Lesson 5 Skeletal System Flashcards
(69 cards)
What is a greenstick fracture?
Incomplete fractures of the ulnar and radial diaphyses
Commonly seen in children due to softer bones.
What process forms the bones of the base of the skull and most remaining bones of the skeletal system?
Endochondral ossification
Begins with cartilage formation at the end of the fourth week of development.
At what age does some ossification begin during endochondral ossification?
About week eight
Some ossification does not begin until 18-20 years of age.
What occurs when the maxillae do not form normally during fetal development?
Cleft lip
A cleft palate occurs when the palatine processes of the maxillae do not fuse.
What is the occurrence rate of cleft lip or palate?
Approximately once in every 1000 births
More common in males.
What condition occurs when the epiphyseal plate ossifies?
Closure of the epiphyseal plate
This occurs between approximately 12 and 25 years of age.
What type of cartilage persists throughout life and does not ossify?
Articular cartilage
Only appositional growth occurs on its surface.
What type of bone growth occurs on the surface of cartilage?
Appositional growth
Interstitial growth cannot occur because the matrix is solid.
What is the primary difference between woven bone and lamellar bone?
Woven bone has randomly oriented collagen fibers
Lamellar bone has fibers oriented in one direction in each layer.
What are the four classes of medications for osteoporosis?
- Bisphosphonates
- Estrogen-like medications
- Antibodies
- Calcitonin-replacement medications
Each class targets different mechanisms of bone density loss.
What dietary recommendation is given for preventing osteoporosis?
Consume at least 1000 mg of calcium per day
1200 mg/day for people over age 50.
What lifestyle factor significantly increases the risk of osteoporosis?
Inadequate calcium intake
Regular weight-bearing exercises can help prevent bone loss.
What is the most common cause of osteoporosis in women?
Decreased reproductive hormone production
Especially after menopause.
What is the effect of proton pump inhibitors (PPIs) on bone health?
Increased risk of fractures
Particularly after long-term use and when other risk factors are present.
What happens to bone density after 8 weeks of immobilization?
Significant amounts of bone are lost
This emphasizes the importance of movement and weight-bearing activities.
What is the function of osteoblasts?
Bone formation
They are responsible for appositional growth.
What is the difference between compact bone and spongy bone?
Compact bone is dense and forms the outer layer, while spongy bone has interconnecting rods or plates
Spongy bone is oriented along lines of stress.
What is the age of Henry, the man with low bone density?
65 years old
What type of fracture did Henry sustain?
Fractured the proximal part of his arm bone (surgical neck of the humerus)
What lifestyle factors contributed to Henry’s low bone density?
Junk food addiction, few vegetables, no dairy, lack of exercise, nocturnal lifestyle
What is the normal range of blood Ca2+ for Henry?
Normal
How do Henry’s eating habits affect his bone density?
Low calcium and vitamin D intake from poor diet
Would Henry’s PTH levels be lower than normal, normal, or higher than normal?
Normal
What effect has Henry’s nocturnal lifestyle had on his bone density?
Reduced exposure to sunlight, leading to lower vitamin D synthesis
