chap 7 Flashcards
blood pressure determined by
amount of blood flowing through vessels, resistance of vessels to blood flow
capillaries
vessels lying between arteries and veins, consist of only an intimal layer, regulate fluid, electrolyte, and nutrient exchange between blood and extracellular space, can proliferate to help repair injured areas
factors mediating exchange of nutrients across capillaries
1) hydrostatic pressure
2) osmotic pressure determined by amount of protein in fluid
3) integrity of endothelial cells
edema
alterations in pressures and or vessels can lead to edema and effusion
- accumulation of fluid in tissues
most common causes of edema
increase in hydrostatic pressure or decrease in osmotic pressure
effusion
accumulation of fluid in body cavities
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
clinical aspects of edema
result of underlying disease
can range from mild to severe and can be fatal
signs, symptoms and tests
visualize localized swelling or puffiness, percussion to detect fluid in pleural cavity, sphygmomanometer for blood pressure, angiography, x-ray
dizziness or headaches
hemangioma
local proliferations of capillaries
lymphangioma
dilated masses of lymphatics
arteriosclerosis
hardening of arteries
artherosclerosis
inflammatory/degenerative disease
- accumulation of fatty deposits and scar tissue in intima of large and medium sized arteries
- atheroma
- plaque
leads to
- obstruction of lumen
- weakening of wall of vessel
pathogenesis of atherosclerosis
endothelial injury leads to endothelial dysfunction
- increased permeability
- macrophage migration
- induction of smooth muscle cell proliferation
atherosclerotic plaques can cause harm by:
- narrowing lumen, causing ischemia in tissue
- weaken a vessel wall, forming an aneurysm, plaque can rupture and expose collagen that forms a thrombus which then can occulde the artery and cause tissue infarction
atherosclerosis of coronary arteries
narrowing of lumen
heart attack
atherosclerosis of abdominal aorta
asymptomatic, but can cause complications such as an aneurysm
atherosclerosis risk factors
major
- elevated blood lipids
- hypertension
- smoking
- diabetes
-obesity
minor
- age
-gender
-stress
- family history
treatment of atherosclerosis
involves preventing further lesions and preventing growth of existing lesions
- taking care of complications as they arise
organs affected by hypertension
kidneys, heart, blood vessels, brain
hypertension complications: aortic dissection
rapidly fatal
symptoms: ripping sensation in chest, dizziness
hypertension treatment
increase physical activity
diet
- reducing salt
- increasing fruits and veg
medication
- diuretics
- angiotensin-converting enzyme inhibitors
thrombus
an abnormal intravascular clot; can occur in any vessel or within the heart
embolus
a detached clot carried into pulmonary or systemic circulation
- plugs vessel of smaller diameter, blocking blood flow and causing necrosis
venous thrombosis
thrombophlebitis
- clot formation in deep leg veins
causes
- prolonged bed rest
- cramped position for an extended period
varicose veins
dilated, tortuous veins, sites: anus, legs
etiology = incompetent valves
common
- tend to run in families
- people who are on their feet a lot
complications
- pain
- visibility of vein
shock
failure to maintain adequate blood pressure
- manifested by:
decreased blood pressure
increased heart rate
decreased urine output
altered states of consciousness
- often fatal
cardiogenic shock
pump failure, cannot maintain perfusion pressure
hemorrhagic shock
decreased blood volume
sepsis
- systemic bacterial infection
- leads to massive vasodilation
treatment for shock
removing inciting agent if possible, fluids, vasoconstricting agents, administer antibiotics, surgically repair bleeding arteries
