Lecture: Anatomy 2: Principles of the skeletal system Flashcards
What are the 2 divisions of the skeletal system?
- Axial
2. Appendicular
What parts of the skeletal system are found in the axial division?
Cranium, thoracic cage, spine and sacrum
What parts of the skeletal system are found in the appendicular division?
Shoulders, hips and limbs
What are the functions of the skeletal system?
- Protection of organs
- Supports the body
- Movement
- Metabolic reservoir
- Production of new red blood cells
Where are the skeletal system and connective tissue derived from?
Derived from the mesoderm which is formed by epiblasts during embryological development.
What is cartilage?
A form of connective tissue which forms the skeleton in parts where flexibility is required.
Avascular.
What is bone?
A hard form of connective tissue that provides a rigid framework.
Either compact or spongy.
Vascular
What is ossification?
Bone development
What are the 2 types of ossification?
- Intramembranous
2. Endochondral
What occurs during intramembranous ossification?
ells divide and condense around capillary network, starting at the primary ossification centre.
What happens to undifferentiated mesenchyme in intramembranous ossification?
Undifferentiated mesenchyme gives rise to bone marrow.
Where does intramembranous ossification take place?
The skull, mandible and clavicle.
What occurs during endochondral ossification?
Cartilaginous template made from the mesenchyme is replaced by bone in a process known as osteogenesis.
Where does endochondral ossification take place?
The skull base, vertebrae, long bones and pelvis.
What are the 4 types of bone cells?
- Osteoprogenitor cells
- Osteoblasts
- Osteocytes
- Osteoclasts
What dietary minerals and vitamins are required for bone maintence?
- Calcium
- Phosphorous
- Vitamin A
- Vitamin C
- Vitamin D
How is bone development controlled by hormones?
Bone development is controlled by endocrine activity of parathyroid hormone and growth hormone.
What is acromegaly?
Acromegaly is a condition caused by the overproduction of growth hormone resulting in large hands and feet.
What is the periosteum?
The connective tissue that covers the skeletal system except where articulation occurs.
What is the perichondrium?
The connective tissue surrounding cartilage.
Describe the structure of compact (cortical) bone
Composed of lamellae (concentric layers) of bone formed by osteoblasts which become osteocytes.
Radiating from each lacunae are canaliculi.
Haversian canal in the centre of compact bone contains the neurovascular supply.
Describe the structure of spongy (cancellous or trabecular) bone
Irregular bony plates called trabeculae which are surrounded by red marrow and are highly vascularised.
What are the 3 classes of joints?
Synovial, fibrous, cartilaginous
What are synovial joints?
Synovial joints have a joint capsule and a synovial cavity, and they permit movement.
What are fibrous joints?
Fibrous joints are connected by collagen and do not permit movement, eg. sutures of skull
What are cartilaginous joints?
Cartilaginous joints are connected by cartilage to allow some movement, eg. pubic symphysis and growth plate.
