[A] 1.17 Local hyperaemia

Question 1

Hyperaemia

Answer 1

Excess of blood in the vessels supplying an organ/body part

Question 2

Regulation of circulation is by…

Answer 2

1. Hydrodynamic factors
2. Neurohormonal regulation → Vasomotion control
3. Terminal circulatory bed

Question 3

Terminal circulatory bed

Answer 3

Section between the arterioles and venules

• Nutrient, oxygen supply & waste removal
• Large capacity but only holds 5% of the blood
• Major place of circulatory disorders

Question 4

The haemostatic function of the endothelium

Answer 4

• Maintains the blood in a fluid state
• Anti-thrombotic and pro-fibrinolytic properties
• Upon injury → Opposit effect

Question 5

The endothelium is critical in…

Answer 5

• Fluid distribution
• Inflammation
• Immunity
• Angiogenesis (development of new blood vessels)
• Haemostasis

Question 6

Local alterations in blood flow and perfusion

Answer 6

Hyperaemia

• Arteries
  
  • Active hyperemia
  • The slowdown of the arterial flow
• Veins:
  
  • Local & systemic venous congestion
• Ischaemia

Question 7

General alterations in the blood flow and perfusion

Answer 7

• Collapse
• Shock

Question 8

Hyperaemia due to decreased blood flow: What is seen?

Answer 8

• Contracted arteriole
• ↓ Influx in the terminal bed
• Vasoconstrictor paralysis
• Prehaemostasis
• ↑ Vascular permeability

Question 9

Prehaemostasis

Answer 9

• Plasma leakage
• Extravasation
• Inflammation produces strong stimuli:
  
  • Mechanical
  • Thermal
  • Chemical
  • Toxic

Question 10

Pathologically increased blood flow: Signs

Answer 10

• Bright red
• Slightly swollen
• Warm area

Question 11

Decreased blood flow: Pathological signs

Answer 11

• Bluish red
• Swollen
• Colder

Question 12

The appearance of distended blood vessels is indicative of…

Answer 12

Vascular injection

Question 13

Local congestion

Answer 13

• Passive process
• Blood accumulated and slows down in the venous circulation
  
  • Prehaemostasis, hemostasis
• Vein is obstructed or compressed
  
  • Torsion of the intestine
  • Strangulation of the spleen
  • Thrombosis

Question 14

Pathology of local congestion: Organ

Answer 14

• Dark red, bluish-red, cyanotic
• Swollen
• Large amount of blood on the cut surface

Question 15

Pathology of local congestion: Mucosal membranes (skin)

Answer 15

• Dark red, bluish-red, swollen
• Oedemic submucosa
• Wrinkled
• Serous fluid in the lumen of the organ

Question 16

Infarceratio - Venous infarction

Answer 16

Caused by blocked outflow

• Infraceratio haemorrhagica
• Long-lasting/final obstruction of a vein
  
  • No nutrient/oxygen supply
  • Plasma & RBCs in the tissues
  • Necrosis of large area

Question 17

Slow occlusion

Answer 17

• Collaterals enlarge
• Remodel
• Drainage is maintained
• Liver cirrhosis
  
  • Compressed portal veins
  • Veins of oesophagus
  • “Medusa head”

Question 18

Systemic venous congestion

Answer 18

Not only the terminal circulatory bed is affected

• Caused by:
  
  • Acute/chronic heart flailure
  • Paralysis of the vasomotor centre
  • Shock
• Appearance
  
  • In all the organs

Question 19

Pathology of venous congestion: Liver

Answer 19

• First centrilobular areas affected first
• Chronic case: nutmeg liver

Question 20

Pathology of venous congestion: Spleen

Answer 20

Hyperemic septic splenitis

Question 21

Pathology of venous congestion: Kidneys

Answer 21

Medulla affected only

Question 22

Pathology of venous congestion: Lung

Answer 22

Oedema

Question 23

Pathology of venous congestion: Intestines

Answer 23

Dark from the serous membranes

Question 24

Congestive induration

Answer 24

• Chronic congestion
• Parenchyma is destroyed
• Replaced by collagenous fibrous connective tissues

Question 25

Congestive induration: Pathological effect

Answer 25

• Firm
• Moist content is less on the cut surface