What are the five layers of the SCALP
- Connective Tissue - highly vascular
- Epicranial Aponeurosis - Strong membranous tendon connecting the anteriorly placed fontalis and posteriorly placed occipitalis
- Loose Connective Tissue - allows the outher three layers to move freely ove the skull
- Pericranium - outside tissue of the bone.
What are the walls of the cranial cavity made up of?
- Inner and outer tables of compact bone that are seperated by spongy bone called "diploe".
- so the spongy bone in the middle is diploe bone.
What is a cranial meninges?
- The meninges are the membranes that surround the brain and that are continous with the meninges of the spinal cord.
What are the two parts of the outer most layer?
- The Dura mater is the outer most layer. It has two layers:
- Periosteal dura: This is the part of the dura mater that is continous with the inner surface of the skull
- Meningeal dura: This part is continous with the dura of the spinal cord.
What is the arachnoid mater? arachnoid trabeculae?
- Delicate membrane that lines the inner surface of the dura.
- Arachnoid trabeculae are fine extensions tha span across the subdural (subarachnoid) space and attach to the pia mater.
What is the pia mater?
The delicate mater that lines the outside of the brain.
What happens when periosteal dura is seperated from meningeal dura?
When this happens, what is the benfit?
What are the four major folds?
- Channels in the dura mater are created.
- The channels are lined with endothelium and receive veins that drain the brain and the mininges.
- So essentially, the channels in the dura matter create venous channels for the drainage of the contents of the cranial cavity.
What folds to dip between the fissures in the brain?
What are the four main folds?
- The meningeal dura.
- Falx Cerebi
- Falx CerebelliT
- entorium Cerebelli
- Diaphragma Sellae
Describe the Falx Cerebri.
- Runs vertical between the hemispheres of the brain. (The longitudinal cerebral fissure) It is continues with the tentorium cerebelli posteriorly. It connects posteriorly to the internal occipital protuberence and anteriorly to the crista galli of the ethemoid and frontal crest of the frontal bone..
Describe the Falx Cerebelli.
Small triangular process of dura mater that is received into the posterior cerebellar notch. It is between the lateral lobes of the cerebellum.Attaches at the internal occipital crest, and partially seperates the cerebellar hemispheres.
Describe the Tentorium Cerebelli.
- Second largest dural infolding. An extension of the dura mater that seperates the cerebellum from the inferior portion of the occipital lobes of the brain. Attaches rostally to the clinoid process of the sphenoid and rostrolaterally to the petrous portion of the temporal bone, posterolaterally to the internal surface of the occipital bone.
Describe the diaphragma sellae.
- Smallest dural infolding. Suspended between the clinoid processes forming a partial roof over the hypophysial fossa in the sphenoid. It covers the pituitary gland and has an opening for passage of the infundibulum and hypophysial veins.
What are the 8 dural sinuses?
- Superior Sagittal Sinus
- Inferior Sagittal Sinus
- Transverse Sinus
- Occipital Sinus
- Cavernous Sinus
- Superior Petrosal Sinus
- Inferior Petrosal Sinus
- Sigmoid Sinus
Where does the superior sagittal sinus run?
- Anterior to posterior. It helps to drain blood. It houses the arachnoid granulations where cerebrospinal fluid drains.
Where does the inferior sagittal sinus run?
- Beneath the brain. Allows drainage of blood from center of brain posteriorly into the straight sinus. It runs inferior to the falx cerebri and superior to the corpus callosum. It ends in the straight sinus.
Where does the transverse sinus run?
- Runs from the back of the head towards the nose. Drains from the superior sagittal sinus and the straight sinus (confluence of sinuses). The left is usually bigger (used more dominantly)
Where does the occiptal sinus run?
The smallest cranial sinus. It starts at the attached border of the falx cerebelli and ends superiorly at the confluence of sinuses.
Where does the cavernous sinus run?
- It is a large venous plexus located on each side of the sellea turcica. The internal carotid runs through it. The cavernous drains into the superior and inferior petrosal sinuses.
Wher eis the superior petrosal sinus located?
- Connects the cavernous sinus to the transverse sinus.
- The sinus runs in the attached margin of the tentorium cerebelli, in a groove in the petrous part of the temporal bone formed by the sinus itself - the superior petrosal sulcus.
Where is the inferior sinus?
It connects the cavernous sinus to the sigmoid sinus.
Where is the sigmoid sinus?
Runs from straight sinus to the Internal jugular vein.
Where is the anterior cranial fossa? What are some of the major contents?
From the body and lesser wings of the sphenoid, the ethemoid, and the frontal bone. The greater part is formed by the orbital parts of the frontal bone, which supports the frontal lobes of the brain and froms the roofs of the orbits.
Where is the middle cranial fossa?
The posterior part of the lesser wings of the sphenoid, the sellea turcica, the greater wings, upto the petrous portion of the temporal bone.
What is the posterior cranial fossa?
From the dorsum sellea, petrous portion and mastoid to the occiput. Houses the cerebellum, pons, and medulla oblongata.
What are the bones of the neural cranium?
two parietal, two temporal, occipital, sphenoid, frontal, ethemoid
What are the bones of hte face?
- Nasal, Vomer, Palatine, Maxillary, Zygomatic, Mandible
What are the sutures?
Coronal, Sagitall, Squamosal, Lambdoidal
What are the features of the occipital bone?
- Foramen Magnum-Junction of spinal cord and brainstem, vertebral arteries, anterior and posterior spinal arteries, meninges.
- Occipital condyles-articulation with atlas
- External Occipital Protuberance (Inion)-
- Superior Nuchal Line-
- Inferior Nuchal Line-
What are the features of the sphenoid bone?
- Greater Wings
- Lesser Wings
- Dorsum Sellae
- Sellea Turcica
- Posterior Clinoid
- Anterior Clinoid
- (Inferior View)
- Pterygoin process
- Pterygoid fossa-
What are the features of the Frontal bone?
- Supraorbital notch
- Temporal line
- Zygomatic process
- Groove for superior sagitall sinus
What are the features of the parietal bone?
What are the featueres of the ethmoid bone?
- Cribriform plate
- Crista Galii-Where the falx cerebri attaches, and divides the cribriform plate
What are the features of the temporal bone?
- Zygomatic process
- Styloid process
- Mastoid Process
- Mandibular fossa
- Carotid Canal
- Internal Auditory Meatus
- External Auditory Meatus
What are the featuers of the maxillae?
What are the features of the mandible?
- Body and vertical ramus
- Angle of the mandible
- Condylar process
- Coronoid process
- Mental foramen
- Mental protuberance
What passes through the Foramen Lacerum?
Small Vascular structures Deep petrosal nerve
What passes through the foramen Magnum?
Spinal cord and brainstem junction. Vertebral arteries, posterior and anterior spinal arteris, meninges.
What passes through the foramen ovale?
Mandibular nerve (branch of trigeminal), lesser petrosal nerve, accesspry maningeal artery
What passes through the froamen rotundum?
What passes through the foramen spinosum?
middle meningeal artery, meningealbranch of CN V-3
What passes through the groove for the greater petrosal?
Greater Petrosal Nerve
What passes through the hypoglossal canal?
The hypoglossal nerve
What passes through the internal auditory meatus?
The vestibulocochlear and facial nerves
What passes through the jugular foramen?
Nerves IX(glossophrangeal), X(Vagus), XI(Accessory), internal jugluar vein as formed by sigmoid sinus, inferior petrosal
What passes through the olfactory foramina in cribriform plate?
The olfactory nerve
What passes through the optic canal?
CN II, Ophthalmic artery, sympathetic nerves from internal carotid plexus for ciliary muscle, dilator of pupil and smoothe muscle of blood vessels in eye
Internal carotid artery and sympathetic carotid plexus
What passes through the greater palatine foramen?
greater palatine vessels and nerves
What passes through the incisive foramen and canal?
Greater palatine arteries; nasopalatine nerve
What passes through the lesser palatine foramina?
Lesser palatine vessels and nerve
What passes through the stylomastoid foramin?
Nerve VII (Facial)
What passes through the superior orbital fissure?
Nerves III(Oculomotor), IV(trochlear), V(Trigeminal-the opthalmis branch), VI(Abducens),
What passes through the supraorbital foramen?
Supraorbital artery, nerve and vein
What passes through the infraorbital foramen?
The V2 Maxillary nerve, Infraorbital nerve, artery and vein.
What passes through the mandibular canal?
inferior alveilar artery, nerve and vein
What passes through the mental foramen?
The mental nerve, artey and vein.