ICL 1.2: Histology of Cardiovascular System Flashcards

Question

what is endocarditis?

Answer 1

an inflammation of the inner layer of the heart and is characterized by lesions, known as vegetations, a mass of platelets, fibrin, microcolonies of microorganisms, and some inflammatory cells infective endocarditis is typically caused by a bacterial infection and less commonly a fungal infection and usually affects the valves. symptoms may include fever, small areas of bleeding into the skin, heart murmur, feeling tired, and may include valvular insufficiency, heart failure, stroke, and kidney failure the bacterial most commonly involved are streptococci or staphylococci diagnosis is suspected based on symptoms and supported by blood cultures or ultrasound.

Answer 2

1. valvular heart disease including rheumatic disease 2. congenital heart disease 3. artificial valves 4. hemodialysis 5. intravenous drug use 6. electronic pacemaker

Answer 3

a mechanical tear that disrupts the innermost layer of a vessel, the tunica intima then you get blood pooling into the vessel wall between the tunica intima and tunica media which destabilizes the integrity of the vessel

Answer 4

1. tunica intima (inner) 2. tunica media 3. tunica adventitia

Answer 5

the innermost layer of the arterial wall comprised of squamous endothelium, basal lamina, subendothelium of loose connective tissue (collagen II, IV & V) and a few longitudinally arranged scattered smooth muscle cells composed of squamous endothelial cells with gap junctions form a nice thick surface for blood to flow past an *internal fenestrated elastic lamina* separates the intima from media

Answer 6

a middle layer of the arterial wall that is smooth muscle smooth muscle cells are helically arranged and prominent in muscular arteries also contains elastic fibers, type III collagen & proteoglycans an external elastic lamina in large muscular arteries separates t. media from t.adventitia

Answer 7

the outer layer of arterial wall comprised of longitudinally arranged elastic fibers, fibroblasts, type I collagen, blood vessels, nerves, muscle (in veins) and vasa vasorum-blood supply to vessels

Answer 8

1. large flattened lumen 2. thickened subendothelium 3. internal elastic lamina that is difficult to discern 4. prominent vaso vasorum in adventitia (blood supply) typically 40-70 elastic lamellae in t. media of adults the elastin allows for passive contraction slide 21

Answer 9

muscular arteries have a round lumen and an attenuated subendothelium with a prominent, scalloped internal elastic lamina these arteries have a thick t. media typically comprised of 5-20 smooth muscle cell layers and a thin t. adventitia often containing vaso vasorum in larger distributing vessels these are called distributing arteries because the myocytes can contract and regulate flow through the arteries slide 21

Answer 10

arterioles have a diameter < 0.1mm and a t. intima that contains an internal elastic lamina only in large arterioles the t. media has 1-3 layers of smooth muscle and NO external elastic lamina the t. adventitia is highly attenuated the smallest arterioles are called metarterioles and have a discontinuous layer of smooth muscle cells that controls blood flow to capillary beds

Answer 11

an inflammatory remodeling of the tunica intima you get accumulation of fatty plaques and cholesterol and macrophages try to clear that material from the damaged vessel walls but sometimes they become residents and can induce changes in the structure of the tunica intima you can an increase of smooth muscle cells and fibroblasts and you get a thickening of the t. intima to the point that you occlude blood flow -- you can even get calcification if the plaques get really bad slide 22

Answer 12

caused by mutations in fibrillin-1, an esential glycoprotein component of the extracellular matrix, including the biogenesis and maintenance of elastic fibers elastic fibers are found throughout the body, but are particularly abundant in the aorta these patients are predisposed to developing aneurysms due to weakening of vessel walls!

Answer 13

a group of genetic connective tissue disorders mutations in these genes usually alter the structure, production, or processing of collagen or proteins that interact with collagen collagen provides structure and strength to connective tissue a defect in collagen can weaken connective tissue in blood vessels potentially resulting in aortic dissection these patients are predisposed to developing aneurysms due to weakening of vessel walls!

Answer 14

doesn't have a standard tunica media but it does have scattered smooth muscle cells that act as capillary sphincters and can alter flow of blood into the capillary beds blood flow through capillary networks is highly controlled!

Answer 15

AV shunt is when blood flows from an arteriole to venule directly and totally bypassing the capillary bed usually this is invoked in response to trying to conserve heat so it doesn't dissipate in the capillary bed ex. Reynaud's syndrome

Answer 16

Raynaud's Disease most commonly manifests after exposure to cold and occurs because of spasm of smooth muscle of small arteries and arterioles that feed some peripheral capillary beds spasms of terminal arterioles would reduce or shunt blood flow away from the peripheral capillary beds the cause of Raynaud's phenomenon is unknown, although abnormal sympathetic nerve control of blood-vessel diameter and nerve sensitivity to cold are suspected of being involved secondary Reynaud’s can result in ulceration of the tissues

Answer 17

capillaries have a single layer squamous endothelial cells oriented with blood flow with marginal folds overlap on upstream edge of cell, a basal lamina, some areola CT and no T.media vessels are 5-10 µm in diameter and cells are joined by occludens (tight) junctions vessels may be encapsulated by myoepithelial pericytes that form gap junctions with endothelium and contract to aid in controlling blood flow

Answer 18

1. transport and exchange of materials between blood & parenchyma 2. deposition of adhesion molecules 3. maintenance of vascular tone 4. produce and exocytoticly release clotting factors such as von Willebrand factor (VWF)

Answer 19

1. continuous 2. fenestrated 3. discontinuous/sinusoids

Answer 20

no pores or fenestrations, cont. basal lamina present in muscle, nerve, c.t. tight junctions (zonula occludens)

Answer 21

fenestrae of 60-80 nm with diaphragm found in pancreas, intestines, endocrine glands renal glomerulus has no diaphragms

Answer 22

they have an incomplete basal lamina and large intracellular clefts these are designed to allow large molecules and cells to pass back and forth! found in the liver, spleen, lymph nodes, marrow

Answer 23

systemic capillary leak syndrome (SCLS) is a rare acquired disorder characterized by acute and severe recurrent attacks associated with a rapid fall in blood pressure repeated flares of massive leakage of plasma from blood vessels into neighboring body cavities and muscles attacks often last several days and require emergency care the underlying cause of SCLS is not known but is thought to be autoimmune

Answer 24

1. large veins 2. medium sized vein (*have valves) 3. venule

Answer 25

- poorly defined IEL - few circularly oriented SMCs - no EEL - thick tunica adventitia - valves! slide 32

Answer 26

return blood to heart 1. thin wall compared to diameter 2. no IEL 3. thick subendothelial c.t. 4. modest tunica media (except legs) 5. prominent tunica adventitia with longitudinal smooth muscle 6. deep vaso vasorum because they're transporting a lot of blood with low oxygen slide 35

Answer 27

arteries have a much thicker tunica media = more smooth muscle arteries have an internal elastic lamina; veins don't slide 36

Answer 28

the right lymphatic duct drains the upper right part of the body the thoracic duct drains the rest of the body interstitial fluid gets taken up into lymphatic capillaries which can be distinguished because unlike veins, don't have RBCs in the lumen, instead they'll have WBCs

Answer 29

swelling in one or more extremities that results from impaired flow of the lymphatic system lymphedema most often affects a single arm or leg, but in uncommon situations both limbs are affected primary lymphedema is the result of an anatomical abnormality of the lymph vessels and is a rare, inherited condition secondary lymphedema results from an identifiable damage to or obstruction of normally-functioning lymph vessels and nodes usually this occurs with parasites that block lymph flow but in the US it's most related to breast cancer surgery where lymph nodes are removed which can lead to bad drainage