文档介绍：Skull, Brain and Cranial Nerves
Head and Neck Continued
Skull
Part of Axial Skeleton
Cranial bones = cranium
Enclose and protect brain
Attachment for head + neck muscles
Facial bones =framework of face
Form cavities for ans
Opening for air + food passage
Hold teeth
Anchor face muscles
Bones of Skull
Flat bones: thin, flattened, some curve
Sutures: immovable joints joining bones
Calvaria = Skullcap =Vault
Superior, Lateral, Posterior part of skull
Floor = Base
Inferior part of skull
85 openings in skull
Spinal cord, blood vessels, nerves
Cranial Fossae
Created by bony ridges
Supports, encircles brain
3 Fossae
Anterior
Middle
Posterior
Other small cavities in skull
Middle Ear, Inner Ear
Nasal
Orbit
Skull through Life
Ossifies late in 2nd month of development
Frontal + Mandible start as 2 halves-then fuse
Skull bones separated by unossified membranes = Fontanels
pression of skull during delivery
Mostly replaced w/bone after 1st year
Growth of Skull
½ adult size by age 9 months
¾ adult size by 2 years
100% adult size by 8-9 years
Face enlarges between ages 6-13 years
4 Parts
Cerebrum
Diencephalon
Brain Stem
Pons
Medulla
Midbrain
Cerebellum
Gray matter surrounded by White matter
The Brain
Meninges: 3 membranes around brain and spinal cord
Made of Connective tissue
Functions
Cover, S
Enclose, protect blood vessels S
Contain CSF
3 Layers
Dura Mater (external)
Arachnoid Mater (middle)
Pia Mater (internal)
Meninges (continued)
Dura mater
Strongest, 2 Layers, Fibrous Connective Tissue
Periosteal layer (Periosteum): External/superficial layer
Meningeal layer: Internal/deep layer
Layers fused except around dural sinuses (venous blood filled internal jugular vein)
Falx Cerebri -vertical partition made of dura mater between Cerebral hemispheres
Falx Cerebelli -vertical partition, continuation of falx cerebri
Tentorium Cerebelli -horizontal partition made of dura mater between cerebrum and cerebellum
Meninges (continued)
Arachnoid Mater
Middle layer
Subarac