Clinical Anatomy 1 Skeletal System Bones on Macroscopic feat

Question 1

What does the skeletal system consist of? (4)

Answer 1

1. Bones
2. Cartilages
3. Joints
4. Special forms of connective tissue

Question 2

What are the 9 cells that are part of the skeletal system?

Answer 2

1. osteoblasts
2. osteoclasts
3. osteocytes
4. chondroblasts
5. chondroclasts
6. chondrocytes
7. mesenchymal cells
8. Monocytes (macrophage linage)
9. Fibroblasts

Question 3

What is Extracellular matrix (ECM)?

Answer 3

• Are the molecules/materials that surround the outside of the cell.
• Contains both organic and inorganic componts
• Makes the bulk of the tissues

Question 4

What are 3 cartilage cells?

Answer 4

1. chondroblasts
2. chondroclasts
3. chondrocytes

Question 5

What are 3 bone cells?

Answer 5

1. osteoblasts(needed when fracture occurs; bone-forming cells)
2. osteoclasts (large cells that resorb or break
   down bone matrix)
3. osteocytes(mature bone cells)

Question 6

What is Mesenchymal cells? (3)

Answer 6

1. Embryonic connective tissue
2. Can differentiate into bone forming cells, cartilage forming cells, blood forming cells, and muscle forming cells.
3. Known as the origin of most cells.

Question 7

What are 2 organic components in ECM?

Answer 7

1. Collagen fibers

2. Ground substance

Question 8

What is collagen fibers in ECM? (3)

Answer 8

1. Is the most abundant
2. Principal fibrous component
3. Confers tensile strength

Question 9

What is ground substance in ECM?

Answer 9

There are two types: Bone & Cartilage

Question 10

What is ground substance Bone in ECM? (7)

Answer 10

1. Mineralized
2. Inorganic components
3. Calcium
4. Phosphates
5. Rigid and Strong
6. Brittle
7. Remodeling

Question 11

What is ground substance Cartilage in ECM? (4)

Answer 11

1. Not mineralized
2. Firm, solid gel-like
3. Stiff and incompressible
4. More flexible and resilient than bone

Question 12

What is cell modulation?

Answer 12

• Change reversible

- Ex: osteocytes can turn to osteoblasts if a bone fracture occurs

Question 13

What are bones lined with? (2)

Answer 13

1. Periosteum

2. Endosteum

Question 14

What is Periosteum?

Answer 14

Lines the bone cavity

Question 15

What are 5 functions of bone?

Answer 15

1. Protection for vital structures
2. Support for the body
3. Mechanical basis for movement
4. Storage for salts (CALCIUM and phosphates)
5. Hematopoiesis (creation of new blood cells; in the bone marrow)

Question 16

What are 2 bone classification based on location?

Answer 16

1. Axial

2. Appendicular

Question 17

What does the Axial skeleton consist of?

Answer 17

• Bones of the skull, vertebral column, and rib cage

- The clavicle and scapula are NOT part of the axial skeleton

Question 18

What does the Appendicular skeleton consist of?

Answer 18

Bones of the upper and lower limbs, shoulder, and hip

Question 19

What are the 6 shapes and sizes of bones?

Answer 19

1. Long
2. Small long bones
3. Short
4. Flat
5. Irregular
6. Sesamoid

Question 20

What is Macroscopic structure?

Answer 20

• Also known as Basic Architecture
• Compact (cortical) bone
• Trabecular (cancellous, spongy) bone

Question 21

What is Microscopic structure? (microscopic differentiation of the bone)

Answer 21

• Also known as Matrix arrangement
• Woven (fibrous/immature) bone tissue
• Lamellar (mature/secondary) bone tissue

Question 22

What are 2 developmental origin in classification of bones? (2 ossification centre)

Answer 22

1. Intramembranous

2. Endochondral

Question 23

What are the 2 requirements for Long Bones?

Answer 23

1. Bone marrow cavity
2. Two epiphysis (one on each end)

*Are tubular shaped

Question 24

What is epiphysis?

Answer 24

• Secondary ossification centers appear

- Most appear during childhood or adolescence

Question 25

What is diaphysis (shaft)?

Answer 25

- Primary ossification centers | - Appears during the 7-20 weeks of intrauterine life

Question 26

What is Metaphysis?

Answer 26

Growing part of diaphysis adjacent to epiphyseal plate

Question 27

What is epiphyseal plate?

Answer 27

- A layer of hyaline cartilage | - Between epiphysis and Metaphysis

Question 28

What are 2 requirements for small long bones?

Answer 28

1. Epiphysis at one end 2. No bone marrow cavity *Ex: clavicle

Question 29

What are short bones?

Answer 29

- Cuboidal in shape | - Ex: Carpus & Tarsus

Question 30

What is flat bones?

Answer 30

- Are meant for PROTECTION - Thin and flattened - Ex: skull, ribs, shoulder girdle, and pelvic girdle

Question 31

What are Irregular bones?

Answer 31

- Bones with complicated shapes - Provide ATTACHMENT - Ex: Vertebrae & Facial bones

Question 32

What are sesamoid bones?

Answer 32

- Develop embedded in tendons closely related to articular surfaces - PROTECT the tendons from excessive wear - Like sesame seeds - Ex: patella

Question 33

What 3 bones develop from a single center of ossification?

Answer 33

1. Carpal and Tarsal bones 2. Auditory ossicles 3. Facial bones

Question 34

What are 2 classification of bones based on macroscopic structure?

Answer 34

1. Compact (cortical/dense) bone | 2. Trabecular (cancellous/spongy) bone

Question 35

What is compact bone? (3)

Answer 35

1. Also known as cortical or dense bone 2. 85% of bones are compact bone 3. Consist of Secondary Osteons (Haversian system)

Question 36

What is Haversian system? (2)

Answer 36

- The structural unit of compact bone - A cylindrical structure parallel to the long axis of the diaphysis -Allow passage of blood vessels and nerves

Question 37

Where is compact bone located? (4)

Answer 37

1. Diaphysis of long bones 2. Ends of long bones 3. Internal and external surfaces of flat bones 4. Surface of irregular and sesamoid bones

Question 38

What is the function of compact bone? (3)

Answer 38

1. Mechanical and protective function 2. Provides strength for weight bearing 3. Encloses Marrow (medullary) cavity that contains yellow marrow(reserve fat cells)

Question 39

What is trabecular bone?

Answer 39

1. Consist of bony trabeculae (spiculae) 2. Projects out from internal surface of compact bone into bone marrow cavity. 3. Composed of irregular lamellae that form anastomosing plates separated by intercommunicating spaces filled with red bone marrow * DO NOT CONTAIN COMPLETE OSTEONS (Haversian system)

Question 40

What is lamellae?

Answer 40

- Layers - column-like matrix tubes

Question 41

Where are trabecular bones located?

Answer 41

1. Inferior of flat bones 2. At expanded ends (epiphyses) of the long bones 3. Interior of Irregular and Sesamoid Bones *Contains Red Marrow, which the function is Hematopoiesis