Musculo-skeletal System

Question 1

What’s the main components of MSK (Musculoskeletal-skeletal System)

Answer 1

5 main components
Bones: Highly vascular continuously remodelled , soft tissues and organs are attached, at birth 270 bones and they merge once adult becomes 206. (Flat = sternum, irregular= vertebrae, long = femur, short = metacarpals).
Ligaments
Cartilage
Skeletal muscle: spongy bone tissue provides framework gives attachment to muscles and tendons, porous highly vascularised function is to reduce bone density and allow ends of long bones to compress (result of repeated stress)
Tendons

Question 2

How does skeletal system help MSK

Answer 2

Compact bone tissue: makes hard outer layer compact due to minimal gaps/spaces. Good as it allows long bones to compress to stop them from shattering.
Honeycomb like bone has lots of blood vessels and allows reduced density so it’s still strong just lighter than if it was only compact bone.has an outer layer of periosteum (very thin lining of blood vessels and nerves covers all bones and provides nutrients) which covers bones.

Question 3

How are long bones structured

Answer 3

Made up of diaphysis (the long shaft bit) and two epiphyses ( extremities usually two smaller bones). The epiphyses outer covering of compact bone with spongy bone (honeycomb) inside. Also has periosteum and inner layer bone cells that are for production breakdown and repair.

Question 4

What are the three types of bone cells

Answer 4

Osteoblasts- bone building cells deposit themselves in new bone and become trapped in tiny pockets and differentiate (into osteocytes)
Osteocytes- mature bone cells don’t divide are responsible for bone formation and calcium homeostasis.
Osteoclasts- bone reabsorbed cells break down bone releasing calcium and phosphate, old bones destroyed by osteoclasts.

Question 5

Describe the process of osteogenesis

Answer 5

1. Osteoblasts secrete osteoid (protein) which replaces fetus cartilage
2. Calcium and phosphate laid down, progressively calcifying it converting it to hard mature bone.
3. Osteoblasts form a matrix cells become trapped and become osteocytes

Bone growth: bone moves outwards from centre as osteoclasts become osteoblasts and develop the epiphyseal plate, osteoblasts from matrix become spongy bone.

Question 6

What’s the best way to maintain bone health

Answer 6

Through exercise (weights) can strengthen bone.
Testosterone and oestrogen increase bone density and mass which is why men usually have larger frames than women.

Question 7

What is the four stages of bone healing?

Answer 7

1. Heamatoma stage: collection of fibrin, platelets causing blood to clot and inflammation to stop bone from moving.
2. Cells formation: large amounts of fibrin lays framework for granulation, fibroblasts migrate to site and lay down collagen tissues, Macrophages remove dead tissue and new capillaries grow to supply blood and nutrients..
3. Bony callus formation: osteoblasts formed to calcify osteoid, callus laid as spongy bone and brings together ends of broken bones supporting and splinting fracture.
4. Recanalisation and Remodelling: remodelling converts external callus to compact bone (whole process takes months)