22. The anatomy of the pulmonary circulation, topography and branches of the pulmonary trunk.

Question 1

topgraphy of pulmonary trunk

Answer 1

Origin:
Begins at the conus arteriosus of the right ventricle.

Course:
Ascends obliquely, slightly posteriorly, and to the left.
Located within the pericardium.

Bifurcation:
Occurs around the level of the sternal angle (T4-T5 vertebral level).

Relations:
Anteriorly: Lies behind the sternum.
Posteriorly: Related to the left atrium and the root of the aorta.
Laterally: Related to the right and left pulmonary arteries after bifurcation.

Question 2

branches of pul trunk

Answer 2

Right Pulmonary Artery:

-Branches within the right lung:
Lobar Arteries: Each supplies a lobe of the right lung.
Segmental Arteries: Each supplies a bronchopulmonary segment.

Left Pulmonary Artery:

-Branches within the left lung:
Lobar Arteries: Each supplies a lobe of the left lung.
Segmental Arteries: Each supplies a bronchopulmonary segment.

Question 3

circulation process

Answer 3

Deoxygenated Blood:

Right ventricle → Pulmonary trunk → Right and left pulmonary arteries → Lobar arteries → Segmental arteries → Pulmonary capillaries.

Gas Exchange:
Occurs in the pulmonary capillaries surrounding the alveoli.
Carbon dioxide is exchanged for oxygen.

Oxygenated Blood:
Pulmonary capillaries → Segmental veins → Lobar veins → Pulmonary veins → Left atrium.