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Cardiovascular System: Blood Vessels
 Components of the Vascular System
 Tunics (Layers) Around Blood Vessels
 Blood Vessel Types
 Movement of Blood Through System
 Capillary Beds and Diffusion
 Major Arteries and Veins of the Body
 Hepatic Portal Circulation
 Fetal Circulation
Blood Vessels: The Vascular System
 Taking blood to the tissues and back
• Arteries
o Arterioles
 Capillaries
o Venules
• Veins
The Vascular System
 Three layers (tunics)
• Tunic intima
o Endothelium
• Tunic media
o Smooth muscle
o Controlled by
sympathetic
nervous system
• Tunic externa
o Mostly fibrous
connective tissue
Figure 11.8b
Differences Between Blood Vessel Types
 Walls of arteries are the
thickest
 Lumens of veins are larger
 Walls of capillaries are
only one cell layer thick
to allow for exchanges
between blood and tissue
Movement of Blood Through Vessels
 Most arterial blood is
pumped by the heart
 Veins use the milking
action of muscles to
help move blood
 Expansion of vein
walls when lungs
inflate pulls
pulmonary artery
blood in
Figure 11.9
Capillary Beds
 Capillary beds consist
of two types of
vessels
• Vascular shunt –
directly connects
an arteriole to a
venule
• Shunt operates
during trauma,
cold temps
Figure 11.10
Capillary Beds
 True capillaries –
exchange vessels
o Oxygen and
nutrients cross to
cells
o Carbon dioxide
and metabolic
waste products
cross into blood
Figure 11.10
Major Arteries of Systemic Circulation
Internal carotid artery
External carotid artery
Common carotid arteries
Vertebral artery
Subclavian artery
Brachiocephalic trunk
Aortic arch
Ascending aorta
Coronary artery
Thoracic aorta (above
diaphragm)
Celiac trunk
Abdominal aorta
Superior mesenteric artery
Renal artery
Gonadal artery
Common iliac artery
Inferior mesenteric artery
Internal iliac artery
(b) Illustration, anterior
view
Arteries that supply
the upper limb
Subclavian artery
Axillary artery
Brachial artery
Radial artery
Ulnar artery
Deep palmar arch
Superficial palmar arch
Digital arteries
Arteries that supply
the lower limb
External iliac artery
Femoral artery
Popliteal artery
Anterior tibial artery
Posterior tibial artery
Arcuate artery
The Arm and Thorax
Vertebral artery
Thyrocervical trunk
Suprascapular artery
Costocervical trunk
Thoracoacromial artery
Axillary artery
Posterior circumflex
humeral artery
Anterior circumflex
humeral artery
Subscapular artery
Brachial artery
Deep artery of arm
Common
interosseous
artery
Common carotid
arteries
Left subclavian artery
Right subclavian artery
Brachiocephalic trunk
Posterior intercostal
arteries
Anterior intercostal
artery
Internal thoracic artery
Descending aorta
Lateral thoracic artery
Radial artery
Ulnar artery
Deep palmar arch
Superficial palmar arch
Digital arteries
Arterial Supply of the Brain
Anterior
Frontal lobe
Optic chiasma
Cerebral arterial
circle
(circle of Willis)
• Anterior
communicating
artery
• Anterior
cerebral artery
• Posterior
communicating
artery
• Posterior
cerebral artery
Basilar artery
Middle
cerebral
artery
Internal
carotid
artery
Mammillary
body
Temporal
lobe
Pons
Occipital lobe
Vertebral artery
Cerebellum
Posterior
(d) Major arteries serving the brain (inferior view, right side
of cerebellum and part of right temporal lobe removed)
Major Veins of Systemic Circulation
Dural venous sinuses
External jugular vein
Vertebral vein
Internal jugular vein
Right and left
brachiocephalic veins
Superior vena cava
Great cardiac vein
Hepatic veins
Splenic vein
Hepatic portal vein
Renal vein
Veins that drain
the upper limb
Subclavian vein
Axillary vein
Cephalic vein
Brachial vein
Basilic vein
Median cubital vein
Ulnar vein
Radial vein
Digital veins
Veins that drain
the lower limb
Superior mesenteric
vein
Inferior vena cava
Inferior mesenteric vein
External iliac vein
Common iliac vein
Popliteal vein
Internal iliac vein
Posterior tibial vein
Femoral vein
Great saphenous vein
Anterior tibial vein
(b) Illustration, anterior
view. The vessels of the
pulmonary circulation
are not shown.
Small saphenous vein
Dorsal venous arch
Dorsal metatarsal veins
Hepatic Portal Circulation
Figure 11.14
Pressure/Pulse Points
Superficial temporal
artery
Facial artery
Common carotid
artery
Brachial artery
Radial artery
Femoral artery
Popliteal artery
Posterior tibial
artery
Dorsalis pedis
artery
Figure 19.12
Circulation to the Fetus
Modif 1
Modif 2
Handling of collapsed lungs
Measuring Arterial Blood Pressure


Measurements by health professionals
are made on the pressure in large arteries
•
Systolic – pressure at the peak of
ventricular contraction
•
Diastolic – pressure when ventricles
relax
Pressure in blood vessels decreases as the
distance away from the heart increases
Listen for the sounds of Kortokoff
Normal BP is 120/75-80
Blood pressure
animation online
Using a cuff online
Comparison of Blood Pressures
Disease causing blood
pressure change
Arteriosclerosis:
Hardening of the artery
walls and decrease of
elasticity, restricting flow
and increasing blood
pressure.
Atherosclerosis: A specific
type of arterosclerosis
where arteries are clogged
by an accumulation of
plaques: cholesterol
particles (lipoproteins), fat,
calcium, cellular waste and
other substances.
One-way valves in veins prevent backflow
where positive pressure is at a mininum
Blood Pressure: Effects of Factors
Blood Pressure = Cardiac Output x Total Peripheral Resistance
BP = CO x TPR

Neural factors
•



Renal factors
•
Regulation by altering blood volume:
salt and water retention
•
Renin – hormonal control
Temperature
•
Heat has a vasodilating effect
•
Cold has a vasoconstricting effect
Chemicals
•

Autonomic nervous system
adjustments (sympathetic division):
vasoconstriction
Various substances can cause
increases or decreases
Diet
•
High salt causes elevated BP
Variations in Blood Pressure
 Human normal range is variable
• Normal
o 140–110 mm Hg systolic
o 80–75 mm Hg diastolic
• Hypotension
o Low systolic (below 110 mm HG)
o Often associated with illness or physical
conditioning
• Hypertension
o High systolic (above 140 mm HG)
o Can be dangerous if it is chronic
Developmental Aspects of the
Cardiovascular System
 A simple “tube heart” develops in the embryo and pumps by the fourth week
 The heart becomes a four-chambered organ by the end of seven weeks
 Few structural changes occur after the seventh week
 Congential heart defects sometimes arise
 Hypertrophy of the heart occurs through regular aerobic exercise
 Varicose veins develop as we age, along with atherosclerosis, & hypertension
Congenital Heart Defects
Varicose Veins