Ch 11: Blood Vessels Flashcards
what are the three cellular components of blood vessels
smooth muscle cells
extracellular matrix
endothelial cells
what is capacitance
measure of the blood vessel’s ability to increase the volume of blood it holds without a large increase in blood pressure
which vessels, arteries or veins, have high capacitance and why
veins because they can hold a large volume of blood under low pressures
what is the structure of a capillary
single-cell lining of endothelial cells atop a basement membrane
what are some features of the intima layer of a vessel
innermost layer made of one sheet of endothelial cells on a basement membrane
what separates the intima and media vessel wall layers
internal elastic lamina - dense elastic membrane
what are some features of the media layer of a vessel
made mostly of smooth muscle cells, extracellular matrix, and loose connective tissue
contains nerve fibers and smaller vessels of adventia
what are some features of the adventitial layer of a blood vessel
made of simple squamous epithelium, basement membrane, connective tissue, blood vessels, and sometimes smooth muscle cells
what is the vasa vasorum
small vessels that supply the walls of large vessels that are susceptible to external mechanical compression
diseases of the vasa vasorum has been seen to affect the development of which disease
diabetic neuropathy
what are some features of large elastic arteries
include aorta, arch vessels, iliac, and pulmonary arteries
have lots of elastic fibers with some smooth muscle cells
allow the wall to stretch and recoil to propel blood
elasticity is lost as we age or get diseases
what are some features of medium sized vessels
include coronary and renal arteries
lots of smooth muscle cells which allow for vasoconstriction and vasodilation
what portion of the neurologic system controls vasoconstriction and vasodilation
autonomic nervous system
endothelial cells of the vessels release what to cause vasodilation
nitric oxide
endothelial cells of the vessels release what to cause vasoconstriction
endothelin
what are some features of small sized vessels
found mostly in connective tissue of organs
main role is to regulate blood flow resistance
measure of the blood vessel’s ability to increase the volume of blood it holds without a large increase in blood pressure
what is capacitance
innermost layer made of one sheet of endothelial cells on a basement membrane
what are some features of the intima layer of a vessel
made mostly of smooth muscle cells, extracellular matrix, and loose connective tissue
contains nerve fibers and smaller vessels of adventia
what are some features of the media layer of a vessel
made of simple squamous epithelium, basement membrane, connective tissue, blood vessels, and sometimes smooth muscle cells
what are some features of the adventitial layer of a blood vessel
include aorta, arch vessels, iliac, and pulmonary arteries
have lots of elastic fibers with some smooth muscle cells
allow the wall to stretch and recoil to propel blood
elasticity is lost as we age or get diseases
what are some features of large elastic arteries
include coronary and renal arteries
lots of smooth muscle cells which allow for vasoconstriction and vasodilation
what are some features of medium sized vessels
found mostly in connective tissue of organs
main role is to regulate blood flow resistance
what are some features of small sized vessels
what are some features of capillaries
thin walled vessels lined by endothelial cells and surrounded by pericytes
allow for rapid exchange of diffusible substances between blood and tissue
what are pericytes
smooth muscle cells found in capillaries
what are some features of veins
large lumen diameter with thinner walls
receive blood from post capillary venules
what is the width of the vena cava
30 mm (3cm)
what is the width of a venule
less than 100-120 micro meters
in which type of arteries does atherosclerosis primarily occur
larger, muscular arteries
which vessels are most affected by hypertension
small arterioles
how many liters of fluid are returned back to the circulation by veins
17 liters
the lymphatic system collects how many liters of excess fluid (now called lymph)
3 liters
what are the 6 components of lymph
water
electrolytes
glucose
fat
proteins
inflammatory cells
what are three of the roles of lymph nodes in the lymphatic system
monitor and cleanse lymph
produce and store lymphocytes
antigen presentation and cell activation
which range of patients have coronary artery variants
1-5%
what are berry aneurysms
saccular out pouches in cerebral vessels
mostly found in the circle of Willis
can spontaneously rupture and cause intracerebral hemorrhage
what type of aneurysm makes up 90% of all brain aneurysms
berry aneurysms
what are the two most common sites for berry aneurysms (with percentages) within the circle of willis
anterior communicating artery (40%)
middle cerebral artery (20%)
what is an arteriovenous fistula (AVF)
abnormal connection between arteries and veins - no capillary bed
can be surgically created to increase blood flow to dialysis patients
can cause cardiac failure by shunting large volumes of blood from the arterial to venous circulation
can affect blood flow based on where they are
what is the most common cause of an arteriovenous fistula (AVF)
developmental defects
what is an arteriovenous malformation (AVM)
complex of tangled web of afferent arteries and draining veins with abnormal dysplastic capillary beds
(blood skips capillary beds and just goes from arteriole to venule)
what is fibromuscular dysplasia
-which arteries does it mostly affect
focal, irregular thickening of the walls of medium and large sized muscular arteries due to a combination of intimal hyperplasia and fibrosis
seen mostly in renal and carotid arteries
can cause luminal stenosis or vascular spasm that reduced flow
appears as a string of beads
which condition presents as a string of beads
fibromuscular dysplasia
who does fibromuscular dysplasia mostly affect
young women
1-5% of Americans
what is an anomalous coronary artery
when both coronary arteries arise over the same coronary cusp of the aortic valve
can be compressed during exercise which can lead to sudden death
what happens to endothelial cells in an activated state
activation is caused by injury or exposure to mediators
cells to develop adhesive, procoagulant surfaces making them sticky
they release factors that lead to smooth muscle contraction and proliferation
what are some features of endothelial cells in a basal state
normal blood pressure
laminar flow
stable growth factor which promotes a non-thrombotic or adhesive surface
what are three things that a dysfunctional endothelium can lead to
can initiate thrombosis
promote atherosclerosis
contribute to the formation of vascular lesions
what 5 factors regulate the movement and proliferation of smooth muscle cells
platelet derived growth factor
endothelin
thrombin
fibroblast growth factors
inflammatory mediators
how is cardiac output calculated
stroke volume X heart rate
what is stroke volume
volume of blood in milliliters ejected from each ventricle during each contraction
how is stroke volume calculated
EDV-ESV
what is the most important determinant of stroke volume
filling pressure
each beat ejects what percentage of blood out of the ventricle
60%
what is peripheral resistance
circulatory system resistance that impacts blood pressure and flow of blood
what are three types of vasoconstrictors
angiotensin 2
catecholamines
endothelin
what are three types of vasodilators
kinins
prostaglandins
N0 (nitric oxide)
how is blood pressure calculated
cardiac output x total peripheral resistance
how do the kidneys influence vascular tone and blood volume
filter 170 liters of plasma that has lots of salt
what percentage of filtered sodium is reabsorbed
98%
how does the liver influence vascular tone and blood volume
releases angiotensinogen which will lead to increase of blood pressure and vascular tone
thin walled vessels lined by endometrial cells and surrounded by pericytes
allow for rapid exchange of diffusible substances between blood and tissue
what are some features of capillaries
smooth muscle cells found in capillaries
what are pericytes
large lumen diameter with thinner walls
receive blood from post capillary venules
what are some features of veins
saccular out pouches in cerebral vessels
mostly found in the circle of Willis
can spontaneously rupture and cause intracerebral hemorrhage
what are berry aneurysms
abnormal connection between arteries and veins - no capillary bed
can be surgically created to increase blood blow to dialysis patients
can cause cardiac failure by shunting large volumes of blood from the arterial to venous circulation
can affect blood flow based on where they are
what is an arteriovenous fistula (AVF)
complex of tangled web of afferent arteries and draining veins with abnormal dysplastic capillary beds
(blood skips capillary beds and just goes from arteriole to venule)
what is an arteriovenous malformation (AVM)
focal, irregular thickening of the walls of medium and large sized muscular arteries due to a combination of intimal hyperplasia and fibrosis
seen mostly in renal and carotid arteries
can cause luminal stenosis or vascular spasm that reduced flow
appears as a string of beads
what is fibromuscular dysplasia
when both coronary arteries arise over the same coronary cusp of the aortic valve
can be compressed during exercise which can lead to sudden death
what is an anomalous coronary artery
stroke volume X heart rate
how is cardiac output calculated
volume of blood in milliliters ejected from each ventricle during each contraction
what is stroke volume
EDV-ESV
how is stroke volume calculated
circulatory system resistance that impacts blood pressure and flow of blood
what is peripheral resistance
cardiac output X peripheral resistance
how is blood pressure calculated
how do the adrenal glands influence vascular tone and blood volume
produce aldosterone in response to angiotensin 2
increases blood pressure
aldosterone causes kidneys to reabsorb sodium and water
how does the myocardium of the heart influence vascular tone and blood volume
produces ANP
ANP causes vasodilation and excretion of water and sodium therefore leading to a lower blood pressure
what percentage of the population are hypertensive
25%
what blood pressure reading is considered hypertension
140/90 mmHg
which demographic has a higher instance of hypertension
African Americans - 2 in 5 have it
what are the four mechanisms of essential (primary) hypertension
reduced renal sodium excretion
increased vascular resistance
genetic factors
environmental factors
what is malignant hypertension and what is it usally caused by
severe hypertension (200/120mmHg)
usually caused by renal failure
how does cocaine cause hypertension
increases levels of dopamine which causes increased peripheral vasoconstriction leading to hypertension
what are the two main categories of arteriosclerosis
arteriolosclerosis and atherosclerosis
severe hypertension (200/120mmHg)
usually caused by renal failure
what is malignant hypertension
what is arteriolosclerosis
plaque build up in the small arteries and arterioles
two types: hyaline and hyperplastic
what is monckeberg medial sclerosis
calcium deposits within the muscular layer of the vessel
typically affects those over 50
do not cause major issues because buildup isn’t within the lumen
what is fibromuscular intimal hyperplasia
thickening of vessel walls in muscular arteries due to an inflammatory response or mechanical injury
healing can cause stenosis
what is hyaline arteriolosclerosis
causes benign hypertension
microscopic appearance is homogeneous, pink hyaline thickening of arteriolar walls, with loss of underlying structural detail and luminal narrowing
what is arterionephrosclerosis
caused by hyaline arteriolosclerosis
arteriolar narrowing that causes diffuse vascular compromise and nephrosclerosis (glomerular scarring)
what is hyperplastic arteriolosclerosis
seen in cases of severe hypertension
vessel exhibit’s onion skin, concentration laminated thickening of arteriolar walls and luminal narrowing due to proliferation of smooth muscle cells
which disease has the onion skin/striated appearance
hyperplastic arteriolosclerosis
what do calcium deposits look like microscopically
dark purple areas
what is atherosclerosis
most common type of arteriosclerosis
hardening of the arteries due to atheroma (plaque) which impinge on the lumen and can rupture or cause sudden occlusion
what are four non modifiable (constitutional) risk factors of atherosclerosis
genetic abnormalities
family history
increasing age
male gender
what are five modifiable risk factors of atherosclerosis
hyperlipidemia
hypertension
cigarette smoking
diabetes
inflammation
what is hyperlipidemia/hypercholesterolemia
excess lipids/cholesterol in the blood
what does low-density lipoprotein (LDL) do
“bad” cholesterol
distributes cholesterol to peripheral tissues
what does high-density lipoprotein (HDL) do
mobilizes cholesterol from plaques and transports it to the liver for biliary excretion
what are statins
class of drugs used to lower circulating cholesterol levels by preventing your liver from making additional cholesterol
plaque build up in the small arteries and arterioles
two types: hyaline and hyperplastic
what is arteriolosclerosis
calcium deposits within the muscular layer of the vessel
typically affects those over 50
do not cause major issues because buildup isn’t within the lumen
what is monckeberg medial sclerosis
thickening of vessel walls in muscular arteries due to an inflammatory response or mechanical injury
healing can cause stenosis
what is fibromuscular intimal hyperplasia
caused by benign hypertension
microscopic appearance is homogeneous, pink hyaline membrane thickening of arteriolar walls, with loss of underlying structural detail and luminal narrowing
what is hyaline arteriolosclerosis
caused by arteriolar narrowing seen in hyaline arteriolosclerosis
causes diffuse vascular compromise and nephrosclerosis (glomerular scarring)
what is arterionephrosclerosis
caused by severe hypertension
vessel exhibit’s onion skin, concentrated laminated thickening of arteriolar walls, and luminal narrowing due to proliferation of the smooth muscle cells in the muscular layer
striations
what is hyperplastic arteriolosclerosis
hardening of the arteries with atheroma that impinge on the lumen and can rupture or cause sudden occlusion
what is atherosclerosis
excess lipids/cholesterol in the blood
what is hyperlipidemia/hypercholesterolemia
“bad” cholesterol
distributes cholesterol to peripheral tissues
what does low-density lipoprotein (LDL) do
mobilizes cholesterol from plaques and transports it to the liver for biliary excretion
what does high-density lipoprotein (HDL) do
class of drugs used to lower circulating cholesterol levels
what are statins
how does having diabetes mellitus affect you
make your cholesterol levels rise and increase the risk for atherosclerosis
doubles your risk for an MI
increases your risk for strokes
100-fold increase in atherosclerosis induced gangrene of lower extremities
what percentage of cardiovascular events occur in the absence of identifiable risk factors
20%
what is clonal hematopoiesis
presence of major clone of cells in the bone marrow that have acquired somatic driver mutations in tumor suppressor genes
increases your risk for atherosclerosis
what are the two most important causes of endothelial dysfunction
observed hemodynamic factors and hypercholesterolemia
what are observe hemodynamic factors
when plaques form where there is turbulent flow (Ostia, branch points, and posterior wall of the abdominal aorta)
laminar flow leads to atheroprotective genes
how are lipids normally transported in the bloodstream
bound to specific apoproteins that form lipoprotein complexes
how does hypercholesterolemia affect endothelial dysfunction
increases local oxygen free radical production which damages endothelial cells
how does inflammation lead to atherosclerosis
normal vessels do not promote inflammatory cell adhesion
when there is inflammation, dysfunctional endocervical cells express adhesion molecules that promote leukocyte adhesion of monocytes and T-cells to vessels
what disease causes more morbidity and mortality (half of all deaths) in the western world
atherosclerosis
what is the basic pathogenesis of atherosclerosis
chronic endothelial injury
monocyte adhesion
macrophages, leukocytes, and foam cells migrate
accumulation of lipoproteins in vessel wall
platelet adhesion
SMC proliferation
lipid accumulation
calcification of ECM
what are fatty streaks
lipid aggregates in a developing atheroma
what three things can an atherosclerotic plaque do
rupture
ulcerate
erode
what are the four major consequences of atherosclerosis
MI
stroke
aortic aneurysm
peripheral vascular disease (gangrene)
what percentage of stenosis is considered critical
70%
what are the top 3 most severe areas to have atherosclerosis
infrarenal abdominal aorta
coronary arteries
popliteal arteries
what are three places that don’t usually have atherosclerosis
vessels of upper extremities
mesenteric arteries
renal arteries
what type of aneurysm is a pulsating one
false or pseudoaneurysm
where are the two most common locations of aneurysms due to atherosclerosis
abdominal aorta and common iliac arteries
what is the rate of rupture in aneurisms greater than 6 cm in size
25%
what is the mortality rate for elective and emergency aneurysm surgery
elective: 5%
emergency: 50%
what are four common risks for thoracic aneurysms
hypertension (most common)
bicuspid aortic valves
marfan syndrome
mutations in TGF-B signaling
presence of major clone of cells in the bone marrow that have acquired somatic driver mutations in tumor suppressor genes
increases your risk for atherosclerosis
what is clonal hematopoiesis
when plaques form where there is turbulent flow (Ostia, branch points, and posterior wall of the abdominal aorta)
laminar flow leads to atheroprotective genes
what are observe hemodynamic factors
lipid aggregates in a developing atheroma
what are fatty streaks
what is an aortic dissection
blood enters and separated the laminar planes of the media to form a blood filled channel
who is most affected by an aortic dissection
90% are 40-60 yr old men with hypertension
rest are younger patients with CT abnormalities like marfans
what are some causes of an aortic dissection
catheterizations and cardiopulmonary bypass (iatrogenic)
pregnancy (vascular remodeling)
what are specific hypertensive related dissections
narrowing of vasa vasorum in aorta in hypertensive patients
can lead to intramural hemorrhage without intimal tear
what is type A debakey/sanford classification of aortic dissections
dissection of either ascending aorta or both ascending and descending
65-85% survival rate if treated
70% mortality rage with hemorrhage
what is a type B debakey/sanford classification
dissection of aorta distal to great vessels (descending aorta)
75% survival rate with treatment
what is vasculitis and what is it caused by
inflammation of vessel wall
caused by immune-mediated inflammation or vascular invasion by a pathogen
can also be caused by physical and chemical injury
what are the three main causes of immune complex associated vasculitis
autoimmune diseases (lupus and RA)
drug hypersensitivity (penicillin)
antigen-antibody immune complexes secondary to infections
what is giant cell (temporal) arteritis
chronic inflammatory disorder with granulomatous inflammation that affects large, medium, and small sized arteries in the head
T-cell mediated
what are the three common sites of giant cell arteritis
vertebral
ophthalmic
aorta
what is Takayasu arteritis
granulomatous vasculitis of medium and large arteries
ocular disturbances and weakening of pulses in upper extremities
what can temporal arteritis lead to
fragmented internal elastic membrane can lead to sudden permanent blindness
what is the most important diagnosis element in temporal arteritis
biopsy of temporal artery
how is takayasu aortitis diagnosed
aortic arch angiogram
cross section of carotid artery (shows thickening with white circles)
destruction and fibrosis of artery
what is polyarteritis nodosa (PAN)
-in which vessels is it mainly seen
vasculitis of small or medium muscular arteries
affects mostly young adults
affects renal and visceral vessels
1/3rd of patients have hepatitis B
what is Kawasaki disease
acute, self limiting illness of childhood (80%) that affects large and medium vessels
symptoms include: coronary artery aneurysms, fever, rash, edema, conjunctivitis, mucositis, and swollen lymph nodes
what is microscopic polyangiitis
necrotizing vasculitis that affect capillaries, arterioles, and venues
fibrinoid necrosis of media, no granulomatous inflammation
what is granulomatosis with polyangiitis (Wegener granulomatosis)
affects middle aged people - 80% mortality rate if untreated
characterized by caseating granulomas
necrotizing vasculitis caused by a triad of things
what are the three things that make up the triad that characterizes Wegener granulomatosis
necrotizing granulomas of the upper respiratory tract
necrotizing or granulomatous vasculitis affecting small/medium vessels
focal necrotizing glomerulonephritis
what is churg-strauss syndrome (allergic granulomatosis)
small vessel necrotizing vasculitis
seen as:
asthma
allergic rhinitis
lung infiltrates
what is thromboangiitis obliterans (buerger disease)
-which vessels does it mostly affect
segmental, thrombosis, acute and chronic inflammation of the medium and small arteries (tibial and radial)
seen mostly in heavy smokers before the age of 35 and certain ethnic groups (Israeli, Indian, Japanese)
what is infectious vasculitis
caused by bacterial or fungal infection that weakens arterial wall and becomes an aneurysm
can lead to sepsis or infective endocarditis embolus
what is a mycotic aneurysm
common pathological finding in a infectious arteritis case
caused by an infection that weakens arterial wall and results in this aneurysm
what is Raynaud phenomenon
vasoconstriction of arteries and arterioles, mostly occurring in the fingers and toes
extremities become pale and cyanotic
primary: cold or emotions
secondary: diseases such as SLE
what is a myocardial vessel vasospasm (cardiac Raynaud)
-what does it cause
artery spasms leading to constriction of blood flow
can cause, angina, MI, ventricular arrhythmias, or sudden death
causes takotsubo cardiomyopathy (broken heart syndrome)
what is another name for broken heart syndrome
takotsubo cardiomyopathy
what are varicose veins
dilated, tortuous veins caused by increased intraluminal pressures and weakened vessel wall support
mostly affects superficial veins
mostly affects women - 1/3
increased risk in those with obesity and who are pregnant
what are esophageal varices
varicose veins of the esophagus
caused by liver cirrhosis, portal vein obstruction, or hepatic vein thrombosis, all leading to portal vein hypertension
what does portal vein hypertension cause
esophageal varices in EGJ
caput medusae - periumbilical veins of the abdominal wall
what are caput medusae
appearance of distended and engorged superficial epigastric veins, which are seen radiating from the umbilicus across the abdomen
what is superior vena cava syndrome
advanced, T4 lesion that compresses or invades superior vena cava
ex. bronchogenic carcinoma or mediastinal lymphoma
causes dilation of veins in head, neck, and arms (cyanosis)
compresses pulmonary vessels leading to respiratory distress
what is inferior vena cava syndrome and which two tumors most commonly cause it
neoplasm that compresses or invades the inferior vena cava or by a thrombus from the hepatic, renal, or lower extremities
ex. hepatocellular carcinoma or renal cell carcinoma
leads to lower extremity edema, dissension of superficial veins of lower abdomen
proteinuria if renal vein is involved
what is vascular ectasia
local dilation of a vascular structure
ex. nevus flammeus
what is a nevus flammeus
type of vascular ectasia (local dilation of vascular structure)
birthmark (fades overtime) or
port wine stain (gets bigger and doesn’t fade)
what is telangiectasia
permanent dilation of preexisting small vessels that form a discrete red lesion
acquired: spider telangiectasia
what is a hemangioma
benign, blood filled vessel
two types: capillary or juvenile
what is a glomus tumor
nest of round cuboidal gloms cells around capillaries
seen in finger nail
solid type: benign but locally invasive
what is kaposi sarcoma
intermediate grade tumor caused by herpes virus 8
forms in tiny vessels below the skin and mouth, nose, ears, and anus
spreads to lungs, liver, stomach, intestine, and lymph nodes
those with HIV (AIDS) at higher risk
what is an angiosarcoma
malignant, endothelial neoplasm of the vessels
ranges from highly differentiated to widely anapestic lesions
5 year survival only 30%
what causes hepatic angiosarcomas
arsenic, thorotrast, and polyvinyl chloride
what vein is most commonly used for a coronary artery bypass
saphenous veins
what is the patency for left internal mammary artery grafts
90% at 10 years
