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;
44 Cards in this Set
- Front
- Back
what are the 3 layers of arteries and veins (starting with the inner most layer and moving outward) |
tunica intima (basement membrane) tunica media tunica adventitia/externa |
|
what are the 2 layers present in a capillary tube (starting with the innermost layer and moving outward) |
basement membrane endothelium |
|
describe the tunica intima |
A single layer of squamous epithelium |
|
what is the function of the tunica intima |
Provides a smooth, friction- reducing lining for the vessel. |
|
describe the tunica media |
it is made of smooth muscle and connective tissue (primarily elastic fibres) |
|
what is the function of the tunica media |
the smooth muscle is activated by the sympathetic nervous system; (Vasoconstriction and vasodilation)
The elastic fibers stretch and then passively recoil |
|
describe the tunica exeterna/adventitia |
The outermost layer, made of fibrous connective tissue |
|
what is the function of the tunica adventitia/externa |
Protective and supporting layer |
|
what is the thickest of the layer of the blood vessels? |
tunica media |
|
what is an anastosome |
reconnection of two streams that previously branched out, such as blood vessels |
|
give an anatomical and functional example of an anastosome |
anatomical --> circle of willis (brain) functional --> mesenteric vessels (GI tract) |
|
define collateral circulation |
Collateral circulation is the redundant circulation in an area of tissue or an organ that blood can reach by more than one pathway. |
|
what causes collateral circulation |
enlargement of anastosomes |
|
are smaller or larger branches more likely to anastosome |
smaller |
|
where is peripheral blood pressure most 'palpable' |
when an artery pushes against a bone |
|
where is the apical pulse |
just below the nipple |
|
where is the popliteal pulse |
behind knee |
|
where is the dorsal pedis pulse |
foot |
|
name 3 things that can go wrong with blood vessels |
• Atherosclerosis |
|
define atherosclerosis |
- “hardening of the arteries” thicken, harden and lose elasticity. - Most common type of arteriosclerosis charaterised by calcification and plaque build up |
|
what is the current hypothesis for why atherosclerosis is formed |
--Endothelial injury/dysfunction of vascular wall leads to chronic inflammatory response --Focal plaques build up within tunica intima with cholesterol and cholesterol esters --Elevated plasma LDL levels causing the deposition of LDL in the subendothelium of blood vessels --Activation of endothelial cells --Recruitment of monocytes/macrophages --Formation of foam cells – fatty streaks --Proliferation of smooth muscle cells --Deposition of extracellular matrix proteins |
|
what general size of arteries does atherosclerosis affect |
medium and large arteries |
|
what are the 3 major components of plaque |
-cellulalar (SMC, macrophages, WBC) -ECM (collagen, elastin, prostoglandin) -lipid (cholesterol) |
|
what 2 major processes occur in plaque formation |
-intimal thickening (SMC proliferation and ECM synthesis) -lipid accumulation |
|
what are the non-modifiable risk factors of atherosclerosis |
increasing age sex family history |
|
what are the modifiable risk factors of atherosclerosis |
• Hyperlipidaemia |
|
when a plaque narrows a lumen, what can this lead to? |
ischaemia, turbulence |
|
what can the weakening of vessel walls lead to |
aneurysms, rupture |
|
what can thrombosis lead to |
narrowing, ischaemia, embolisation |
|
when a plaque breaks loose what can this lead to |
ahtero-embolisation |
|
define aneurysmal disease |
localised dilation of the affected artery over 50% of the normal diameter |
|
in the adventitia/externa what is the main function collagen |
tensile strength |
|
in the tunica media, what is the main role of the elastin |
recoil capacity |
|
list the features of aneurysmal disease |
– Damage and loss of intima
– Collagen:tensile strength (adventitia) |
|
what are the risk factors of aneurysmal disease |
smoking, hypertension, hypercholesterolaemia |
|
define laplace's law |
(Tension varies directly with radius when pressure is constant) The larger the vessel radius, the larger the wall tension required to withstand a given internal fluid pressure |
|
what are the main causes of aneurysms |
Atherosclerotic Congenital - Marfan’s syndrome, Berry aneurysms Post-stenotic - Coarctation of the aorta, Cervical rib, Popliteal artery entrapment syndrome Traumatic - Gunshot, stab wounds, arterial punctures Inflammatory - Takayasu’s disease, Behcet’s disease Mycotic - Bacterial endocarditis, syphilis |
|
define embolism |
Embolism is the blockage of a blood vessel by solid, liquid or gas at a site distant from its origin |
|
what is a thromboemboli |
starts of as a thrombus, then a bit breaks off and goes further "downstream" and become an embolism |
|
if there is a thrombus in the systemic veins, where is the embolus likely to form |
the lungs (pulmonary emboli) |
|
if there is a thrombus in the heart muscle, where is the embolus likely to form |
heart --> aorta --> renal, mesenteric, and lower limb arteries |
|
if the carotid arteries are atheromatous, where is the embolism likely to form |
brain |
|
if the abdominal aorta is atheromatous, where is the embolism likely to form |
lower limb arteries |
|
which point in the carotid artery is a very common sight of atherosclerosis |
Common carotid bifurcation (where it splits) is common site of atherosclerosis causing luminal narrowing and potential embolisation to the brain |