Exam 2 Flashcards
What are the functions of the skeletal system?
Support, Protect, Allow for movement, Ca and Phosphorous homeostasis (withdraw and deposit)
Osteology
Study of bones
Ossification
Matrix that has been hardened by the deposition of calcium and other minerals
Bones are made up of what 2 things?
Compact bones and spongy bones
What are compact bones?
-acts as outer shell
-75% of skeleton
What are spongy bones?
-Inner sections of bone
-25% of skeleton
Long bones
bones are longer than they are wide
-femur
Short Bones
-Bones that are similar in length and width
-carpals and tarsals
Flat bones
-wide and thin
-parietal bone
-Portion of scapula
Sesamoid Bones
-Shape like a sees or bean
-Patella in the femur
Irregular bones
-do not have uniform shape
-Thoracic vertebra
Diaphysis shaft in a long bone
-compact bone on outer space
-medullary cavity in middle with bone matrix
Epiphysis head in a long bone
-at the ends
-filled with spongy bone
-spaces have bone marrow
Epiphyseal Plate in a long bone
-separates epiphysis and diaphysis
Surface tissues on a long bone:
Endosteum
-Line marrow cavity
Surface tissues of a long bone:
-Periosteum
-Supply bone with blood
-Protects bone
Surface tissues of a long bone:
-Articular Cartilage
-Provide slippery surface where 2 bones can glide
Features of flat and short bones
-Sandwich like constuction
-2 layers of compact bone with spongy layer in between
Why is a blow to the skull not always fatal?
Skull can fracture the outer compact bone, spongy layer absorbs the blow, and leaves the inner layer of compact bone unharmed
Red Bone Marrow (myeloid tissue)
-Create RBC
-Everywhere in children
-Adults: ribs, skull, pelvis, head, humerus, and femur
Yellow bone marrow
-Everywhere in adults
-Triglyceride storage
Bone matrix
-Matrix component of bone tissue
-Osteoclasts absorb this and osteoblasts build this around cell
-Ceramic: (crystallized salts of hydoxyapatities): gives strength, able to support body weight
-Polymer: (collagen fibers): gives flexibility
and bones don’t shatter easily
Osteogenic Cells:
-Creating, making
-Divide and become something else
-Found in endosteum, periosteum, and central canals
-Give rise to osteoblasts
Osteoblasts
-Brand new bone cell
-Build matrix around cell
-Found on bone surfaces
Osteocytes
-Stuck in the bone matrix and maintain it
-Found in lucanae
Osteoclasts
-Break the bone and gets matrix into blood stream
-“bank robbers”
-Multinucleated
-massive
-live under periosteum
-ruffles border absorbs bone matrix and increase surface area
Bone Progenitor Line
Osteogenic- osteoblasts- osteocyte
Blood Progenitor Line
Blood stem cells- Osteoclasts
Compact Bone:
Central Canal
Spaces for arteries, veins, and nerves to pass through
Compact Bone:
Concentric Lamellae
Osteocytes arranged into circular layers in the individual osteon
Compact Bone:
Lacuanae
Space from the osteocyte
Compact Bone:
-Canaliculi
Osteocyte extenstions
Circumferential lamellae
layers of osteocyte circumference of long bone
Perforating canals
connect vascular structures together
Interstitial lamellae
Fill spaces b/n osteons
Spongy Bone
-Trabeculae: Irregular lamellae
-No osteons
-Space is filled with bone marrow
Nutrient Foramen
-Hole that allows bone to receive blood an nerve supply
Nutrient artery/ vein
Supply bone marrow
