Osteology Flashcards
What are the 3 types of bone cells?
Osteoblast
Osteocytes
Osteoclast
The realatively active cell aht secrete the fibers and the ground substance
Osteoblasts
What does the fibers and ground substance form?
Osteoid
Relatively sedentary cells that are entrapped in the extracellular matrix
Osteocytes
Large, multinucleated cells that are active in bone reasbsorption.
Osteoclasts
2 physicall types of bone tissue
Compact & spongy
Compact is “dense bone”
Spongy is “cancelous bone”
The connective tissue proper sheath that envelopes the whole bone except where muscles, ligaments, retinacula, and joint capsules attach.
Periosteum
The solid cortical bone tissue of nearly all bones surrounds a space termed the
Medullary cavity
The Medullary cavity is lined with a thin sheet of connective tissue proper termed?
Endosteum
Both the endosteum and periosteum are firmly attached to the adjacent bone tissue by thick collagenous strands termed
Perforating fibers
3 physical functions of bones
1) Body shape and Posture
2) Protection
3) Locomotion
2 Metabolic Functions of bones
1) Hemopoiesis (formation of RBC & WBC)
2) Fat depository
3) Calcium/Phosphorous storage
How many bones in the human body
214
How many bones in the head,
29
How many vertebrae
26
How many ribs
24
How many bones in each superior limb
34
How many bones in each inferior limb
33
What are the 5 classifications of bones by shape
Long bones Short bones Flat bones Irregular bones Sesamoid bones
How many long bones in the human boddy
88
How many short bones in the human body
30 (16 Carpal & 14 Tarsal)
What charaterizes Flat bones
Significantly reduced in one dimension
WHat characterizes Irregular bones
Jutting process
How many sesamoid bones?
10
2 in each thumb
2 in each big toe
and 2 patellaes
A reduction in total bone mass, which weakns the skeleton and predisposes the patient to fractures involving minimal trauma
Osteoporosis
An inflammation of bones involving the contiguous joints and may have traumatic infectious, neoplastic, or developmental implications as weel as degenerative ones
Osteoarthritits
a developmental anomaly wherein the spinal cord is exposed due to failure of the left and right laminae of the vertebrae to complete closure of the vertebral arch
Spina bifida
Too little growth hormone during childhood results in
Dwarfism, and too much causes Gigantism
After skeletal maturity, excess growth hormone causes
acromegaly
Vitamin D deficiency in children reduces the incorporation of calcium into growing bones and causes
Rickets
In adults, low vitamin D produces softened bones for the same reason and is called
Osteomalacia
Most bones begin their development embryologically as tiny hyaline cartilage precursors. These hyaline cartilage models are then converted to the definitive bones by a multistep proccess called?
Endochondral ossification
what are the 4 steps to Endochondral ossification
1) hyaline cartilage model of the bone forms
2) Cartilage mineralizes to become calcified cartilage
3) Mineralized cartilage is reabsorbed by chondroclasts.
4) As cartilage is reabsorbed, cells differentiate into osteoblasts, secrete osteoid, and then bone salt precipitate into bone tissue
Areas of hyaline cartilage which remain between enlarging centers of ossification are called
Epiphyseal cartilages
Bone tissue formed within the periosteum is deposited on the outer surface of the cortex and allows GROWTH IN DIAMETER, is called
Intramembranous Ossification
A break or crack in a bone is called a
Fracture
Putting the broken endes back into proper alignment is called
Reducing (“setting”) the fracture
Adding casts, pins, screws, wires, plates to reduce movement to a minimum is called
Stablilization
Fractures that require an exceptionally long time to heal are called
Delayed Unions
Sometimes healing never occur and this develops
False Joints
When bones are surgically fractured for the purpose of realignments it is called
Corrective osteotomies
