• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/32

Click to flip

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.



2/3 have anti-endothelial cell and anti-smooth muscle cell Abs. Casual or consequence of other immune injury - unclear.

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
BEFORE established.

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.