The Skull - Week 2 Flashcards
what are meninges?
- connective tissue layers that house and support the brain
- outer layers are called dura mater
- folds of dura put tension on bone and produce features
what are the outer layers of dura mater?
- outer periosteal layer follows bone
- inner meningeal layer follows major brain partitions
dural venous sinuses
formed at junction of periosteal dura mater and meningeal dural folds
- venous drainage of blood from brain
cranial nerves
peripheral nerves originating from the brain and brainstem
how many cranial nerves are there?
12
cranial nerve I
olfactory nerve
CNI exit and function
- exit: cribiform plate (ethmoid)
- function: olfactory mucosa
Cranial Nerve II
optic nerve
CN II exit and function
- exit: optic canal (sphenoid)
- target/function: retina - vision
Cranial Nerve III
oculomotor nerve
CN III exit and function
- exit: superior orbital fissure (sphenoid)
- target/function: extrinsic and intrinsic eye muscles
Cranial Nerve IV
trochlear nerve
CN IV exit and function
exit: superior orbital fissure (sphenoid)
target/function: extrinsic eye muscle
Cranial Nerve V
trigeminal nerve
what are the divisions of the trigeminal nerve?
V1, V2, and V3
CN V1 exit and function
ophthalmic nerve
exit: superior orbital fissure
function: cutaneous innervation of upper face
CN V2 exit and function
maxillary nerve
exit: foramen rotundum (sphenoid)
function: cutaneous innervation of midface
CN V3 exit and function
mandibular nerve
exit: foramen ovale (sphenoid)
function: cutaneous innervation of lower face/jaw, muscles of mastication
Cranial Nerve VI
abducens nerve
CN VI exit and function
exit: superior orbital fissure (sphenoid)
target/function: extrinsic eye muscle
Cranial Nerve VII
facial nerve
CN VII exit and function
exit: internal auditory meatus (temporal)
target/function: glands, mm of facial expression, and taste
Cranial Nerve VIII
vestibulocochlear nerve
CN VIII exit and function
exit: internal auditory meatus (temporal)
target/function: inner ear (balance and hearing)
Cranial Nerve IX
glossopharyngeal nerve
CN IX exit and function
exit: jugular foramen (occipital/temporal)
target/function: parotid gland, stylopharyngeus muscle, taste
Cranial Nerve X
vagus nerve
CN X exit and function
exit: jugular foramen (occipital/temporal)
target/function: gut, pharyngeal, and laryngeal mm, and taste
Cranial Nerve XI
accessory nerve
CN XI exit and function
exit: jugular foramen (occipital/temporal)
target/function: trapezius and sternocleidomastoid mm
Cranial Nerve XII
hypoglossal nerve
CN XII exit and function
exit: hypoglossal canal (occipital)
target/function: all intrinsic (most extrinsic) tongue mm
cartoid canal
internal cartoid artery
goes through the auditory canal in the petrous portion
foramen spinosum
middle meningeal artery
foramen lacerum
few vessels
craniometrics
- quantitative description of skull size and shape
- provides standardized protocol, comparable data
- statistical evaluation of populations
frankfort horizontal position
- plane is defined by three points with the skull facing to the left
- right porion
- left porion
- left orbitale
maximum cranial height
ba - b
maximum cranial length
g - op
cranial base length
ba - n
basion - prosthion length
ba - pr
maximum cranial breadth
eu - eu
maximum frontal breadth
ft - ft
bizygomatic diameter
zy - zy
nasal breadth and height
breadth: al - al
height: n - ns
upper facial height
n - pr
arachnoid mater
- the middle layer of your meninges that lies directly below the dura mater
- thin layer that lies between dura and pia mater
- no blood vessels or nerves
pia mater
- the delicate, innermost membrane enveloping the brain and spinal cord
- made of connective tissue and tiny blood vessels
arachnoid granulations
tufts of arachnoid membrane invaginated into the dural sinuses through which cerebrospinal fluid (CSF) enters the venous system. The lesions are primarily located in the parasagittal region along the superior sagittal sinus[1], which is occasionally seen at the transverse sinus.
arachnoid fovea
pits or depressions found on the endocranial surface
pituitary gland
- It sits in an indent in the sphenoid bone called the sella turcica.
- functions in making several horomones and is apart of the endocrine system
sella turcica
depression in the sphenoid that contains the pituitary gland
falx cerebri
the largest of the four partitions of the dura mater, and represents an invagination of the meningeal layer of dura into the longitudinal fissure of the brain
crista galli
- a thick, midline, smooth triangular process arising from the superior surface of the ethmoid bone, projecting into the anterior cranial fossa.
- It separates the olfactory bulbs, which lie on either side of it in the olfactory fossae of the cribriform plate
dural venous sinuses
- a group of sinuses or blood channels that drains venous blood circulating from the cranial cavity.
- sagittal sulcus
sigmoid sulcus
The inner surface of the mastoid portion of the temporal bone presents a deep, curved groove, the sigmoid sulcus, which lodges part of the transverse sinus
jugular foramen
- soft tissue structures: CN IX, X, and IX
- located inferior to the foramen ovale
internal jugular vein
x
