Vasculature Of The Head Flashcards
What is the main arterial blood supply to the meninges?
Middle meningeal artery (arising from foramen spinosum)
Which nerve innervates the meninges?
CN V1-3
What is cerebrospinal fluid?
A clear colorless liquid that circulates in the ventricles and subarachnoid space
Bathes the exposed surfaces of the CNs and completely surrounds it
What are the functions of CSF?
Buoyancy, protection and environmental stability
What is CSF formed by?
The choroid plexus in each ventricle of the brain and is produced by secretion of fluid from the ependymal cells that originate from blood plasma
What is the concentration of ions in CSF?
Similar to blood plasma but has greater amounts of Na, H and Ca, but less K
Describe the drainage of CSF to DV sinuses
Located within the subarachnoid space -> through arachnoid granulations/villi —> to dura venous sinuses
What are emissary and diploic veins?
Drainage of CSF from the scalp (emissary) and bone (diploic)
What is hydrocephallus?
“Water on the brain”
Typically from an obstruction in CSF flow that restricts its reabsorption in the venous bloodstream
Causes downward rotation of the eyes and a large swollen head
How is hydrocephallus treated?
By inserting a ventriculoperitoneal shunt that drains to the abdominal cavity
Or a ventriculostomy (ETV) that creates a hole in the floor of the 3rd ventricle that drains into the subarachnoid space
Describe the venous drainage of the superficial face and scalp
Superficial temporal vein -> posterior branch of retromandibular vein -> external jugular vein
Facial vein -> anterior branch of retromandibular vein -> internal jugular vein
Which two veins form the external jugular vein?
Posterior auricular and retromandibular veins
The internal jugular vein receives blood from which veins?
Facial, lingual, occipital, superior and middle thyroid veins
Describe venous drainage of the orbit and eyeball
Supra-orbital vein -> superior ophthalmic and angular vein (to cavernous sinus)
Facial vein -> inferior ophthalmic and angular vein (to pterygoid venous plexus)
What are the branches of the common carotid?
Internal and external carotid
Forms a carotid sinus superior to the bifurcation of branches
What are the baroreceptors of the carotid sinus innervated by and what is its function?
Glossopharyngeal nerve (CN IX) Indirectly modulates activity of sympathetic and parasympathetic response to blood pressure
What is the mnemonic for external carotid branches?
Some - superior thyroid A Anatomists - ascending pharyngeal A Like - lingual A Freaking - facial A Out - occipital A Poor - posterior auricular A Med - maxillary A Students - superficial temporal A
Which arteries does the superior thyroid A give rise to?
Infrahyoid, superior laryngeal and sternocleidomastoid branch
The superior laryngeal A runs with what structure?
Superior laryngeal N
What does the ascending pharyngeal A supply?
Pharynx musculature
What is the arterial course of the lingual artery?
Obliquely upwards and medially to the greater horns of the hyoid bone
Curves down and forward passing beneath the digastric and stylohyoid M (crossed by the hypoglossal N)
Runs deep to hyoglossus M
What are the terminal branches of the lingual artery?
Sublingual and deep lingual arteries
What does the sublingual A supply?
Sublingual gland and oral floor
What does the deep lingual A supply?
Base of the tongue
What structure does the deep lingual A run with?
Lingual N (superficial to hyoglossus M)
What is the arterial course of the facial A?
Arises in carotid triangle
Runs beneath digastric and stylohyoid M (superficial to hypoglossal N)
Enters groove on posterior submandibular gland
Curves upward over the body of the mandible running anteroinferior to masseter M
Runs obliquely past the nose
What are the cervical branches of the facial A?
Ascending palatine (pharyngeal wall, soft palate, pharyngotympanic tube) Tonsillar branch (palatine tonsils) Submental and glandular branches (submandibular and oral floor)
What are the facial branches of the facial A?
Inferior labial A, superior labial A, lateral nasal branch and angular A
What is the terminal branch of the facial A?
Angular A
What is the arterial course of the occipital A?
Arises in carotid triangle from posterior aspect of the external carotid A
Runs posterior and upwards
Terminal portion runs with greater occipital N