External cranium Flashcards
what is the neurocranium and what makes it up?
the bony covering of the brain and the 4 meninges. formed by 8 total bones
Paired: parietal and temporal
unpaired: frontal, occipital, sphenoid bone, ethmoid bone
which bone is the most complex of the human bones>
sphenoid
the sphenoid bone contributes to what?
the orbit, middle cranial fossa and the lateral skull
what does the sphenoid bone house?
pituitary gland
what is the hollowed out area of the sphenoid bone called?
sphenoid sinus
what do the foramina within the sphenoid bone include?
foramen rotundum, foramen ovale, superior orbital fissure, optic canal, and foramen spinosum
which bone is a part of the neurocranium and the viscerocranium?
ethmoid bone
what does the ethmoid bone contain?
cribriform plate
what does the ethmoid bone contribute to?
the orbit, the lateral walls of the nasal cavity (Conchae), the nasal septum, and contains many air cells (called sinuses)
what is the dome like roof of the cranium called?
calvaria
what is the floor if the cranial vault of the skull called?
cranial base
how are most of the bones joined?
sutures
what type of joint are sutures?
syndesmosis
what is the anterior fontanelle?
a diamond shaped region between the frontal and parietal bones at the junction of the coronal and saggital sutures and called the bregma
what is the posterior fontanelle?
triangular shape at the lambda which is the junction between the lambdoid and sagittal sutures
what is the viscerocranium and what makes it up?
fascial bones (surrounding the orbits the nasal cavity and the mouth. made up of 15 irregularly shaped bones
paired: maxilla, inferior nasal conchae, zygomatic bone, palatine bone, nasal bone, and lacrimal
unpaired: mandible, ethmoid and vomer
describe the maxilla
contains sockets for the teeth of the upper jaw. the two maxillae contribute the largest mass of anterior bones, which are fixed to the cranial base
where are the 3 unpaired bones of the viscerocranium centered?
in the midline
describe the mandible
contains sockets for the teeth of the lower jaw. the only movable bone of the skull due to TMJ
what is the orbitmeatal plate and what does it include?
a horizontal plate that included the inferior border of the orbit and the superior border of the external acoustic meatus, position of the head in anatomical neutral
where do the facial muscles lie?
in the subcutaneous tissues of the scalp
why do all the face muscles share the same innervation form the facial nerve?
because they are all derived from one embryonic structure called the second pharyngeal arch
what are the facial muscles?
occipitofrontalis, orbicularis oris, orbicularis oculi, levator labii superioris, depressor labii inferioris, zygomaticus major, riorius, depressor anguli oris, mentalis, platysma, buccinator
posterior rami innervates what?
the skin of the posterior scalp and areas just posterior to the ears
anterior primary rami innervates what?
the superior most neck
where is the temporal fossa?
superior to the zygomatic arch
what is the posterior boundary of the temporal fossa?
the temporal lines
what is the anterior boundary of the temporal fossa?
the frontal and zygomatic bones