STUDY GUIDE J - UNIT 2 Flashcards
(24 cards)
Why is cartilage growth discussed in the bone chapter?
Bone growth and development begin with cartilage models.
What are the two types of cartilage growth?
- Interstitial growth: From within the cartilage (length).
- Appositional growth: Along the outer edge (width).
Where does interstitial growth occur?
Inside the cartilage, between existing chondrocytes.
Where does appositional growth occur?
Along the periphery of cartilage, under the perichondrium.
What is ossification?
The formation and development of bone.
What is mesenchyme?
Embryonic connective tissue that gives rise to bone and cartilage.
What bones are formed via intramembranous ossification?
Flat bones of the skull, mandible, and clavicle.
What bones are formed via endochondral ossification?
Most bones in the body, including long bones.
Where does cartilage remain after endochondral ossification?
Articular cartilage and epiphyseal plate.
What are the two types of bone growth?
Interstitial (length) and appositional (width).
Where does interstitial growth occur?
At the epiphyseal plate.
What is the epiphyseal plate vs. epiphyseal line?
Plate = growth area in children; Line = remnant in adults.
Where does appositional growth occur?
In the periosteum.
What is bone remodeling?
Ongoing replacement of old bone tissue by new bone tissue.
Which cells are involved in bone remodeling?
Osteoblasts, osteoclasts, and osteocytes.
What is the effect of growth hormone on bone?
Stimulates growth of cartilage at the epiphyseal plate.
What is the effect of thyroid hormone?
Regulates metabolism and helps maintain bone growth.
What do sex hormones do to bones?
Promote bone growth and later close the epiphyseal plates.
What is the function of calcitriol?
Increases calcium absorption in the small intestine.
What do PTH and calcitriol do to bone and kidneys?
Stimulate bone resorption and reduce calcium excretion in urine.
When are PTH and calcitriol released?
When blood calcium levels are low.
What does calcitonin do?
Lowers blood calcium by inhibiting bone resorption.
What happens to bones with age?
Loss of bone mass, reduced collagen, and weaker bones.
What is osteoporosis and who is most at risk?
Severe bone density loss; postmenopausal women are at highest risk.
