Bone, Bone Marrow, Blood Vessels

Question 1

What are the 5 types of Bone?
Give examples of each
Compare Axial and Appendicular skeleton

Answer 1

1. Long- Humerus
2. Flat- Skull, Pelvis,
3. Short- Wrist/ ankle joints (Carpals/ tarsals)
4. Sesamoid- Patella
5. Irregular- Vertebrae

Axial: Skull, Ribs, Sternum, Spine, Vertebrae
Appendicular: Hangs off axial Skelton

Question 2

Give functions of each of the 5 bone types

Answer 2

Long- Support Body weight
Short- Provide stability
Flat- Protect internal organs, provide areas of attachment for muscles
Irregular- Protect internal organs, provide anchor points for muscles
Sesamoid- Protect tendons from stress and ‘wear and tear’

Question 3

What re the 2 types of Bone marrow?
Which part of bone are they found in?
What are the functions of each?

Answer 3

Yellow Marrow- Diaphysis- Can convert to red marrow/ shock absorber due to adipocytes

Red Marrow- Epiphysis - Haemopoiesis

Question 4

Compare Vasculogenesis and Angiogenesis

Answer 4

V: New blood vessels formed from bone marrow

A: Blood vessels formed from existing vessels, as branches

Question 5

Once released into blood, how long does an RBC take to mature?

Answer 5

2 days

Question 6

What are collateral blood vessels?

Answer 6

New blood vessels formed to redirect blood flow when a tissue is compromised

Question 7

What is a pericyte?

What is their function?

Answer 7

An immature smooth muscle cell with contractile properties

To maintain tight capillaries

Question 8

What structures control Capillary Blood Flow?

How?

Answer 8

Pre-capillary sphincters, open to allow blood flow, close to stop blood flow

Question 9

What is the structure of a Capillary?

Answer 9

• Narrow lumen (One RBC wide)
• Walls are one cell thick
• Fenestrations (High exchange rate)

Question 10

What are Sinusoids?

Answer 10

Vessels with an incomplete basement membrane

Allow cells to pas through easily

Question 11

Structure of a vein?

• 4 layers

Answer 11

Endothelium
Tunica Intima- Endothelial cells
Tunica Media- Elastic fibres, Smooth Muscle
Tunica Externa- Elastic

Question 12

Structure of an artery?

• 5 Layers

Answer 12

Tunica Intima- Elastic, smooth endothelium
Internal Elastic Membrane

Tunica Media- Smooth muscle, elastic fibres (Thicker in arteries)
External Elastic Membrane

Tunica Externa- Collagen, Elastic fibres

Question 13

What are the 2 bone types?

What are their synonyms?

Answer 13

Compact/ Cortical

Cancellous/ Spongy

Question 14

What is the Structure of Cancellous Bone?

Answer 14

• Avascular

- Made of trabeculae with bone marrow in the spaces

Question 15

What is the structure of Compact bone?

Answer 15

• Vascular

- Osteons surrounded by periosteum

Question 16

In an Osteon, what are;

• Lacuna
• Canciculi
• Lamellae

Answer 16

Lacuna- Spaces where osteocytes are held

Caniculi- Projections that connect osteocytes to each other and to the Haversian system

Lamellae- Concentric layers of bone,with osteocytes between them

Question 17

What are the 3 sections of bone?

Answer 17

• Epiphysis
• Metaphysis
• Diaphysis

Question 18

What are the cell types in bone?

Where are they found?

Answer 18

Osteoprogenitor- Form osteoblasts. On Endosteum + Periosteum
Osteoblasts- Lay down new bone, on Endosteum
Osteocytes- Maintain matrix, an osteoblast embedded in Osteon
Osteoclasts- Resorb exisiting bone, On Endosteum + Periosteum

Question 19

What are the two parts of the Matrix of bone?

What do they consist of, what is their function?

Answer 19

Inorganic: Mainly Ca salts, Resists Bending + compression forces

Organic: Collagen 1, GAGs, Resists Pulling + Tension forces

Question 20

What are the 3 functions of bone?

Answer 20

Mechanical- Protection, Framework
Synthetic- Haemopoiesis
Metabolic- Mineral storage, Fat storage