Blood Supply to Head & Venous Drainage

• What are the final stages of venous drainage?

  the internal and external jugular, as well as the vertebral

  veins descend towards the base of the neck whereby venous blood is delivered into the brachiocephalic vein.

  
• where does the side of the face and scalp ultimately drains into?

  external jugular vein
• where does the Anterior aspect of face ultimately drains into?

  internal jugular vein
• Where do the different parts of the face drain into?

  Anterior aspect of face ultimately drains into internal jugular vein whilst side of face & scalp goes to external jugular vein

  
• What are the venous sinuses exiting the skull?

  
• What are the venous sinuses?

  1. Sigmoid sinus

  2. Superior petrosal sinus

  3. Ophthalmic vein

  4. Cavernous sinus

  5. Superior petrosal sinus

  6. Sigmoid sinus

  7. Great cerebral vein

  8. Confluence of sinuses

  9. Straight sinus

  10. Superior sagittal sinus

  11. Inferior sagittal sinus
• Where do superficial & deep cerebral veins drain the brain tissue into?

  Vessels, either close to the surface or the great cerebral vein inferiorly

  
• What does the internal carotid artery primarily contribute towards?

  Supplying the brain, after travelling through the carotid canal at the base of the skull.

  
  

  Also supplies the eyes, upper nose & forehead --> ophthalmic arteries

  
• where does the internal carotid artery travel?

  much deeper in the neck and has fewer branches than the external.

  
• the branches of the external carotid do not communicate between both sides of the head

  TRUE/FALSE

  FALSE

  the branches of the external carotid DO communicate between both sides of the head
• the external carotid artery provides a useful target to obtain the carotid pulse or to insert a line.

  TRUE/FALSE

  TRUE
• what arch does the maxillary run deep to?

  the zygomatic arch

  (before branching to provide blood to the deep structures of the face)

  
• Where does the superior thyroid artery arise from?

  Just below the hyoid & descends to supply the thyroid gland

  
• what does the external carotid artery branch off into?

  The external carotid provides several branches that target the face and neck.

  
  

  mnemonic : 'Some Anatomists Like Freaking Out Poor Medical Students'

  - Superior thyroid artery

  - Ascending pharyngeal artery

  - Lingual artery

  - Facial artery

  - Occipital artery

  - Posterior auricular artery

  - Maxillary artery

  - Superficial temporary artery

  
• Where does the common carotid split into the external & internal carotid arteries?

  On either side of the head and close to the upper border of the thyroid cartilage

  
• where does the common carotid artery travel?

  the head

  
• branches of the thyrocervical trunk

  
  

  where does the suprascapular artery run?


  runs behind sternocleidomastoid (SMC) to the superior border of the scapula giving branches to the SCM as it passes

  
• branches of the thyrocervical trunk

  
  

  where does the Transverse cervical artery run?

  passes laterally in front of scalenus anterior and the brachial plexus to supply trapezius

  
• branches of the thyrocervical trunk

  
  

  where does the Ascending cervical artery run?

  ascends between the anterior scalene and longus capiIs, sending small branches to supply the spinal cord and membranes, as well as the bodies of vertebrae

  
• branches of the thyrocervical trunk

  
  

  where does the Inferior thyroid artery run?

  runs superiorly to supply the inferior aspect of the thyroid gland giving muscular branches as well as pharyngeal and inferior laryngeal branches

  
• what does the thyrocervical trunk branch into?

  - Inferior thyroid artery

  - Ascending cervical artery

  - Transverse cervical artery

  - Suprascapular artery

  
• describe the thyrocervical trunk


  A very short, thick vessel that soon branches into supplying the thyroid gland and muscles of the neck.

  
• What is the Circle of Willis?

  A redundancy system of vessels that ensures that the brain receives adequate blood supply- cerebral perfusion- even if 1 of its elements becomes compromised (e.g. narrowed)

  
• What are the greatest contributors of blood to the brain?

  Basilar & internal carotids

  (they also form part of the circle of Willis)

  
• What do both right and left vertebral arteries merge to form?

  Basilar artery

  
• where does the vertebral artery go?

  - Proceeds superiorly within the vertebrae, only providing small spinal arteries to supply surrounding structures

  - This vessel then enters the skull through the foramen magnum

  
• what are the branches of the first part of the subclavian artery?

  (branches of the 1st part are mostly supplying the head and neck)

  - vertebral

  - thyrocervical trunk

  - internal thoracic

  
• how many parts does the subclavian artery have?

  3 parts which are divided by the scalenus anterior (one of the lateral muscles of the neck, belonging to the scalene group)

  
• where does the subclavian artery travel?

  under the clavicle (aka collar) bone to target primarily the arm

  
• What emerges directly from the aorta on the RHS?

  both the carotid and subclavian arteries arise instead from a common branch emerging from out of the aorta called brachiocephalic.

  (the source of blood to the arm (brachium) and head (cephalic))

  
• What emerges directly from the aorta on the LHS?

  Common carotid & subclavian artery

  
• show the branches of the aorta

  
• what are the 4 main arteries are involved in the blood supply to the head and neck region?

  - External carotids

  - Internal carotids

  - Vertebral

  - Thyrocervical trunk

  
  

  (All stem from the arch of the aorta)

  -> First 3 supply the head, while the 4th is confined to the neck

  (the area each supplies do overlap, which allows for collateral blood to reach all areas even if any of these sources becomes compromised)
• how many arteries are involved in the blood supply to the head and neck region?

  4
• why are anastomoses important especially in the head and neck?

  they provide "alternate route" connections from where two or more arteries supply the same body region to provide alternate routes in case of obstruction.
• what are anastomoses?

  systems of channels formed between blood vessels

  (where vessels unite or interconnect)