Flashcards in Module 102 - Development and growth of human skeleton Deck (32):
Skeletal system division
Axial and appendicular
What does the axial system consist of?
Skull, vertebrae, ribs, sternum, hyoid bone
What does the appendicular system consist of?
Limb bones and bones of pectoral and pelvic girdle
Features of cartilage
- Connective tissue
- Forms the skeleton in parts where flexibility is required
- Proportions of bone to cartilage change as the individual develops
Features of bone
- Hard form of connective tissue
- Provides a ridged framework
- Two types of bone(compact and spongy)
Describe the coverings of bone
- A connective tissue element covers the skeletal system(except where an articulation occurs)
- The connective tissue surrounding bone is called the periosteum
- The connective tissue surrounding cartilage is called the perichondrium
What are the 4 types of cells in bone
- Osteoprogenitor cells
What are the two types of cells that shape bone
- Bone is constantly remodelled as a result of activity between osteoclasts and osteoblasts
How is compact bone formed?
- Lamella is laid down by osteoblasts
- Lamella form the haversian canal in the centre
- Haversian canal contains vascular and nerve supply
- Osteoblasts become
trapped and turn into osteocytes
- Each osteocyte occupies its own lacunae
- Radiating from each lacunae are minute canals(canaliculi)
- Nutrients travel in the canaliculi to the osteocyte
What is spongy bone also known as?
Features of spongy bone
- Irregular lamellae
- Has red bone marrow surrounding it
- Highly vascular
What are the 5 types of bones
What is a trochanter
- any of a number of bony protuberances by which muscles are attached to the upper part of the thigh bone.
What is a foramen
an opening, hole, or passage, especially in a bone
What is a condyle
a rounded protuberance at the end of some bones, forming an articulation with another bone
What is a tuberosity
a rounded prominence; especially : a large prominence on a bone usually serving for the attachment of muscles or ligaments.
What is an epicondyle
Any of several prominences on the distal part of a long bone serving for the attachment of muscles and ligaments
What is a trochlea?
A structure resembling or acting like a pulley, such as the groove at the lower end of the humerus forming part of the elbow joint
Process of skeletal system development from blastocyst stage
Blastocyst(inner cell mass) --> epiblast --> Mesoderm --> Skeletal system
When does bone development begin and end
Begins at week 8 and finishes at 20 years
What part of the mesoderm is bone specifically derived from?
Paraxial and lateral plate mesoderm
What are the two ways in which ossification can occur?
Describe how intramembranous ossification occurs?
- Direct mineralisation of connective tissue(mesenchyme)
- Cells divide and condense around capillary network
- Grows radially, finally fusing together replacing the connective tissue
- Connective tissue that remains penetrated by blood cells and undifferentiated mesenchyme gives rise to bone marrow
What is the starting point in intramembranous ossification called?
- Primary ossification center
What are examples of intramembranous ossification
Skull, mandible and clavicle
Describe how endochondral ossification occurs
- Cartilaginous template made from the mesenchyme
- Template is replaced by bone-osteogenesis
- Different ossification centres emerge, a primary one in the diaphysis and secondary ones in the epiphysis
- Initially, a bone collar is produced and from here, the primary centre develops
- The epiphyseal late(growth plate) exists between the diaphysis and the epiphysis
When do blood vessels penetrate developing bone
What diminishes with maturity during bone development
The epiphyseal plate is abolished with maturity
Role of vit a in bone development
role of vit c in bone development
connective tissue formation
role of vit d in bone development