MSS Week 4

Question 1

What are the seven functions of the Skeletal System?

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Answer 1

1) Support: provides structural framework for our body
2) Protection: protects brain and organs
3) Movement: muscles attach to bones, acts as a leader system
4) Mineral Storage Release: Calcium phosphorous are for normal functioning in the body, gives bone it’s strength
5) Blood cell production: red bone marrow (Hematopoiesis: production of red blood cells)
6) Hormone production: Growth hormone, parathyroid hormone and calcitonin
7) Triglyceride storage: Yellow bone marrow: fat storage, can be used as a source of energy

Question 2

Differentiate between spongy and compact bone

Answer 2

Spongy Bone
 Trabeculated bone
 Trabecular contain irregularly arranged lamellae and osteocytes interconnected by canaliculi Internal surface of bones
 Gets nutrients from the bone marrow

Compact Bone 
	Cortical Bone 
	Outside 
	Solid and relatively dense 
	External surface of bones 
	Has an osteon which contains a central canal

Question 3

Define each of the Following

A) Haversian Canal
B) Lamellae
C) Osteocytes (in lacuna)
D) Canaliculi

Answer 3

A) Haversian Canal: contains blood vessels and nerves
B) Lamellae: contains concentric rings
C) Osteocytes (in lacuna): contains cytoplasm extensions that is needed to communicate with other cells, receive nutrients, need to know what’s going on, sending signals
D) Canaliculi: passageway that allows communication between osteocytes

Question 4

Differentiate between organic components and inorganic components in bone composition

Answer 4

Organic components (1/3)
o Allows the bone to put more force
o 35% flexibility and tensile strength cells
o Collagen fibers which provide resistance
o Ground substance

Inorganic components (2/3)
o	Want to the bone to be strong 
o	65% compression strength 
o	Bone salt crystals: hydroxyapatite 
-	Calcium phosphate and hydroxide

Question 5

Define the components in the structure of the long bone

A) Epiphysis
B) Metaphysis
C) Diaphysis
D) Medullary Cavity

Answer 5

A) Epiphysis: Ends of the bone
B) Metaphysis: Narrow portion of a long bone between epiphysis and the diaphysis
C) Diaphysis:Tubular shaft that runs between the proximal and distal ends of the bone medullary cavity
D) Medullary Cavity: Known as the marrow cavity

Question 6

Differentiate between Endosteum and Periosteum

Answer 6

Endosteum: lines medullary cavity, usually resorbed during long periods of malnutrition, resulting in less cortical thickness
Periosteum: Membranous tissue that covers the surface your bones
- Outer fibrous layer (contains collagen and nerve fibers that cause pain)
- Inner cellular layer (contains cambium)
 Osteoblasts
 Osteoclasts

Question 7

Describe the stages of Endochondral ossification

A) Stage 1 (BC) and Stage 2 (C and OB)
B) Stage 3 (1st O)
C) Stage 4 (MeCa) Stage 5 (2nd O)
D) Stage 6 (O of the Eph)

Answer 7

A) Stage 1 and 2: Bone Collar is formed around the hyaline cartilage model, cavitation also occurs within the cartilage model, Chondroblasts forms the hyaline cartilage they will die in the centre and leave the cavity, surrounded by perichondrium, osteoblasts forms the bone collar around diaphysis

B) Stage 3: Primary ossification starts to appear in the diaphysis , Blood vessels penetrate through the cartilage into the centre cavity, osteogenic cells, osteoclasts, nerve, red marrow, Spongy bone replaces the cartilage

C) Stage 4 and 5: Medullary cavity is formed, secondary ossification centres appear in the epiphysis, Spongy bones turns into compact bone in the diaphysis

D) Stage 6: Ossification of the epiphyses when completed, Formation of Epiphyseal growth plate

Question 8

Describe Osteoporosis

Answer 8

o Problem with our modelling units, meaning that our osteoclasts and osteoblasts are not working together
o Not going to divide, it’s not going to be that strong
o Resorption is faster than bone deposition
o Cancellous bones are the first ones to be affected, lead to that change in posture
o Leading to more fractures in spongy areas
o Women have low levels of estrogen, estrogen has a role of osteoblasts and osteoclasts, their absence leads to estrogen
o Lack of calcium in diet, malabsorption of nutrients

Question 9

Describes the stages of Bone Repair
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A) Stage 1 (HF)
B) Stage 2 (FibCarF)
C) Stage 3 (BoCaFo)
D) Stage 4 (BonRem)

Answer 9

A) Hematoma Formation: Blood vessels are broken accumulation of blood, meaning there is no blood supply, bones cells die but they stimulate things to happen

B) Basically Clean up, new blood vessels are formed, Osteoblasts replace Chondroblasts

C) Osteoblasts form spongy bone, Woven bone

D) Callus is remodelled, need to get rid of the bumpiness to get back to normal shape and puts mechanical stress on the fracture site to repair properly

Question 10

What are the three functional joint classes?

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Answer 10

1) Synarthroses: immobile and stable
2) Amphiarthroses: Slightly mobile
3) Diarthroses: freely mobile and unstable

Question 11

What are the three structural joint classes?

Answer 11

1) Fibrous joints
2) Cartilaginous joints
3) Synovial joints