Bird Heart Diagram Blank – Two Views of a Chicken's Heart

All 15 parts on the diagram

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Outside the heart 8

Right atrium The upper chamber on the bird's right. Blood from the body enters it through three large veins.
Left atrium The upper chamber on the bird's left. Blood comes back to it from the lungs.
Right ventricle The lower chamber that pumps blood to the lungs. Its wall is thin.
Left ventricle The lower chamber that pumps blood to the whole body. It makes up most of the cone.
Apex The pointed end of the heart. In the bird it points toward the tail and a little to the left.
Aortic arch The aorta where it bends over from the heart. In a bird it arches to the bird's right.
Brachiocephalic arteries Two large arteries from the aorta, a left and a right. Each sends blood to the head and a wing.
Pulmonary trunk The artery from the right ventricle. It soon splits in two, one branch to each lung.

The ventricles cut open 7

Right atrioventricular valve A thick flap of muscle between right atrium and right ventricle. It has none of the fine cords of the left valve.
Left atrioventricular valve Thin flaps between left atrium and left ventricle. Fine cords hold them from below.
Chordae tendineae Fine cords from the left valve's flaps down to the papillary muscles.
Papillary muscle A mound of muscle on the ventricle wall. The valve's cords are fixed to it.
Interventricular septum The wall of muscle between the two ventricles. It bulges toward the right one.
Right ventricle wall The thin outer wall of the right ventricle. The chamber inside it is a narrow, curved space.
Left ventricle wall The thick outer wall of the left ventricle. It is several times thicker than the right wall.

How this list was compiled: Every name was checked on 2026-10-01 in two sources, for facts only and with nothing copied: (1) O. Charnock Bradley, The Structure of the Fowl, 1915 (public domain), the chapter on the circulatory system, https://archive.org/details/structureoffowl00braduoft; (2) an open-access study of the heart and great arteries of the common pheasant, a close relative of the chicken, in a veterinary journal, 2026, https://pmc.ncbi.nlm.nih.gov/articles/PMC12802561/; (3) Wikipedia, Bird anatomy, for the four chambers. A part only one of them names is not a part of this page. Licence: own work

The drawing: Drawn for this site on 2026-10-01 from plain geometry; nothing traced. Licence: own work

How it works

This bird heart diagram is blank: a chicken's heart seen from the breast side, first whole and then with the ventricles cut open. Fifteen lines end in empty space, eight on the whole heart and seven on the cut one.

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Eight names on the whole heart

Right atrium, left atrium, right ventricle, left ventricle, apex, aortic arch, brachiocephalic arteries and pulmonary trunk. Seen from the breast, the bird's right is on the left of the sheet, so the narrow band down the left edge of the cone is the right ventricle.

Seven names on the cut heart

Right atrioventricular valve, left atrioventricular valve, chordae tendineae, papillary muscle, interventricular septum, right ventricle wall and left ventricle wall. The two wall lines stop on the outer wall itself, not in the space inside it. The septum line comes down from the top.

The artery that sends two branches up in a V is the aortic arch; the one that forks sideways is the pulmonary trunk.
One line serves both brachiocephalic arteries. It stops on the right-hand branch of the V.
The cords and the mound of muscle they reach have a line each: chordae tendineae above, papillary muscle below.

Questions and answers

Do birds have a tricuspid valve?

Not one of thin flaps. In the fowl the opening from the right atrium to the right ventricle is closed by a strong plate of muscle, which takes the place of the tricuspid valve of mammals. Here it is the right atrioventricular valve.

What is left off the blank bird heart diagram?

The veins that enter the two atria, the three-pocket valves at the foot of the aorta and the pulmonary artery, and the coronary arteries. Each would crowd a small heart, so none has a line.

Is there an answer key for the bird heart diagram?

Yes. The key is the same two views with all fifteen names. Two are shortened to fit, to Right AV valve and Left AV valve. AV stands for atrioventricular: between an atrium and a ventricle.