4 functions of the skeletal system
support, protection, movement, storage
Hemopoesis
the act of making blood cells
Red marrow
where blood cells are made
Yellow marrow
fat and lipid storage
Periosteum
membrane covering bone
Endosteum
membrane lining bone
Medullary Cavity
marrow cavity in long bones
Compact Bone
hard outer layer of bone
Cancellous Bone
spongy bone (red marrow is here)
Long Bones
longer than wide, articulation on each end (Ex: femur)
Short Bones
approximately as tall as wide (Ex: carpals)
Irregular Bones
irregular in shape (Ex: vertebrae)
Flat Bones
Flat, smooth areas (Ex: scapula, ribs, frontal bone)
4 curves of the spine
cervical, thoracic, lumbar, sacral
Age at which the sacrum begins to fuse
16-18 years
Age at which the sacrum is fully fused
25-30 years
Sesamoid Bones
bones formed within tendon to protect a joint (Ex: patella)
Number of cervical vertebrae
7
Number of thoracic vertebrae
12
Number of lumbar vertebrae
5
Number of vertebrae that fuse into the sacrum
5
Bones of the vertebral column
vertebrae, sacrum, coccyx
Number of vertebrae in adults
24
Spinal curves present at birth
thoracic and sacral
Fontanelle
soft spots on babies' heads where skull isn't yet fused
What is T-3?
third thoracic vertebrae
What is L-4?
Fourth lumbar vertebrae
What are C-1 and C-2 called?
the atlas and axis
Costal bones
ribs
How many ribs do we have?
24
How many PAIRS of ribs do we have?
12
Which ribs are called the "true ribs"?
the first seven pairs of ribs
What are the very bottom ribs called?
the floating ribs
Ribs are joined to the sternum by...
costal cartilage
head of the sternum
manubrium
inferior tip of the sternum
xiphoid process
Rib Cage
thoracic cage
Ribs protect ...
the thoracic cavity
Thoracic Cavity holds...
heart and lungs
What mineral do we "bank" in bones?
calcium