Ch. 7 Skeletal Tissues (exam 2) Flashcards
Hemopoieses
Production of blood cells and platelets which occurs in the bone marrow
Ossification
The process of bone formation
Sinus
A hollow space or cavity in the body
What are the two types of bones?
-cancellous (spongy)
-compact
What are the characteristics of cancellous (spongy) bones?
Porous, light, fragile
What are the characteristics of compact bone?
Dense, hard, solid
What are some examples of long bones?
-femur
-humerus
-tibia
-fibula
-ulna
-radius
What are some examples of short bones?
-carpal bones
-tarsal bones (talus, calcaneus)
What are some examples of flat bones?
-skull
-occipital
-frontal
-parietal
-nasal
-lacrimal
-ribs
What are some examples of irregular bones?
-coccyx
-sacrum
-mandible
-maxilla
-vertebrae
-hyoid
What are the parts of a long bone?
Diaphysis, epiphysis, periosteum, endosteum, articular cartilage
What is the periosteum of a long bone?
Outer surface
Inorganic matrix of bone
composed of inorganic salt called hydroxyapatite made up of calcium phosphate which gives the bone its hardness
Organic matrix of bone
Composed of protein fibers (collagen) and glycoproteins. Gives bone its flexibility
Where is compact bone located?
Outer layer of long bones
What is compact bone useful for?
Providing protection and support
Where is spongy bone located?
Ends of long bones, within pelvic, ribs, and skull bones
What is spongy bone useful for?
Lightweight and provides tissue support
What is spongy bone appearance formed by?
Plates of bone called trabeculae
Where does trabeculae develop?
Along bone’s line of stress
Osteoblasts
Cells that form new bones and grow and heal existing bones
Osteoclasts
Cells that break down old or damaged bone to make room for new bone tissue
What is another word for bone marrow?
Myeloid tissue
Where is bone marrow located?
In medullary cavity (long bone) and among trabeculae (spongy bone)
What is the function of bone marrow (myeloid tissue)?
Site for production of blood cells
Red marrow
-produces blood cells
-in vertebrae, ribs, sternum, pelvic girdle, and proximal heads of femur and humerus in adults
Yellow marrow
Fatty marrow of long bones in adults (stores fat and connective tissue)
What are the functions of the skeletal system?
-support
-protection
-movement
-mineral storage (calcium)
-production of red blood cells
-homeostasis of calcium levels
How much calcium do bones store?
99% of the body’s calcium
Parathyroid hormone
Released when calcium levels in the blood are decreased
How does parathyroid hormone work?
Osteoclasts are stimulated to increase bone resorption and calcium is released in the blood
Calcitonin
Released when calcium levels are increased in the blod
How does calcitonin work?
Osteoblasts are stimulated to increase bone deposition and calcium is removed from the blood
Osteogenesis
Bone formation
Intramembranous ossification
Occurs within a connective membrane. Adds bone tissue to outer surface
Endochondral ossification
Occurs within a cartilage model. increases in diameter and length
How do most bones develop?
Endochondrial ossification
Where do bones grow in length?
Epiphyseal plate
How do bones grow in diameter?
Combined action of osteoclasts and osteoblasts
When does remodeling of bone happen?
Throughout life
What is remodeling activity important for?
Homeostasis of blood calcium levels
What happens when a bone fractures?
Tears and destroys blood vessels that carry nutrients to osteocytes
What is callus?
Specialized repair tissue that binds the broken ends of the fracture together so healing can proceed
How long does it take for fractures to repair?
Normally 8-12 weeks (longer in elderly)
Stages of healing: fracture hematoma (1)
Clot forms, then osteogenic cells form granulation tissue
Stages of healing: soft callus (2)
Fibroblasts produce fibers and fibrocartilage
Stages of healing: hard callus (3)
Osteoblasts produce a bony collar in 6 weeks
Stages of healing: remodeling (4)
3-4 months. Spongy bone replaced by compact bone
Phases of repair of fractures
-
Reactive phase- formation of fracture hematoma
2a. Reparative phase- fibrocartiliginous callus formation
2b. Reparative phase- bony callus formation - Bone remodeling phase
How does deficiency of vitamin A affect bone growth?
Delays bone development
How does deficiency of vitamin C affect bone growth?
Results in fragile bones
How does deficiency of vitamin D affect bone growth?
Rickets, osteomalacia (softening of bone)
Insufficient growth hormone (bone growth)
Dwarfism
Excessive growth hormone (bone growth)
Gigantism, acromegaly
Insufficient thyroid hormone (bone growth)
Delays bone growth
Sex hormones (bone growth)
Promote bone formation; stimulate ossification of epiphysis plates
Physical stress (bone growth)
Stimulates bone remodeling
Ligaments
-connect bone to bone
-strengthen and reinforce capsule
Bursae
Sacs outside most synovial joints where ligaments, muscles, tendons, and/or bones rub
Tendon sheaths
Elongated bursae around tendons, particularly in confined areas where tendons rub each other
Osteoporosis
Bones lose mass and become increasingly brittle and subject to fractures (more prevalent in women)
Scoliosis
Curvature of the spine. Affects thoracic or lumbar area
Kyphosis
Flattening of the spine (hunchback). Affects thoracic area
Lordosis
Anterior pushing in of the spine. Affects lumbar area
