Module 102 - Development and growth of human skeleton Flashcards Preview

Year 1 - Module 102 > Module 102 - Development and growth of human skeleton > Flashcards

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
- Avascular
- Proportions of bone to cartilage change as the individual develops


Features of bone

- Hard form of connective tissue
- Provides a ridged framework
- Vascular
- 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
- Osteoblasts
- Osteocytes
- Osteoclasts


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?

Cancellous bone


Features of spongy bone

- Irregular lamellae
- Has red bone marrow surrounding it
- Highly vascular


What are the 5 types of bones

- Long
- Flat
- Irregular
- Short
- Sesamoid


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?

1. Intramembranous
2. Endochondral


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

Week 9


What diminishes with maturity during bone development

The epiphyseal plate is abolished with maturity


Role of vit a in bone development

bone remodelling


role of vit c in bone development

connective tissue formation


role of vit d in bone development

calcium absorption


What is acromegaly as a result of?

Excess growth hormone production by the pituitary gland