Exam 3: Sec. 4: Vascular Pathologies Pt1 Flashcards
What are more common and cause more serious/clinically significant signs/symptoms, venous pathologies or arterial pathologies?
arterial pathologies
What are the two main mechanisms that vascular pathologies involve?
- Narrowing or Obstruction of the lumen
2. Weakening of the Vessel wall
What are the two ways that Narrowing or Obstruction of the lumen may occur?
- Gradual = atherosclerosis or thickening of tunica intima after prolonged injury
- Rapid = Thromboembolism
How may Weakening of the vessel wall occur?
following a congenital defect–> may be ass. with CT disorder
Dilation –> aneurysm
Rupture–> dissection
What is the thickening and hardening of the walls of the arteries?
Arteriosclerosis
What is a form of arteriosclerosis whereas the hardening of the arterial walls is the result of atherosclerotic plaque deposition?
Atherosclerosis
What is a tear along the inside of an artery called?
dissection
What is a blood clot that forms within the vascular lumen, which impeded blood flow?
Thrombus
What is the similar organization along all arteries and veins?
tunica intima
tunica media
tunica adventitia
When it comes to the three layers or vessels, describe the difference b/w arteries and veins.
arteries have thick of tunica media (smooth muscle)
veins have relatively thin layers of smooth musculature, AND contain valves
Why are arterial walls thicker than the walls of veins?
to accomodate pulsation and higher BP
What are small arteries that are the primary sites for blood pressure regulation and what does it ultimately regulate?
arterioles
via vasodilation or vasoconstriction –> regulates peripheral resistance
T/F. Veins are thin-walled vessels that hold larger volumes of blood than arteries, but are more easily compromised, dilated, and invaded by inf. microbes or tumors
True
What are examples of large elastic arteries?
- aorta
- vessels branching from aortic arch
- iliac arteries
- pulmonary arteries
What are examples of medium-sized muscular arteries?
coronary arteries, renal arteries
What are examples of small arteries and arterioles?
various small arteries throughout body which are located just before body’s many capillary beds
How do small or thin-walled vessels get their nutrient supply?
nutrients and oxygen may diffuse from w/in arterial lumen to entire vascular wall
How do thick-walled arteries, such as large and medium-sized arteries get their nutrient supply?
Tunia intima and inner 1/2 of tunica media–> diffusion from blood w/in lumen
Outter 1/2 of tunica media and tunica adventitia–> nutrients delivered from vasa vasorum
What cells make up the inner lining of all blood vessels and lymphatic vessels?
Endothelial cells
How are endothelial cells organized?
single-layer that creates a “non-thrombogenic blood-tissue interface”
What three things are endothelia cells involved in?
modulating - intravascular inflammatory responses
- assist in regrowth and repair of injured smooth muscle cells w/in tunica media
- secrete vasoactive substances (NO, Endothelin)
What are the vasoactive substance that endothelial cells release? How do they affect the vessel?
Nitric oxide–> potent vasodilator
Endothelin–> potent vasoconstrictor
What do we call when the endothelial lining is injured or irritate and an inflammatory response is initiated?
endothelial activation
What may cause endotheial activation?
- microbial infs
- hypoxia
- hemodynamic stress
- diabetes mellitus
- inflam. cytokines
- high cholesterol levels
- activated compliment system
- chemicals from tobacoo smoke
What are the three more common or unique vascular congenital anomilies we are focusing on?
- Saccular Aneurysm
- Arteriovenous (AV) Fistula
- Fibromuscular Dysplasia
What are the most common form of cerebrovascular malformation?
intracranial Saccular Aneurysm (“berry” aneurysms)
Where are saccular aneurysm most likely to develop?
branch points on Circle of Willis
What are saccular aneurysms at risk of doing and causing what?
rupturing and causing a subaracnoid hemorrhage–> “thunderclap” HA
What are patients that develop saccular aneurysms believe to have? What other disease is ass.?
born w/ congenitally weak spots w/in tunica media of intracranial vessels
ass. with Polycystic kidney disease
What is an Arteriovenous (AV) Fistula?
fistula = abnormal connection b/w medium-to-large artery and vein and blood bypasses the related capillaries
How does one acquire an Arteriovenous Fistula?
- may be congenital vascuarl anomalies
- may be traumatically acquired from a penetrating injury
What is a lethal complication of large Arteriovenous (AV) Fistulas?
High-Output Heart Failure
What is High-Output Heart Failure?
- -> occurs when large volumes of oxygenated arterial blood is returned to the heart and lungs
- bypassing capillaries causes HR to increase
- sets up positive feedback loop–> eventually causing heart to fail
What condition is when the tunica media and tunica intima of medium-sized arteries become overgrown, due to hyperplasia and fibrosis?
Fibromuscular Dysplasia
Where is the most common place for Fibromuscular Dysplasia to occur? What percent of all cases does this occur in? What may it stimulate?
MC renal artery –> 75%
may stimulate–> Renovascular hypertension
What features and symptoms to inds with Fibromuscular Dysplasia have?
--most asymptomatic But may have: - HA - light-headedness - vertigo - transient neurological deficits - unexplanted HTN
What age is Fibromuscular Dysplasia MC discovered in?
MC in young women (reproductive age)
What is a relatively rare form of HTN that develops following ischemia to a kidney?
Renovascular Hypertension
How does Renovascular Hypertension develop from a kidney detecting hypoxia?
reduced blood supply activated
“renin-angiotensin-aldosterone system (RAAS)”–> retain Na+ and water and increase total blood volume
- arterioles vasocontrict
= BP rises
What will the managment of Renovascular Hypertension from Fibromuscular dysplasia involve?
- surgical correction
- antihypertensive meds
- even removal of involved kidney
What is the term for regulating blood pressure w/in a narrow range of what is normal ?
normotension
What is BP the result of?
What is CO the resutl of?
BP = CO x PVR (peripheral vascular resistance)
CO = HR x SV
How is the peripheral vascular resistance primarily regulated?
by body’s arterioles
What other factors influence the blood pressure regulation?
- heart
- kidneys
- lungs
- adrenal glands
What is low blood pressure known as? What is it defined as?
hypotension = BP that is less than 90/60 mm Hg
What is a hypotension a feature of all forms of?
shock
What is high blood pressure known as?
Hypertension (HTN)
What BP does High BP Stage 1 begin at?
at or above 130/80 mm Hg
What BP is:
- Normal
- Elevated
- High BP Stage 1
- High BP Stage 2
- Hypertensive Crisis
- less than 120/80
- 120/ less than 80
- at or above 130/80
- at or above 140/90
- at or above 180/120
How is the myocardium involved in BP regulation? Stimulus? Response? Effect?
Stimulus = increase BP Response = secrete ANP (atrial natriuretic peptide) Effect = increase exretion of Na+/H2O (reduce BP), and vasodilation
How are the kidneys involved in BP regulation? Stimulus? Response? Effect?
Stimulus = low BP Response = secrete renin (actiavte RAAS) Effect = Renin interacts with liver
How is the liver involved in BP regulation? Stimulus? Response? Effect?
Stimulus = exposed to renin Response = renin cleaves angiotensinogen to angiotension I Effect = angiotension I interacts with lungs
How are the lungs involved in BP regulation? Stimulus? Response? Effect?
Stimulus = exposure to angiotensin I Response = ACE enzyme converts angiotensin I into II Effect = angiotensin II interacts w/ adrenal galnds and stimulates vasocontriction
How are the Adrenal Glands involved in BP regulation? Stimulus? Response? Effect?
Stimulus = Exposure to angiotensin II Response = secrete aldosterone Effect = cause kidney to increase Na+/H2O resorption which increases blood vol.
What are the genetic risk factor to developing HTN?
- having family history
- identical twin with HTN
- being African American
- inds. with Polycystic Kidney disease
What are env. risk ractors for HTN?
- psychological stress
- obesity
- physical inactivity
- consumption of high salt diet
- drinking too much alc
- diabetes mellitus
- smoking tobacco
What is referred to as the “silent killer”? Why?
Hypertensive Vascular Disease (HTN, high BP, HBP)
– b/c patients are most likely asymptomatic for many years as condition progresses
What will about 50% of inds with prolonged HTN suffer from?
What will about 33% suffer?
lethal ischemic heart disease (i.e. MI, CHF)
lethal cerebral infarction
What conditions are associated with HTN?
- atherosclerosis
- coronary artery disease
- CHF
- cardiac hypertrophy
- Cerebral infarction
- aortic dissection
- renal failure
- arteriolosclerosis
- MI
- vascular dementia
- Primary brain parenchymal hemmorrhage
- HTN retinopathy
What represents ~90% of all cases of HTN?
Essential HTN (Primary HTN or idopathic HTN) --age-related
What is Essential Hypertension?
cases of HTN that are NOT attributable to any other known pathology
–age-related disease
What is the term for a known cause of HTN? What may it develop following?
Renovascular Hypertension
- -May Develop following:
- any form of renovascular disease
- fibromuscular dysplasia
- polyarteritis nodosa (involve renal artery)
What is a rare form of HTN involving extreme elevations in BP (>180/120 mm Hg) and end organ damage? What percent of all HTN does it represent?
Malignant Hypertension
~1%
What organs are most likely to be damaged by Malignant HTN?
- CNS
- cardiovascular system
- renal system
What may Malignant HTN cause?
- cerebral infarction
- cerebral edema
- intracranial hemorrhages
What is a component of Malignant HTN that involves the swelling of optic disc and indicates presence of increased ICP?
Papilledema
What does Malignant HTN frequently manifest with?
- retinal hemorrhages
- kidney damage
What is an adrenal gland tumor that may cause episodic spikes in BP?
Pheochromocytoma
– a neuroendorine tumor composed of abnormal chromaffin cells that secrete catecholamines
What does the circulating catecholamines from Pheochromocytoma cause episodic features of?
- HBP
- HA
- tremors
- sweating
- tachycardia
- temporary cardiac arrhythmias
What episodes of HBP from Pheochromocytoma are a risk factor for what?
HTN-related conditions such as:
- MI
- cerebral infarction
- renal failure
What percentage of cases is Pheochromocytoma malignant in? Can it be cured?
~10% and may be cured following surgical removal
What are some things that can cause injury to the tunica intima?
- mechanical trauma
- immunological injury
- hemodynamic stressors (prolonged HTN or turbulent blood flow)
- septic inf
- toxic expsure (tobacco, oxidized lipids)
What is the nonspecific response the vascular wall has to all forms of injury?
- thickening of the tunica intimal (internal thickening) –> narrows intravascular lumen–> inhibits blood flow through involved vessel
- -> cause sig. vascular stenosis, end-organ damage, and inhibited vasoreactivity
T/F. After vascular wall injury and thicking of the tunica intima, the body can heal and the vessel can go back to normal.
False– usually the damage is irreversible and is unlikely to return to pre-injured state
T/F. Arteriosclerosis does not suggest a cause of the hardening and is purely descriptive.
True
= hardening of arterial wall and loss of elasticity
What are the three main causes of arterioslcerosis?
- Arteriolosclerosis
- Monckenberg Medial Sclerosis
- Atherosclerosis
What is a form of arteriosclerosis that is specifically describing a hardening of the small arterioles?
Arteriolosclerosis
What is Arteriolosclerosis typically the result of?
- HTN
- diabetes mellitus
What are two distinct forms of arteriolosclerosis that we talk about?
- Hyaline arteriolosclerosis
2. Hyperplastic arteriolosclerosis
What develops following prolonged period of low-level hypertension (benign HTN) or diabetes mellitus and produces a homogenous “pink” thickening detected upon cross section?
Hyaline arteriolosclerosis
What does Hyaline arteriolosclerosis cause? What is it characteristically ass. with?
significant stenosis of involved arterioles
ass. w/ kidney damage and kidney failure
What type of arteriolosclerosis develops following periods of severe blood pressure elevation (malignant HTN)?
Hyperplastic arteriolosclerosis
What is characteristic to Hyperplastic arteriolosclerosis that is detectable on a cross section?
produces a layered or “onion skin” thickening
What does Hyperplastic arteriolosclerosis cause? What is it characteristically ass. with?
vascular stenosis
ass. wth kidney damage and kidney failure
(same as Hyaline arteriolosclerosis)
What is a form of arteriosclerosis that characteristically involves the deposition of calcium ions w/in the tunica media of medium-to-large arteries?
Monckeberg Medial Sclerosis
Monckenberg’s arteriosclerosis, Monckenberg’s sclerosis, medial calcific sclerosis
What age group is Monckeberg Medial Sclerosis limited to?
older adults, beginning at age 50
T/F. Monckeberg Medial Sclerosis causes vascular stenosis and clinically significant features.
FALSE– it does NOT produce vascular stenosis and it does NOT cause clinically sig. features
How is Monckeberg Medial Sclerosis usually detected?
incidental finding that appears on advance imaging (mammography or X-ray)
What causes the vast majority of all cases of arteriosclerosis? (the MC cause)
Atherosclerosis (info in neck deck of notecards)