Hyperemia, Congestion and Haemorrhages

Question 1

Define hyperemia

Answer 1

Increased blood flow to an organ due to arteriolar dilation.

It is an active process

Question 2

Erythema is the reddish color observed after hyperemia

True or false

Answer 2

True

Question 3

Define congestion

Answer 3

Congestion is reduced outflow of blood from a tissue which presents as a reddish color.
It commonly leads to edema

Question 4

Briefly describe the morphology of congested tissues

Answer 4

There’s a discoloration- Blue color (cyanosis) due to stasis and accumulated deoxyhemoglobin.

Question 5

Describe the microscopic appearance of the lungs in acute pulmonary congestion

Answer 5

1. Engorged alveolar capillaries
2. Alveolar septal edema
3. Focal intraveolar haemorrhage

Question 6

Describe the microscopic appearance of the lungs in chronic pulmonary congestion

Answer 6

1. Fibrotic septal walls

2. Heart failure cells in the alveoli (hemosedrin-laden macrophages)

Question 7

Describe the microscopic appearance of the liver in acute hepatic congestion

Answer 7

1. Distended sinusoids and central vein
2. Ischemic centrilobular hepatocytes
3. Oxygenated periportal hepatocytes(proximal to hepatic arterioles)but may develop fatty change

Question 8

Describe the appearance of the liver in chronic hepatic congestion

Answer 8

Grossly- centrilobular regions are red-brown and depressed(cell death)

Microscopically-

1. Centrilobular hemorrhage
2. Heart cells(hemosiderin-laden macrophages)
3. Hepatocytes degeneration

Question 9

Define hemorrhage and list it’s causes

Answer 9

Hemorrhage is the extravasation of blood into the extravascular space

Causes:
1. Vascular injury; trauma, atherosclerosis, inflammation, neoplastic erosion

2. Bleeding diathesis(hypocoagulative state)

Question 10

Describe petechiae

Answer 10

•1-2mm hemorrhages into skin, mucous membranes or serosal surfaces

•Associated with:
⬆️Intravascular pressure(locally)
⬇️Platelet count/Defective platelet function

Question 11

What is purpura?

Answer 11

Hemorrhages >= 3mm

Associated with disorders that cause petechiae

Can be secondary to trauma, vascular inflammation(vasculitis) or increased vascular fragility

Question 12

Ecchymosis. A brief description.

Answer 12

• > 1-2cm subcutaneous hematoma
• red cells are degraded and phagocytized by macrophages
• color change from red to brown
• Could be denoted as hemothorax, hemopericardium, hemoperitoneum or hemarthrosis
• Excessive bleeding can lead to jaundice

Question 13

What is the clinical significance of hemorrhage?

Answer 13

• > 20% loss of blood volume can cause hypovolemic shock
• site of hemorrhage is important, eg skin vs brain
• External blood loss can lead to iron deficiency anemia and internal blood loss may not