Skeletal System

Chapter 7

Adult Skeleton (review)• How many bones?

• What of the 2 main divisions?

• What are the 4 main shapes?

• What are the 2 shapes not included in the first answer?

• Bone box: study tool

Skeletal System• Axial

– Skull• Cranium• Facial bones

– Thoracic cage • Sternum• Ribs

– Vertebral column• Appendicular

– Upper limbs– Lower limbs– Pectoral girdle– Pelvic girdle

Paranasal Sinuses

Vertebral Column

• Cervical (7)– Atlas (yes) and axis (no)

• Thoracic (12)– Same as number of ribs

• Lumbar (5)• Sacrum (5 fused)• Coccyx (4 fused)

Vertebrae Classification

Cervical (C1-C7)

Thoracic (T1-T12)

Lumbar (L1-L5)

Body small, ovalmedium, heart-shaped

large, kidney-shaped

Spinous process

short, projectsposteriorly,bifurcated

long, projectsinferiorly

short, projectsposteriorly

VertebralForamen large, triangular medium, circular small, triangular

Transverseprocess contain foramina facets for ribs thin and tapered

Thoracic Cageand

Hyoid • Sternum

– Manubrium– Body– Xiphoid process

• Ribs– True (7)– False (5/3)– Floating (2)

• Hyoid*

Pelvic Differences

Female Male

BoneThickness

Lighter, thinner, and smoother

Heavier, thicker, andmore markings

AcetabulaSmaller, farther

apart Larger, closer

Pubic Arch Rounded, >100˚ Narrower, <90˚

Sacrum Shorter, wider Longer, narrower

Ishcial Spine Further apart Closer together

Coccyx Straighter Curves ventrally

Pelvic Inlet Wider, ovalNarrower, heart

shaped

Bones of the Hand

• Carpals (8)– Some Lovers Try Positions That They Can’t Handle

– scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, hamate

• Metacarpals (5)• Phalanges (14)

– Pollex – Proximal, middle, distal

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Left hand; Anterior view

• Tarsals (7)– Tiger cubs need milc– Talus, calcaneus, navicular, medial, intermediate, lateral cuneforms, cuboid

• Metatarsals (5)• Phalanges (14)

– Hallux – Proximal, middle, distal

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1

Right foot; Superior view

Bones of the Foot

• A human fetus has 275 bones

• Single bones in adult have not ossified and fused yet

• Fontanels• Pelvic girdle

Fetal Skeleton

Need to Know for Lecture

• Names of bones (same as for lab)• Location/articulation of bones• Differences between vertebrae• Differences between male and female pelvis• Number of bones (where appropriate)