Brain Blood Supply

Question 1

Vascular components of brain and brainstem

Answer 1

Internal carotid arteries, maxillary artery and basil are artery

Vertebral to brainstem

Question 2

Circle of Willis

Answer 2

Surrounds pituitary

Provide all blood to the brain

Rostral, middle and caudal cerebral arteries from here

Question 3

Internal carotid

Answer 3

Main supply in dog and horse

Rudimentary in car and cow, have rete mirabile system, room smaller vasculature

Question 4

Rete mirabile

Answer 4

Vascular redundancy or collateral paths of blood to the brain

Can compensate for carotid blockage and avoid brain damage

Cow

Question 5

Circle of Willis makeup

Answer 5

Basilar supplies majority of blood to the brain

Cerebral hemispheres supplied by 3 cerebral arteries

Cerebellum by 2 pairs of arteries

Left and right internal carotids feed the circle

Question 6

Dog/horse/human

Answer 6

In dogs maxillary artery is a significant contribution to the internal carotid

Dogs can have rudimentary rete

Pharyngeal arteries can also anastomose along with external ophthalmic and ethmoidal arteries

Vertebrobasilar system supplies blood to cerebral hemispheres via caudal cerebral arteries

Question 7

Cat/small ruminants

Answer 7

Internal carotid A regress after birth

Blood supply to circle via numerous small dorsal branches of maxillary arteries

Rostral epidural rete mirabile which coalesce into intracranial carotid arteries supplying cerebral arteries

Vertebrobasilar arteries though present have reduced contribution to the brain

Blood flow directed caudal in basilar artery so cerebral hemispheres sourced room intracranial internal carotid

Question 8

Cow

Answer 8

Internal carotid regress and replaced by maxillary arteries which supply rete mirabile and intracranial off of here

Caudal rete connects to rostral

Vertebral arteries and spinal branches contribute to caudal rete which connects to rostral rete so the vertebrobasilar system contributes to whole Brain

Question 9

Cetaceans

Answer 9

After exiting heart supply complex anastomoses

Almost all blood to circle of Willis supplied by epidural retia rather than carotid branches

Question 10

Dog anastomoses

Answer 10

5 can contribute to brain supply so can avoid defects when carotid and vertebral arteries are blocked

Occipital and vertebral

Ascending pharyngeal and internal carotid

Intracranial and maxillary

Maxillary and internal carotid

Ophthalmic and carotid

Question 11

Venous drainage

Answer 11

Internal and external jugular veins and vertebrobasilar veins

Question 12

Internal jugular vein

Answer 12

Begins as sigmoid and ventral petrodollars sinuses which join the vertebral vein

Question 13

Maxillary vein

Answer 13

Branch of external jugular

Retroarticular vein connection from the temporal Dural sinus

Question 14

Vertebral veins

Answer 14

Bilateral, receive blood from Brain through sigmoid sinus and vein of the hypoglossal canal

Question 15

Internal vertebral venous plexus

Answer 15

Basilar sinuses

Numerous anastomoses connect to the external vertebral plexus that surrounds cervical and cranial thoracic vertebrae

Question 16

Emissary vein

Answer 16

Join with ophthalmic, pterygoid and palatine plexus

Also connect cavernous sinuses and maxillary vein

Question 17

Intracranial veins

Answer 17

Directly drain the brain

Plain veins draining parts of the surface of the brain

Dural veins/ sinuses within subarachnoid and intradural spaces

Question 18

Dural veins and sinuses

Answer 18

Receive the blood draining into the cerebral veins

Question 19

Intracranial vein drainage

Answer 19

Cortical and central veins which have different draining

Cortical veins turn to dorsal and ventral cerebral which drain into dorsal Sagittal and petrosal sinuses

Central veins drain into great cerebral

Question 20

Cortical veins

Answer 20

Dorsal and ventral cerebral veins which drain the cortex and nearly the whole cerebrum

Question 21

Central veins

Answer 21

Drain the great cerebral vein, corpus callosal, basal , internal cerebral and thalamostriate veins

Question 22

Brainstem veins

Answer 22

Medullary and pontine veins

Question 23

Dog cavernous sinuses

Answer 23

Significant portion of blood from Dural sinuses also drains into neural canal of the vertebral column

Vertebral plexus receive large volume of the blood draining from the CNS

Question 24

Species variation in venous drainage

Answer 24

Aquatic mammals have an increased dependence on epidural venous drainage of blood from the brain

Question 25

Brain cooling and pulse dampening

Answer 25

Sensitive to temperature changes

Veins regulate temperature and cool arteries to prevent dysfunction

Lack of carotid rete precludes cooling

Carotid rete and epidural retia have pulse dampening effect

Question 26

Extracranial veins

Answer 26

Jugular veins and vertebral veins

Internal and external vertebral venous plexus
Internal within neural canal, external around vertebral column

Question 27

Spinal cord arterial supply

Answer 27

Cervical- vertebral arteries

Thoracic spinal cord- dorsal and supreme intercostal arteries

Lumbar spinal cord- lumbar dorsal segmental arteries

Question 28

Pia network

Answer 28

Anastomoses between dorsal and ventral root arteries and ventral spinal artery

White matter supplied by Pial network, and gray matter by ventral spinal artery

Question 29

Spinal cord venous drainage

Answer 29

1. Central veins, radial veins and coronal plexus (pial)
2. Ventral median and dorsal spinal veins
3. Radicular and medullary veins
4. Internal and external vertebral plexus
5. Intervertebral veins

Question 30

CNS components

Answer 30

Blood, neural tissue and cerebrospinal fluid

Increase in volume increases pressure

Question 31

Internal and external carotid brain supply

Answer 31

Internal to external

Horse, dog, cat then cow

Question 32

3 main paths of blood to the brain

Answer 32

Internal And external carotid and vertebral artery

Question 33

3 main blood drainage from the Brain

Answer 33

Internal and external jugular and vertebrobasilar/ epidural veins

Internal and external jugs in soft tissue so can have pressure increase

Collateral epidural venous system protected inside neural canal

Question 34

Blood supply to spinal cord review

Answer 34

Begins in aorta and moves up segmental arteries which give off spinal Ramus which enters neural canal and divides into dorsal and ventral root arteries

Ventral medullary artery enters the median ventral spinal artery and dorsal medullary artery enters one of the dorsal spinal arteries