1.3 Bone and the Skeleton Flashcards
What is bone?
A type of connective tissue made up of cells suspended in a matrix.
What are bones?
Organs made up of bone tissue with cortical bone (compact) on the outside, trabecular bone (spongy) on the inside, and a central medullary cavity.
Where is cortical bone found?
The outside of a bone.
Where is trabecular bone found?
The inside of a bone.
What are three types of bone?
Long, flat, short
Describe a flat bone.
no medullary cavity, two layers of compact bone surroundin gspongy bone and air space.
Describe a short bone
no medullary cavity, develops from a single centre of ossification.
What is the PERIOSTEUM?
covers the outside of a bone in two layers, contains sensory nerves and blood/lymphatic vessels.
Does more osteogenesis or osteolysis occur in periosteum?
Osteogenesis.
What is the ENDOSTEUM?
Lines the medullary cavity in a single layer.
Does more osteogenesis or osteolysis occur in endosteum?
Osteolysis.
How do arteries enter bones?
Arteries enter via nutrient foramen in diaphysis.
How is calcified cartilage supplied with blood?
Blood vessels pass through subchondral bone to supply calcified cartilage.
How is cortical bone supplied with blood?
Haversian and Volkmann canals.
How is trabecular bone supplied with blood?
Via bone marrow.
What are osteons?
Circles of bone marrow with a central canal, important structurally.
What do sesamoid bones do? (3)
Ease tendon pathway, prevent excessive tendon wear, increase movement arm of muscle.
What do surface markings do? (3)
provide leverage
respond to strain within bones
articulation with other bones
What do osteoblasts do?
Bone formation
What do osteoclasts do?
Bone resorption
What do osteocytes do?
Support/maintain bone structure
Where do osteoblasts originate?
Mesenchymal cells in bone marrow.
Where do osteocytes originate?
Mesenchymal cells in bone marrow.
Where do osteoclasts originate?
Hematopoitic cells in bone marrow.
