Intramembranous ossification, by which most flat bones begin to form, takes place within condensed sheets (“membranes”) of embryonic mesenchymal tissue. Most bones of the skull and jaws, as well as the scapula and clavicle, are formed embryonically by intramembranous ossification.
২.
Growing end is present in-
ক
ক) Lower end of humerus
খ
খ) Lower end of tibia
গ
গ) Lower end of radius
ঘ
ঘ) Upper end of ulna
সঠিক উত্তর: গ
গ) Lower end of radius
উত্তর
সঠিক উত্তর: গ
গ) Lower end of radius
গ
ব্যাখ্যা
In the upper extremity, shoulder and wrists ends of the bones are the growing ends. In the lower extremity, knee ends of femur, tibia, fibula are the growing ends.
৩.
What type of epiphysis is present in coracoids process of scapula?
ক
ক) Pressure
খ
খ) Traction
গ
গ) Atavistic
ঘ
ঘ) Aberrant
সঠিক উত্তর: গ
গ) Atavistic
উত্তর
সঠিক উত্তর: গ
গ) Atavistic
গ
৪.
What type of epiphysis is present in head of 1st metacarpal?
ক
ক) Pressure
খ
খ) Traction
গ
গ) Atavistic
ঘ
ঘ) Aberrant
সঠিক উত্তর: ঘ
ঘ) Aberrant
উত্তর
সঠিক উত্তর: ঘ
ঘ) Aberrant
ঘ
৫.
What type of epiphysis is present in coracoids process of scapula?
ক
ক) Pressure
খ
খ) Traction
গ
গ) Atavistic
ঘ
ঘ) Aberrant
সঠিক উত্তর: গ
গ) Atavistic
উত্তর
সঠিক উত্তর: গ
গ) Atavistic
গ
৬.
Enchondral ossification occurs in-
ক
Parietal bone
খ
Clavicle
গ
Maxilla
ঘ
Ribs
সঠিক উত্তর: ঘ
Ribs
উত্তর
সঠিক উত্তর: ঘ
Ribs
ঘ
ব্যাখ্যা
1. Intramembranous ossification: Involves direct conversion of mesenchymal tissue to bone. Bones produced by this process are called membranous (flat) bones. Examples:Bones of cranial vault, facial bones.
2. Endochondral (cartilaginous) ossification Involves conversion of mesenchyme to hyaline cartilage that later gets replaced by bone. Examples: All long bones (except clavicle), base of skull, vertebrae & ribs are formed by cartilaginous ossification.