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Circulatory System

The cardiovascular system


intima, media and adventiva

What are the layers of a blood vessel for both arteries and veins?


the inner most layer of a blood vessel; including the endothelial lining of the vessel and an underlying layer of connective tissue that contains elastic fibers (THE ELASTIC MEMBRANE IS ONLY IN ARTERIES)


The middle layer of a blood vessel; including sheets of smooth muscle tissue. In arteries you will find thin bands of elastic fibers and on the outer edge of the media you will find an external elastic membrane


the outermost layer of a blood vessel; composed mainly of collagen fibers.
>In arteries you will find scattered bands of elastic fibers
>this layer is usually thicker in veins

1. Walls of arteries are thicker than those of veins.
>The media of artery contains MORE smooth muscle and elastic fibers than does that of a vein.

2. Arterial walls contract. for this reason they may appear smaller, this is because they hold there shape better than veins. they are thick and strong. veins, when cut tend to collapse where as arteries hold there shape.

3. the endothelial wall of arteries does not contract which gives it a pleated/folded look.

What are three differences in veins and arteries?


What are three types of arteries?

Elastic arteries (conducting arteries)

--Large vessels (e.g., pulmonary trunk and aorta)
--Tunica media has many elastic fibers and few muscle cells
--Elasticity evens out pulse force
--transport large volumes of blood away from the heart.

Muscular arteries (distribution arteries)

--Are medium-sized (most arteries)
--Tunica media has many muscle cells
--Transport blood to the body's skeletal muscle and internal organs.
--Greater density of smooth muscle within the media than elastic arteries.


--Are small
--Have little or no tunica externa
--Have thin or incomplete tunica media
--they control the blood flow between arteries and capillaries.
--is poorly defined and the media consists of scattered smooth muscle fibers that may not form a complete layer.


The smallest and most delicate blood vessels; permit exchange between the blood and the surrounding interstitial fluids

capillary structure

a typical capillary consists of an endothelial tube with nucleus enclosed within a delicate basal lamina

1. Continuous capillaries
2. Fenestrated capillaries
3. Sinusoids

What are three types of capillaries?

Continuous capillaries

--Found in most regions of the body
--the endothelium is a complete lining
--the endothelial cells are connected by tight junctions and desmosomes more fitted

Fenestrated capillaries

--found in endocrine organs (glands), filtration sites of kidneys and in the choroid plexus
--they have a "swiss cheese" appearance.
--they contain pores in there walls due to an incomplete/perforated endothelial lining.


--resemble fenestrated capillaries, BUT they have larger pores and a thinner basal lamina. *in some organs they have no basal lamina* --they follow the internal contours of complex organs. The liver, bone marrow and suprarenal glands.

Capillary Beds

The exchange; this is where anterioles (arteries) and venules (veins) come together through capillary beds!

Precapillary Sphinters

--a band of smooth muscle that guards the entrance to every capillary.
--control by reducing or stopping the blood flow that travels through capillaries.
--they dilate with an increase in carbon dioxide
--they contract with a decrease of carbon dioxide indicating the need for oxygen and nutrients.


intermediate between anterioles and thoroughfare channel

thoroughfare channel

the rest of the passage way that resembles a typical passage way

capillary autoregulation

the automatic adjustment of blood flow to each tissue in proportion to its needs, and is controlled intrinsically by modifying the diameter of local arterioles and sphincters

arteriovenous anastomoses

direct connections between arterioles and venules. this is helpful within visceral organs and joints when blood supply is lacking going through the capillary bed due to the position of your body.

1. venules (smallest)
2. medium-sized veins
3. large veins

What are three types of veins?

purpose of veins

to collect blood from tall tissues and organs and return it to the heart.

*Note* veins walls are structurally not as strong as there corresponding artery so they may have a greater diameter in different regions.


the smallest venules lack a media. However, in the largest venules you will find scattered smooth muscle cells


contain a thin media and the thickest layer is the adventitia which contains longitudinal bundles of elastic and collagen fibers


*Ex. superior and inferior venae cavae* all of the layers are thickest in large veins. Still a slender media which is surrounded by a thick adventitia, mix of elastic and collagenous fibers

There really isn't a huge difference between the different types of veins

venous valves

infoldings of the intima layer. they prevent the back flow of blood. explanation: venous valves break the blood flow back to the heart into compartments so to speak, and contractions in the surrounding skeletal muscles help to squeeze the blood towards the heart

total blood volume

this is the distribution of blood among the arteries, veins, heart..etc.


when smooth muscles in the walls of venous veins contract reducing the volume of the venous system

blood reservoir

the venous system acts as a blood reservoir for when the body is undergoing blood loss and can help to maintain the volume within the arterial system at near-normal levels despite a significant blood loss. (liver acting as primary reservoir)

venous reserve

the change in volume

At this point attempt to do the concept check questions on the bottom right of page 577! (in the study guide)


Blood vessel distribution is broken into...



composed of arteries and veins that transport blood between the heart and the lungs.


transports oxygenated blood between the heart and all other tissues.

There are 3 important functional patterns of the pulmonary and systemic circuit...

1. the peripheral distribution of arteries and veins on the left and right sides is usually identical except near the heart, where the largest vessels connect to the atria or ventricles

2. A single vessel may have several different names as it crosses specific anatomical boundaries, making accurate anatomical descriptions possible when the vessel extends far into the periphery.

3. Arteries and veins often make anastomotic connections that reduce the impact of a temporary or even permanent blockage of a single vessel

Two arteries formed by the division of the brachiocephalic trunk

subclavian and common carotid

First artery that branches off the ascending aorta; serves the heart

coronary artery

two paired arteries, serving the brain

internal carotid and vertebral

largest artery of the body


arterial network on the dorsum of the foot

dorsalis pedis

artery that serves the posterior thigh

deep artery of the thigh

artery that supplies the diaphragm


artery that splits to form the radial and ulnar arteries


artery that supplies the last half of the large intestine

inferior mesenteric

artery that serves the pelvis

common iliac

external iliac becomes this artery on entering the thigh


Major artery serving the arm


artery that supplies most of the small intestine

superior mesentric

the terminal branches of the dorsal, or descending aorta

right and left common iliac

arterial trunk that has three major branches, which serve the liver, spleen, and stomach

celiac trunk

mahor artery, serving the tissues external to the skull

external carotid

artery general auscultated to determine blood pressure in the arm


these were not all of the arteries that need to be known but most of them (: refer to the in class ws for the rest.


deep veins, draining the forearm

ulnar and radial

veins that receive blodd from the arm via the axillary vein


veins that drain venous blood from the myocardium of the heart into the coronary sinus


vein that drains the kidney


vein that drains the dural sinuses of the brain

internal jugular

two veins that join to become the superior vena cava

right and left brachiocephalic

veins that drain the leg and foot

femoral and posterior tibial

large vein that carries nutrient rich blood from the digestive organs to the liver for processing

hepatic portal

superficial vein that drains the lateral aspect of the arm


vein that drains the ovaries and testes


vein that drains the thorax, empties into the superior vena cava

azygos vein

largest vein below the thorax

inferior vena cava


Know all the major arteries in the body

Vertebral artery

Identify A: _______ artery

Right subclavian

Identify B: _______ artery

Brachiocephalic trunk

Identify C: _______ artery

Aortic arch

Identify D:_______ artery

Ascending aorta

Identify E:_______ artery

Celiac trunk

Identify F: _______ artery


Identify G: _______ artery


Identify H:_______ artery


Identify I:_______ artery

External iliac

Identify J:_______ artery

Palmar arches

Identify K:_______ artery


Identify L:_______ artery

Posterior tibial

Identify M: _______ artery

Anterior tibial

Identify N: _______ artery


Identify O: _______ artery

Plantar arch

Identify P: _______ artery

Dorsalis pedis

Identify Q: _______ artery

Descending genicular

Identify R:_______ artery


Identify S: _______ artery

Deep femoral

Identify T: _______ artery

Internal iliac

Identify U: _______ artery

Common iliac

Identify V: _______ artery

Inferior mesenteric

Identify W: _______ artery


Identify X: _______ artery

Superior mesenteric

Identify Y: _______ artery


Identify Z: _______ artery


Identify AA: _______ artery

Descending aorta

Identify BB: _______ artery

Pulmonary trunk

Identify CC: _______ artery


Identify DD: _______ artery

Left subclavian

Identify EE: _______ artery

Left common carotid

Identify FF: _______ artery

Right common carotid

Identify GG: _______ artery

Systemic Venous System

Be able to identify the major veins in the body.


Identify A: _______ vein

External jugular

Identify B: _______ vein


Identify C: _______ vein


Identify D: _______ vein


Identify E: _______ vein


Identify F: _______ vein


Identify G: _______ vein


Identify H: _______ vein

Median cubital

Identify I: _______ vein


Identify J: _______ vein

Median antebrachial

Identify K: _______ vein


Identify L: _______ vein

Palmar venous arches

Identify M: _______ vein


Identify N: _______ vein

Great saphenous

Identify O: _______ vein


Identify P: _______ vein

Small saphenous

Identify Q: _______ vein


Identify R: _______ vein

Dorsal venous arch

Identify S: _______ vein

Plantar venous arch

Identify T: _______ vein

Anterior tibial

Identify U: _______ vein

Posterior tibial

Identify V: _______ vein


Identify W: _______ vein

Deep femoral

Identify X: _______ vein

Internal iliac

Identify Y: _______ vein

External iliac

Identify Z: _______ vein

Left and right common iliac

Identify AA: _______ vein


Identify BB: _______ vein


Identify CC: _______ vein


Identify DD: _______ vein

Inferior vena cava

Identify EE: _______ vein


Identify FF: _______ vein

Superior vena cava

Identify GG: _______ vein


Identify HH: _______ vein

Internal jugular

Identify II: _______ vein

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