the heart and others

Superior vena cava

Vein that carries deoxygenated blood from the upper body to the right atrium of the heart.

Inferior vena cava

Vein that carries deoxygenated blood from the lower body to the right atrium of the heart.

Coronary sinus

Vein that collects deoxygenated blood from the heart muscle itself and drains into the right atrium.

Tricuspid valve

Valve between the right atrium and right ventricle; prevents backflow of blood into the atrium when the ventricle contracts.

Pulmonary semilunar valve

Valve located between the right ventricle and the pulmonary trunk; prevents backflow into the ventricle once blood is pumped to the lungs.

Pulmonary veins

Veins that carry oxygenated blood from the lungs to the left atrium of the heart.

Mitral valve

Valve between the left atrium and left ventricle; also known as the bicuspid valve.

Aortic semilunar valve

Valve located between the left ventricle and the aorta; prevents backflow into the ventricle once blood is pumped into the body.

Epicardium

The visceral layer of the serous pericardium that covers the heart.

Myocardium

The muscular middle layer of the heart responsible for contraction.

Endocardium

The inner lining of the heart chambers, consisting of endothelial cells.

Systole

The phase of the heartbeat when the heart muscle contracts and pumps blood.

Diastole

The phase of the heartbeat when the heart muscle relaxes and fills with blood.

Intercalated discs

Specialized connections between cardiac muscle cells that allow synchronized contraction.

SA node

The sinoatrial node; the heart's natural pacemaker located in the right atrium.

AV node

Atrioventricular node that relays impulses from the atria to the ventricles.

Fasciae adherens

Adhesive junctions between cardiac muscle cells at intercalated discs.

Gap junctions

Connections that allow electrical impulses to pass between cardiac muscle cells.

Parasympathetic innervation

Nerve supply from the vagus nerve that decreases heart rate.

Sympathetic innervation

Nerve supply that increases heart rate and strength of contraction.

Coronary arteries

Arteries that supply blood to the muscle of the heart.

Cardiac veins

Veins that collect deoxygenated blood from the heart and return it to the right atrium.

Coronary sulcus

Groove that separates the atria from the ventricles.

Trabeculae carneae

Ridges of muscle inside the ventricles of the heart.

Chordae tendineae

Tendinous cords that connect the atrioventricular valves to the papillary muscles.

Pectinate muscles

Ridges of muscle in the anterior part of the right atrium.

Crista terminalis

Landmark in the right atrium used to locate the veins entering the atrium.

Fossa ovalis

Depression in the interatrial septum, a remnant of the foramen ovale.

Papillary muscles

Muscles located in the ventricles that connect to the chordae tendineae.

Apex of the heart

The pointed tip of the heart, located at the left side.

Base of the heart

The broad, superior aspect of the heart where major blood vessels attach.

Interventricular septum

The muscular wall that separates the right and left ventricles.

Interatrial septum

The wall that separates the right and left atria.

Anterior interventricular sulcus

The groove that marks the boundary between the ventricles and is located on the anterior surface of the heart.

Posterior interventricular sulcus

The groove on the posterior side of the heart that indicates the septum between the ventricles.