13 Bone, Bone Marrow, Vessels And Blood

Question 1

5 types of bone

Answer 1

Long (humerus)
Short (trapezoid)
Flat (sternum)
Irregular (vertebra)
Sesamoid (patella)

Question 2

Cancellous or spongy bone

Answer 2

Forms network of fine body columns to combine strength with lightness
Spaces filled with bone marrow
In middle of bone

Question 3

Compact or cortical bone

Answer 3

Forms external surfaces of bones

80% of body’s skeletal mass

Question 4

Red bone marrow

Answer 4

Full of developing blood cells
Rich blood supply
Only in spongy bone
Replenishes cells in blood (haemopoesis)

Question 5

Yellow bone marrow

Answer 5

Full of adipocytes
Poor blood supply
Shock absorber and energy source
Can convert to red marrow

Question 6

Red and white blood cells in circulation

Answer 6

Newly formed RBCs move from venue to intermediate vein to larger vein to vena cava

Question 7

Immature cells

Answer 7

Need to be activated
T cells need actions of thymus and lymphatics
B cells already mature but need activating

Question 8

Micro circulation in capillaries

Answer 8

Flow is controlled by precapillary sphincters
Between arterioles and capillaries
Contains smooth muscle
When open, blood flows to capillary beds
Controls fluid exchange between capillaries and body tissues takes place at capillary bed
Larger cells cannot pass through

Question 9

Vein definition

Answer 9

Elastic blood vessel that transports blood from various regions of body to heart

Question 10

What are the 3 layers of veins?

Answer 10

Tunica intima - endothelial cells
Tunica media - elastic fibres and smooth muscle cells
Tunica externa - elastic fibrous capsule

Question 11

Valves in veins

Answer 11

Non-return fibroelastic cartilaginous valves assist flow towards heart
Low pressure system
Relies on muscle contraction to return blood to heart

Question 12

2 veins types

Answer 12

Pulmonary veins - carry oxygenated blood from lungs to left atrium of heart
Systemic veins - return deoxygenated blood from rest of body to right atrium of heart

Question 13

Vein size

Answer 13

1mm-1.5cm in diameter
Smallest are venules
Venules branch into larger veins
Superior and inferior vena cava drain into right atrium

Question 14

Arteries definition

Answer 14

Elastic blood vessels that convey blood away from heart

Question 15

What re the 3 layers of arteries

Answer 15

Tunica intima - elastic membrane lining, smooth muscle endothelium
Tunica media - smooth muscle and elastic fibres (thicker in arteries than veins)
Tunica externa - collagen and elastic fibres (arteries can stretch)

Question 16

How structure fits function of arteries

Answer 16

Strength and elasticity needed to withstand pulsing of blood, prevent bursting, maintain pressure wave
Maintains BP, prevents blood flowing backwards

Question 17

How structure fits function of capillaries

Answer 17

Not strong walls as low BP
Thin walls, narrow lumen bring blood close to body tissue, allows diffusion
WBC can squeeze between cells of wall