Bone Structure Flashcards
What are 5 functions of bones?
Support Protection Movement Red Blood Cell Development Nutrient Storage
What is compact bone?
The smooth, dense outer layer of a bone
What is spongy bone?
The softer, honeycomb like collection of osseous tissue internal to the compact bone
what is trabeculae?
small needle like or flat piece of bone that make up spongy bone
What are the proximal and distal epiphysis?
the rounded ends of a long bone
What is the Diaphysis?
the “shaft” of a long bone
what is the Periosteum?
a white, double layer membrane that covers the external surface of a long bone, it provides anchoring points for tendons and ligaments. it is richly supplied with nerve fibers and blood vessels
what is the Epiphyseal Line?
the remnant of the Epiphyseal plate, a line separating teh proximal epiphysis and the diaphysis
What is endosteum?
a delicate connective tissue that covers internal bone surfaces
What is Hematopoietic tissue?
red marrow
Where is red marrow typically found?
within the trabecular cavities in the spongy bone of long bones and in the diploe of flat bones - called red marrow cavities
What is the Medullary Cavity?
The Cavity inside the diaphysis of a long bone aka the yellow marrow cavity in adults
bone markings serve as..?
sites for muscle, ligament and tendon attachment; as joint surfaces or as conduits for blood vessels and nerves
What are the types of bone markings?
Projections - head, trochanters, spines
Depressions and openings - fossa, sinuses, foramen and grooves
What are the 5 cell types that make up bone tissue?
Osteogenic cells Osteoblast Osteoclast Osteocytes Bone lining cells
What is an Osteogenic Cell?
a mitotically active stem cell, found in membranous periosteum and endosteum. When stimulated they differentiate into Osteoblastor bone lining cells while other persist as Osteogenic cell
What is an Osteoblast?
a bone forming cell that secrete a bone matrix - responsible for bone growth. actively mitotic. They play a role in matrix calcification. When they become completely surround by the matrix they secrete they become Osteocytes
What is a mitotic cell?
a cell that participates in mitosis. the division of a single cell into 2 daughter cells
What is a Bone Lining Cell?
flat cells found on the bone surface where bone remodelling is not occurring. periosteal or endosteal cells
What is an Osteoclast?
giant multi-nucleate cells located at sites of bone resorption - breaks down bone
What is an Osteocyte?
mature bone cells that monitor and maintain the bone matrix. Stress or strain sensors, respond to mechanical stimuli and communicate the information to osteoblast and osteoclast cells so that a bone matrix can be made or degraded as necessary to preserve calcium homeostasis
What is Ossification?
the process of bone formation
what is endochondral ossification?
Before week 8 the skeleton of the human body is entirely hyaline cartilage and fibrous membrane. Endochondral ossification I bone that develops by replacing hyaline cartilage. All bones below the base of the skull except the Clavical are formed by endochondral ossification
What is intramembranous ossification ?
Before week 8 the skeleton of the human body is entirely hyaline cartilage and fibrous membrane. Intramembraneous ossification is bone that develops by replacing fibrous membrane. Forms cranial bones and clavical. Most bones are flat
