ch 7 Flashcards
skeletal system
Axial- 80 bones (skull, vertebral column, thoracic cage) / Appendicular- 126
20% body mass
Bones, cartilages, joints, ligaments
Skull
Cranial Bone (8)- Encloses brain in cranial cavity
Facial bone (14)- Framework of face
Site of attachment for head and neck muscle
Suture
Sutural Bone- small, extra bone plates located within the sutures of cranial bones
Sutures- jointed areas where flat bones come together
Fontanels
Mesenchyme filled space between cranial bones at birth close at 6months- 2 years
8 cranial bones
Frontal bone Parietal bones (2) Occipital bone Temporal bones (2) Sphenoid bone Ethmoid bone
Frontal Bone
Anterior portion of cranium, contains air filled frontal sinous
Facial bone
(14)
Framework of face
Cavities for special sense organs for sight, taste, and smell
Openings for air and food passage
Sites of attachment for teeth and muscles of facial expression
14 Facial Bones
Mandible Maxillary bones (maxillae) (2) Zygomatic bones (2) Nasal bones (2) lacrimal bone (2) palatine bone(2) vomer inferior nasal cochea
orbit
Root of Orbit-
- lesser wing of sphenoid
- orbital plate of frontal bone
Lateral wall of orbit-
zygomatic process
greater wing of sphenoid
Medial wall- sphenoid body orbital plate of ethmoid frontal process of maxilla lacrimal bone
Floor of orbit-
orbital process of palatine
orbital surface of maxillary bone
zygomatic bone
Hyoid
Lone bone, support tongue with muscle attachment
vertebral column
Transmit weight of trunk to lower limbs, Protect spinal cord
flexible curved structure
Cervical-thoracic-lumbar-sacrum-coccyx-
Intervertebral Disk
Cushionlike pad composed of 2
Nucleus Pulpous- inner gelatinous nucleus
gives disk elasticity and compressibility
Anulus Fibrosus- Outer collar composed of collagen and fibrocartilage
General Vertebral Structure
body (centrum)- anterior weight bearing region
vertebral Arch- Composed of pedicles and laminae that, along with centrum, enclose vertebral foramen
Vertebral Foramina- Together make up vertebral canal for spinal cord
Intervertebral Foramina- Lateral openings between adjacent vertebrae for spinal nerves
7 Process per vertebra
Spinous process—projects posteriorly
Transverse processes (2)—project laterally
Superior articular processes (2)—protrude superiorly
Inferior articular processes (2)—protrude inferiorly
C1 Atlas
No body or spinous process
Consists of anterior and posterior arches, and two lateral masses
Superior surfaces of lateral masses articulate with occipital condyles
Movement for “Yes”
C2 Axis
Dens projects superiorly into anterior arch of atlas
Is “missing” body of atlas
Dens is a pivot for rotation of atlas
Movement for “No”
Thoracic Vertebrae
T1 to T12
All articulate with ribs at facets and demifacets
Long, spinous process that points inferiorly
Circular vertebral foramen
Location of articular facets allows rotation of this area of spine
Lumbar Vertabrae
L1 to L5
Receives most stress
Short, thick pedicles and laminae
Flat hatchet-shaped spinous processes point posteriorly
Vertebral foramen triangular
Orientation of articular facets locks lumbar vertebrae
together to prevent rotation
Sternum
Three fused bones
Manubrium – Superior portion
Articulates with clavicles and ribs 1 and 2
Body (midportion)
Articulates with costal cartilages of ribs 2 through 7
Xiphoid process – Inferior end
Site of muscle attachment
Not ossified until ~age 40
