Cranium And Scalp Flashcards
Viscerocranium
Facial skeleton derived from 1st 2 pharyngeal arches
- Mandible
- Maxilla
- Zygomatic
- Nasal
- Lacrimal
- Sphenoid - pterygoid process
- Temporal - tympanic part (styloid)
- Palatine
- Vomer
- Ethmoid and inferior nasal concha
Neurocranium
Houses brain, derived from paraxial mesoderm
- Frontal
- Temporal
- Occipital
- Parietal
- Sphenoid
- Ethmoid - cribiform plate
Anterior cranial fossa
Frontal lobe cerebrum
Middle cranial fossa
Temporal lobe cerebrum
Posterior cranial fossa
- Cerebellum
- Pons
- Medulla oblongata
Paranasal sinuses
- Frontal
- Maxillary
- Sphenoidal
- Ethmoid air cells
Sagittal cranial suture
Along sagittal plane between parietal bones
Coronal cranial suture
Between frontal and parietal bones
Lamboidal cranial sutures
Between occipital and parietal bones
Metopic (frontal) cranial suture
Between growth centers in frontal bone
Squamosal cranial suture
Squamous part of temporal and parietal bones
Occipitomastoidal cranial suture
Between occipital and petrous part temporal bones
Sphenoparietal cranial suture
Between sphenoid and parietal bones
Bregma
Cranial landmark where sagittal and coronal sutures meet
Lambda
Cranial landmark where sagittal and lamboidal sutures meet
Glabella
Cranial landmark most anterior midline point on frontal bone
Nasion
Cranial landmark where nasofrontal suture and mid-sagittal plane intersect
Pterion
Cranial landmark where frontal, temporal, sphenoid, and parietal bones intersect
1. Very variable
Inion
Cranial landmark: external occipital protuberance
Asterion
Cranial landmark: squamosal, lamboidal, and occipitomastoidal sutures intersect
Gonion
Cranial landmark: most inferior and position point at mandibular angle
Gnathion
Cranial landmark: most anterior and inferior mid-line point of mandible
Basion
Cranial landmark: mid point at anterior margin of foramen magnum
Opisthion
Cranial landmark: mid point at posterior margin of foramen magnum
Functional matrix hypothesis
- Cranium broken into fxnal units that house soft tissue matrix responsible for fxn
A. Neurocranium: houses and protects brain
B. Orbit: eye
C. Nasopharynx: olfaction and respiration
D. Oral cavity: process food, communication
E. Facial buttress system: mastication, communication - Cranial growth controlled by underlying soft tissue
Viscerocranium development
From neural crest w/in 1st 2 pharyngeal arches
1. Arches develop week 4
2. Endochondral ossification
A. Styloid process
B. Inner ear bones
C. Hyoid
3. Intramembranous ossification: rest of viscerocranium
Neurocranium development
Mixed neural crest and paraxial mesoderm 1. Grow as external layer of brain 2. Endochondral ossification: cranial base bones 3. Intramembranous ossification A. Parietals B. Frontal C. Superoposterior part occipital D. Greater wing sphenoid E. Squamous part temporal
Cranial suture and Fontanelle closure
1. Birth: thin cranial bones w/o diploe A. Connected membranous fiber joints 2. 2 mo: small fontanelles fuse 3. 18 mo: large fontanelles fuse 4. Suture fusion: 8-40 yrs 5. Suture obliteration > 50 yrs