patho chapter 15: alterations in blood flow

what are the primary functions of the circulatory system?

-transportation of oxygen and nutrients

-removal of metabolic waste products

what does effective human operation depend on?

proper functioning of the circulatory system

what are the three distinct layers of blood vessels

tunica intima

tunica media

tunica adventitia

what is the anatomy of a capillary?

single layer of endothelial cells attached to a basement membrane

what determines a capillaries permeability?

the tightness of the endothelial cell connection

how do lymphatic vessels resemble veins?

they have thin walls and valves

what is the equation to calculate blood flow?

flow=pressure/resistance

what is the equation to calculate blood pressure?

flow (cardiac output) times resistance

what is the equation to calculate resistance?

resistance=pressure

/flow

how does the velocity of blood flow relate to the total cross-sectional area of the vascular bed?

the velocity of blood flow varies inversely with the total cross-sectional area of the vascular bed

what factors are considered in the hemodynamics of the circulatory system?

wall tension and compliance, as well as the dynamics in the microcirculation, including capillaries and lymphatics

what is laplace's law in the context of hemodynamics?

relates to wall tension and compliance in blood vessels, describing how tension in the wall of a vessel is related to the pressure and radius of the vessel.

what regulates blood flow centrally?

the autonomic nervous system

what regulates blood flow locally?

the organ or tissue

how do lymphatic vessels maintain flow?

by contracting when stretched with lymph

what prevents lymphatic backflow?

intraluminal valves

how does external compression affect lymph flow?

by contracting muscles to enhance lymph flow

what are some common obstructions that cause altered blood flow?

thrombus

embolus

vasospasm

inflammation

mechanical compression

what are two types of structural alterations that cause altered blood flow?

artherosclerotic plaques

aneurysms

what is the most common cause of chronic progressive arterial obstruction?

artherosclerosis

what are risk factors for arteriosclerosis/atherosclerosis?

smoking

hyperlipidemia

male gender

advancing age

sedentary lifestyle

obesity

glucose intolerance

family history of cardiovascular disease

what are symptoms of arteriosclerosis?

chest pain

blood clots

shortness of breath

heart failure

headache

how is arteriosclerosis treated?

change to low fat, high-fiber diet and increase exercise

what is thromboangiitis obliterans also known as?

buerger disease

what is thromboangiitis obliterans (buerger disease)?

a rare inflammatory condition affecting both small and medium size arteries and veins of the upper and lower extremities

what is raynaud syndrome?

extreme vasoconstriction producing cessation of flow to the fingers and toes

what does vasoconstriction associated with raynaud syndrome cause?

color changes

what are aneurysms?

bulging blood vessels that can burst (localized arterial dilations)

how are aneurysms classified?

true or false

what are the six Ps of acute arterial occlusion?

pallor

paresthesia

paralysis

pain

pulselessness

polar (cold to touch)

true or false-emboli (blood clots) are associated with acute arterial occlusion

true

what causes valvular incompetence in veins?

overstretching the valves due to excessive venous pressures

what are common clinical manifestations of venous insufficiency?

feeling of heaviness or tension

pruritus

edema and stasis dermatitis

ulcer formation

when might valcular incompetence occur?

obesity

pregnancy

right heart failure

prolonged standing

how is valvular incompetence treated?

exercise

medication

revascularization procedures

what are varicose veins?

superficial, darkened, raised, and tortuous (twisted) veins due to valvular incompetence involving superficial veins

what are the clinical manifestations of varicose veins?

aching

heavy discomfort

venous ulcers

how are varicose veins treated?

elevation

elastic stockings

exercise

weight loss

sclerotherapy

vein stripping

vein ligation

what are the clinical manifestations of chronic venous insufficiency?

edema

venous stasis ulcers

pain

when does chronic venous insufficiency result?

when valvular incompetence involves the deep veins of the legs

how is chronic venous insufficiency treated?

compression

true or false-upper extremities are more frequently affected by deep vein thrombosis

false; upper extremities are less frequently affected

what is deep vein thrombosis?

an acute venous obstruction (clot) that is most frequently secondary to a thrombus in a deep vein of the lower extremities

what are the clinical manifestations of deep vein thrombosis:

asymptomatic

edema

inflammation

dilated superficial veins

pain

why is deep vein thrombosis potentially life threatening?

because of the likelihood of embolization (blocking blood flow) to the pulmonary circulation

how is deep vein thrombosis treated?

aggressively with anticoagulants

what is lymphedema?

obstruction of lymph flow

what does lymphedema often result from?

the surgical removal of, or radiation damage to, lymphatic vessels during treatment of cancer

what are the clinical manifestations of lymphedema (lymphatic obstruction)?

regional edema

thickened subcutaneous tissue