Lecture 1: Introduction Flashcards
How many bones are in the human body?
206
How many bones are in the appendicular skeleton?
126
How many bones are in the axial skeleton?
80
What is the last bone to ossify?
Clavicle
What are the 4 functions of bone and connective tissue?
- ) Supports mechanical loads
- ) Protects vital organs
- ) Contributes to mineral homeostasis
- ) Serves as a site for hematopoiesis
What are the 3 germ layers?
- ) Ectoderm
- ) Mesoderm
- ) Endoderm
From what germ layer is bone formed?
Mesodermal tissue
What does long bone begin as in the fetus?
Hyaline cartilage
What are the 2 types of bone formation?
#1 Intramembranous ossification #2 Endochondral ossification
What is intramembranous ossification?
Embryonic connective tissue transforms to bone
During intramembranous bone formation growth occurs by transformation of _____ to _____ without a _____ pre-modeling.
Mesenchymal cells, bone, cartilagenous
What type of bones are formed from intramembranous bone formation?
Flat bones
Intramembranous ossification increases the _____ of bone.
Diameter
What are 4 bone that are ossified in membrane?
- ) Parietal bone
- ) Temporal bone
- ) Upper occipital squamosa
- ) Frontal bone
What are the 2 forms of ossification within cartilage?
- ) Primary ossification
2. ) Secondary ossification
What is endochondral bone formation?
Growth occurs by the laying down of bone on a cartilagenous scaffold
What types of bones are formed by endochondral ossification?
Long and short tubular bones
_____ tissue from _____ transforms to bone.
Cartilagenous tissue, mesenchymal cells
Primary ossification _____ bone.
Lengthens
When does primary ossification occurs?
In utero
How many primary ossification centers are there?
3
Where are the 3 primary ossification centers?
Vertebral body center = 1
Posterior arches = 2 (one each side with growth plate at each end)
Primary ossification centers are usually fused at the midline by what age?
7
Where does secondary ossification occur?
Within the epiphyses and apophyses