Chapter 19 Flashcards
_____ in all blood vessels - opening that is in contact with blood
Lumen
Three layers of all blood vessels except capillaries
Tunica intima, tunica media, tunica externa
Tunica Intima
Simple squamous endothelial cells tightly packed in order to reduce friction as blood passes through
Tunica Media is the ______ layer consisting of circular layers of ____ ______ ______ with elastin fibers
Middle, Smooth muscle fibers
Tunica media is innervated via the ______. They have the ability to ______. Has a very large influence of blood pressure and flow
Sympathetic Nervous System. Vasoconstrict
Tunica Externa is the _____ layer consisting mainly of loosely woven cologne fibers. Contain small blood vessels within the layer called ____ ________
Outermost, Vasa Vasorum
Three types of arteries
Elastic arteries, muscular arteries, arterioles
Elastic arteries are the ____ of the 3 types. Closest to the _____. Largest elastic composition. Largest opening, therefore, ___ _______. Referred to as ______ ________
Largest. Heart. Low resistance. Conducting arteries.
Muscular arteries have _____ size lumen. Most ______ (thickest tunica media). Highly responsible for _____ ______ via sympathetic nervous system causing either vasoconstriction or vasodilation. Sometimes called ______ arteries
Medium. Muscular. Blood shunting. Distributing.
Arterioles are the _____ of the arteries. Some have _ layers but smallest ones just before the capillaries have only one. Sometimes called ________ vessels. When they constrict they ______ capillaries. When they dilate they increase ______ ____ to capillaries
Smallest. 3. Resistance. Bypass. Blood flow.
Capillaries are only ___ layer thick (tunica intima). Only allow 1 ___ to pass through at a time
One. RBC.
Pericytes are a ____ ______ location on outside of some capillaries. Can help control ______ of capillaries
Spider shaped. Permeability.
Capillaries consist of ____ _____ that hold together endothelial cells. Breaks in the tight junctions are called ________ ______ which allow fluid passages/permeability.
Tight junctions. Intercellular clefts.
Three types of capillaries
Continuous, fenestrated, sinusoid
Continuous is the _____ permeable/fewest intercellular clefts, with pericytes. Abundant in _____, ____ and _____
Least. Skeletal muscle, skin lungs.
Fenestrated is an ____ ______ area.
Active filtration
Sinusoid are located in the _____, _____, and ____ medulla. ____ _____ in the endothelial layer. Large intercellular clefts. Large irregularly shaped ______
Liver, spleen, adrenal medulla. Large holes. Lumen.
Blood flow =. Blood flow also =
Change in pressure divided by resistance. Cardiac output
Resistance =
Length of blood vessels x blood viscosity / radius4
Systolic blood pressure is
Pressure on artery walls during ventricular contractions
Diastolic blood pressure is
Pressure on artery walls while heart is at rest
Pulse pressure is
The difference between systolic and diastolic
Three components of venous return
Muscle pumps, respiratory pumps, sympathetic venoconstriction
Muscle pumps work as
Muscles contract they squeeze veins forcing the blood upward to the right atrium
Respiratory pumps
When inhaling, abdominal pressure increases while thoracic pressure decreases forcing the blood up into the right atrium
Sympathetic venoconstriction
Sympathetic nervous system signals the smooth muscle to contract, thus inducing venoconstriction. Stiffens veins meaning they are unable to pool / clot.
Cardiac output =
Heart rate x Stroke volume
Increasing heart rate = increasing ______. Increasing stroke volume = _______
Cardiac output.
Three main factors regulate blood pressure
Cardiac output, peripheral resistance, blood volume.
