Vascular Pathology Flashcards
Definition of a thrombus
A solid mass of blood constituents formed within the vascular system during life
OR blood clot within the circulation
Definition of embolism
The passive transport of a substance within the vascular system
Definition of ischaemia
An inappropriate reduction in blood supply to an organ or tissue
Definition of infarction
Death of tissue due to ischaemia
infarct = stuffed with blood
Definition of aneurysm
A localised permanent abnormal dilatation of a blood vessel due to weakening of the blood vessel wall
Ischaemia doesn’t always result in death of tissue. It can also result in _________ and _________.
Fibrosis
Scarring
The 3 fators that can lead to thrombosis are known as the ________ ______.
Virchow’s Triad
What are the factors included in the Virchow’s Triad that can lead to the formation of thrombus?
- Changes in the intimal surface of the vessel (eg ulceration)
- Changes in the pattern of blood flow (eg stagnant blood flow in haemostasis or turbulence in injury)
- Changes in the blood constituents (making the blood hypercoagulable eg oestrogen, platelet abnormalities etc)
What happens during arterial thrombosis? (6 points)
- Platelet aggregation
- Localised activation of the clotting cascade (by the release of clotting factors)
- Fibrin formation
- Trapping of RBCs
- Repeat from 1-4
- Propagation (of thrombus across and obstruct a vessel)
When seeing thrombus microscopically, it has a striped appearance (alternating pale and dark stripes) known as ________ of _____. Histological section shows pale areas which are comprised of __________ and __________. Dark and pink areas are where ____ _______ ______ are trapped.
Lines of Zahn, platelets, thrombin, red blood cells
Venous thrombosis occurs mostly as a result of ______, often around _______ of the veins.
Stasis, valves
Venous thrombosis can also be secondary to:
6 points
- Burns and trauma
- Surgery
- Cardiac failure
- Pregnancy
- Immobility
- Long haul flights
What are the two conditions categorised under deep vein thrombosis (DVT)?
- Thrombophlebitis
- Phlebothrombosis
Definition of thrombophlebitis
Inflammation of the deep vein related to thrombosis/formation of a thrombus
Definition of phlebothrombosis
Formation of a thrombus in a vein that is not inflamed
Cardiac thrombosis is thrombosis that occurs due to heart conditions such as atrial ___________, mitral _________, rheumatic fever, endocarditis, and myocardial infarction. These heart conditions cause blood flow to be altered, causing platelets to contact the endothelium they wouldn’t normally contact, so thrombus can form.
Fibrillation
Stenosis
Thrombosis can also happen on the ________ of the heart valves eg in rheumatic fever and endocarditis where there are ________ that thrombosis can occur on top of.
Edges, vegetations
In myocardial infarction, the underlying dead heart muscle causes the overlying __________ lining the heart chamber to become abnormal, which is one of the factors described in the Virchow’s Triad which leads to thrombosis.
Endothelium
What is the fate of thrombi? (4 points)
- Lysis and resolution
- Retraction and recanalisation
- Organisation and scarring
- Embolism
What is an embolus?
A mass of material in the vascular system able to become lodged within a vessel and block its lumen
Majority of emboli are fragments of _______.
Thrombus
Emboli can also result from:
7 points
- Atheromatous debris
- Vegetations on heart valves (infective endocarditis)
- Fat (fatty marrow)
- Gas (Caisson’s disease aka depression sickness)
- Amniotic fluid
- Tumour
- Foreign material
Pulmonary embolism occurs on the ________ side. It most often comes from the _____ where we have DVT as a result of thrombophlebitis or phlebothrombosis. It can also occur in the _______ veins. The consequences depend on the ______ of the embolus.
Venous, legs, pelvic, size
If a large thrombus blocks the entire pulmonary artery, it can cause shock effect in the lung and lead to ________ _______.
If thrombus is smaller and just blocks the branch of pulmonary artery then classic symptoms of _______ ______ and _______________ will occur.
If thrombus blocks small arteries, it can lead to pulmonary _____________.
Sudden death
Chest pain, breathlessness
Hypertension
Systemic embolism occurs on the ________ side or the ______ side of the heart. It is typically caused by thrombi forming on ______________ _________. The consequences depend on the size of the embolus and the site it lodges eg heart, brain, spleen, kidney, intestine or limbs and digits.
Arterial, left, atheromatous plaques
What are possible causes of (ischaemia hence) infarction? (7 points)
Atheroma
Thrombosis
Embolism
Vasculitis
Compression
Spasm
Hyperviscosity
What is the difference in histology of kidney after infarction?
Blue dot-like staining on the nuclei are lost as the nuclear material degrades (karyorrhexis) and cytoplasm becomes a uniform pink colour.
Evolution of myocardial infarction:
<6 hours
24-48 hours
Several days
Several weeks
<6 hours: no visible changes (ECG changes)
24-48 hours: pallor with red rim
Several days: pallor with red rim and becomes soft (haemopericardium)
Several weeks: grey and fibrotic
Necrosis secondary to infarction resulting in the transformation of completely dissoluted dead tissue into a liquid, viscous mass is called ___________ ________.
Colliquative necrosis
Embolism occurring to the digits (finger or toe) results in necrosis and ___________ of the digits.
Gangrene
What factors are determinants of infarction? (5 points)
- Vascular anatomy
- Duration of occlusion
- Metabolic requirements of tissue
- General circulatory factors eg heart failure vs anaemia
- Reperfusion injury
What are the 6 different types of aneurysm?
- Atherosclerotic
- Mycotic
- Syphilitic
- Berry
- Micro-
- False
syphilis (sexually transmitted bacterial infection)
syphilitic (arise during tertiary syphilis due to chronic inflammation in the tunica adventitia of large elastic arteries, particularly the aorta)
mycotic (bacterial/viral/fungal infection of vessel wall)
berry (occur in the circle of Willis in the brain)
micro (occur in the small vessels within the brain and retina <300 micrometres in diameter)
What is a false aneurysm?
A blood filled space due to following vascular rupture (just a haematoma rather than a true aneurysm)
An example of a false aneurysm is a __________ aneurysm
Dissecting
What are the 2 affected aorta and 3 consequences of atherosclerotic aneurysm?
Thoracic aorta and abdominal aorta
Pulsatile abdominal mass, lower limb ischaemia, retroperitoneal haemorrhage
Mycotic (infective) aneurysm affects the _____ of aorta in aortic valve endocarditis and cerebral arteries leading to __________, __________ and cerebral __________.
Root, thrombosis, haemorrhage, infarction
Rupture of ______ aneurysm which occurs in the Circle of ______ can result in ___________ ___________.
Berry, Willis, subarachnoid haemorrhage
Micro-aneurysms are also known as _________-_________. They can occur in the ____________ capillaries, __________ capillaries, during ___________ or ___________. Rupture can result in ___________ and _________ haemorrhage.
Charcot-Bouchard, intracerebral, retinal, hypertension, diabetes, cerebal, retinal
Dissecting aneurysm usually occurs in the ________ aorta, in elderly people and in those who have _______ _________ (disorder of the body’s connective tissues). It can result in loss of peripheral _______, haemopericardium, __________________ haemorrhage, and double barelled aorta.
Thoracic, Marfan Syndrome, pulses, retroperitoneal
Retroperitoneal = area outside or behind the peritoneum (tissue lining the abdominal wall and covers most of the organs in the abdomen)
Types of infarction:
1. Heart attack - _______ infarction due to ________ thrombosis
2. Stroke - _________ infarction due to _______ thrombosis or embolism
3. Gangrene - ___________ infarction, eg leg, from atherosclerosis/thrombosis/embolism
- Myocardial, coronary
- Cerebral, cerebral
- Peripheral
