flat bones of the skull and the base of skull 1) frontal, 2) occipital, 3) ethmoid, 4) sphenoid, 5) paired parietal bones, 6) paired temporal bones
What 14 bones comprise the viscerocranium?
consists of the bones of the face that develop from the pharyngeal arches in embryologic development: 1) mandible, 2) vomer, 3) paired lacrimal bones, 4) paired nasal bones, 5) paired palatine bones, 6) paired inferior turbinate bones, 7) paired maxillary bones, 8) paired zygomatic bones
Name the 5 dense connective tissue joints that separate the flat bones during infancy or fetal life?
Describe the loose connective tissue layer of the scalp
allows free movement of the scalp over the cranium; contains the emissary veins through which infection can easily spread to the intracranial sinuses; sponge-like layer w/ potential spaces that can potentially distend w/ fluid
Dura mater of the cranium
2-layered membrane consisting of external periosteal layer & internal meningeal layer, which is continuous w/ the dura of the vertebral canal & forms the dural infoldings/reflections that divide the cranial cavity
Dural infolding that extends between the cerebral hemispheres; contains the inferior sagittal sinus and superior sagittal sinus
Dural infolding extending between the cerebellar hemispheres
dural infolding; supports the occipital lobes of the cerebral hemispheres and covers the cerebellum; encloses the transverse & petrosal sinus
Dural infolding; forms the roof of the sella turcica covering the hypophysis
What is the arterial supply of the dura mater?
middle meningeal artery (branch of the maxillary artery) it branches into anterior and posterior branches
What is the venous drainage of the dura mater?
middle meningeal veins-->drain into pterygoid plexus
What is the innervation of the dura mater?
Meningeal branches from CN V1, CN V2, CN V3 supply most... Meningeal dura of the posterior cranial fossa is innervated by the C1, C2, and C3 spinal nerves and by CN X.
Describe the arachnoid layer of the brain
-connected to the pia mater by the arachnoid trabeculae -seperated from the pia mater by the subarachnoid space (CSF-filled; enlargements are subarachnoid cisterns) -projects arachnoid villi into the cranial venous sinues
Where does CSF diffuse into venous blood?
arachnoid villi form collections called arachnoid granulations that project into the cranial venous sinuses; serve as sites where CSF diffuses into the venous blood
Describe the pia mater
-shiny, delicate, closely applied to brain -cerebral arteries penetrate as they enter the brain, reflecting it onto the surface of the cerebral artery as the tunica adventitia
Headaches are associated with...
Dura mater is sensitive to pain; if irritated or stretched, a headache results were pain is referred to regions supplied by CN V
-inflammation of the pia arachnoid area of brain &/or spinal cord -Group B strep, E. coli, Listeria monocytogenes, S. pneumo, N. meningitidis -pain, fever, headache, nuchal rigidity, Kernig sign -decreased glucose, increased protein, numerous neutrophils
-caused by mumps, echovirus, Coxackie virus, EBV, HSV-2 -CSF shows numerous lymphocytes, normal glucose levels, increased protein levels -Fever, headache, nuchal rigidity, Kernig sign
What artery forms the anterior circulation of the circle of Willis?
the internal carotid artery
Describe the opthalmic artery
a branch of the internal carotid artery; enters the orbit w/ optic nerve (CN II) & branches into the central artery of the retina occlusion can result in monocular blindness
Describe the anterior cerebral artery
a branch of the internal carotid artery; supplies the motor cortex & sensory cortex for the leg occlusion results in contralateral paralysis and contralateral anesthesia of the leg
Describe the middle cerebral artery
a branch of the internal carotid artery; occlusion of the main stem results in contralateral hemiplegia and contralateral hemianesthesia, homonymous hemianopia, and aphasia if the dominant hemisphere is involved
Describe the lenticulostriate arteries (deep branches) or lateral striate
-branches of the middle cerebral artery; supply the basal ganglia & internal capsule occlusion results in "paralytic stroke" w. contralateral hemiplegia & poss. contralateral hemianesthesia
What does destruction of descending motor fibers of posterior limb of internal capsule cause?
What does destruction of ascending sensory thalamocortical fibers in the internal capsule cause?
What most commonly causes strokes?
Occlusion of cerebral vessels by thrombosis or embolism (not hemorrhage)
What cerebral arteries are prone to hemorrhagic infarction? Why?
lenticulostriate arteries due to hypertension or atheroschlerotic occlusion since these arteries branch at right angles
Describe the outer cortical branches
-branches of the middle cerebral artery -supply motor and sensory cortex for the face & arm -occlusion results in contralateral paralysis & contralateral anesthesia of the face & arm
Describe anterior communicating artery
-connects the 2 anterior cerebral arteries -most common site of an aneurysm; if ruptured would result in a subarachnoid hemorrhage & bitemporal lower quadrantanopia (due to proximity to optic chiasm)
Describe posterior communicating artery
-connects the anterior circulation of the circle of Willis -second most common site of an aneurysm; if ruptured, would result in subarachnoid hemorrhage & possibly oculomotor nerve (CN III) paralysis
What are the symptoms of oculomotor nerve paralysis?
droopy upper eyelid, eye looks down & out, diplopia, ficed & dilated pupil, lack of accomodation
Want to see the other 75 Flashcards in HEAD (HYGA)?JOIN TODAY FOR FREE!