1. HYPEREMIA & CONGESTION II

2. HYPEREMIA AND CONGESTION:
There are 3 main basic requirements for normal circulatory function:-
Normal anatomic features
Normal physiologic controls, and
Normal biochemical composition of the blood.
NB: These are essential to maintain normal blood flow and perfusion of tissues

3. Hyperemia and congestion cont--
Derangements of blood flow or haemodynamic disturbances are considered under 2 broad headings:-
Disturbances in the volume of the circulating blood. These include:
Hyperemia and congestion
Haemorrhage and shock
Circulatory disturbances of obstructive nature:
thrombosis, embolism, ischaemia and infarction

4. DISTURBANCES IN THE VOLUME OF CIRCULATING BLOOD:
Hyperemia and congestion:
Are the terms used for increased volume of blood within dilated vessels of an organ or tissue.
Hyperemia (Active hyperemia):-
Is the increased volume from arterial and arteriolar dilatation
Venous congestion (Passive hyperemia):
Is the impaired venous drainage

5. ACTIVE HYPEREMIA
The dilatation of arteries, arterioles and capilaries is effected through;
Sympathetic neurogenic mechanism or
Via the release of vasoactive substances
The affected tissue or organ is pink or red in appearance (erythema).
Examples of active hyperemia are:-
Inflammation e.g. in pneumonia
Muscular exercise
High grade fever
Blushing i.e. flushing in the skin of face in response to
emotions.

6. HYPEREMIA & CONGESTION
The dilatation of veins and capillaries due to impaired venous drainage results in passive hyperemia or venous congestion, commonly referred to as congestion
Congestion may be of 2 types:
Acute congestion or
Chronic congestion – this being more common and is called Chronic Venous Congestion(CVC)
In CVC the affected tissue or organ is bluish in colour due to accumulation of venous blood (Cynosis)

7. Examples of disorders cont---
Passive congestion:-
Mechanical obstruction due to thrombosis of veins of lower legs
Vericosities
Pressure by pregnant uterus
Tumours, etc
Postural oedema:-
Transient oedema of feet and ankles due to increased venous pressure seen in individuals who remain standing erect for a long time e.g.traffic constables

8. CVC cont----
Obstruction to the venous outflow may be local or systemic
Accordingly, venous congestion may be of 2 types:
Local venous congestion:
Results from obstruction to the venous outflow from an organ or part of the body
- e.g. portal venous obstruction in cirrhosis of the liver, pregnancy, hernia, thrombosis

9. CVC cont-- Systemic venous congestion:
Is engorgement of systemic veins, e.g.
- left-sided and right-sided heart failure
- diseases of the lungs which interfere pulmonary blood flow, such as
Pulmonary fibrosis
Emphysema

10. MORPHOLOGY OF CVC OF ORGANS
Morphologic changes is seen most commonly in the lungs, liver, spleen and kidney
CVC LUNG:
CVC of lung occurs in left heart failure, so that there is consequent rise in pulmonary venous pressure.

11. Morphology of lung cont---
Grossly:
The lungs are heavy
Lungs are firm in consistency
The sectioned surface of the lung is;
- dark brown in colour, referred to as brown induration of the lung due to the haemosiderin pigmentation and fibrosis
Histologically:
The alveolar septa are widened due to;
- interstitial oedema and
- dilated and congested capillaries

12. Morphology of lung histologically cont---
The septa are midly thickened due to;
- slight increase in fibrous connective tissue
Minute intra-alveolar haemorrhages due to
- rupture of dilated and congested capillaries
haemosiderin pigment due to;
- breakdown of erythrocytes
Heart failure cells – are alveolar macrophages which has taken up haemosiderin pigment

13. Lung-in heart failure (hemosiderin pigment, congestion)

14. Lung: CVC perl’s prussian blue for iron (Fe+)

15. Heart failure cells -lung

16. Heart failure cells - lung

17. MORHOLOGY cont--- CVC LIVER: Occurs in RHF or
Occlusion of inferior vena cava and hepatic vein
Grossly:
The liver is enlarged
C/S – nutmeg appearance of liver due to:-
- red and yellow mottled appearance corresponding to ( congested centre of lobules and fatty peripheral zone respectively)

18. NUTMEG LIVER

19. NUTMEG LIVER

20. NUTMEG LIVER

21. CVC Liver cont-- Microscopically:
More marked congestion in centrilobular zone – due to severe
hypoxia
Central veins and sinusoids – distended and filled with blood
Centrilobular hepatocytes-haemorrhagic necrosis due to degenerative changes

22. CVC Liver cont-- Long standing cases:- - fine centrilobular fibrosis
- regeneration of hepatocytes – resulting in cardiac sclerosis (cirrhosis)
- fatty change of hepatocytes – in peripheral zone of the lobule because this zone is less severely affected by chronic hypoxia

23. CVC: LIVER-nutmeg around central vein from (RHF)

24. LIVER: pronounced CVC(light yellow pigment”lipochrome” in necrotic hepatocytes) around central vein

25. LIVER:longstanding CVC (cardiac sclerosis “cirrhosis”)

26. CVC SPLEEN: Occurs in the following situations;
Right-sided heart failure or
Portal hypertension – due to cirrhosis of the liver
Grossly:-
Enlarged spleen
The organ is deeply congested and cynotic

27. CVC SPLEEN CONT-- Microscopically: Red pulp: Congestion
Marked sinusoidal dilatation
Areas of recent and old haemorrhage
Organized areas of haemorrhage – called Gamna gandy bodies or siderofibrotic nodules ( = are deposits of haemosiderin pigment and calcium salts) on fibrous connective tissue.

28. CVC spleen-microcopically cont--
Late stages:
- hyperplasia of microphages
- hyperplasia of fibroblasts
- hyperplasia of red pulp

29. MORPHOLOGY OF THE KIDNEY
Grossly:
Slightly enlarged kidneys
The medulla is congested
Microscopically:
Degenerative changes of tubules:
- cloudy swelling
- fatty change
The glomeruli: - mesangial proliferation