PPT 3 EXAM 3: arteries, veins, and circuits

Question 1

CARDIOVASCULAR SYSTEM
what does it transport?

about which main organ?

related with which blood vessels? (AVC)

Answer 1

• it transports oxygen, nutrients and wastes
• the heart
• all blood vessels: AVC
  Arteries: various sizes
  Veins: various sizes
  Capillaries: smallest vessels

Question 2

VEINS
carry blood in which direction?

what are their characteristics (2) (TL)

compare sizes

Answer 2

• they carry blood TO the heart

characteristics:
- thin walls
- larger lumen

veins > venules > ‘‘venous’’ capillaries

Question 2

ARTERIES
carry blood in which direction?

what are their characteristics (3) (TES)

compare sizes

Answer 2

• thay carry blood AWAY from the heart

characteristics: TES
- thick walls= resist to more pressure
- elastic walls = can expand and recoil
- have smaller lumen

arteries > arterioles > ‘‘arterial’’ capillaries

Question 3

3 LAYERS OF ARTERIES (histological pov)

Answer 3

1st layer: simple squamous epithelium

2nd layer: smooth muscle with ELASTIC fibers
- responds to nerves, hormones and chemicals
- vasoconstriction and vasodilation (under brain control)

3rd layer:
connective tissue (elastic and collagenous fibers) with blood vessels and endings

Question 4

3 LAYERS OF VEINS (histological pov)

Answer 4

1st layer: simple squamous epithelium inside (for impermeability)
- valves are present in larger veins

2nd layer: smooth muscle with COLLAGENOUS fibers
- pushes blood upaward to the heart
- responds to nerves, hormones and chemicals
- vasoconstriction and vasodilation (LESS than arteries because less elasticity)

3rd layer:
OUTER connective tissue (collagenous fibers only) with blood vessels

Question 5

CAPILLARIES
- what to they supply to the body?

• characteristics (3)?
• what do they link?
• when they are regrouped, what are they called?

Answer 5

• they supply blood to the tissues

characteristics:
- single cell thick
- leaky walls (squamous epithelium and basement membrane only)
- permeable to gases, nutrients and cellular wastes

• they link arteries and veins
• group of capillaries= capillary beds

Question 6

how are the 3 layers of capillaries named?

Answer 6

• basement membrane
• endothelial layer (or tunica intima)
• intercellular cleft

Question 7

what is the importance of pressure gradients between blood and interstitial fluid?

about 1) hydrostatic pressure?
2) osmotic pressure?