Musculoskeletal System 2 Flashcards
What is hypertrophy?
Increase in cell size
No change in cell number
What is hyperplasia?
No change in cell size
Increase in cell number
What is the initial stage of longitudinal bone growth?
- bone growth starts as the formation of a bony collar around the cartilage template
What is the second stage of longitudinal bone growth?
Blood vessels invade the tissue
What is the third (middle) stage of longitudinal bone growth?
Osteoblasts enter the cartilage shaft and lay down bone matrix
What is the fourth (2nd to last) stage of longitudinal bone growth?
Osteoblasts enter epiphysis and lay down bone matrix.
What is the last (5th) stage of longitudinal bone growth?
Cartilage is retained between the epiphysis and the shaft.
What are the two types of bone growth?
Interstitial Growth
Appositional Growth
What is interstitial bone growth?
Largening of the bone longitudinally
Growth from within the cartilage
Division of chondroblasts
Replicate and enlarge - allowing lengthening of the cartilage template
What is Appositional growth?
Thickening of the bone
Surface cells differentiate - growing into perichondrium –> dense fibrous connective tissue
What is longitudinal bone growth?
Indirect growth via interstitial cartilage growth at the growth plate and ossification
Ends at skeletal maturity
What is circumferential bone growth?
Occurs directly via appositional growth at the bone surface
Continues throughout life
What are the steps in the process of longitudinal bone growth?
Bone growth starts at formation of bony collar around cartilage template
Blood vessels invade tissue
Osteoblasts enter cartilage shaft, lay down bone matrix
Osteoblasts enter epiphysis and lay down bone matrix
Cartilage is retained between epiphysis and shaft
What is the epiphyseal growth plate?
Site of indirect bone growth via interstitial cartilage growth
Increase in bone length complete at skeletal maturity when the growth plate “closes” and interstitial cartilage growth stops
What does endochondral (bone formation) mean?
Within cartilage
What does intramembranous (bone growth) mean?
Inside a membrane
How does skeletal muscle growth occur?
Achieved through upregulation of protein synthesis within muscle cells
Result of hypertrophy rather than hyperplasia
= Increase in muscle mass
What is the main hormone involved in growth in the musculoskeletal system?
Growth Hormone (GH)