Skeletal System Functions
Support
Framework for the whole body
Long bone
Longer than they are wide, (e.g.) humerus, femur, phalanges, ulna, radius, tibia, fibula
Epipysis
the end of a long bone, initially growing separately from the shaft
Osteoblasts-
Osteoclasts-
Osteocytes-
cells that make bone tissue (matrix) and make more cells
multinucleated bone cells, breakdown bone (resorbs)secretes acidic substance that destroys bone
mature cell; maintains bone but doesn't make bone
Canaliculi-
small canals
Protection
1. skull-
2. vetebral column (spine)-
3. thoracic cage(rib cage)-
1. protects brain
2. protects spinal cord
3. protects lungs and heart
Short bones
Equal in length and width (e.g.) carpals of the wrist
Diaphysis
The shaft or central parts of the long bone
Compact bone-
Composed of structures called osteon- long cylinder of cells and bone with layers at the center of the osteon- are artery, vein, nerve
Thyroid gland-
Parathyroid gland-
monitors calcium blood levels, when calcium gets too high, it secretes calcitonin
monitors the level of calcium in our blood, when it gets too low PTH is made and stimulates the osteoclasts to act and bone is broken done releasing calcium into the bone
Movement/anchorage
points of attachment for
1, 2, and 3
1. muscles
2. tendons
3. ligaments
Flat bones
Thin, flat curved bones that protect internal organs, (e.g.) bones of the skull, ribs
Periosteum
Medullary cavity
Compact bone
Red bone marrow
Dense connective covering, encircles the bone
Hollow space
dense, thick, heavy bone (supports)
tissues that make blood cells
Lamella
Layer of osteocytes and bone matrix
*Osteons are the functional unit of compact bone
Rickets
A bone disease in children that is a result in vitamin D deficiency
Storage
1. minerals-
2. lipids (fats)-
1. calcium, phosphate, magnesium
2. yellow bone marrow
Irregular bones
Bones that don't fit into an specific categories
(e.g.) vertebrate
Yellow bone marrow-
Spongy bone-
tissues that store lipids
trabecular bone
Circumferrential Lamellae
large outer rings of ground substance and osteocytes- that make up the outer layer of compact bone
Osteoporosis
a disease that makes bones very fragile and occurs when bone resorption exceeds bone deposition
Hematoiesis
the process of blood cell formation
red bone marrow
Sesamoid bones
Bones that are embedded in tendons
ex) patella- knee cap
How many bones are in the fully grown human body?
206
Lacuna
cavity in which the osteocyte lives
Athritis
an inflammation of one or more joints