m Flashcards
Layers covering and protecting the brain
• Scalp • Skull- bone • Meninges & cerebral spinal fluid – under skull
What are the part of the skulll?
• SCALP o Skin o Connective tissue – Tela subcutanea o Aponeurotica- galea aponeurotica o Loose areolar connective tissue o Pericranium- Periosteum- Connective tissue covering calvaria
Muscle of head?
• Epicranius muscle Frontalis – frontal belly Occipitalis – occipital belly • Temporalis
What is the skull caps name and sutures ?
• Calvaria Coronal Suture -Separates frontal bone from 2 parietal bones Sagittal Suture -Separates parietal bones Lambdoid Suture -Separating the occipital bone (Squamous) suture - Seperates parietal from the temporal bone
What is Wormian Bone?
• Intra sutural bones • Extra piece of bone • Commonly seen : Inca bone or preinterparietal bone • Peruvian descent
What are base of the skull and what do they contain?
Anterior cranial fossa- frontal lobe Middle cranial fossa- Temporal lobe Posterior- Cerebellum, brainstem- passes through the foramen magnum continuous with SC
Cranial fossae divided by
Lesser wing of sphenoid bone separates anterior and middle cranial fossae
Petrous ridge of temporal bone separates the middle and posterior cranial fossae
Brainstem- Dorsal surface
¨Midbrain: Corpora quadrigemina, Superior colliculi, Inferior colliculi
¨Pons- Superior cerebellar peduncle, Middle cerebellar peduncle, Facial colliculus
Medulla- Inferior cerebellar peduncle, Hypoglossal trigone, Vagal trigone, Obex, Nucleus cuneatus (lateral) & Nucleus gracilis (medial)
Brainstem- ventral surface
¨Midbrain: Cerebral peduncles, Interpeduncular fossa
Pons: Middle cerebellar peduncle, Inferior pontine sulcus
Medulla- Pyramid & pyramidal decussation, Ventral median fissure, Inferior olive, Preolivary sulcus, Postolivary sulcus
Dura mater is 2 layers –
Periosteal- outer layer, closer to bone
Meningeal- Received blood primary from middle meningeal artery
Area where layers of dura mater is not fused
Falx cerebri- Vertical midline partition located in the longitudinal fissure b/w cerebral hemispheres.
Tentorium cerebelli- Separating the superior surface of cerebellum from the inferior surface of the occipital lobes. Forms roof of the posterior fossa Tent shaped. Tentorium and Falx cerebri fuse with one another. Separates the cerebral hemispheres from cerebellum
Dural venous sinuses- Provide openings for blood vessels and nerves
Superior sagittal sinus
Fourth ventricle goes to -
Central canal
Epidural hematomas are most commonly caused by the rupture of the:
Middle meningeal artery
The dura mater gets its blood supply from the:
Middle meningeal artery
What are the names of the apertures that come off of the 4th ventricles?
Foramen of Magendie and Foramen of Luschka
The falx cerebrix is a structure associated with the:
A. Dura mater
The 4th ventricle communicates or connects with what structure?
Subarachnoid cisterns
Middle Meningeal artery travels through what foramen?
Foramen Spinosum
Which space(s) or layer(s) is/are considered not “true” space(s)/layer(s) because it/they only show up because of a cranial bleed? Check all that apply
B. Subdural space. D. Epidural space
How many horns does the lateral ventricle have?
3
The lateral ventricle is connected to the 3rd ventricle by the?
Intraventricular foramen
The 4th ventricle is found within what 3 structures of the brain?
A. Pons, medulla, and cerebellum
The narrow, slit-shaped 3rd ventricle occupies most of the midline region of the:
Diencephalon
What makes up the choroid plexus?
Ependymal layer, Pia, Capillaries
Temporal horn is located in ventricle?
Lateral ventricle
Cerebral spinal fluid produce
Produced by: choroid plexus within ventricles itself ~600 ml/day it is in the space of meninges
Cisterns
areas of increased subarachnoid space containing CSF
Cisterna magna
Largest
Located: Inferior to cerebellum
Lumbar cistern
Cauda equina- collection of rootlets and nerves
located: Lumbar puncture- no spinal cord tissue
Choroid Plexus
Produces/composed of
Produces: CSF in all ventricles
Composed of: Tufts of blood vessels (thin, fenestrated endothelial cells)
Cover with a type of Modified ependymal cells (epithelium)
Joined by tight junctions creating barrier regulating what can pass from the blood in these capillaries into the ventricules this called the CSF barriers
Microvilli
CSF is a filtrate of
blood ventricular spaces
Trabeculae
Granulation
Trabeculae - Delicate fibrous threads given off from the inner surface
Granulations - Collection of villi, principal sites of reabsorption of CSF
Pia
Adheres to cortical surface- following every curve and sulcus, Thin
Epidural space (potential)
Middle meningeal artery, dura mater receives arterial blood from the middle meningeal artery from foramen spinosum from the external carotid artery, Giving blood supply to meninges
leaves impression on the bone itself
Subdural (potential)
Area between the dura and arachnoid space
Bridging veins - Connecting to the sinus area draining our blood supply
Subarachnoid space
Majority of Cerebral arteries & veins are transversing to get blood to and from brain, Fill with Cerebral spinal fluid (CSF)
Dura venous sinus are where?
Between dura layers
Superior sagittal sinus
location, size, contains
Location: Extends along superiorly attached border of the falx cerebri,
Sizes: increasing in size as it progresses posteriorly
Contains: venous lacunae
Straight sinus
Runs post. And infer. In the line of attachment of the falx cerebri and tentorium
Transverse sinus
Runs along the post., attached border of the tentorium cerebelli
Confluence of sinuses
Located at the internal occipital protuberance
Superior sagittal sinus and transverse sinus are meeting
Dural Venous Sinuses drain into the
Internal Jugular Vein, this is how we get blood supply draining from our cerebrum
Meninges of spinal cord
Same 3 meningeal layers, filled with a cushion layer of fat, continues beyond inferior end of spinal cord, filum terminale continuous with pia mater
Filum terminale
continuous with pia mater
Epidural space (describe brain vs spinal cord)
Epidural space - brain potential
Spinal cord - epidural space is an actual space and filled with fatty cushion layer in spinal cord
Intracranial hemorrhage
Epidural hematoma
Epidural hematoma, Rupture of middle meningeal artery, Bleeding between dura and the bone, Dura separates from skull
Intercranial Hemorrhage
Subdural hematoma
Rupture of bridging veins- veins from subachronoid space transverse through sinus areas, Arachnoid separates from dura
Intercranial Hemorrhage
Subarachnoid Hemorrhage
Subarachnoid Hemorrhage
Intercranial Hemorrhage
Intracerebral Hemorrhage
Intracerebral Hemorrhage
What are ventricles?
Interconnected Spaces within the brain – ventricles formed from lumen neural cavity inside neural tube, Filled with CSF
Left and right ventricles
there are 4 different regions
Frontal horn
Body
Occipital horn
Temporal horn
Interventricular foramen
connects lateral ventricles to the third
Third ventricle
Can go from the lateral ventricle to the third ventricle via the interventicular forearm
Cerebral Aqueduct
Connects third ventricle with the fourth ventricle
Fourth ventricle
Roof of the fourth ventricle is Cerebellum
Central Canal
CSF can only have a volume of :
~ 150-250 ml total volume of CSF
Cerebral Spinal Fluid produced in
Lateral, third and fourth ventricles
Cerebral spinal fluid reabsorbed (drains) by
Arachnoid Villi into superior sagittal sinus
What is the layers of the brain
. Scalp- Skin, Connective tissue – Tela subcutanea , Aponeurotica- galea aponeurotica, Loose areolar connective tissue , Pericranium- Periosteum
- Epidural space- Potential space between periosteum of inner surface of skull and dura, MMA
- Dura mater – periosteal, meningeal layer, falx cerebri, tentorium cerebelli, Dural venous sinuses, superior sagittal sinus
- Subdural space- Space between dura mater and arachnoid, contains bridging veins and cranial venous sinusesMMA
- Arachnoid mater- granulations , trabeculae, adheres to the dura
- Subarachnoid space- filled with CSF
- Pia mater- adheres to brain
