Chapter 7 Flashcards
vascular system is composed of..
- blood vascular system
- pulmonary artery caries deoxygenated blood
- arteries carry blood away from heart, veins carry blood to the heart
tunica intima
- innermost layer
- made up of endothelial cells
tunica media
- middle layer
- smooth muscle
tunica adventita
- outer layer
- connective tissue
capillaries only contain which layer?
tunica intima because they’re site of exchange and need thin walls
blood pressure
pressure exerted on vessel walls
blood pressure is determined by ..
- amount of blood flowing through vessels
- resistance of vessels to blood flow
normal blood pressure
- maximum systolic pressure = 120 (heart contracting, # on top)
- lowest diastolic pressure = 80 (heart relaxed, # on bottom)
capillaries
vessels lying between arteries and veins
what are capillaries function?
- regulate fluid, electrolyte, and nutrient exchange between blood and extracellular space
- can proliferate to help repair injured areas
what are factors mediating exchange of nutrients across capillaries?
- hydrostatic pressure (due to fluid)
- osmotic pressure (determined by amount of protein in fluid)
- integrity of endothelial cells
what is the fluid that leaks out of vessels into the interstitial space?
lymph: composed primarily of water, proteins and WBC (excess picked up by lymphatic vessels)
edema
fluid in interstitial space, accumulation of fluid in tissues
what can lead to edema/effusion?
alterations in pressures and or vessels
effusion
accumulation of fluid in body cavities
what are the most common causes of edema?
- increase in hydrostatic pressure (more blood leaks out)
- decrease in osmotic pressure (less albumin decreases fluid inside)
pathogenesis of edema
- increased capillary permeability (causes swelling of tissues with acute inflammation)
- low plasma proteins (excess protein loss/kidney disease, inadequate synthesis/malnutrition)
- increased hydrostatic pressure (heart failure, localized venous obstruction)
- lymphatic obstruction (cancer)
clinical aspects of edema (always pathological)
- edema is result of underlying disease
- range from mild to severe
- can be fatal (cerebral or pulmonary edema)
ascities
swelling in the abdomen
anasarca
whole body, severe generalized edema
most frequent serious problems
- edema
- atherosclerosis
- hypertension
- thrombus
- varicose veins
- shock
signs/symptoms of serious problems
- visual local swelling or puffiness
- dizziness (low BP)
- headaches (high BP)
tests of serious problems
- percussion to detect fluid in pleural cavity
- sphygmomanometer for blood pressure
- angiography evaluates arterial integrity
- x ray (looks for effusion)
angiography
inject dye and x ray to look at arteries
specific diseases
- genetiic/developmental disease
- atherosclerosis
- hypertension
- thrombus or thrombophlebitis
- varicose veins
- neoplasm
- organ failure
congenital diseases are..
hormonal
hemangioma (not cancerous)
local proliferations of capillaries, common in skin
lymphangioma
dilated masses of lymphatics
arteriosclerosis
hardening of arteries
atherosclerosis
plaque in heart arteries, inflammatory/degenerative disease, accumulation of fatty deposits and scar tissue in intima
what does atherosclerosis lead to?
obstruction of lumen and weakening of wall of vessel
pathogenesis of atherosclerosis
- endothelial injury (increased permeability, macrophage migration, induction of smooth muscle cell proliferation)
- leads to lipid accumulation
causes of fatty streaks
- high BP
- increase blood glucose
- increased lipids
- smoking
fibrous cap
atheroma
plaques can cause harm by..
- narrowing lumen causing ischemia in tissue
- weaken a vessel wall, forming an aneurysm
- rupture and expose collagen that forms a thrombus
rupturing of a plaque can..
- occlude the artery and cause tissue infarction
- tissue die because of rupture
- heart attacks happen quickly because of thrombus
development of atherosclerosis
- begins in childhood
- asymptomatic for many years
- clinical appearance in 6th decade (doesn’t manifest until then)
complications of atherosclerosis
- coronary arteries: narrowing of lumen and heart attacks
- abdominal aorta: asymptomatic, aneurysm
- arteries of lower limbs: intermittent claudication and ulcers
major risk factors of atherosclerosis
- elevated blood lipids (too much cholesterol or LDL)
- hypertension
- cigarette smoking
- diabetes
- obesity
minor risk factors of atherosclerosis
- age
- gender
- stress
- family history
what can detect atherosclerosis?
angiogram
atherosclerosis treatment
- preventing further lesions and preventing growth of existing lesions
- taking care of complications as they arise
- plaques get bigger
- exercise
organs effected by hypertension
- kidneys (failure)
- heart (has to work harder)
- blood vessels
- brain (stroke)
aortic dissection
- hypertension complication
- rapidly fatal, decreases blood flow to aorta
aortic dissection symptoms
- ripping sensation in chest
- dizziness
etiology of aortic dissection
- primary = idiopathic or essential
- secondary = secondary to something else
hypertension treatment
- increase PA
- diet (reduce salt, increase fruits and veggies)
- medications
diuretics
reduces blood volume
angiotensin-converting enzyme
(ACE) inhibitors
thrombus
abnormal intravascular clot, can occur in any vessel or within the heart
embolus
detached clot carried into pulmonary or systemic circulation (travels)
- plugs vessel of smaller diameter, blocking blood flow and causing necrosis
thrombophlebitis
inflammation of a vein due to thrombus, clot formation in deep leg veins can cause pulmonary embolism
causes of venous thrombus
- prolonged bed rest
- cramped position for an extended period
- genetic factors
varicose veins
dilated, tortuous veins
sites of varicose veins
- anus: hemorrhoids
- legs due to prolonged standing
etiology oof varicose veins
incompetent valves
are varicose veins common?
yes, tend to run in families, people on feet a lot (gravity pulls blood down)
complications of varicose veins
- pain
- visibility of vein
treatment of varicose veins
make a snip in skin and pull vein out
shock
failure too maintain adequate blood pressure by the heart (drives blood flow)
shock manifestations
- decreased blood pressure
- increased heart rate
- decreased urine output
- altered states of consciousness (dizzy/light headed)
cardiogenic shock
- pump failure
- LV not pumping blood to other organs
- heart attacks can cause this
- cannot maintain perfusion pressure
hemorrhagic shock
decreased blood volume
anaphylactic shock
- reaction to something
- immune system overdrive
- vasodilation increases
septic shock
- systemic bacterial infection
- leads to massive vasodilation (decreased BP)
- multi-organ failure
shock treatment
- removed causing agent
- fluids
- vasoconstricting agents
- antibiotics
- surgically repair bleeding arteries
neoplastic disease
rare, blood vessel cancers
