Vascular Disorders and Thrombosis

Question 1

CIRCULATORY SYSTEM

Answer 1

CONSIST OF

1) BLOOD
2) THE HEART
3) BLOOD DISTRIBUTION NETWORK
- arterial and venous networks
4) THE MICROVASCULATURE (MICROCIRCULATION)
5) LYMPHATIC SYSTEM

Question 2

ARTERIES

Answer 2

RELATIVELY LARGE DIAMETER LUMENS TO FACILITATE BLOOD FLOW WITH MINIMAL RESISTANCE

Question 3

ARTERIOLES

Answer 3

1) THE MAJOR RESISTANCE VESSELS
2) RELATIVELY NARROW LUMENS
3) DIAMETER IS CONTROLLED BY THE SMOOTH MUSCLE CELLS IN WALL
4) CONTROLLED BY EXTRINSIC SYMPATHETIC INNERVATION + LOCAL INTRINSIC STIMULI

Question 4

CAPILLARIES

Answer 4

1) SITE OF NUTRIENT AND WASTE PRODUCT EXCHANGE BETWEEN BLOOD AND MUSCLE
2) NARROW LUMENS
3) WALL CONSISTING OF SINGLE CELL LAYER (ENDOTHELIUM)

Question 5

TYPES OF CAPILLARIES

Answer 5

1) CONTINOUS
2) FENESTRATED
3) DISCONTINOUS

Question 6

CONTINOUS CAPILLARIES

Answer 6

1) FORMS A BARRIER THAT STRICTLY CONTROLS TRANSFER OF MOLECULES ACROSS THE CELL
2) ONLY ALLOWS TRANSFER OF H2O, O2, CO2 AND IONS
3) IN:
- Brain (Blood-brain barrier)
- Muscle
- Lung
- Bone

Question 7

FENESTRATED CAPILLARIES

Answer 7

1) HAS FENESTRAE (PORES) THAT ARE BRIDGED BY A THIN MEMBRANE
2) CONTROLLED TRANSFER OF SMALL MOLECULES AND LIMITED AMOUNTS OF PROTEIN
3) IN:
- Renal glomeruli
- Intestinal villi
- Endocrine glands
- Choroid plexuses
- Ciliary processes of the eye

Question 8

DISCONTINOUS (SINUSOIDAL) ENDOTHELIUM

Answer 8

1) HAS LARGE “GAP” OPENINGS
2) ALLOWS FREE TRANSFER OF PLASMA PROTEINS, RED AND WHITE BLOOD CELLS, WATER AND MOST MOLECULES
3) IN
- Liver sinusoids
- Spleen sinusoids
- Bone marrow
- Lymph nodes

Question 9

ENDOTHELIAL CELL FUNCTIONS AND RESPONSES IN HOMEOSTASIS AND DISEASE

Answer 9

INVOLVED IN

1) FLUID DISTRIBUTION AND BLOOD FLOW
2) HEMOSTASIS
3) INFLAMMATION
4) GROWTH FACTORS
5) FIBRINOLYSIS

Question 10

ENDOTHELIUM: ROLE IN FLUID DISTRIBUTION AND BLOOD FLOW

Answer 10

1) SEMIPERMEABLE MEMBRANE FOR FLUID DISTRIBUTION
- Interendothelial junctions
2) VASODILATATION
- Nitric Oxide, Prostacyclin, endothelial-derived hyperpolarizing factor, C-type natriuretic peptide
3) VASOCONSTRICTION
- Endothelin, Reactive oxygen species, Angiotensin II, Products of prostaglandin H2 (e.g thromboxane A2)

Question 11

ENDOTHELIUM: ROLE IN HEMOSTASIS

Answer 11

1) ANTIHEMOSTATIC SUBSTANCES
- PGI2, Endothelin cell protein C receptor, Tissue factor
pathway inhibitor, Tissue plasminogen activator (tPA),
heparin sulfat, ADPase, ATPase, Protein S,
Thrombomodulin
2) PROHEMOSTATIC SUBSTANCES
- von Willebrand factor, Tissue factor (TF, = Factor III), plasminogen activator inhibitor-1 (PAI-1), Protease-activated receptors (PARs)

Question 12

ENDOTHELIUM: ROLE IN INFLAMMATION

Answer 12

1) CYTOKINES
- Interleukin (IL)-1, IL-16, IL-8
2) ACUTE PHASE PROTEINS
- C-reactive protein
3) ENHANCED EXPRESSION OF TF
4) EXPRESSION OF LEUKOCYTE ADHESION MOLECULES
- Cell adhesion molecule family (MadCAM-1, ICAM-1,
VCAM-1, PECAM-1)
- Selectin family (P-selectin, E-selectin)