Blood Supply

Question 1

Subclavian Artery

Answer 1

Scalenus Anterior divide in into 3 part
> 1st gives
- vertebral
- internal thorasic
- thyrocervical - 
—inferior thyroid - thyroid, parathyroid, thymus, cervical part of esophagus
—supra scapular, 
—transverse cervical = superior and deep(sometimes replace dorsal scapular)

> 2nd part - costocervical
3rd part - dorsal scapular

Question 2

Vertebral artery

Answer 2

1st part -
Related to stellate ganglion (Inferior cervical ganglion + 1st thorasic ganglion) near C7

2nd part
- enter Foramen transversarium at C6.
C7 doesn't transmit Vertebral artery.
- run till C1 
- # of vertebra - laceration of vertebral artery

3rd part
- in sub occipital triangle run at Posterior arch of atlas

4th part
- enter cranial cavity through Foramen magnum
Both side join and form basilar artery.

Branch from Vertebral artery

• Anterior ( arise as a one but joint together and form one )and Posterior spinal artery (two) - supply medulla and Spinal cord.
• PICA - supply medulla and cerebellum.

Question 3

Blood supply to medulla

Answer 3

• medullary branch of vertebral artery
• ant and Posterior spinal artery
• PICA
• medullary branch of basilar artery.

Medial medullary syndrome - ant spinal artery
Lateral - vertebral > pica

Question 4

1) branches from basilar artery
2) blood supply to pons
3) labyrinthine Artery
4) blood supply to cerebellum
5) Posterior cerebral artery
6) blood supply to mid brain

Answer 4

1) below to above
medullary
- AICA 
- pontine
- superior cerebellar Artery

2) AICA - involved in lateral pontine syn
- pontine branch
- superior cerebellar Artery

3) labyrinthine Artery
- supplies inner ear
From AICA> basilar

4) superior cerebellar Artery
- AICA
- PICA

5) basilar artery split into two Posterior cerebral artery in midbrain
- supply thalamus and visual cortex
- lesion leads to mid brain syndrome

3 and 4 CN pass through PCA and Superior cerebellar artery

6) Posterior cerebral artery
Branches from basilar Artery
Superior cerebellar Artery

Question 5

Internal carotid artery

Answer 5

Comman carotid artery divide into internal and external at level of C3 - C4 upper border of lamina of thyroid cartilage

Part 1 cervical - no branch in neck
Part 2 petrous
- Enters by carotid canal to traverses superior aspects of foramen lacerum.
Branch
- cortidotympanic Artery
- artery to pterygoid canal
Part 3 cavernous
- meningial branch
- ganglionic branch
- sup and inf hypophyseal branch
Part 4 cerebral
- terminate as middle and ant cerebral artery
- Posterior communicating Artery (joint ICA and PCA)
- Anterior choroidal artery
- opthalmic artery.

Both ACA connect by Anterior communicating Artery.

Question 6

Circle of wills

Answer 6

Anterior cerebral artery
Anterior communicating Artery
Posterior cerebral artery
Posterior communicating Artery

MCA IS NOT INCLUDE

Aneurysm of Anterior communicating Artery - compression f optic chiasma - both side hemianopia
Aneurysm of Posterior communicating Artery : compression of CN 3