Skeletal Classification Flashcards
formation of the bones
ossification
What are the two types of ossification?
intramembranous and endochondral
What is intramembranous ossification?
spongy bone forms between two sheets of fibrous connective tissue membranes, forms flat bones
what is endochondral ossification?
forms most bones, including all long bones. hyaline cartilage model is replaced by spongy bone, then compact bone, results in the plates and lines
histology
the study of tissue
What is abundant in bone tissue?
bony matrix
25% water, 25% collagen fibers, 50% minerals
What is calcification
osteoblasts make collagen fibers, mineral salts crystalize in between and all around collagen fibers
What are the four types of bone cells?
osteoprogenitor cells, osteoblasts, osteocytes, osteoclasts
What are osteoprogenitor cells?
undifferentiated bone cells, give rise to osteoblasts, found in periosteum and endosteum
What are osteoblasts?
immature bones cells that make collagen of bony matrix and initiate bone deposition of calcium from blood to bone
What are lacunane
osteoblasts that surround themselves with bone matrix and eventually become trapped in cavities
What are osteocytes?
mature bone cells that carry out daily activities located in the lacunae
What are osteoclasts?
macrophages for breakdown of bone and absorption of calcium into blood
What are osteoclasts responsible for?
they are responsible for bone resorption, bone must be removed to replaced, this happens when healing happens to an injured bone
What are the two types of bone tissues?
compact and spongy bone
What is compact bone?
thick layer that forms diaphysis of long bones, thin shell of compact bone surrounds spongy bone. This is also called cortical bone
What is spongy bone?
also called cancellous bone or trabecular bone, found within epiphyses of long bones, forms most of other bone shapes surrounded by thin shell of compact bones
What is trabecule?
spongy bone that is made of bony spike and spurs
What is osteon
circular units, compact bones are made of this.
What is lamella?
layers of bony matrix that are in concentric circles around a central canal
What is the central canals
it runs longitudinally through the centers of osteons, holds nerves and blood lymph vessels. Connect via the perforating canals
What are found within the lamellae?
lacunae that contain osteocytes
what is canaliculi?
one of the canals in the compact bones
What is trabeculae?
internal beams, spurs, spikes of bones
What is the spongy bone structure?
matrix formed into trabeculae, the trabeculae also align along bone’s lines of stress to provide increased stability, no osteon, central canal. Open areas between trabeculae are filled with red bone marrow
