Hemodynamic disturbances

Question 1

What are the causes of arterial/ active hypermia

Answer 1

increase colume of circulating blood

Increasing of amount of erthrocytes

inflammation

arterio-venous fistula

Question 2

What causes venous/ passive hypermia

Answer 2

This is due to a blockage such as left sided heart failure, tumour or disease in the lungs, blood clot

Question 3

Morphology of congestions in different organs

Answer 3

Generally, they wil be an increase of venous blood to that organ.
The organ will appear swollen and purple, outer wall will be thickened.

Lungs= Brown stain of hemosiderin

Spleen= Congestion of the spleen is characterized by excessive distension of sinuses within the red pulp by erythrocytes

Liver= The liver appears to have yellow , red and orange in colour. thus appears like a nutmeg.
Microscopically, their are fatty deposits, and brown dots

Question 4

Define Hemorrhage and what are the causes

Answer 4

This is the escape of blood from the vessel.
This can be caused by destruction of the blood vessel wall. I.e. trauma, ruptured aneurysm.
and transmigration of leukocytes

Question 5

What is Hemoperitoneum

Answer 5

Hemorrhage in the abdomen cavity

Question 6

what are the types of internal hemorrhages

Answer 6

Petechia- this is when the capillaries break open it is characterised by tiny spots of purple, red basically bruise like colour

Purpura/hemorrhagic infiltration- accumulation of some erythrocytes in tissue between cells.

Question 7

Define Ischemia

Answer 7

deficient supply of blood to a body part (as the heart or brain) that is due to obstruction of the inflow of arterial blood (as by the narrowing of arteries by spasm or disease)

This may be due to obstruction, compression and the redistribution of blood

Question 8

Outline the what happens in the body due to ischemia

Answer 8

the primary response to acute ischemia is cellular swelling oedema. If the durations of ischemia is short the cells will not be damaged, however if it persist this will cause irreversible cell injury leading to cell death

Question 9

Define Infarction

Answer 9

Infarction is tissue death (necrosis) due to inadequate blood supply to the affected area. It may be caused by artery blockages, rupture, mechanical compression, or vasoconstriction.

Question 10

What is the pathogenesis of infarction

Answer 10

This happens when localised hyperemia, oedema of the cells occur and hemorrhage. Cell changes becomes cloudy and degeneration happens. Progressive breakdown takes places of autolysis of the nectrotic tissue and hemolysis of the red cells. Acute inflammatory reaction and hyperemia appears at the same time in surrounding tissues. Blood pigments of hematoidin and hemosiderdin shows

Question 11

What are the different morphological types of thrombi

Answer 11

White thrombus- platelets, fibrin, leukocytes

Red thrombus- platelets, fibrin, red blood cells

Hyaline thrombus- plasma proteins, red blood cells, leukocytes and thrombocytes, they do not contain fibrin

Agonal thrombus- consist of yellow fibrin and found in the right ventricle of the heart and may extend into pulmonary artery. It appears in the last minute of death

Question 12

Define embolism

Answer 12

Any material that is capable of blocking a blood vessel. There are different types of embolism depending on the material such as solid- parasites, thromboemolism. Liquid- fat and amniotic fluid
and then Gas air

Question 13

Define Shock

Answer 13

Shock is defined as a reduction of blood flow to the entire body. It is due to the blood pressure, for example a lower resistance will impact on the blood vessals diameter and the cadiac output( heart rate and stoke volume) so if one or all of these are not working someone can develop shock.

Question 14

What are the different types of Shock

Answer 14

Hypovolemic shock is due to a reduction of blood volume. There are 2 categories which are; haemorrhagic and non-haemorrhagic(due to dehydration or sweating) This causes the body temperature to reduce do to vasconstriction of the blood vessels and the Mixed venous oxygen saturation to reduce MV02

Cardiogenic shock- This may be due to obstruction, deficient emptying such as myocardial infarction or deficient in the cardiac muscles filling. Again the pt will present with similar conditions to hypovolemic shock

Septic shock - reduces perfusion is due to a pathogen mainly bacteria and this produces endotoxins these damages the vessels and due to the damage vessels they produce nitrogen which is a vasodilator along with other vasodilator such as histamine and cytokines , plateltes which are pro inflamation.All of these inflammatory chemicals damage the endothelial cells and increases their vascular permeability, making the blood vessels “leaky.” in addition to this the endothelial cells increase in blood coagulation which my block the blood vessels

Anaphylactic shock, neurogenic shock and septic shock are all classified as distributive shock - this means an abnormal distribution of blood flow due to vasodilation this causes temperature to rise

Question 15

What are the stages of shock

Answer 15

Initial- anaerobic metabolism creates lactic acid. Lactic acid starts to build up this damages cell

Compensatory- The body tries to increase tissue perfusion. This is done through vasoconstriction. This is sensed by baroreceptors which releases catecholamine. The heart and the brain increase perfusion first and not the vital organs. The kidneys also activate the renin-angiotensin system and aldosterone. GI reduces peristalsis, reduce perfusion and generally works slower. The skin perfusion low, cool, moist and pale this is except disstributive shock. The lungs, low 02, level VQ mismatch and incresed respiration.

progressive- The body systens are failing and the body can no longer compensate and this lead to death. This causes a complete drop-in cardiac output and the cells start to die due to hypoxic injury and increase capillary permeability, fluids leave to the intersitual space.

refractory- Unmanagable stage this leads to death

Question 16

What is observed in shock

Answer 16

Microscopically- it is characterized by generalized spasms of the vessels, microthrombosis, signs of increased vascular permeability in microcirculatory system, hemorrhages, degenerations, necroses connected with hypoxia and damaging effect of endotoxins.

Also DIC (disseminated intravascular coagulation)
This is characterised by the formation of blood clots that eventually forms a haemorrhage. This often develops in pregnancy, profuse uterine bleeding, large injuries. 
You will see fibrin clots, thrombocytes, fibrinogen, prothrombin in blood.

Question 17

Define Oedema

Answer 17

This is defined as the accumulation of fluids in the interstitial spaces.
Oedema can be transudate or Exudate.

“Transudate” is fluid buildup caused by systemic conditions that alter the pressure in blood vessels, causing fluid to leave the vascular system. “Exudate” is fluid buildup caused by tissue leakage due to inflammation or local cellular damage.