Skeletal System

� 206 (as an adult)

� 270!

� Bones fuse together over time

� Purpose:

◦ Protects Organs

◦ Support, protection, and flexibility

◦ Forms blood cells

◦ Stores Calcium (essential vitamin)

� Major Purpose: Protect the Brain!!!!

� 22 Bones in the skull

� Basically your upper chest area

� Manubrium: forms joints with clavicles/ attaches to ribs

� Body: attaches to ribs

� Xiphoid Process: attaches to diaphragm and other muscles

◦ Cartilage (flexible!) is eventually replaced by bone in adulthood

� Ribs: Protect the lungs and heart ◦ Also aids in breathing

� Clavicle: Stability and muscle attachment◦ One of the most commonly broken bones

� All contribute to arm motion

� Ulna: Radial

� Radius: Distal

� 7

� 12

� 5

� Spine = Vertebra

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� Sacrum: Connects spine to hip bones

� Coccyx: Attachment site for tendons, ligaments, and muscles◦ May fuse to sacrum later in life

� Takes place in Red Marrow

� Only in: long bones, flat bones (ribs and cranial), vertebrae, and pelvis

� All blood cells (Red, white [T cells…]) are produced in red marrow

� Produced by stem cells!

� Blood cells last at most a few days!

� https://www.youtube.com/watch?v=rDGqkMHPDqE