Cranial Cavity, dural sinues (veins). Innervation of Head and Neck Flashcards
How is Circle of Willis formed?
not the best arterial anastomoses
PRIMARILY BLOOD FROM 2 AA-
1. INTERNAL COMMON CAROTID A.
2. RL VETERBRAL A.
INTERNAL COMMON CAROTIS HAD NO BRANCES IN NECK
Neck-
RAortic arch__Brachiocephalic a._R sublcavian_R carotid
L Aortic arch_R subclavia_R carotid
R/L Subclavian_R/L vertebral a. (ENTER transvers foramina)(ENTER foramen magnum)
RL vertebral aa. from._Basilar (ant. a on bone FX red flag)
Basilar a__Post and Ant. cerebral aa.
Internal carotid (enter carotid canal) _opthalmic a, middle a., anterior cerebral a.
Anterior communicating-connects circle (horizontal btwn RL anterior cerebral)
Posterior communicating-connects circle (vertical connections btwn RL ICA.
What are the Dorsal Rami of Cervical spinal nerves?
T1-L2
No GVEs in cranial cavity
Where/what is the Cervical Plexus?
Ventral rami C1-C4
Describe route of GVEs (pre) and post in the head and neck?
All GVEs (pres) synapse in the superior cerical ganglion of the sympatheic train
Where is the subarachnoid?
btwn pia and acrahnoid. CSF fluid is withing this space.
what is the Epi/Extradural space?
there is no dural space. thus when injury blood accumulates above dura mater (btwn dura and bone) and pushes on brain
Location of the Subdural?
Space btwn dura and arachnoid.
Blood hemorrhage is venous, from tearing of vein after blow to head. Brain moves, bt dura attached to bone doesn’t move, thus tears.
What is clinical relevance btwn dural sinuses and veins external to the cranial cavity
CAvernous communicates with
- superior ophthalmic vein
- Pterygoid venous plexus
- Inferior ophthalmic vein
- Central v. of the retina
Describe Cranial Hemorrhages-Extra/Epidural
Lateral blow to the head may rupture ant. division of mid meningeal artery (branch of maxillary artery crosses pterion)= EXTRADURAL hemorrhage
Subarachnoid-arterial in orgin. Spinal tap for CSF check
Describe Cavernous sinus thrombosis
pieces of infected clots fro external veins . May affect other structure traveling through. Resulting in meningitis.
common-infections in orbit, nasal sinues, superior part of face.
What are fontanelles?
soft spots of fibrous tissue membranes on unossified bones in newborns. Ant closed 18mo. Bulging up or low indicate low or high pressure.
What is the Fascia of head?
all comparts enveloped in fascia. This creastes space but also, crease risk of infection potential space
What are the Cranial meinges?
Pia mater- deepest and delicate. Follows sulci and gyri
Arachnoid Mater- middle delicate membrane connected to pia mater by TRABECULAE
Encloses subarachnoid space which contains CSF.
Dural Mater
What are the Dural sinuses?
CSF- drains to the venous system via arcachnoid granulaions
Layers of the Dura Mater
ottermost tough lat
Falx cerebri-btwn cerebrums. on innue surface of calvarium, deep to sagital suture) from frontal crest and crista galli(ant) to internal occipital protuber (post), continuous w/ tentorium cerebelli
Falx cerebelli-btwn cerbellar, internal to occipital crest, superiorly becomes continuous w/ tentorium cerebelli
Tentorium cerebelli- btwn cerebrum and cerebellum
ANt- attached to clinoid process
Antlat- attaced to petroucs crest
Post- attached to parietal and occipitalbones
Diaphragma sellae- holds pituitary gland down in the hypophyseal fossa of the sphenoid bone
Where are the Dural Folds?
Dura mater- outtermost toughest layer connected to skull.
1. Inner meningeal layer (continue w/ dura mater of spinal cord 2. Outer periosteal layer
creates DURAL FOLDS- dural matter folds and creates compartments that support the brain. Formed where the inner(internal) meningeial layer separates from the outer (external periostial layer)
What are Arachnoid granulations?
prolongations of the arachnoid, protrudes through menegial dura mater. provide absorbtion of excess CSF into he venus system
name the Viscerocranium Bones
ethmoid (unpaired) lacrimal nasal maxilla mandible sphenoid (unpaired) zygoma
name the neurocranium
Frontal bone Parital Ethymoid Sphenoid Temporal bone Occipital
Metopic suture
Most sutures close up to 8yrs. IF unclosed on an adult this can be seen.
Superior sagittal sinus
within root of falx cerebri
ends at Conflueenc of sinues
Has lateral venous laccunae
common site for transfer of CSF to the venous system via arachniod granulations
Confluence of sinuses
located in interna occipatl progtuerance.
Superior sagital, straight, occipital, and tranveser sinuses all communicate here
Inferior sagital sinues
free inferior edge of falx cerebri
Straight sinsus
fomred by inferior sinue sand great cerebral vein of Galen
runs btwn falx cerebri, tentoriusm cerebelli
