Lecture 3: Head and Neck Vasculature I: Sinuses and Veins Flashcards
Most of the CSF is produced by the ________ of the _______.
Most of the CSF is produced by the choroid plexuses of the lateral, third, and fourth ventricles
CSF is resorbed in the ______.
Arachnoid villi
Atrophy of the cerebral cortex may result in ______.
External Hydrocephalus
Occlusion of the cerebral aqueduct would result in _______ of the ______ and _________
Occlusion of the cerebral aqueduct would result in hydrocephalus of the 3rd and lateral ventricles
Occlusion of the right interventricular foramen would result in _____ of the _______.
Occlusion of the right interventricular foramen would result in Hydrocephalus of the Lateral Ventricle
Obstruction of the subarachnoid space at the level of the tentorial notch may result in _________.
Communicating Hydrocephalus
CSF enters the subarachnoid space via the ________ and ________.
Medial and Lateral Foramina
Secondary to a subarachnoid hemorrhage blood in the CSF may occlude the _______ and result in _________.
Secondary to a subarachnoid hemorrhage blood in the CSF may occlude the Arachnoid villi and result in secondary (chemical) Meningitis.
Retromandibular vein is formed by which 2 veins?
Superficial Temporal V. + Maxillary V.
Where is the Pterygoid plexus of veins and what does it drain into?
- Extensive venous network located on lateral surface of the medial pterygoid muscle and surrounding lateral pterygoid muscle
- Drains into: deep facial, maxillary, and retromandibular veins
What are the main differences between the superior bulb versus inferior bulb of the IJV; where is each located?
- Superior bulb is in the jugular fossa and does not have a valve
- Inferior bulb is posterior to the interval between sternoclavicular heads of the SCM, and has a valve
What are the Pericervical lymph nodes and where do they drain?
- Form a “collar” of superficial LN’s around the base of head
- Include the: occipital, mastoid, parotid, submandibular, buccal, and submental group
- Drain directly into the: deep cervical LN’s
What are the Superficial Cervical LN’s; where are they found; where do they drain?
- Two groups
- Posterior Superficial Cervical LN’s adjacent to the external jugular vein in the posterior (lateral) triangle
- Anterior Superficial Cervical LN’s adjacent to the anterior jugular vein in the anterior triangle
- Both groups drain into the: deep cervical LN’s
Where are the Deep Cervical LN’s located; which 2 are most important; which group is related to the tonsils?
- Located along the length of the IJV
- Jugulo-digastric nodes = tonsillar
- Jugulo-omohyoid nodes
Where is the Thoracic duct located; where does it receive lymph from?
- Runs in front of the anterior scalene and behind the left carotid sheath
- Is located only on the left side of the root of the neck
- Receives lymph from the left side of the head, and all of the body except the RUE and head
Where is the lateral ventricle and what forms its borders?
- C-shaped, arc-shaped cavity in core of each cerebrum (right and left)
- Corpus callosum forms the lateral walls, and the caudate nucleus in on its floor
What is the interventricular foramen of Monroe and why is it clinically significant?
- Connects the lateral ventricles to the third ventricle
- One of both foramina may be obstructed by tumors such as a choroid plexus ependymomas in the third ventricle
The thoracic fuct drains into the __________.
IJV/subclavian vein junction
The retromandibular vein has a direct relationship with the ______nerve.
Facial
The distal branches of the inferior thyroid artery have a direct relationship with the _______ nerve.
Recurrent laryngeal nerve
The _______ is embedded in the prevertebral fascia just posterior to the common carotid artery.
Cervical sympathetic chain
Where is the third ventricle and what is it connected to?
- Thin vertical chamber in the midline between the thalami
- Continous with the lateral ventricles via the interventricular foramina
- Continous with the fourth ventricle via the cerebral aqueduct
A midbrain tumor such as astrocytomas may obstruct the cerebral aqueduct and lead to?
Hypertrophy of the lateral and third ventricles (supratentorial internal hydrocephalus)
What is the central canal of the brain?
A cul-de-sac extending from the obex of the fourth ventricle to C5-8
Pathologically, the central canal may enlarge and develop a cavity (syrinx) in the center of the cord (myelia), what is this condition called and what do patients complain of?
- Syringomyelia
- Complain of bilateral anesthesia of the shoulders and upper limbs
The fourth ventricle is shaped like a four-sided pyramid and what are each of its sides continous with?
- The third ventricle via the cerebral aqueduct
- Cerebellomedullary cistern via the medial and lateral foramina
- Blind-ending central canal at the obex, which becomes central canal of spinal cord
The brain is floating in the CSF-filled _________ space, which is bounded by ______ and ________ mater
The brain is floating in the CSF-filled subarachnoid space, which is bounded by pia mater and arachnoid
What is the cerebellomedullary cistern (cisterna magna)?
Large CSF-filled space just above the foramen magnum and posteior to the medulla
How many mL of CSF in ventricles, in the entire system, and produced each day?
- 20-25 mL in the ventricles
- 140 mL in the system
- 600-700 mL produced each day
What is the Hydrocephaly?
Increase in cerebral mass and/or size due to presence of an excessive amount of CSF in the ventricular system, the subarachnoid space, or both
External Hydrocephalus is an excessive accumulation of CSF where; what are the 2 types?
- In the subarachnoid space
1) Supratentorial is most commonly associated with senile atrophy of the cortex, i.e., Alzheimer’s disease
2) Infratentorial is seen in combination with communicating hydrocephalus
What is Internal Hydrocephalus often called, why?
- Noncommunicating hydrocephalus, because it:
- Does not drain into the subarachnoid space
Internal Hydrocephalus may be caused by obstruction of what 3 strucutres?
1) Interventricular foramen (third ventricle choroid plexus ependymoma)
2) Cerebral aqueduct (midbrain astrocytoma)
3) Medial and lateral foramina (Arnold Chiari malformation, Dandy Walker Cyst)
The superior sagittal sinus usually empties into the ______.
Right transverse venous sinus
The sigmoid sinus empties into the _______ at the ________.
The sigmoid sinus empties into the IJV at the Jugular foramen
The superior opthalmic vein empties into the ________.
The superior opthalmic vein empties into the Cavernous Sinus
The veins of the spinal cord collectively drain into what, which is located in what space?
- Drain into the internal venous plexus of Batson
- Located in the epidural space
What 2 major veins of the cerebral hemisphere drain into the Great Vein of Galen?
1) Internal Cerebral Vein
2) Basal Vein of Rosenthal
What vein drains most of the deep cerebrum and what can obstruction of this vein lead to?
- The great vein of Galen
- Obstruction of this vein is usually fatal
- May also become dilated and form a venous varix; a great vein varix may compress the pineal body and posterior commissure
The superior sagittal sinus drains most of what part of the brain and drains into which vein?
Drains most of the cerebral cortex and empties into the right transverse sinus
Where is the straight sinus formed, what major vein drains into it, and what does the straight sinus drain into?
- Formed at the intersection of the falx and the tentorium
- The great cerebral vein of Galen drains vital deep structures of the cerebrum and empties into the straight sinus
- Straight sinus drains into the left transverse sinus
The confluens receives venous drainage from what sinuses?
Superior sagittal, straight, and occipital sinuses
In 2/3’s of the cases the superior sagittal sinus empties directly into the ________ sinus, and the straight sinus drains directly into the __________ sinus.
- Supeior sagittal sinus empties directly into the right transverse sinus
- Straight sinus drains directly into the left transverse sinus
Thrombosis of the straight venous sinus or left transverse venous sinus results in?
Ischemia and/or necrosis of structures in the deep cerebrum. This is usually fatal
What is a falx herniation?
- Falx cerebri only partially separates the cerebral hemispheres, so unilateral space-occupying lesions of the cerebrum may cause the cingulate gyrus to herniate across the midline beneath the free edge of the falx
- Midline shift
What is a Tentorial or Uncal Herniation?
- Profuse, high-pressured bleeding rapidly expands the epidural space, thereby pressing upon adjacent cerebral hemisphere and herniating the cerbrum under the falx cerebri (falx herniation) and/or through the tentorial notch (tentorial or uncal herniation)
- Compresses and displaces the midbrain
- Bilateral compression of the midbrain reticular formation results in progressive decrease in the level of conciousness
What is Tonsilar Herniation?
- Space expanding or occupying masses in the posterior cranial fossa may cause the cerebellar tonsil to herniate through the foramen magnum, which can compress the lower medulla/upper cervical spinal cord.
- Seen in Arnold-Chirari Malformation
A fracture of the pterion may rupture which artery and lead to?
- Middle meningeal artery
- Epidural hematoma
- Profuse high-ressure bleeding rapidly expans the epidural space, and may cause a midline shift of cerebral hemispheres (falx herniation) and/or an uncal herniation
Increased intracranial pressure applies a cuff-like pressure to the small veins on the optic nerve via of the adjacent subarachnoid extension; what can this lead to?
Decreased venous drainage from the retina results in edema of the retina and swelling of the optic disc (papilledema)
Thrombosis of the posterior portion of the superior venous sinus or right transverse venous sinus results in?
Cortical ischemia and/or necrosis
All of the major blood vessesl supplying the CNS pass through or course in the subarachnoid space, rupture of one of these vessesl in this space is called; clinically how can you determine this?
- Subarachnoid Hemorrhage
- Indicated by the presence of erythrocytes in the CSF
- CSF is usually sampled by inserting a needle into either the cerebellomedullary or lumbar cisterns
Trauma to which veins may lead to rupture and a Subdural Hematoma?
- Cerebral (bridging) veins
- May rupture as they cross the subdural space
- Same signs and symptoms as epidural hematomas, but their onset may be delayed for days or weeks
