Concepts Flashcards
What are the three major components of the musculoskeletal system?
- Bones
- Muscles
- Connective tissues
Which germ layers do the components of the MSK system arise from?
Mesoderm layer
What are the functions of bone?
- Support
- Protection
- Metabolic
- Storage
- calcium, phosphate, protein and fat
- Movement (of joints)
- Haematopoiesis
What are the functions of skeletal msucle?
- locomotion
- posture
- metabolic
- glycogen metabolism
- venous return
- thermogenesis
- continence
- pelvic floor
What are the different types of connection tissue in the MSK system?
‘Firm’ tissue:
- tendon
- ligament
- fascia
- cartilage
‘Soft’ tissue
- synovial membrane
- bursa
What are tendons?
Strong fibrous collagen tissue that connects muscle to bone, connecting transmission of movement.
What is a ligament?
A short band of tough fibrous connective tissue which connects or supports two bones. Holds joints together.
What is fascia?
Dense sheets of fibrous connective tissue that compartmentalises muscle groups and protects them by forming a stocking like feature around muscles.
What is cartilage?
Firm connective tissue but is softer and more flexible than bone. Made of a dense network of collagen fibres embedded in gelatinous ground substance. Subtypes: articular and fibrocartilage.
Articular (hyaline cartilage):
- low in fibres
- found at the end of bones
- decreases friction at joints
Fibrocartilage:
- encapsulated for shock absorption
- increases bone congruity
What is the synovial membrane?
A layer of connective tissue that lines the cavites of joints, tendon sheaths and bursae producing synovial fluid which has a lubricating function.
What are bursae?
Synovial fluid filled sacs that protect tendons and liagments from friction
What is the histology of bone?
Connective tissue
- Extracellular membrane: rich in CaPO<strong>4</strong> (calcium phosphate which give rigidity)
- Fibres
- Collagen
- elastin
- Ground substance
- water
- GAGs, proteoglycans etc.
- Fibres
- Cells
- Osteocytes
- Osteoblasts
- Osteoclasts
- fibroblasts
- macrophages
- mast cells
- adipocytes
What is an osteoblast?
A cell which synthesises bone by producting the extra cellular matrix. Responsible for calcification.
What is an osteoclast?
Multinucleated bone cells that absorbs bone tissue.
What is an osteocyte?
A bone cell that releases bone matrix periodically but becomes embedded within its own matrix.
What is the difference betwen compact and spongey bone?
These are the two basic structural bone types.
Compact Bones:
- also known as cortical cones
- found at:
- outer layer of bone
- shaft of the long types of bone
- geometric structure
Spongey Bones:
- also known as cancellous bone
- arranged in different directions
- found at the heads of long bones
How are bones classified?
- Long
- femur and humerus
- Flat
- sternum, ribs, skull, pelvis
- Short
- wrist and ankle joints
- Irregular
- vertabrae
- Sesamoid
- patella
What are long bones?
Bones that are longer than they are wide. Mostly found in the appendicular skeleton. Act as rigid levers and are positioned by the action of the muscles.
What is the general structure of a long bone?
The shaft of the bone is called the diaphesis. At each end of the shaft the bone flares into the metaphysis. On each side of the growth plate there are epiphysises (proximal and distal)
- Articulating surfaces are covered with hyaline cartilage and the remainder of the bony surfaces is covered with periosteum.
- Medually cavity is lined with endosteum
- MC has red marrow in the child (active haematopoiesis) and yellow marrow in adults due to a high fat content
Where does the nutrient artery normally enter in long bones?
Through a nutrient foramen, normally near the middle of the diaphysis. Supplies the marrow.
What are the two divisions of the skeleton?
Axial:
- Forms the longitudinal axis of the body
Appendicular
- Formed of upper and lower extremities.
What are flat bones an their function?
The function is the protect the internal organs such as the brain heart and pelvic organs
