Musculoskeletal - Anatomy

Question 1

What does the skeletal system consist of?

Answer 1

Bones, cartilages and joints

Question 2

What are the types of bones (by shape)?

Answer 2

Long - humerus, radius, ulnar, femur, tibia, fibula
Short - carpal, tarsal
Flat - parietal, hip
Irregular - maxilla, hyoid, sacram

Question 3

What are the fns of bones?

Answer 3

• Support
• Movement
• Protection of organs
• Blood formation
• Electrolyte balance + acid-base balance (Ca, P)
• Storage of energy (fat in yellow bone marrow)

Question 4

What are the functions of osetoblasts?

Answer 4

Formation of new bone matrix and osteocytes?

Question 5

What are the functions of osteocytes?

Answer 5

Located within the lacunae of bone matrix. Bone maintenance, remodelling, mechanosensing

Question 5

Describe the bone composition.

Answer 5

Bone tissue - cells, mineralised matrix
Periosteum, Endosteum
Marrow cavity
Articular cartilage
Diaphysis, Epiphysis, Metaphysis

Question 5

What are the functions of osteoclasts?

Answer 5

Much larger than osteocytes. Related to wbc.. Responsible for bone resoprtion, remodelling, growth according to physiological need.

Question 6

What is the mineralised matrix in the bone tissue?

Answer 6

Organic - organic materials e.g. protein fibres (mainly collagen)
Inorganic - ions CaCo3, Mg2+, Na+, K+, CO3^2-, SO4^2-, hydroxyapatite

Question 7

What are the periosteum and endosteum?

Answer 7

Periosteum = fibrous outer & osteogenic underneath layer coverg outer surface of bones
Endosteum = type of hard calcified CT lining wall of shaft marrow cavity

Question 8

What is the articular cartilage?

Answer 8

The cartilage @ ends of bone whr articulating w other bones

Question 9

What is the diaphysis of a bone?

Answer 9

The shaft

Question 10

What is the epiphysis?

Answer 10

The end of the bone, whr it forms articulation w other bones

Question 11

What is the metaphysis?

Answer 11

Exists in children or individuals to contain the growth plates?

Question 12

Describe the organisation of compact bone.

Answer 12

Osteons (structural unit of compact bone)
- Osteocytes, lacunae, canaliculi
- Concentric lamellae: layers of bone tissue
- Outer/inner circumferential lamellae: layers of bone matrix at outer and inner surface of bone
- Interstitial lamellae: space in bet osteons
- Central canal
- Perforating canal: joint channel bet central canals of neighbouring osteons

Question 13

What are the types of joints?

Answer 13

1. Fibrous joints
2. Cartilaginous joints
   (These 2 have limited mobility, not of focus)
3. Synovial joints

Question 14

Describe the synovial joints.

Answer 14

Most mobile of the three types of joints. Actively moved by contraction of skeletal muscles that stretches across.

Question 15

What are the components of a synovial joint?

Answer 15

Joint (Synovial) cavity
Joint (Synovial) capsule: a layer of CT surrounding the synovial cavity
Synovial membrane: layer of epithelial cells lining the inside of the joint capsule, secretes fluid to lubricate the joint
Articular cartilage: cartilage between articulating bones at the joint

Question 16

What are the types of synovial joints?

Answer 16

Ball and socket
- E.g. Hip joint
- 3D movement

Hinge
- E.g. Elbow, knee
- Flexion, extension

Pivot:
- E.g. radioulnar
- Rotational

Planar:
- E.g. intercarpal
- Gliding but limited

Question 17

What are the types of cartilages?

Answer 17

1. Hyaline cartilage
2. Fibrocartilage
3. Elastic cartilage

Question 18

Describe the composition of muscles.

Answer 18

Plasma mem: sarcolemma
Cytoplasm: sarcoplasm
Myofilaments
Myofibrils: a bundle of thin and thick myofilaments
A bundle of muscle fibres: muscle fibre fascicles
Endomysium: inner most CT sheath surrounding indi muscle fibres
Perimysium: CT sheath covering each fascicle
Epimysium: outermost CT sheath surrounding a muscle