WESLEY D. ANDERSON 
787 
Table II. — Portions of the brain and spinal cord sup- 
plied by the vertebral-basilar system in ten dogs " 
Table II. — (Continued) 
Artery 
Portion of Central Nervous 
System Supplied 
Artery 
Portion of Central Nervous 
System Supplied 
1. Dorsal spinal artery 
Posterior inferior cerebellar 
artery 
Middle inferior cerebellar 
artery 
4. 
Anterior inferior and acces- 
sory anterior inferior 
cerebellar arteries 
6. Superior cerebellar artery 
1. Perforating branches to the 
lateral funiculi of the 
cranial segments of 
spinal cord 
2. Choroid plexus of fourth 
ventricle 
1. Perforating branches to the 
lateral medullary funiculi 
2. Choroid plexus of fourth 
ventricle 
Nodulus 
Uvula 
Pyramis 
Tuber vermis 
Paramedian lobule 
Dorsal paraflocculus 
Ventral paraflocculus 
Flocculus 
Ansiformis 
Choroid plexus of fourth 
ventricle 
Medullary perforating 
branches 
Uvula 
Pyramis 
Tuber vermis 
Paramedian lobule 
Ansiformis 
Dorsal paraflocculus 
Ventral paraflocculus 
Flocculus 
Medullary perforating 
branches 
Pontine perforating 
branches 
Vasa nervorum to cranial 
nerves V. VII and VIII 
Membranous labyrinth by 
labyrinthine arteries 
Choroid plexus 
Ventral paraflocculus 
Dorsal paraflocculus 
Cerebellar peduncles 
Arterial trunk 
a. Perforating branches to 
erus cerebri 
b. Artery to caudal 
colliculus 
c. Perforating branches to 
pontine nuclei 
2. Lateral branch 
a. Rostral portion of dorsal 
paraflocculus 
b. Rostral portion of ven- 
tral paraflocculus 
c. Lateral lobus simplex 
d. Ansiform lobule 
e. Medial and dorsal cere- 
bellar peduncles 
3. Intermediate branch 
a. Medial and dorsal cere- 
bellar peduncles 
b. Culmen 
c. Declive 
d. Lobus simplex 
e. Dorsal paraflocculus 
4. Medial branch 
— Crus cerebri 
— Brachium of caudal colli- 
culus 
3. 
4. 
6. 
6. 
7. 
8. 
9. 
10. 
11. 
1. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 
1. 
2. 
3. 
—Rostral colliculus 
Para ascendens, medial 
branch 
— Central lobule 
—Ascending lobule 
— Ascending lobule 
— Culmen 
— Paramedian lobule 
— Declive 
— Folium 
— Lobus simplex 
— Dorsal portion of ansi- 
formis 
— Tuber vermis 
Pare descendena, medial 
branch 
— Lingual 
— Central lobule 
— Ascending lobule 
— Culmen 
makes the dog an interesting potential experi- 
mental model for the study of diseases of the 
trigeminal nerve, as aberrant arteries have been 
described in the region of the sensory root of the 
trigeminal nerve in man and their accidental 
section during surgery of the sensory root has 
resulted in fatal hemorrhage.^^ 
Although the basilar artery of man generally 
arises from the vertebral arteries at the lower 
border of the pons, more rostrally than in the 
dog, the branches of the basilar artery are 
similar in many respects in the two species. 
With the exception of the middle inferior cere- 
bellar artery not listed in Nomina Anatomica all 
other branches of the basilar artery of man 
may be found in the dog. 
BLOOD FLOW MEASUREMENTS IN 
THE BASILAR ARTERY 
Following the study of the anatomy of the 
vertebral-basilar system in the dog, an inter- 
mandibular-transclival approach to the poste- 
rior cranial fossa was developed which allowed 
exposure of the basilar artery for attachment 
of a small electromagnetic blood flow transducer 
(Figure 32) and basilar blood flow was meas- 
ured in this manner in 15 experiments.^* The re- 
sults of single intravenous injections of betahis- 
tine hydrochloride indicate a mean increase in 
basilar artery blood flow of 54% and a simul- 
taneous decrease in systemic arterial blood 
pressure of a duration of action of approxi- 
