Meninges, Blood Supply of the Brain, Sinuses Flashcards
The brain, as well as the spinal cord, is surrounded by three layers of membranes called ______.
meninges
What are the three meninges?
dura mater, arachnoid mater, pia mater
The tough, outer layer.
Dura Mater
The delicate, middle layer.
Arachnoid Mater
The inner layer firmly attached to the surface of the brain.
Pia Mater
The ______ meninges are continuous with, and similar to, the spinal meninges through the foramen magnum, with one important distinction — the ______ mater consists of two layers, and only one of these is continuous through the foramen magnum.
cranial, cranial dura
The ______ mater is a thick, tough, outer covering of the brain.
cranial dura
The cranial dura mater consists of an ______ layer and an ______ layer.
outer periosteal, inner meningeal
The ______ layer is firmly attached to the skull, is the periosteum of the cranial cavity, contains the meningeal arteries, and is continuous with the periosteum on the outer surface of the skull at the foramen magnum and other intracranial foramina.
outer periosteal
The ______ layer is in close contact with the arachnoid mater and is continuous with the spinal dura mater through the foramen magnum.
inner meningeal
The two layers of dura separate from each other at numerous locations to form two unique types of structures: ______ and ______.
Dural Partitions, Intracranial Venous Structures
These project inward and incompletely separate parts of the brain.
Dural Partitions
The ______ project into the cranial cavity and partially subdivide the cranial cavity.
dural partitions
The dural partitions project into the cranial cavity and partially subdivide the cranial cavity. They include the?
Falx cerebri, Tentorium cerebelli, Falx cerebelli, Diaphragma sellae
The ______ is a crescent-shaped downward projection of meningeal dura mater from the dura lining the calva that passes between the two cerebral hemispheres.
Falx cerebri
It is attached anteriorly to the crista galli of the ethmoid bone and formal crest of the frontal bone.
Falx cerebri
Posteriorly it is attached to and blends with the tentorium cerebelli.
Falx cerebri
The ______ is a horizontal projection of the meningeal dura mater that covers and separates the cerebellum in the posterior cranial fossa from the posterior parts of the cerebral hemispheres.
Tentorium cerebelli
It is attached posteriorly to the occipital bone along the grooves for the transverse sinuses. Laterally, it is attached to the superior border of the petrous part of the temporal bone, ending anteriorly at the anterior and posterior clinoid processes.
Tentorium cerebelli
The anterior and medial borders of the tentorium cerebelli are free, forming an oval opening in the midline (the ______), through which the midbrain passes.
tentorial notch
The ______ is a small midline projection of meningeal dura mater in the posterior cranial fossa.
Falx cerebelli
It is attached posteriorly to the internal occipital crest of the occipital bone and superiorly to the tentorium cerebelli.
Falx cerebelli
Its anterior edge is free and is between the two cerebellar hemispheres.
Falx cerebelli
It is the final dural projection.
Diaphragma sellae
This small horizontal shelf of meningeal dura mater covers the hypophyseal fossa in the sella turcica of the sphenoid bone.
Diaphragma sellae
There is an opening in the center of the diaphragma sellae through which passes the ______, connecting the pituitary gland with the base of the brain, and any accompanying blood vessels.
infundibulum
The arterial supply to the dura mater travels in the outer periosteal layer of the dura and consists of:
- ______ arteries in the anterior cranial fossa.
- ______ and ______ arteries in the middle cranial fossa.
- ______ artery and other meningeal branches in the posterior cranial fossa.
anterior meningeal, middle, accessory meningeal, posterior meningeal
All are small arteries except for the ______ artery, which is much larger and supplies the greatest part of the dura.
middle meningeal
The anterior meningeal arteries are branches of the ______ arteries.
ethmoidal
The middle meningeal artery is a branch of the ______ artery.
maxillary
The middle meningeal artery enters the middle cranial fossa through the foramen spinosum and divides into ______ and ______ branches.
anterior, posterior
The ______ branch of the middle meningeal artery passes in an almost vertical direction to reach the vertex of the skull, crossing the pterion during its course.
anterior
The ______ branch of the middle meningeal artery passes in a posterosuperior direction, supplying this region of the middle cranial fossa.
posterior
The ______ artery is usually a small branch of the maxillary artery that enters the middle cranial fossa through the foramen ovale and supplies areas medial to this foramen.
accessory meningeal
The posterior meningeal artery and other meningeal branches supplying the dura mater in the posterior cranial fossa come from several sources:
- The posterior meningeal artery, the terminal branch of the ______ artery, enters the posterior cranial fossa through the jugular foramen.
- Meningeal branches from the ______ artery enter the posterior cranial fossa through the jugular foramen and the mastoid foramen.
- A meningeal branch from the ______ artery arises as the vertebral artery enters the posterior cranial fossa through the foramen magnum.
ascending pharyngeal, occipital, vertebral
Innervation of the dura mater is by small meningeal branches of all three divisions of the ______, the ______, and the first, second, and, sometimes, third ______.
trigeminal nerve [V1, V2, and V3], vagus nerve [X], cervical nerves
In the anterior cranial fossa meningeal branches from the ______ nerves, which are branches of the ______, supply the floor and the anterior part of the falx cerebri.
ethmoidal, ophthalmic nerve [V1]
Additionally, a meningeal branch of the ______ turns and runs posteriorly, supplying the tentorium cerebelli and the posterior part of the falx cerebri.
ophthalmic nerve [V1]
The middle cranial fossa is supplied medially by meningeal branches from the ______ and laterally, along the distribution of the middle meningeal artery, by meningeal branches from the ______.
maxillary nerve [V2], mandibular nerve [V3]
The posterior cranial fossa is supplied by meningeal branches from the first, second, and, sometimes, third ______ nerves, which enter the fossa through the foramen magnum, the hypoglossal canal, and the jugular foramen.
cervical
The ______ is a thin, avascular membrane that lines, but is not adherent to, the inner surface of the dura mater.
arachnoid mater
From its inner surface thin processes or trabeculae extend downward, cross the subarachnoid space, and become continuous with the pia mater.
Arachnoid mater
Unlike the pia, the ______ does not enter the grooves or fissures of the brain, except for the longitudinal fissure between the two cerebral hemispheres.
arachnoid
The ______ is a thin, delicate membrane that closely invests the surface of the brain.
pia mater
It follows the contours of the brain, entering the grooves and fissures on its surface, and is closely applied to the roots of the cranial nerves at their origins.
Pia Mater
There is a unique arrangement of meninges coupled with real and potential spaces within the cranial cavity. A ______ space is related to the dura mater, while a ______ space exists between the arachnoid mater and the pia mater.
potential, real
The potential space between dura mater and bone is the ______. Normally, the outer or periosteal layer of dura mater is firmly attached to the bones surrounding the cranial cavity.
extradural space
This potential space between dura and bone can become a fluid-filled actual space when a traumatic event results in a vascular hemorrhage.
Extradural Space
Bleeding into the extradural space primarily due to rupture of a meningeal artery or less often from a torn dural venous sinus results in an ______.
extradural hematoma
Anatomically, a true ______ space does not exist.
subdural
Blood collecting in the subdural space (______) due to injury represents a dissection of the dural border cell layer, which is the most innermost lining of the meningeal dural.
subdural hematoma
______ cells are flattened cells surrounded by extracellular spaces filled with amorphous material.
Dural border
Bleeding due to the tearing of a cerebral vein as it crosses through the dura to enter a dural venous sinus can result in a ______.
subdural hematoma
Deep to the arachnoid mater is the only normally occurring fluid-filled space associated with the meninges, the ______.
subarachnoid space
It occurs because the arachnoid mater clings to the inner surface of the dura mater and does not follow the contour of the brain, while the pia mater, being against the surface of the brain, closely follows the grooves and fissures on the surface of the brain.
Subarachnoid Space
The subarachnoid space surrounds the brain and spinal cord and in certain locations it enlarges into expanded areas (______). It contains ______ and blood vessels.
subarachnoid cisterns, cerebrospinal fluid (CSF)
______ is produced by the choroid plexus, primarily in the ventricles of the brain.
Cerebrospinal fluid
It is a clear, colorless, cell-free fluid that circulates through the subarachnoid space surrounding the brain and spinal cord.
Cerebrospinal Fluid
The CSF returns to the venous system through ______. These project as clumps (______) into the superior sagittal sinus, which is a dural venous sinus, and its lateral extensions, the ______.
arachnoid villi, arachnoid granulations, lateral lacunae
______ is a dilation of the cerebral ventricular system, which is due to either an obstruction to the flow of CSF, an overproduction of CSF, or a failure of reabsorption of CSF.
Hydrocephalus
Cerebrospinal fluid is secreted by the ______ within the ______, ______, and ______ ventricles of the brain.
choroid plexus, lateral, third, fourth
As the CSF is produced it passes from the lateral ventricles through the ______ (the foramina of ______) to enter the third ventricle.
interventricular foramina, Monro
From the third ventricle the CSF passes through the cerebral aqueduct (aqueduct of ______) into the fourth ventricle, and from here it passes into the subarachnoid space via the midline foramen or the two lateral foramina (foramen of ______ and foramina of ______).
Sylvius, Magendie, Luschka
The ______ passes around the spinal cord inferiorly, envelops the brain superiorly, and is absorbed through the arachnoid granulations in the walls of the dural venous sinuses.
CSF
In adults almost ______ of CSF is produced per day.
half a liter
In adults the commonest cause of hydrocephalus is an interruption of the normal CSF absorption through the ______. This occurs when blood enters the subarachnoid space after subarachnoid hemorrhage, passes over the brain, and interferes with normal CSF absorption.
arachnoid granulations
To prevent severe hydrocephalus it may be necessary to place a small catheter through the brain into the ______ system to relieve the pressure.
ventricular
Other causes of ______ include congenital obstruction of the aqueduct of Sylvius and a variety of tumors, where the mass obstructs the aqueduct.
hydrocephalus
Rare causes of hydrocephalus include ______ tumors that secrete CSF.
choroid plexus
In children, ______ is always dramatic in its later stages.
hydrocephalus
The ______ increases the size and dimensions of the ventricle, and as a result the brain enlarges. Because the skull sutures are not fused, the head expands.
hydrocephalus
______ in utero may make a vaginal delivery impossible, and delivery then has to be by caesarean section.
Cranial enlargement
Both ______ and ______ enable a radiologist to determine the site of obstruction and in most cases the cause of the obstruction.
CT, MRI
Leakage of ______ from the subarachnoid space may occur after any procedure in and around the brain, spinal cord, and meningeal membranes. These procedures include lumbar spine surgery, epidural injection, and CSF aspiration.
CSF
In “______” syndrome, CSF leaks out of the subarachnoid space and through the dura mater for no apparent reason.
cerebrospinal fluid leak
______ is a rare infection of the leptomeninges.
Meningitis
The ______ are a combination of the arachnoid mater and the pia mater.
leptomeninges
Infection of the meninges typically occurs via a ______ route, though in some cases it may be by direct spread or from the nasal cavities through the cribriform plate in the ethmoid bone.
blood-borne
Certain types of bacterial inflammation of the meninges are so virulent that overwhelming ______ and ______ with cerebral irritation can cause the patient to rapidly pass into a coma and die.
inflammation, sepsis
Meningitis is usually treatable with ______.
antibiotics
Certain types of bacteria that produce meningitis produce other effects; for example, ______ (ecchymoses) is a feature of meningococcal meningitis.
subcutaneous hemorrhage
The typical history of meningitis is ______ at first.
nonspecific
The patient may have mild headache, fever, drowsiness, and nausea. As the infection progresses, ______ (light intolerance) and ______ may ensue.
photophobia, ecchymosis
Straight leg raising causes marked neck pain and discomfort (______) and an emergency hospital admission is warranted.
Kernig’s sign
Determination of the anatomical structure from which a tumor arises is of the utmost importance, particularly when it arises within the ______.
cranial vault
When assessing any lesion in the brain, it is important to define whether it is ______ (within the brain) or ______ (outside the brain).
intra-axial, extra-axial
Typical extra-axial tumors include ______ (tumors of the meninges) and ______.
meningiomas, acoustic neuromas
______ typically arise from the meninges, with preferred sites including regions at and around the falx cerebri, the free edge of the tentorium cerebelli, and the anterior margin of the middle cranial fossa.
Meningiomas
______ are typically at and around the vestibulocochlear nerve [VIII] and in the cerebellopontine angle.
Acoustic neuromas
Intra-axial lesions are either ______ or ______. By far the commonest type are the ______ brain lesions, which in most cases are metastatic tumor deposits.
primary, secondary, secondary
______ lesions are typically found in patients with either breast carcinoma or lung carcinoma, though many other malignancies can give rise to cerebral metastases.
Metastatic tumor
______ lesions are rare and range from benign tumors to extremely aggressive lesions with a poor prognosis.
Primary brain
______ may occur at any age, though there is a small peak incidence in the first few years of life followed by a later peak in early to middle age.
Primary brain tumors
The brain is a component of the ______.
central nervous system
During development the brain can be divided into five continuous parts. From rostral (or cranial) to caudal they are:
•______ (Cerebrum)
•______
•______ (Midbrain)
•______
•______ (Medulla Oblongata)
TELENCEPHALON, DIENCEPHALON, MESENCEPHALON, METENCEPHALON, MYELENCEPHALON
______ (______) becomes the large cerebral hemispheres. The surface of these hemispheres consists of elevations (______) and depressions (______), and the hemispheres are partially separated by a deep longitudinal fissure.
Telencephalon, cerebrum, gyri, sulci
The ______ fills the area of the cranial cavity above the tentorium cerebelli and is subdivided into lobes based on position.
cerebrum
______, which is hidden from view in the adult brain by the cerebral hemispheres, consists of the thalamus, hypothalamus, and other related structures, and classically is considered to be the most rostral part of the brainstem.
Diencephalon
However, in common usage today, the term ______ usually refers to the midbrain, pons, and medulla.
brainstem
The ______ (______) , which is the first part of the brainstem seen when an intact adult brain is examined, spans the junction between the middle and posterior cranial fossae.
mesencephalon, midbrain
The ______, which gives rise to the ______ (consisting of two lateral hemispheres and a midline part in the posterior cranial fossa below the tentorium cerebelli) and the pons (anterior to the cerebellum, and is a bulging part of the brainstem in the most anterior part of the posterior cranial fossa against the clivus and dorsum sellae).
metencephalon, cerebellum
The ______ (______), the caudalmost part of the brainstem, ends at the foramen magnum or the uppermost rootlets of the first cervical nerve and to which cranial nerves VI to XII are attached.
myelencephalon, medulla oblongata
The brain receives its arterial supply from two pairs of vessels, the ______ and ______ arteries, which are interconnected in the cranial cavity to produce a ______ (of Willis).
vertebral, internal carotid, cerebral arterial circle
The two vertebral arteries enter the cranial cavity through the foramen magnum and just inferior to the pons fuse to form the ______ artery.
basilar
Each vertebral artery arises from the first part of each ______ artery in the lower part of the neck, and passes superiorly through the foramen transversarium of the upper ______ cervical vertebrae.
subclavian, six
Continuing forward, the vertebral artery gives rise to three additional branches before joining with its companion vessel to form the basilar artery:
- The first is a ______ artery.
- A second branch is the ______ artery, which passes posteriorly around the medulla and then descends on the posterior surface of the spinal cord in the area of the attachment of the posterior roots—there are two posterior spinal arteries, one on each side.
- A third branch joins with its companion from the other side to form the ______ artery, which then descends in the anterior median fissure of the spinal cord.
posterior inferior cerebellar, posterior spinal, single anterior spinal
The basilar artery travels in a ______ direction along the anterior aspect of the pons. Its branches in a caudal to rostral direction include the ______ arteries, several ______ arteries, and the ______ arteries.
rostral, anterior inferior cerebellar, small pontine, superior cerebellar
The basilar artery ends as a bifurcation, giving rise to two ______ arteries.
posterior cerebral
The two ______ arteries arise as one of the two terminal branches of the common carotid arteries. They proceed superiorly to the base of the skull where they enter the carotid canal.
internal carotid
Entering the cranial cavity each internal carotid artery gives off the ______ artery, the ______ artery, the ______ artery, and the ______ artery.
ophthalmic, posterior communicating, middle cerebral, anterior cerebral
The ______ is formed at the base of the brain by the interconnecting vertebrobasilar and internal carotid systems of vessels. This anastomotic interconnection is accomplished by:
- an ______ artery connecting the left and right anterior cerebral arteries to each other, and
- two ______ arteries, one on each side, connecting the internal carotid artery with the posterior cerebral artery.
cerebral arterial circle (of Willis), anterior communicating, posterior communicating
A stroke, or ______, is defined as the interruption of blood flow to the brain or brainstem resulting in impaired neurological function lasting more than 24 hours.
cerebrovascular accident (CVA)
Neurological impairment resolving within 24 hours is known as a ______ or mini-stroke.
transient ischemic attack (TIA)
Based on their etiology, strokes are broadly classified as either ______ or ______.
ischemic, hemorrhagic
______ strokes are further divided into those caused by thrombotic or embolic phenomena. The latter is by far the commonest type of stroke and is often caused by emboli that originate from atherosclerotic plaques in the carotid arteries that migrate into and block smaller intracranial vessels.
Ischemic
______ strokes are caused by rupture of blood vessels.
Hemorrhagic
The symptoms and signs of a stroke depend on the distribution of impaired ______.
brain perfusion
______ is a neurological emergency.
Stroke
______ (blood-thinning) drugs can restore cerebral blood flow and improved patient outcome if administered within ______ hours of onset of the patient’s symptoms
Potent thrombolytic, 3 to 4.5
Following initial clinical history taking and neurological examination, all patients with suspected stroke should undergo urgent brain imaging with ______.
computed tomography (CT)
In ______ stroke, early CT imaging may appear normal or can show a relatively darker area of low density that corresponds to the region of abnormal brain perfusion.
ischemic
If ______ is performed, a 24-hour follow-up CT scan is routinely carried out to evaluate for complications such as intracranial hemorrhage.
thrombolysis
______ and ______ blood tests to identify causes such as hypoglycemia or underlying clotting disorders.
Hematological, biochemical
A ______ may be useful to identify substance intoxication, which can mimic stroke.
toxicology screen
The full extent of neurological injury can be evaluated on subsequent ______ of the brain, which has better soft tissue resolution compared to CT.
magnetic resonance imaging (MRI)
______ is also useful for identifying strokes that may be too small to detect on a CT scan.
MRI
______ scans are produced by using complicated algorithms that create a series of images, also known as ______.
MRI, sequences
A ______, whether acute or chronic, will appear as a bright region on a sequence that is sensitive to fluid (T2 weighted).
stroke
To identify whether a stroke is acute, further sequences are obtained, known as ______ and the ______ map.
diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC)
If the region of abnormality appears bright on the DWI sequence and dark on the ADC map, this is known as ______, which is compatible with an acute stroke.
restricted diffusion
Imaging of the ______ and ______ arteries is also performed to assess for any treatable atherosclerotic changes and stenosis.
carotid, vertebral
Management of a stroke is ______.
multidisciplinary
Long-term use of ______ drugs such as aspirin and modification of cardiovascular disease risk factors are important in the secondary prevention of stroke.
antiplatelet
______ is a surgical procedure to remove atheromatous plaque from arteries.
Endarterectomy
______ occur in the subendothelial layer of vessels and consist of lipid-laden macrophages and cholesterol debris.
Atheromatous plaques
______ commonly occurs around vessel bifurcations, limiting blood flow, and may embolize to distal organs.
Plaque
During ______, plaque is removed and the vessel reopened.
endarterectomy
______ arise from the vessels in and around the cerebral arterial circle (of Willis).
Cerebral aneurysms
They typically occur in and around the anterior communicating artery, the posterior communicating artery, the branches of the middle cerebral artery, the distal end of the basilar artery, and the posterior inferior cerebellar artery.
Intracerebral aneurysms
As the aneurysm ruptures, the patient complains of a sudden-onset “______” headache that produces neck stiffness and may induce vomiting. In a number of patients death ensues, but many patients reach the hospital, where the diagnosis is established.
thunderclap
An initial CT scan demonstrates blood within the subarachnoid space, and this may be associated with an intracerebral bleed. Further management usually includes ______, which enables the radiologist to determine the site, size, and origin of the aneurysm.
cerebral angiography
Venous drainage of the brain begins internally as networks of small venous channels lead to larger cerebral veins, cerebellar veins, and veins draining the brainstem, which eventually empty into ______.
dural venous sinuses
The dural venous sinuses are endothelial-lined spaces between the outer periosteal and the inner meningeal layers of the dura mater, and eventually lead to the ______.
internal jugular veins
Also emptying into the dural venous sinuses are ______, which run between the internal and external tables of compact bone in the roof of the cranial cavity, and ______, which pass from outside the cranial cavity to the dural venous sinuses.
diploic veins, emissary veins
The ______ veins are important clinically because they can be a conduit through which infections can enter the cranial cavity because they have no valves.
emissary
The ______ include the superior sagittal, inferior sagittal, straight, transverse, sigmoid, and occipital sinuses, the confluence of sinuses, and the cavernous, sphenoparietal, superior petrosal, inferior petrosal, and basilar sinuses.
dural venous sinuses
The ______ sinus is in the superior border of the falx cerebri. It begins anteriorly at the foramen cecum, where it may receive a small emissary vein from the nasal cavity, and ends posteriorly in the confluence of sinuses, usually bending to the right to empty into the right transverse sinus.
superior sagittal
The ______ sinus communicates with lateral extensions (lateral lacunae) of the sinus containing numerous arachnoid granulations.
superior sagittal
The ______ sinus usually receives cerebral veins from the superior surface of the cerebral hemispheres, diploic and emissary veins, and veins from the falx cerebri.
superior sagittal
The ______ sinus is in the inferior margin of the falx cerebri. It receives a few cerebral veins and veins from the falx cerebri, and ends posteriorly at the anterior edge of the tentorium cerebelli, where it is joined by the great cerebral vein and together with the great cerebral vein forms the straight sinus.
inferior sagittal
The ______ sinus continues posteriorly along the junction of the falx cerebri and the tentorium cerebelli and ends in the confluence of sinuses, usually bending to the left to empty into the left transverse sinus.
straight
The ______ sinus usually receives blood from the inferior sagittal sinus, cerebral veins (from the posterior part of the cerebral hemispheres), the great cerebral vein (draining deep areas of the cerebral hemispheres), superior cerebellar veins, and veins from the falx cerebri.
straight
The superior sagittal and straight sinuses, and the occipital sinus (in the falx cerebelli) empty into the ______, which is a dilated space at the internal occipital protuberance and is drained by the right and left transverse sinuses.
confluence of sinuses
The ______ sinuses extend in horizontal directions from the confluence of sinuses where the tentorium cerebelli joins the lateral and posterior walls of the cranial cavity.
paired transverse
The ______ sinus usually receives blood from the superior sagittal sinus and the ______ sinus usually receives blood from the straight sinus.
right transverse, left transverse
The ______ sinuses also receive blood from the superior petrosal sinus, veins from the inferior parts of the cerebral hemispheres and the cerebellum, and diploic and emissary veins.
transverse
As the transverse sinuses leave the surface of the occipital bone, they become the ______, which turn inferiorly, grooving the parietal, temporal, and occipital bones, before ending at the beginning of the internal jugular veins.
sigmoid sinuses
The ______ sinuses also receive blood from cerebral, cerebellar, diploic, and emissary veins.
sigmoid
The ______ sinuses are against the lateral aspect of the body of the sphenoid bone on either side of the sella turcica. They are of great clinical importance because of their connections and the structures that pass through them.
paired cavernous
The ______ sinuses receive blood not only from cerebral veins but also from the ophthalmic veins (from the orbit) and emissary veins (from the pterygoid plexus of veins in the infratemporal fossa).
cavernous
Structures passing through each cavernous sinus are: the ______ artery, and the ______ nerve.
internal carotid, abducent
Structures in the lateral wall of each cavernous sinus are, from superior to inferior:
the oculomotor nerve [III], the trochlear nerve [IV], the ophthalmic nerve [V1], and the maxillary nerve [V2].
Connecting the right and left cavernous sinuses are the ______ sinuses on the anterior and posterior sides of the pituitary stalk.
intercavernous
______ sinuses drain into the anterior ends of each cavernous sinus. These small sinuses are along the inferior surface of the lesser wings of the sphenoid and receive blood from the diploic and meningeal veins.
Sphenoparietal
The ______ sinuses drain the cavernous sinuses into the transverse sinuses.
superior petrosal
Each ______ sinus begins at the posterior end of the cavernous sinus, passes posterolaterally along the superior margin of the petrous part of each temporal bone, and connects to the transverse sinus.
superior petrosal
______ sinuses connect the inferior petrosal sinuses to each other and to the vertebral plexus of veins. They are on the clivus, just posterior to the sella turcica of the sphenoid bone.
Basilar
______ is a common injury and is a significant cause of morbidity and death.
Head trauma
______ may occur in isolation, but often the patient has other injuries; it should always be suspected in patients with multiple injuries. Among patients with multiple trauma, 50% die from the ______.
Head injury
At the time of the initial head injury two processes take place. First the primary brain injury may involve ______, which results from the shearing deceleration forces within the brain. These injuries are generally not repairable.
primary axonal and cellular damage
Further primary brain injuries include intracerebral hemorrhage and penetrating injuries, which may directly destroy gray and white matter. The ______ injuries are sequelae of the initial trauma.
secondary
What are the types of Intracranial Hemorrhage?
Primary brain hemorrhage, Extradural hemorrhage, Subdural hematoma, Subarachnoid hemorrhage, Tuberculosis of the central nervous system, Concussion
The many causes of a ______ include aneurysm rupture, hypertension (intracerebral hematoma secondary to high blood pressure), and bleeding after cerebral infarction.
primary brain hemorrhage
An ______ is caused by arterial damage and results from tearing of the branches of the middle meningeal artery, which typically occurs in the region of the pterion. Blood collects between the periosteal layer of the dura and the calvaria and under arterial pressure slowly expands.
extradural hemorrhage
A ______ results from venous bleeding, usually from torn cerebral veins where they enter the superior sagittal sinus. The tear and resulting seepage of blood separates the thin layer of dural border cells from the rest of the dura as the hematoma develops. Patients at most risk of developing this are the young and elderly. The increased CSF space in patients with cerebral atrophy results in a greater than normal stress on the cerebral veins entering the sagittal sinus. The clinical history usually includes a trivial injury followed by an insidious loss of consciousness or alteration of personality.
subdural hematoma
______ may occur in patients who have undergone significant cerebral trauma, but typically it results from a ruptured intracerebral aneurysm arising from the vessels supplying and around the arterial circle (of Willis).
Subarachnoid hemorrhage
______ may invade the central nervous system, including the brain, spinal cord, and meninges.
Tuberculosis (TB)
______ (______) is the most common type of traumatic brain injury. The injury typically results from a rapid deceleration of the head or by a rotation of the brain within the cranial cavity.
Concussion, mild traumatic brain injury [MTBI]
