PBL 1 Flashcards
what are the 2 functions of the meninges?
to provide a supportive framework for the cerebral and cranial vasculature
to act with the CSF to protect the CNS from mechanical damage
what are the 2 connective tissue layers of the dura matter?
endosteal layer (lines inner surface of bone of cranium) meningeal layer (lines endosteal layer)
where are the dorsal sinuses found?
between the endosteal and meningeal layers of the dura matter
what are venous sinuses responsible for?
Venous vasculature of the cranium, draining into the internal jugular veins.
what are arachnoid granulations?
structures filled with CSF that extend into the venous sinuses through openings in the dura mater and allow the drainage of CSF from subarachnoid space into venous system
what are the 3 layers of the meninges from superficial to deep?
dura mater, arachnoid mater, pia mater
what are the 2 groups of bones of the skull?
cranial bones and facial bones
what makes up the cranial bones?
frontal bone, parietal bone, temporal bone, occipital bone, sphenoid bone, ethmoid bone
in which bone is the foramen magnum found?
at the base of the occipital bone
what are the layers of the scalp?
skin, connective tissue, epicranial aponeurosis, loose areolar connective tissue and periosteum
where does the epicranial aponeurosis run from and to?
from the frontal muscle to the occipitalis
what is the function of the periosteum?
to provide nutrition to the bone and the capacity for repair
what are the 2 main arteries that supply blood to the brain?
internal carotid artery and vertebral arteries
what is the function of the circle of Willis?
to provide collateral blood flow between the anterior and posterior circulations of the brain, protecting against ischemia in the event of vessel disease or damage in one or more areas
describe the path of the internal carotid artery?
They originate at the bifurcation of the left and right common carotid arteries, at the level C4.
They move superiorly within the carotid sheath, and enter the brain via the carotid canal of the temporal bone.
Once in the cranial cavity, the internal carotids pass anteriorly through the cavernous sinus
what does the internal carotid artery give rise to?
ophthalmic artery posterior communicating artery middle cerebral artery anterior choroidal artery anterior cerebral artery
describe the cerebral venous drainage?
The cerebral veins empty into the dural venous sinuses situated within the subarachnoid space.
what do the superficial veins of the cerebrum drain into?
superior sagittal sinus
what do the deep veins of the cerebrum drain into?
transverse, straight and sigmoid sinuses
outline the pathology of subdural bleeds
usually a tear of cerebral veins occurs causing blood to escape from the blood vessel and form a blood clot/haematoma that puts pressure on the brain and damages it
what are the common causes of subdural bleeds?
RTCs, brain atrophy in elderly patients and alcoholics, assault
how do subdural bleeds present?
headache, feeling/being sick, confusion, personality changes, feeling drowsy, loss of consciousness