Ch. 6- Bones Flashcards
What are sutural (wormian) bones?
Small, flat, irregularly shaped bones between flat bones of the skull
What are irregular bones?
Have complex shapes
Don’t do not fit into any other categories
Exs:
- spinal vertebrae
- pelvic bones
What are short bones?
About Equal in length and width
Small and thick
Consist mainly of spongy bone covered with a thin layer of compact bone
Exs:
Ankle and wrist bones
What are sesamoid bones?
Small and flat
develop inside tendons near joints of knees, hands and feet
Ex: patella
What are flat bones?
Thin
Contains 2 layers of compact bone with a layer of spongy bone b/n cranium
Many are curved
Exs: Skull Sternum Ribs Scapulae
What are long bones?
Longer than they are wide
Consists mainly of compact bone in the diaphysis and spongy bone in epiphysis
Exs: Femur Tibia Humerus Radius Metacarpals Metatarsals Phalanges
What are bone markings and the different types?
Surface features, bones have characteristics
Exs:
- Depressions or groves
- Elevations or projections
- Openings
What are depressions or grooves?
A long bone surface when blood vessels or nerves lie
Exs:
Sulcus and fossa
What are elevations or projections?
Where tendons and ligaments attach
Articulations with other bones
Exs:
Processes and ramus
What are openings?
Where blood and nerves enter bone
Exs:
Foramen and canal
What is the diaphysis of a long bone?
The shaft
Consist of a thick outer layer of compact bone that’s around a central medullary cavity
What is the epiphysis of a long bone?
The wide ends of bones
Exterior is compact bone and the interior is spongy bone
Consists of the part that articulates with other bones
The joint surface of the epiphysis is covered with articular cartilage
What is the metaphysis of a long bone?
Where diaphysis and epiphysis meet
What is compact bone?
Also known as cortical bone
The dense external layer of bone
What is spongy bone?
Also called trabecular or cancellous bone
Consists of an open network of struts or plates of bone tissue that resembles latticework
Open spaces b/n trabeculae are filled with red or yellow marrow
Do not have osteons
Consists of lamellae irregularly arranged in thin columns called trabeculae
Covered in endosteum
Always surrounded by layer of compact bone
What is an osteon (haversian system)?
Structural unit of compact bone
Consists of:
- concentric lamellae
- central canal (haversian canal)
- lacunae
- canaliculi
Each osteon is long tube like cylinder that is parallel to the long axis of the bone
What is a concentric lamellae?
Concentric rings of bone matrix arranged around a central canal
What is a central/ Haversian canal?
A passageway through the center of each osteon and runs parallel to the long axis of the bone
Contains:
- blood vessel
- lymphatic vessels
- nerves
What are lacunae?
Small cavities, in the bone matrix, that contain osteocytes
Located between concentric lamellae
What are canaliculi?
Narrow passageways in bone matrix that radiate out in all directions from the lacunae
Connect to Laguna with one another and with central canal
Provides a passageway for nutrients to reach the osteocytes and removal of waste products
What is the volmann’s/ perforating canal?
Passageways that run perpendicular to the long axis of the bone
Connects the blood and nerve supply of the periosteum to those in the central canals and the medullary cavity
Lined with endosteum
What are interstitial lamellae?
Remanants of osteoid whose matrix have almost been completely recycled by osteoclasts
Fill in the spaces between osteons in compact bone
What are circumferential lamellae?
Outer circumferential lamellae- Located deep to the periosteum
Inner circumferential lamellae-
Located superficial to the medullary cavity
Is spongy or compact bone lighter?
Spongy bone
What does trabeculae consist of?
Concentric lamellae (irregularly arranged)
Osteocytes in Lacunae
Canaliculi
Are there blood vessels in the matrix of spongy bone?
No
What do blood vessels in Marrow tissue do?
Delivers nutrients to the trabeculae and removes waste generated by the osteocytes
How does nutrients reach the osteocytes?
Diffusion from capillaries
Spongy bone makes up most of the interior bone tissue of what kind of bones?
Short, flat, sesaamoid and irregularly shaped bones
Core of epiphysis
Narrow rim bordering medullary cavity of diaphysis
What is red bone marrow?
Highly vascularized CT
Main function hematopoiesis
Contains:
- reticular tissue
- capillaries
- fibroblasts
- macrophages
- collagen fibers
In newborns, What color is bone marrow and where is it located?
Red
Located in the medullary cavity of the diaphysis and all areas of spongy bone
In Adults where is red and yellow bone marrow found?
Red- located b/n trabeculae of spongy bone
Yellow- medullary cavity of long bones
What is the periosteum?
A double layered CT sheath
Outer fibrous layer- dense irregular CT
Inter cellular level- osteoblasts, osteoclasts and osteogenic cells
Covers compact bone except joint cavity
Attached to underlying bone by perforating/ sharpey’s fibers
Supplied with nerve fibers, lymphatic and blood vessels
What is the endosteum?
CT layer
Covers internal bone surfaces
Covers trabeculae of spongy bone
Lines central canals, medullary cavity and volkmann’s canal
Contains osteoblasts, osteoclasts and osteogenic cells
What is the nutrient artery and vein?
Supply the diaphysis through the nutrient foramen and in most bones have only one artery and vein
What are the metaphyseal and epiphyseal vessels?
Supply the metaphyses and epigyses
What is the periosteal vessel?
Supply blood to the periosteum and superficial osteons
What is a fracture?
A crack or break in a bone caused by physical stress or pathological processes
What is an impact fracture?
Caused by direct trauma
What is a stress fracture?
Caused by repeated, abnormal stress to a bone
What is a pathological fracture?
Break in a bone weakend by some other disease like bone cancer or osteoporosis
What is a non-displaced fracture?
Bone ends retained normal position after fracture
What is a displaced fracture?
Bones ends out of normal alignment after fracture
What is a complete fracture?
Bone is broken all the way through
What is an incomplete fracture?
Bone is not broken all the way through
What is a linear fracture?
The Fracture line is parallel to long axis of the bone
What is a transverse fracture?
The fracture line is perpendicular to long axis of the bone
What is an oblique fracture?
The fracture line is oblique to the long axis of the bone
What is a spiral fracture?
The fracture line spirals along the long axis of the bone
What is a compound Fracture?
Open
Bone ends penetrate the skin after fracture
What is a simple fracture?
Bone ends do not penetrate the skin after a fracture
What is a comminuted fracture?
Bone breaks into multiple pieces
