Head and neck blood vessels, cervical plexus

Question 1

Pathway of internal common carotid artery

Answer 1

1. Branches of at C4 from right or left common carotid artery
2. Passes through carotid canal
3. Enters skull as cranial artery to supply brain

Question 2

External common carotid artery pathway

Answer 2

1. Branches of at C4 from common carotid
2. Branches into 3 arteries
   - facial artery, which enters face at anterior mass ether and lower mandible border
   - superficial temporal artery - ascends in front of external acoustic meats to supply lateral scalp
   - Maxillary artery -enters face behind the TMJ joint to supply deep cavities of the face

Question 3

Subclavian artery divisions and supply

Answer 3

1. vertebral - pass through transverse foreamen c1-c6 and through foramen magnum to supply brain
2. costocervical- supplies intercostal and neck (levator and selenium)
3. thyrocervical - branches of behind vertebral artery to supply thyroid gland and neck root supply
   - branches into transverse cervical (for Trapezius) and suprascapular nerve
4. Internal thoracic - enters thorax on both sides of sternum and branches off into anterior intercostal arteries and superior epigastric artery

Question 4

Cervical plexus

Answer 4

A somatic plexus formed by ventral rami of C1-C4 spinal nerves
- motor branch reach skeletal muscles
- sensory branches supply the skin

Question 5

Sensory branches of cervical plexus and supply

Answer 5

Lesser occipital (C2)- supplies skin at back of head
Greater auricular (C2) - supplies skin on posterior ear and skin on mastoid process
Transverse cervical (C3) - runs horizontally on neck to supply anterior triangle
Supraclavicular (C3,C4) - descends down to chest to supply upper chest and skin at root of neck

Question 6

Motor branches of cervical plexus and their supply

Answer 6

Superior root to ansacervicalis (C1) - branches into geniohyoid and thyrohyiod before, then supplies infrahyoid muscles
Inferior root ansacervicalis (C2, C3) - supply remaining infrahyoid
Phrenic (C3,C4, C5) - runs in front of anterior scalene to supply diaphragm