Segmental bronchi

In animals, for bronchoscopic purposes, is described a system of letters and numbers to identify lobar, segmental, and subsegmental bronchi on the basis of their origination and anatomic orientation.

The segmental bronchi arise from the dorsal (“B”), the ventral (“V”), the cranial (“R”or “Cr”) or the caudal (“C”or “Cd”) surfaces of the lobar bronchi and named subsequently.

Lower case (“a” and “b”) represent subsegmental bronchi.

For example, here is listed  the principal lobar and segmental bronchi of the dog as they are usually described in the main sources (MIller, Isaac…). The segmental bronchi arise from the dorsal (“B”) and ventral (“V”) surfaces of the lobar bronchi except the right middle lobe where they arise from the cranial (“R”or “Cr”) and caudal (“C”or “Cd”) surfaces:

• Right main bronchus (RBP)

  • Right cranial lobar bronchus (RB1)

    • Dorsal segmental bronchi from the right cranial lobar bronchus (RB1D)

      • RB1D1: first dorsal segmental bronchus from the right cranial lobar bronchus

      • RB1D2: second dorsal segmental bronchus from the right cranial lobar bronchus

      • RB1D3: third dorsal segmental bronchus from the right cranial lobar bronchus

    • Ventral segmental bronchi from the right cranial lobar bronchus (RB1V)

      • RB1V1: first ventral segmental bronchus from the right cranial lobar bronchus

      • RB1V2: second ventral segmental bronchus from the right cranial lobar bronchus

      • RB1V3: third ventral segmental bronchus from the right cranial lobar bronchus

      • RB1V4: fourth ventral segmental bronchus from the right cranial lobar bronchus

  • Right middle lobar bronchus (RB2)

    • Cranial segmental bronchi from the right middle lobar bronchus (RB2Cr)

      • RB2Cr1: first cranial segmental bronchus from the right middle lobar bronchus

      • RB2Cr2: second cranial segmental bronchus from the right middle lobar bronchus

    • Caudal segmental bronchi from the right middle lobar bronchus

      • RB2Cd1:first caudal segmental bronchus from the right middle lobar bronchus

      • RB2Cd2: second caudal segmental bronchus from the right middle lobar bronchus

      • RB2Cd3: third caudal segmental bronchus from the right middle lobar bronchus

  • Right accessory lobar bronchus (RB3)

    • Dorsal segmental bronchi from the right accessory lobar bronchus (RB3D)

      • RB3D1: first dorsal segmental bronchus from the right accessory lobar bronchus

      • RB3D2: second dorsal segmental bronchus from the right accessory lobar bronchus

    • Ventral segmental bronchi from the right accessory lobar bronchus (RB3D)

      • RB3V1: first ventral segmental bronchus from the right accessory lobar bronchus

      • RB3V2: second ventral segmental bronchus from the right accessory lobar bronchus

  • Right caudal lobar bronchus (RB4)

    • Dorsal segmental bronchi from the right caudal lobar bronchus (RB4D)

      • RB4D1: first dorsal segmental bronchus from the right caudal lobar bronchus

      • RB4D2: second dorsal segmental bronchus from the right caudal lobar bronchus

      • RB4D3: third dorsal segmental bronchus from the right caudal lobar bronchus

      • RB4D4: fourth dorsal segmental bronchus from the right caudal lobar bronchus

      • RB4D5: fifth dorsal segmental bronchus from the right caudal lobar bronchus

      • RB4D6: sixth dorsal segmental bronchus from the right caudal lobar bronchus

    • Ventral segmental bronchi from the right caudal lobar bronchus (RB4D)

      • RB4V1: first ventral segmental bronchus from the right caudal lobar bronchus

      • RB4V2: second ventral segmental bronchus from the right caudal lobar bronchus

      • RB4V3: third ventral segmental bronchus from the right caudal lobar bronchus

      • RB4V4: fourth ventral segmental bronchus from the right caudal lobar bronchus

      • RB4V5: fourth ventral segmental bronchus from the right caudal lobar bronchus

• Left main bronchus (LBP)

  • Left cranial lobar bronchus (LB1)

    • Dorsal segmental bronchi from the left cranial lobar bronchus (LB1D)

      • LB1D1: first dorsal segmental bronchus from the left cranial lobar bronchus

      • LB1D2: second dorsal segmental bronchus from the left cranial lobar bronchus

    • Ventral segmental bronchi from the left cranial lobar bronchus (LB1V)

      • LB1V1: first ventral segmental bronchus from the left cranial lobar bronchus. Note that in the dog, this segmental bronchus is analogous to a left middle lobe bronchus (of lingular bronchus), with its subsegmental bronchi termed as:

        • LB1V1a: first subsegmental bronchi of first ventral segmental bronchus from the left cranial lobar bronchus

        • LB1V1b: second subsegmental bronchi of first ventral segmental bronchus from the left cranial lobar bronchus

        • LB1V1c: third subsegmental bronchi of first ventral segmental bronchus from the left cranial lobar bronchus

      • LB1V2: second ventral segmental bronchus from the left cranial lobar bronchus

      • LB1V3: third ventral segmental bronchus from the left cranial lobar bronchus

      • LB1V4: fourth ventral segmental bronchus from the left cranial lobar bronchus

  • Left cranial lobar bronchus (LB2)

    • Dorsal segmental bronchi from the left caudal lobar bronchus (LB2D)

      • LB2D1: first dorsal segmental bronchus from the left caudal lobar bronchus

      • LB2D2: second dorsal segmental bronchus from the left caudal lobar bronchus

      • LB2D3: third dorsal segmental bronchus from the left caudal lobar bronchus

      • LB2D4: fourth dorsal segmental bronchus from the left caudal lobar bronchus

      • LB2D5: fifth dorsal segmental bronchus from the left caudal lobar bronchus

      • LB2D6: sixth dorsal segmental bronchus from the left caudal lobar bronchus

    • Ventral segmental bronchi from the left caudal lobar bronchus (LB2V)

      • LB2V1: first ventral segmental bronchus from the left caudal lobar bronchus

        • LB2V1a: first subsegmental bronchi of first ventral segmental bronchus from the left caudal lobar bronchus

        • LB2V1b: second subsegmental bronchi of first ventral segmental bronchus from the left caudal lobar bronchus

      • LB2V2: second ventral segmental bronchus from the left caudal lobar bronchus

      • LB2V3: third ventral segmental bronchus from the left caudal lobar bronchus

      • LB2V4: fourth ventral segmental bronchus from the left caudal lobar bronchus

      • LB2V5: fifth ventral segmental bronchus from the left caudal lobar bronchus

      • LB2V6: sixth ventral segmental bronchus from the left caudal lobar bronchus