CHAPTER 18 ANATOMY OF
BLOOD VESSELS
Joe Pistack MS/ED
CIRCULATORY SYSTEM


Circulatory System consists of the heart and
blood vessels.
The blood vessels are a series of connected,
hollow tubes that begin and end in the heart.
PULMONARY CIRCULATION


Carries blood from the
right ventricle of the
heart to the lungs and
back to the left atrium of
the heart.
Pulmonary circulation
transports unoxygenated
blood to the lungs, where
oxygen is loaded and
carbon dioxide is
unloaded.
SYSTEMIC CIRCULATION




The larger circulation.
Blood vessels are
arteries, capillaries, and
veins.
Provides the blood supply
to the rest of the body.
Carries oxygen and other
nutrients to the cells and
picks up carbon dioxide
and other waste.
BLOOD VESSELS

Highway of the body.
Classified as:
 Arteries
 Capillaries
 Veins


Blood vessels are
composed of three
layers except for
capillaries.
ARTERIES
 Called
conductance
vessels, carry blood
away from the
heart.
 Thick
wall with
three layers:

1 - Tunica intima-
innermost layer,
continuous with the
endocardium, blood
flows easily here.
ARTERIES

2 - Tunica mediamiddle layer, thickest
layer, composed of
elastic tissue and
smooth muscle. Made
up of elastic tissue
and smooth muscle,
capable of stretching
in response to the
pumping of blood by
the heart.
ARTERIES


3 -Tunica adventitiathe outer layer,
composed of tough
connective tissue,
function is to support
and protect.
Arterioles-the
smallest artery,
numerous and branch
out.
CAPILLARIES


Smallest and most
numerous of all blood
vessels.
Close to every cell,
numerous, provide the
cells with oxygen and
nutrients.
ARTERIOLES



Smallest of the arteries.
Composed of smooth
muscle that contract and
relax.
Called resistance vessels able to change their size
which alters the pressure
in the blood to less
resistance when dilated
and more resistance when
constricted.
CAPILLARIES
 Have
the thinnest walls
of all blood vessels.
 Single
layer epithelium
on a delicate basement
membrane.
 Called
exchange vessels
- allow the exchange of
nutrients, gases and
waste.
VEINS
 Blood
vessels that
carry blood back to
the heart.
 Smallest
veins are
called venules.
 The
largest veins
empty the blood into
the right atrium of
the heart.
VENULES
 Converge
from
capillaries.
 Wall
of venule is
slightly thicker than
capillary wall.
 Pressure
in veins is
less than pressure in
the arteries.
VEINS
 Most
veins contain one-way valves
which direct the flow of blood toward
the heart.
 Called
capacitance vessels, store
about 70% of our blood volume.
 When
stored blood is needed, the
veins constrict and move blood to the
heart for circulation.
MAJOR ARTERIES OF SYSTEMIC CIRCULATION
Aorta



Largest of all arteries.
Average diameter of a
garden hose.
Originates in the left
ventricle of the heart,
curves in an archlike
fashion and descends
through the thorax.
AORTA
 The
aorta ends in
the pelvic cavity
where it splits into
two common iliac
arteries.
 The
aorta is divided
into segments, each
named according to
two systems.
AORTA
 System
I, path that
the aorta follows as it
courses through the
body.
1.
2.
3.
Ascending aorta
Arch of the aorta
Descending aorta
AORTA
 System
II, path
named according
to location within
the body cavities.
1. thoracic aorta
2. abdominal aorta
AORTA


Arteries arise directly
from the aorta or from
vessels that are
branches of the aorta.
The ascending aorta
arises from the left
ventricle, begins at
the aortic semilunar
valve and extends to
the aortic arch.
AORTA


Right and left coronary
arteries branch from
the ascending aorta.
Coronary arteries are
distributed throughout
the heart and supply
oxygenated blood to the
myocardium.
BRANCHES OF THE AORTIC ARCH


The aortic arch extends
from the ascending aorta
to the beginning of the
descending aorta.
Three large arteries arise
from the aortic arch:
1. brachiocephalic arterysupplies blood to the right
side of the head, neck,
right shoulder, and right
upper extremity.
BRANCHES OF THE DESCENDING AORTA



(Thoracic aorta)
Upper portion of the
descending aorta. It
extends from the aortic
arch to the diaphragm.
Intercostal arteries
arise from the aorta and
supply the intercostal
muscles between the
ribs.
BRANCHES OF THE AORTIC ARCH
2. Left common
carotid arteryextends upward from
the highest point of
the aortic arch and
supplies the left side
of the head and neck.
3. Left & right
subclavian arteries
supply blood to the
shoulders and upper
arms.
BRANCHES OF THE DESCENDING AORTA



(Abdominal aorta)
Extends from the
thoracic aorta to the
lower abdomen.
Branches include:
1. celiac trunk-short
artery that divides into
the gastric artery,
splenic artery, and
hepatic artery.
BRANCHES OF THE DESCENDING AORTA
2. Two mesenteric arteries
are the:
1. superior mesenteric
artery-supplies most of the
small intestine and part of
the large intestine.
2. inferior mesenteric
artery - supplies the rest of
the large intestine.
BRANCHES OF THE DESCENDING AORTA
3.
3. Renal arteriessupply blood to the
right and left
kidneys.
4.
4. The common iliac
arteries-supply the
pelvic organs, thigh,
and lower
extremities.
VEINS OF THE SYSTEMIC CIRCULATION



Superficial veins-located superficially and can be
seen.
Deep veins-located more deeply and usually run
parallel to the arteries.
The names of the deep veins are the same name
as the companion artery, with few exceptions.

Ex. Femoral artery is accompanied by the femoral
vein.
VENAE CAVAE



Veins carry blood from
all parts of the body to
the venae cava for
delivery to the heart.
The venae cava is the
main vein.
Divided into the
superior vena cava
(SVC) and the inferior
vena cava.
SUPERIOR VENAE CAVA


Veins draining blood
from the head, the
shoulders, and the
upper extremities
empty into the SVC.
Veins may drain
directly or indirectly.
SUPERIOR VENA CAVA
Veins that empty into the SVC:
 The cephalic vein
 The basilic vein
 Subclavian veins
 External jugular veins
 Internal jugular veins
 Brachiocephalic veins
 Azygos vein
INFERIOR VENA CAVA
IVC returns blood to the heart from all regions of
the body.
 Veins that empty into the IVC:
 Tibial veins
 Peroneal veins
 Femoral veins
 Great saphenous veins
 Renal veins
 Hepatic veins

VARICOSE VEINS

Veins that are
distended and
twisted, usually
involving the
superficial
veins of the
legs.
VARICOSE VEINS



Caused by a
structural defect in
the vessel wall.
Dilation of the vessel
can lead to
incompetent venous
valves.
Blood will backflow
and pool inside the
vein.
BLOOD SUPPLY TO THE HEAD AND BRAIN


Brain requires a continuous supply of oxygen.
Rich supply of blood is supplied by two pair of
arteries, the carotid arteries and the vertebral
arteries.
ARTERIES OF THE HEAD AND NECK
 Right
common arteryarises from the
brachiocephalic artery.
 Left
common artery
arises directly from the
aortic arch.
 Common
artery splits
into the external and
internal carotid
arteries.
ARTERIES OF THE HEAD AND NECK



External carotid arteries
supply the superficial
areas of the neck, face,
and scalp.
Internal carotid arteries
extend to the front part of
the base of the brain.
Inside the cranium, each
internal carotid artery
divides to supply
numerous parts of the
brain.
ARTERIES OF THE HEAD AND NECK


Vertebral arteries-pass
upward from the
subclavian arteries
toward the brain and
the back of the neck.
The basilar artery is an
extension of the
vertebral artery,
numerous branches
supply the brain, brain
stem, and cerebellum.
CIRCLE OF WILLIS


Circular arrangement of
arteries that penetrate
the brain and maintain
the rich blood supply.
If the carotid arteries
become blocked, the
arteries cannot supply
sufficient blood to the
brain resulting in
impaired brain function
as observed in dizziness
and impaired cognitive
thinking.
VENOUS DRAINAGE OF THE HEAD AND BRAIN



External and internal
jugular veins are the two
major veins that drain blood
from the head and neck.
The external jugular veins
are more superficial and
drain blood from the
posterior head and neck
region.
The internal jugular veins
drain the anterior head, face,
and neck.
BLOOD SUPPLY TO THE LIVER AND HEPATIC
PORTAL CIRCULATION
 Three
groups of blood
vessels are associated
with hepatic circulation:
1. The portal vein
2. The hepatic veins
3. The hepatic artery
HEPATIC PORTAL CIRCULATION


Portal vein is a large vein
that carries blood from the
organs of digestion to the
liver.
Formed by the union of two
large veins:
1. Superior mesenteric vein
2. Splenic vein
HEPATIC PORTAL CIRCULATION
Purpose:
 Carry blood rich in digestive end products from
organs of digestion to the liver.

Liver needs easy access to the digestive and end
products to aid in metabolism.
HEPATIC PORTAL CIRCULATION



Liver prevents nitrogen from
entering the general
circulation as ammonia.
Nitrogen is excreted by the
liver into the blood in the
form of urea.
Urea is less toxic than
ammonia and is excreted by
the kidneys.
THE LIVER
Largest organ in the body.
 Essential for keeping the body functioning
properly.



Functions:
1. Removes poisons from the blood.
2. Produces immune agents to control infection.
3. Removes germs and bacteria in the blood.
4. Makes proteins that regulate blood clotting.
5. Produces bile to help absorb fats and fatsoluble vitamins.
Cannot live without a functioning liver.
CIRRHOSIS OF THE LIVER



Scar tissue replaces
normal, healthy
tissue.
Scar tissue blocks the
normal flow of blood
through the liver.
Liver is unable to
function properly.
SPLANCHNIC CIRCULATION




Blood flow to the stomach,
spleen, pancreas, intestines
and liver.
Blood flow is very adjustable.
Blood flow may increase up to
eight times following a meal.
When digestion is complete,
the blood can be diverted to
other organs.
SWIMMING AFTER EATING


Should not go for a
vigorous swim after
eating.
Your splanchnic blood
vessels are using the
blood to digest the food
that your swimming
skeletal muscles need.
PULSE


Pulse-the pressure wave that is created by the
expansion and recoiling of the arteries with each
heart beat.
Rhythmic contraction of the ventricles of the
heart.

Most common site is the wrist.

Normal heart rate is about 72 beats per minute.
PULSE
Pulse Points:
 Temporal
 Facial
 Carotid
 Brachial
 Radial
 Femoral
 Popliteal
 Posterior tibial
 Dorsalis pedis