Part II Axial Skeleton (A-D)

II Axial Skeleton Forms the longitudinal part of the body Divided into three parts Skull Vertebral column Thoracic cage (Bony thorax)

The Axial Skeleton Figure 5.6

II Axial Skeleton Two sets of bones Cranium Facial bones Bones are joined by sutures Only the mandible is attached by a freely movable joint

II Axial Skeleton A. Cranial Bones (8) 1. parietal (x2) 2. temporal (x2) 3. frontal 4. occipital 5. sphenoid 6. ethmoid

II Axial Skeleton B. Facial Bones (14) 1. mandible 2. vomer 3. maxilla (x2) 4. nasal (x2) 5. zygomatic (x2) 6. lacrimal (x2) 7. inferior nasal concha (x2) 8. palatine (x2)

II Axial Skeleton C. Cranial Sutures (4) sagittal – between parietals lambdoid – between parietal and occipital squamous – between parietal and temporal coronal – between parietal and frontal

Paranasal Sinuses Hollow portions of bones surrounding the nasal cavity Figure 5.10

Paranasal Sinuses Functions of paranasal sinuses Lighten the skull Give resonance and amplification to voice Figure 5.10

II Axial Skeleton D. Paranasal Sinuses 1. sphenoid sinus 2. ethmoid sinus 3. frontal sinus 4. maxillary sinus cranial sinuses facial sinus

acoustic (auditory) meatus 8 Cranial Bones 5 sphenoid 1 2 frontal parietal x2 6 ethmoid 4 temporal x2 3 occipital acoustic (auditory) meatus 7 9 styloid process mastoid process 8 10 mental foramen

Cranial Sutures coronal suture sagittal suture squamous suture lambdoid suture

14 Facial Bones lacrimal x2 nasal x2 zygomatic maxilla mandible zygomatic arch zygomatic x2 maxilla x2 mandible

maxilla hard palate palatine x2 vomer

inferior nasal concha x2

Name the two facial bones that are NOT paired??? mandible Name the two facial bones that are NOT paired??? vomer

frontal ethmoid sphenoid temporal foramen magnum occipital

Sinuses frontal ethmoid sphenoid maxillary

Bones of the Skull Figure 5.11

The Skull Figure 5.7

Human Skull, Inferior View Figure 5.9

Human Skull, Superior View Figure 5.8

The Fetal Skull The fetal skull is large compared to the infants total body length Figure 5.13

The Fetal Skull Fontanelles – fibrous membranes connecting the cranial bones Allow the brain to grow Convert to bone within 24 months after birth Figure 5.13