Chapter 7 Skeletal Organization. Number of Bones Average number of bones is 206 – People may have...
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Transcript of Chapter 7 Skeletal Organization. Number of Bones Average number of bones is 206 – People may have...
Chapter 7
Skeletal Organization
Number of Bones
• Average number of bones is 206– People may have varying numbers of bones• Ex – sutural bones, sesamoid bones in tendons
Divisions of the Skeleton
• Axial skeleton– Bony and cartilaginous parts that support and
protect the organs of the head, neck, and trunk• Appendicular skeleton– Bones of the upper and lower limbs and the bones
that anchor the limbs to the axial skeletion
Divisions of the Skeleton
Axial Skeleton
• Skull– Includes cranium and facial bones
• Hyoid Bone– Located in neck between lower jaw and the larynx– Does not articulate with any other bones (held in
place by muscles and ligaments)– Supports the tongue– Serves as an attachment point for muscles
associated with the tongue
Axial Skeleton
• Vertebral Column– Consists of vertebrae separted by cartilaginous vertebral discs– Five vertebrae near the distal end are fused to form the
sacrum (part of the pelvis)– Four vertebrae are fused to form the tailbone (coccyx) below
the sacrum• Thoracic Cage– Protects the organs of the thorax and upper abdomen– Consists of 12 pairs of ribs (which articulate with the thoracic
vertebrae) and the sternum (with which most ribs articulate anteriorly)
Appendicular Skeleton
• Pectoral Girdle– Formed by the scapula and the clavicle– Connects the bones of the upper limbs to the axial
skeleton– Aid in upper limb movements
• Upper Limbs– Consists of humerus, radius, ulna, and hand bones
• The humerus, radius, and ulna articulate at the elbow joint• The hand consists of 8 carpals, 5 metacarpals, and 14
phalanges
Appendicular Skeleton
• Pelvic Girdle– Formed by two hipbones (coxae) which attach to the
sacrum posteriorly and each other anteriorly– Connects the bones of the lower limbs to the axial skeleton– Forms the pelvis with the sacrum and coccyx
• Protects the lower abdominal and reproductive organs
• Lower Limbs– Consists of the femur, tibia, fibula, and foot
• The femur and tibia articulate at the knee joint which is covered by the patella
• The foot contains 7 tarsals, 5 metatarsals, and 14 phalanges
Terms used to describe skeletal structures: