2, Right auricle. 3, Left ventricle. 4, Right ventricle. 5, Right and left pulmonary veins. 6, Trachea.

The Heart

A diagram of the heart. Labels: 1. Left auricle. 2, Right auricle. 3, Left ventricle. 4, Right ventricle.…

A diagram of the heart. Labels: 1. Right auricle. 2, Left auricle. 3, Right ventricle. 4, Left ventricle. 5, Right and left pulmonary veins. 6, Trachea.

The Heart

A diagram of the heart. Labels: 1. Right auricle. 2, Left auricle. 3, Right ventricle. 4, Left ventricle.…

The heart. Labels: A, the right ventricle; B, the left ventricle; C, the right auricle; D, the left auricle.

Heart

The heart. Labels: A, the right ventricle; B, the left ventricle; C, the right auricle; D, the left…

A symbol of a heart used to represent love.

Heart

A symbol of a heart used to represent love.

An illustration of a heart.

Heart

An illustration of a heart.

In the class of Crustacea there is a single ventricle, which receives the blood from the gills and propels it to other parts of the body. Shown is the heart and arteries of a lobster. Labels: 1, The heart. 2, The abdominal artery. 5, Venous sinuses. 6, The branchia from which the blood returns to the hear.

The Heart and Arteries of a Lobster

In the class of Crustacea there is a single ventricle, which receives the blood from the gills and propels…

In high orders of Mollusca the circulation resembles that of fish. Shown is the heart and arteries of a snail. Labels: 2, The stomach. 3, Intestines. 5, Heart. 6, Aorta. 7, Pulmonary artery.

The Heart and Arteries of a Snail

In high orders of Mollusca the circulation resembles that of fish. Shown is the heart and arteries of…

The heart and blood vessels diagrammatically represented, showing the direction of blood flow.

Heart and Blood Vessels

The heart and blood vessels diagrammatically represented, showing the direction of blood flow.

1, The trachea or windpipe; 2 and 3, right and left common carotid arteries; 4 and 5, right and left sub clavian arteries; 6, innominate artery; 7 and 8, right and left innominate veins; 9, Superior vena cava; 10, arch of the aorta; 11, ascending aorta; 12, pulmonary artery; 13, right atrium and auricula; 14 and 15, right and left lung; 16, conus arteriosus; 17, right ventricle; 18, left ventricle.

Heart and Lungs

1, The trachea or windpipe; 2 and 3, right and left common carotid arteries; 4 and 5, right and left…

The heart and lungs. 1, right ventricle; 3, right auricle (atrium); 6, 7, pulmonary artery; 9, aorta; 10, superior vena cava; 11, innominate artery; 12, right subclavian vein; 14, innominate vein; 15, left common carotid; 17, trachea; 20, pulmonary veins; 22 to 25, lungs, partially turned back to show veins on left side.

Heart and Lungs

The heart and lungs. 1, right ventricle; 3, right auricle (atrium); 6, 7, pulmonary artery; 9, aorta;…

A view of the bronchia and blood vessels of the lungs, as shown by dissection, as well as the relative position of the lungs to the heart.

Relative Position of the Heart and Lungs

A view of the bronchia and blood vessels of the lungs, as shown by dissection, as well as the relative…

The heart, showing its relative position to the lungs. The heart is almost wholly covered up by the lungs and it is encased in a sack or bag (the pericardium), and around this there is considerable padding. The lungs are represented as drawn apart, so that a full view of the heart with its arteries and veins can be seen, and the sac of the heart and packing material is also removed. At <em>a</em> is the trachea or windpipe; on each side are the two arteries that go to the head; <em>c</em> is the artery that goes to the arm; <em>b, b</em> are the veins coming from the head, and <em>d, d</em> the veins from the arms, all emptying into a large vein that goes to the right auricle of the heart, <em>e</em>; <em>f</em> is the large vein that brings the blood from below to this auricle; <em>g</em> is the right ventricle, <em>i</em> the left, and <em>h</em> is the aorta as it goes down from the heart.

Heart and Lungs

The heart, showing its relative position to the lungs. The heart is almost wholly covered up by the…

The heart and lungs.

The Heart and Lungs

The heart and lungs.

View of heart and lungs in situ. The front portion of the chest wall, and the outer or parietal layers of the pleurae and pericardium have been removed. The lungs are partly collapsed.

Heart and Lungs

View of heart and lungs in situ. The front portion of the chest wall, and the outer or parietal layers…

Diagram of the heart completely divided into right and left halves, and of a double (systematic and pulmonary) circulation. Ad, right auricie; Vcs, anterior vena cava; Vd, right ventricle; Ap, pulmonary artery; P, lung; Vp, pulmonary vein; As, left auricle; Vs, left ventricle; Ao, aorta; D, gut; L, liver; Vp, portal vein; Lv, hepatic vein.

Heart Divided into Left and Right Halves

Diagram of the heart completely divided into right and left halves, and of a double (systematic and…

Fetal heart in successive stages of development. 1, venous extremity; 2, arterial extremity; 3, pulmonary branches; 4, ductus arteriosus.

Fetal Heart in Successive Stages of Development

Fetal heart in successive stages of development. 1, venous extremity; 2, arterial extremity; 3, pulmonary…

View of the heart enclosed in its bag, or pericardium, which is a serious membrane. It is here laid open and turned back.

Heart in the Pericardium

View of the heart enclosed in its bag, or pericardium, which is a serious membrane. It is here laid…

Heart of a chick at the 45th, 65th, and 85th hours of incubation. I, the venous trunks; 2, the auricle; 3, the ventricle; 4, the bulbus arteriosus.

Development of the Heart of a Chick

Heart of a chick at the 45th, 65th, and 85th hours of incubation. I, the venous trunks; 2, the auricle;…

A diagram of the heart of a fish. Labels: 1, Pericardium. 2, The ventricle that receives the blood from the body. 3, The ventricle that sends the blood to the gills.

A Diagram of the Heart of a Fish

A diagram of the heart of a fish. Labels: 1, Pericardium. 2, The ventricle that receives the blood from…

The heart of a frog (Rana esculenta) from the front. Labels: V, ventricle, Ad, right auricle; As, left auricle; B, bulbus arteriosus, dividing into right and left aorta.

Heart of a Frog

The heart of a frog (Rana esculenta) from the front. Labels: V, ventricle, Ad, right auricle; As, left…