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Chapter 22- Cardiovascular system

Circulatory System
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The cardiovascular system
THE CIRCULATION OF BLOOD THROUGHOUT THE BODY
intima, media and adventiva
What are the layers of a blood vessel for both arteries and veins?
intima
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)
media
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
adventitia
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?
1. ELASTIC
2. MUSCULAR
3. ARTERIOLES
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.
Arterioles
--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.
Capillaries
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.
Sinusoids
--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.
metarterioles
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.
VENULE
the smallest venules lack a media. However, in the largest venules you will find scattered smooth muscle cells
MEDIUM-SIZED VEINS
contain a thin media and the thickest layer is the adventitia which contains longitudinal bundles of elastic and collagen fibers
LARGE VEINS
*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.
venoconstriciton
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...
1. PULMONARY CIRCUIT
2. SYSTEMIC CIRCUIT
PULMONARY CIRCUIT
composed of arteries and veins that transport blood between the heart and the lungs.
SYSTEMIC CIRCUIT
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
aorta
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
phrenic
artery that splits to form the radial and ulnar arteries
brachial
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
femoral
Major artery serving the arm
brachial
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
brachial
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.
THE FOLLOWING SLIDES 59
deep veins, draining the forearm
ulnar and radial
veins that receive blodd from the arm via the axillary vein
subclavian
veins that drain venous blood from the myocardium of the heart into the coronary sinus
cardiac
vein that drains the kidney
renal
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
cephalic
vein that drains the ovaries and testes
gonadal
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
Brachial
Identify G: _______ artery
Radial
Identify H:_______ artery
Ulnar
Identify I:_______ artery
External iliac
Identify J:_______ artery
Palmar arches
Identify K:_______ artery
Popliteal
Identify L:_______ artery
Posterior tibial
Identify M: _______ artery
Anterior tibial
Identify N: _______ artery
Fibular
Identify O: _______ artery
Plantar arch
Identify P: _______ artery
Dorsalis pedis
Identify Q: _______ artery
Descending genicular
Identify R:_______ artery
Femoral
Identify S: _______ artery
Deep femoral
Identify T: _______ artery
Internal iliac
Identify U: _______ artery
Common iliac
Identify V: _______ artery
Inferior mesenteric
Identify W: _______ artery
Gonadal
Identify X: _______ artery
Superior mesenteric
Identify Y: _______ artery
Renal
Identify Z: _______ artery
Diaphragm
Identify AA: _______ artery
Descending aorta
Identify BB: _______ artery
Pulmonary trunk
Identify CC: _______ artery
Axillary
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.
Vertebral
Identify A: _______ vein
External jugular
Identify B: _______ vein
Subclavian
Identify C: _______ vein
Axillary
Identify D: _______ vein
Cephalic
Identify E: _______ vein
Brachial
Identify F: _______ vein
Basilic
Identify G: _______ vein
Hepatic
Identify H: _______ vein
Median cubital
Identify I: _______ vein
Radial
Identify J: _______ vein
Median antebrachial
Identify K: _______ vein
Ulnar
Identify L: _______ vein
Palmar venous arches
Identify M: _______ vein
Digital
Identify N: _______ vein
Great saphenous
Identify O: _______ vein
Popliteal
Identify P: _______ vein
Small saphenous
Identify Q: _______ vein
Fibular
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
Femoral
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
Lumbar
Identify BB: _______ vein
Gonadal
Identify CC: _______ vein
Renal
Identify DD: _______ vein
Inferior vena cava
Identify EE: _______ vein
Intercostal
Identify FF: _______ vein
Superior vena cava
Identify GG: _______ vein
Brachiocephalic
Identify HH: _______ vein
Internal jugular
Identify II: _______ vein