Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
32 Cards in this Set
- Front
- Back
•Vasculararchitecture - types of vessels |
•Arteries•Arterioles•(Met)Arterioles•Capillaries•(Postcapillary) Venules•(Muscular)Venules•(Collecting)Venules•Veins |
|
•Arterieshave 3 major tunics or layers |
•Tunicaintima Endotheliallining•Subendotheliallayer•Internalelastic lamina •Tunicamedia •Smoothmuscle cells•Collagenfibres•Extracelularmatrix•Elasticsheaths •Tunicaexterna(adventitia)•Connectivetissue• |
|
Largeelastic arteries |
•conducting vessels |
|
Pathology in arteries
|
Aortic Aneurysm Localised abnormal dilation of blood vessel |
|
True aneursyms |
Attenuated but intact arterial wall True - saccular type Wall focally bulges outward and may be attenuated but is otherwise intact True - fusiform. Dilation of vessel, without rupture |
|
False aneursyms |
Defect in vascular wall leading to an extravascular haematoma
False - wall is ruptured, collection of blood that is bounded externally by adherent extravasular tissues - haematoma. OR Dissection - blood enters wall of vessel through tear in intima |
|
•Mediumsized muscular arteries |
Distributing vessels •Large–medium-small –arterioles •Intima–endothelium –subendothelium-internalelastic lamina •Media–smooth muscle fibres |
|
Arterioles |
resistance vessels •vasculartone– vasoconstriction/dilatation •Circularlyarranged smooth muscle fibres •Intima–endothelium-subendothelium-internalelastic lamina •Media -2-5 concentric layers of smooth muscle cells •Adventitia–collagenous tissue |
|
Role of •Metarteriole |
–terminal branch of arterial system•Localregulator of blood flow |
|
Capillaries |
•exchangevessels •Endothelial cell •Basal lamina |
|
Three types of capillarires
|
- Continuous •Tightjunctions Brain, skin - Fenestrated •Poreswith or without diaphragms Kidney tubules and glomerulus - Sinusoid •Incomplete endothelial lining and basal lamina Liver, spleen |
|
What are veins? What unique feature do they contain? |
•reservoir vessels
Valves - projections into lumen of intima. Covered by endothelial cells and have a core of elastic fibres |
|
Change in vein diameter
|
•Progressivelylarger diameter •Compliance |
|
Layers in veins |
•Intima– endothelium, subadjacent basal lamina. No internal elastic lamina
•Media– thinner than arteries, smooth muscle cells approximately circular in orientation •Adventitia– collagen fibres and fibroblasts |
|
Clinical significance of veins |
Varicose •Intrinsic weakness of muscular tunica media •Increased intraluminal pressure •Defects in structure and function of the valves - leaky valve allows blood to flow back and forth |
|
Where do varicose veins occur? |
Superficial veins of upper and lower leg - venous pressure is elevated by prolonged dependent posture.
|
|
Another veins pathology |
Vasculitis - Multisystem disorder - •highlyvascularisedtissue •Skin,renal glomerulus, upper respiratory and GI tract |
|
Vasculitis mechanism |
•Immune cell complex deposition; antiendothelial cell Abs Direct invasion of vascular walls by infectious pathogens |
|
Types of vasculitis |
•Cranial(giant cell) arteritis Pulseless (takayasu’s)disease Buerger's disease •Infectious Vasculitis |
|
•Cranial(giant cell) arteritis |
•Older people•Arteries in head (principally), neck, aorta. can result in blindness. Evidence suggests that T-cell mediated immune response against vessel wall antigens. Drives TNF production. Treated through coritcosteroid therapy or anti-TNF. |
|
Pulseless (takayasu’s)disease |
•Aorta and proximal branches, renal. •Transmural scarring and thickening of the aorta with severe luminal narrowing •Young or middle aged females •Hypertensionor ischaemicsymptoms in the arms |
|
Vascularitis - which vessels are most affected?
|
Small vessels
|
|
Vasculitis - medium vessel |
Buerger's disease Segmental, thrombosing, acute and chronic inflammation. Occurs almost exclusively in heavy cigarette smokers. •Endothelialcell toxicity caused by some component of tobacco is suspected |
|
what is Buerger's disease? |
•Rare and strongly associated with smoking Leg arteries and veins (gangrene) •Lumen of artery occluded by thrombus containing abscesses and vessel wall is infiltrated with leucocytes Neutrophils, granulomas |
|
Example of immune complex-associated vasculitis |
SLE - in small vessels. Goodpastures |
|
Buerger Disease - clinical features Treatment |
Early maifestations - Cold-induced Raynaud phenomenon Smoking abstinence can ameliorate further attacks |
|
Infection and Vasculitis |
•Infectious Vasculitis •Bacteria or fungi directly invade arteries Pseudomonas •Weaken arterial walls so they leak ! Can result in thrombosis and infarction. |
|
Inflammation in brain |
Inflammation-induced thrombosis of meningeal vessels in bacterial meningitis can eventually cause infarction of the underlying brain |
|
Disorders of blood vessel hyperactivity |
•Exaggerated vasoconstriction of blood vessels |
|
Example - |
Raynaud phenomenon - vasoconstriction of arteries and arterioles in extremities |
|
Primary |
•Exaggerated central and local vasomotor responses to cold or emotion •Young women. Affects 3-5% of population •Structural changes in arterial wall absent except late in the course, when intimal thickening may occur •Chronic-atrophy of skin, subcutaneous tissues and muscles may occur •Ulceration and ischaemic gangrene (rare) |
|
Secondary |
•Vascular insuffficiency due to arterial disease Extent and severity worsens over time Can be caused by SLE. |