Arterial and Venous Arterial and Venous SupplySupply

Types of Blood VesselsTypes of Blood Vessels

ArteryArtery – carry blood away from heart to – carry blood away from heart to arteriolesarterioles– ArteriolesArterioles – carry blood from arteries to – carry blood from arteries to

capillaries. capillaries. ““Resistance VesselsResistance Vessels”” VeinVein – carry blood to the heart from the – carry blood to the heart from the

– VenulesVenules-Acts as collector and reservoir -Acts as collector and reservoir vessels. vessels. ““Capacitance VesselsCapacitance Vessels””

Capillaries Capillaries – carry blood from Arterioles – carry blood from Arterioles to Venules.to Venules.

Artery Artery Arterioles Arterioles Capillaries Capillaries Venules Venules Veins Veins

Structure of Blood VesselStructure of Blood Vessel

Three layers for both arteries and Three layers for both arteries and veinsveins

Tunica adventitiaTunica adventitia Tunica mediaTunica media Tunica intimaTunica intima

Tunica AdventitiaTunica Adventitia

Outermost layer Outermost layer Flexible Fibrous Connective TissueFlexible Fibrous Connective Tissue Helps hold vessel openHelps hold vessel open Prevents tearing of vesselPrevents tearing of vessel In veins – thickest layerIn veins – thickest layer In arteries – middle layer is thickerIn arteries – middle layer is thicker

Tunica MediaTunica Media

Middle layerMiddle layer Made of smooth muscle with a layer Made of smooth muscle with a layer

of elastic connective tissueof elastic connective tissue Allows blood vessel to change Allows blood vessel to change

diameterdiameter Thicker in Arteries than in veinsThicker in Arteries than in veins

Tunica IntimaTunica Intima

Inner most layerInner most layer Made of endotheliumMade of endothelium In arteries – smooth liningIn arteries – smooth lining In veins forms semilunar valvesIn veins forms semilunar valves

CapillariesCapillaries

Only one layer – EndotheliumOnly one layer – Endothelium One layer allows for diffusion One layer allows for diffusion

between plasma and interstitial fluidbetween plasma and interstitial fluid Function in delivery and collection of Function in delivery and collection of

substances – substances – ““Exchange VesselsExchange Vessels””

Control of Blood FlowControl of Blood Flow

Precapillary sphincters – circular, valve-Precapillary sphincters – circular, valve-like muscle at arteriole-capillary like muscle at arteriole-capillary junctionjunction

Vasoconstriction – narrowing blood Vasoconstriction – narrowing blood vessel’s lumen (“passageway”vessel’s lumen (“passageway”

Vasodilation – explanding bloodVasodilation – explanding blood

  vessel’s lumenvessel’s lumen

Blood FlowBlood Flow

Blood flow through veins – not very Blood flow through veins – not very efficient. Slow, weak “pushing” by arterial efficient. Slow, weak “pushing” by arterial blood pressure is not much of a factor at blood pressure is not much of a factor at all. Important factors include: all. Important factors include:

1. Contraction of the diaphragm. 1. Contraction of the diaphragm.

2. Pumping action of the skeletal muscles. 2. Pumping action of the skeletal muscles.

3. Valves in the veins.3. Valves in the veins.

Circulatory RoutesCirculatory Routes Systemic Circulation – blood flows Systemic Circulation – blood flows

from the left ventricle of the heart from the left ventricle of the heart through blood vessels to all parts of through blood vessels to all parts of the body, excluding lungs, and back to the body, excluding lungs, and back to the right atrium.the right atrium.

Pulmonary Circulation – Venous blood Pulmonary Circulation – Venous blood moves form right atrium to right moves form right atrium to right ventricle to pulmonary artery to lung ventricle to pulmonary artery to lung capillaries where gas exchange occurs, capillaries where gas exchange occurs, then returns to left atrium and left then returns to left atrium and left ventricle.ventricle.

Some Major Some Major ArteriesArteries Carotids (Common, Internal and External)Carotids (Common, Internal and External) SubclavianSubclavian BrachiocephalicBrachiocephalic BrachialBrachial RadialRadial UlnarUlnar CoronaryCoronary CeliacCeliac SplenicSplenic RenalRenal Mesenteric (Inferior and Superior)Mesenteric (Inferior and Superior) Abdominal AortaAbdominal Aorta Iliac (Common, Internal and External)Iliac (Common, Internal and External) FemoralFemoral PoplitealPopliteal Tibial (Anterior and Posterior)Tibial (Anterior and Posterior)

Some Major Some Major VeinsVeins FacialFacial Jugular (External and Internal)Jugular (External and Internal) BrachiocephalicBrachiocephalic SubclavianSubclavian CephalicCephalic AuxiliaryAuxiliary Vena cava (Superior and Inferior)Vena cava (Superior and Inferior) PulmonaryPulmonary Cardiac (Great and Small)Cardiac (Great and Small) BasilicBasilic Hepatic and Hepatic portalHepatic and Hepatic portal SpleenicSpleenic Mesenteric (Inferior and Superior)Mesenteric (Inferior and Superior) Iliac (Common, External and Internal)Iliac (Common, External and Internal) FemoralFemoral Saphenous (Great and Small)Saphenous (Great and Small) PoplitealPopliteal Tibial (Anterior and Posterior)Tibial (Anterior and Posterior)

Sites To Take PulseSites To Take Pulse

Temporal ArteryTemporal Artery Facial ArteryFacial Artery Common Carotid ArteryCommon Carotid Artery Brachial ArteryBrachial Artery Radial ArteryRadial Artery Femoral ArteryFemoral Artery Popliteal ArteryPopliteal Artery Posterior Tibial ArteryPosterior Tibial Artery Dorsalis Pedis ArteryDorsalis Pedis Artery

Aneurysm Aneurysm

An aneurysm is An aneurysm is a balloon-like a balloon-like bulge in an bulge in an artery. artery.

http://www.nhlbi.nih.gov/health/dci/Diseases/arm/http://www.nhlbi.nih.gov/health/dci/Diseases/arm/arm_types.htmlarm_types.html

StentsStents A stent is a wire metal A stent is a wire metal

mesh tube used to prop mesh tube used to prop open an artery during open an artery during angioplasty. angioplasty.

The stent is collapsed to a small diameter and The stent is collapsed to a small diameter and put over a balloon catheter. It's then placed into put over a balloon catheter. It's then placed into the area of the blockage. Then the balloon is the area of the blockage. Then the balloon is inflated, the stent expands, locks in place and inflated, the stent expands, locks in place and forms a scaffold. forms a scaffold.

The stent stays in the artery permanently, holds The stent stays in the artery permanently, holds it open, improves blood flow to the heart muscle. it open, improves blood flow to the heart muscle. 

Within a few weeks the inside lining of the artery Within a few weeks the inside lining of the artery grows over the stent. grows over the stent. http://www.americanheart.org/presenter.jhtml?identifier=4721http://www.americanheart.org/presenter.jhtml?identifier=4721

Stent VideoStent Video

Video Showing a Stent and Angioplasty (Mayo Clinic)(Mayo Clinic)