end of unit 4 beginning of unit 5 module 2

Fibrillation

cardiac muscle tissue “quivering”

A-fib

caused by prolonged use of steroids, makes clot formation not occur as well

defibrillation

when an electrical current is applied other the heart to “reset” conduction of the current

what causes Dysrhythmia

scar tissue from myocardial infarction, CAD, acidity/acidosis

order of blood flow leaving the heart

LV - arteries - arterioles - metarterioles - capillaries - venues - veins - RA

Arteries

thick layer of smooth muscle

Arteries have () stimulation from the SNS = vasoconstriction

increased

Arteries have () stimulation from the SNS = vasodilation

decreased

compliance

walls will expand with applied pressure without being damaged. especially the aorta, subclavian. Helps to keep blood moving as they recoil

Arterrioles

smooth muscle in the wall of the vessel. Is important for regulation blood flow into the capillaries. influences blood pressure

Metarterioles

positioned between the arterioles and capillaries, have very little smooth muscle

Capillaries

exchange of gases and nutrients between the blood and tissue occurs, endothelium only one cell thick, contains precapillary sphincters, open/closes to regulate blood flow

pre-capillary sphincters

ring of smooth muscle

venues

small veins, a collection of capillaries flowing into one another, carry blood toward heart

veins

not as elastic, thinner walls, larger lumen, have valves, blood reservoir

2/3 of blood in your body is located in your

veins

The CVC in the medulla will stimulate

vasoconstriction of the veins in times of increased demand (exercise, blood loss)

what also acts as blood reservoirs

liver and spleen

varicose veins are

caused by the failure of the distal and proximal valves. Can be induced by standing or sitting all day or being pregnant

venous return

the volume of blood returning to the right atrium

Venous return is largely determined by

blood pressure

the pressure in the right atrium is referred to as

central venous pressure

if BP is so low in the veins how does the blood return to the heart

Through the valves, surround skeletal muscle tissue contraction, these two working together is know as “milking”

Left ventricle continues to eject blood (closed circuit which means it helps to push good through)

arteries are () than veins

more oxygenated

veins are () than arteries

less oxygenated

blood pressure

hydrostatic pressure exerted by blood on the vessel walls. decreases as blood flows through the systemic circulation. is at its lowest in the vena cava

BP is influenced by

Cardiac output (CO=SVxHR) if cardiac output increases, () also increases

vascular resistance

opposition to blood flow

what increases blood volume

polycythemia

if BLOOD VOLUME increases, resistance

increases

if resistance in blood volume increase then the BP

increases

blood viscosity

if () increases resistance then BP increases as well

Vessel diameter

if blood () decreases (vasoconstriction) resistance increases. If that increases then BP increases as well