Transcript 19 - Jackson County School District

PowerPoint® Lecture Slides
prepared by
Barbara Heard,
Atlantic Cape Community
Ninth Edition
College
Human Anatomy & Physiology
CHAPTER
19
The
Cardiovascular
System: Blood
Vessels
© Annie Leibovitz/Contact Press Images
© 2013 Pearson Education, Inc.
Blood Vessels
• Delivery system of dynamic structures that
begins and ends at heart
– Arteries: carry blood away from heart;
oxygenated except for pulmonary circulation
and umbilical vessels of fetus
– Capillaries: contact tissue cells; directly serve
cellular needs
– Veins: carry blood toward heart
© 2013 Pearson Education, Inc.
Figure 19.1a Generalized structure of arteries, veins, and capillaries.
Artery
Vein
© 2013 Pearson Education, Inc.
Structure of Blood Vessel Walls
• Lumen
– Central blood-containing space
• Three wall layers in arteries and veins
– Tunica intima, tunica media, and tunica
externa
• Capillaries
– Endothelium with sparse basal lamina
© 2013 Pearson Education, Inc.
Figure 19.1b Generalized structure of arteries, veins, and capillaries.
Tunica intima
• Endothelium
• Subendothelial layer
• Internal elastic membrane
Tunica media
(smooth muscle and
elastic fibers)
• External elastic membrane
Valve
Tunica externa
(collagen fibers)
• Vasa vasorum
Lumen
Lumen
Artery
Capillary network
Vein
Basement membrane
Endothelial cells
Capillary
© 2013 Pearson Education, Inc.
Tunics
• Tunica intima
– Endothelium lines lumen of all vessels
• Continuous with endocardium
• Slick surface reduces friction
– Subendothelial layer in vessels larger than
1 mm; connective tissue basement membrane
© 2013 Pearson Education, Inc.
Tunics
• Tunica media
– Smooth muscle and sheets of elastin
– Sympathetic vasomotor nerve fibers control
vasoconstriction and vasodilation of
vessels
• Influence blood flow and blood pressure
© 2013 Pearson Education, Inc.
Tunics
• Tunica externa (tunica adventitia)
– Collagen fibers protect and reinforce; anchor
to surrounding structures
– Contains nerve fibers, lymphatic vessels
– Vasa vasorum of larger vessels nourishes
external layer
© 2013 Pearson Education, Inc.
Blood Vessels
• Vessels vary in length, diameter, wall
thickness, tissue makeup
• See figure 19.2 for interaction with
lymphatic vessels
© 2013 Pearson Education, Inc.
Figure 19.2 The relationship of blood vessels to each other and to lymphatic vessels.
Venous system
Large veins
(capacitance
vessels)
Arterial system
Heart
Elastic
arteries
(conducting
arteries)
Large
lymphatic
vessels
Lymph
node
Lymphatic
system
Small veins
(capacitance
vessels)
Muscular
arteries
(distributing
arteries)
Arteriovenous
anastomosis
Lymphatic
capillaries
Sinusoid
Arterioles
(resistance
vessels)
Terminal
arteriole
Postcapillary
venule
© 2013 Pearson Education, Inc.
Thoroughfare
channel
Capillaries
(exchange
vessels)
Precapillary
sphincter
Metarteriole
Arterial System: Elastic Arteries
• Large thick-walled arteries with elastin in
all three tunics
• Aorta and its major branches
• Large lumen offers low resistance
• Inactive in vasoconstriction
• Act as pressure reservoirs—expand and
recoil as blood ejected from heart
– Smooth pressure downstream
© 2013 Pearson Education, Inc.
Arterial System: Muscular Arteries
• Distal to elastic arteries
– Deliver blood to body organs
• Thick tunica media with more smooth
muscle
• Active in vasoconstriction
© 2013 Pearson Education, Inc.
Arterial System: Arterioles
• Smallest arteries
• Lead to capillary beds
• Control flow into capillary beds via
vasodilation and vasoconstriction
© 2013 Pearson Education, Inc.
Table 19.1 Summary of Blood Vessel Anatomy (1 of 2)
© 2013 Pearson Education, Inc.
Capillaries
• Microscopic blood vessels
• Walls of thin tunica intima
– In smallest one cell forms entire
circumference
• Pericytes help stabilize their walls and
control permeability
• Diameter allows only single RBC to pass
at a time
© 2013 Pearson Education, Inc.
Capillaries
• In all tissues except for cartilage, epithelia,
cornea and lens of eye
• Provide direct access to almost every cell
• Functions
– Exchange of gases, nutrients, wastes,
hormones, etc., between blood and interstitial
fluid
© 2013 Pearson Education, Inc.
Capillaries
• Three structural types
1. Continuous capillaries
2. Fenestrated capillaries
3. Sinusoid capillaries (sinusoids)
© 2013 Pearson Education, Inc.
Continuous Capillaries
• Abundant in skin and muscles
– Tight junctions connect endothelial cells
– Intercellular clefts allow passage of fluids and
small solutes
• Continuous capillaries of brain unique
– Tight junctions complete, forming blood brain
barrier
© 2013 Pearson Education, Inc.
Figure 19.3a Capillary structure.
Pericyte
Red blood
cell in lumen
Intercellular
cleft
Endothelial
cell
Basement
membrane
Tight junction
Endothelial
nucleus
Pinocytotic
vesicles
Continuous capillary. Least permeable, and most
common (e.g., skin, muscle).
© 2013 Pearson Education, Inc.
Fenestrated Capillaries
• Some endothelial cells contain pores
(fenestrations)
• More permeable than continuous
capillaries
• Function in absorption or filtrate formation
(small intestines, endocrine glands, and
kidneys)
© 2013 Pearson Education, Inc.
Figure 19.3b Capillary structure.
Pinocytotic
vesicles
Red blood
cell in lumen
Fenestrations
(pores)
Endothelial
nucleus
Basement membrane
Tight junction
Intercellular
cleft
Endothelial
cell
Fenestrated capillary. Large fenestrations (pores)
increase permeability. Occurs in areas of active
absorption or filtration (e.g., kidney, small intestine).
© 2013 Pearson Education, Inc.
Sinusoid Capillaries
• Fewer tight junctions; usually fenestrated;
larger intercellular clefts; large lumens
• Blood flow sluggish – allows modification
– Large molecules and blood cells pass
between blood and surrounding tissues
• Found only in the liver, bone marrow,
spleen, adrenal medulla
• Macrophages in lining to destroy bacteria
© 2013 Pearson Education, Inc.
Figure 19.3c Capillary structure.
Endothelial
cell
Red blood
cell in lumen
Large
intercellular
cleft
Tight junction
Incomplete
basement
membrane
Nucleus of
endothelial
cell
Sinusoid capillary. Most permeable. Occurs in special
locations (e.g., liver, bone marrow, spleen).
© 2013 Pearson Education, Inc.
Capillary Beds
• Microcirculation
– Interwoven networks of capillaries between
arterioles and venules
– Terminal arteriole  metarteriole
– Metarteriole continuous with thoroughfare
channel (intermediate between capillary and
venule)
– Thoroughfare channel  postcapillary
venule that drains bed
© 2013 Pearson Education, Inc.
Capillary Beds: Two Types of Vessels
• Vascular shunt (metarteriole—
thoroughfare channel)
– Directly connects terminal arteriole and
postcapillary venule
• True capillaries
– 10 to 100 exchange vessels per capillary bed
– Branch off metarteriole or terminal arteriole
© 2013 Pearson Education, Inc.
Blood Flow Through Capillary Beds
• True capillaries normally branch from
metarteriole and return to thoroughfare
channel
• Precapillary sphincters regulate blood
flow into true capillaries
– Blood may go into true capillaries or to shunt
• Regulated by local chemical conditions
and vasomotor nerves
© 2013 Pearson Education, Inc.
Figure 19.4 Anatomy of a capillary bed.
Precapillary sphincters
Vascular shunt
Metarteriole Thoroughfare
channel
True
capillaries
Terminal arteriole
Postcapillary venule
Sphincters open—blood flows through true capillaries.
Terminal arteriole
Postcapillary venule
Sphincters closed—blood flows through metarteriole – thoroughfare
channel and bypasses true capillaries.
© 2013 Pearson Education, Inc.
Venous System: Venules
• Formed when capillary beds unite
– Smallest postcapillary venules
– Very porous; allow fluids and WBCs into
tissues
– Consist of endothelium and a few pericytes
• Larger venules have one or two layers of
smooth muscle cells
© 2013 Pearson Education, Inc.
Veins
• Formed when venules converge
• Have thinner walls, larger lumens
compared with corresponding arteries
• Blood pressure lower than in arteries
• Thin tunica media; thick tunica externa of
collagen fibers and elastic networks
• Called capacitance vessels (blood
reservoirs); contain up to 65% of blood
supply
© 2013 Pearson Education, Inc.
Figure 19.5 Relative proportion of blood volume throughout the cardiovascular system.
Pulmonary blood
vessels 12%
Systemic arteries
and arterioles 15%
Heart 8%
Capillaries 5%
Systemic veins
and venules 60%
© 2013 Pearson Education, Inc.
Veins
• Adaptations ensure return of blood to
heart despite low pressure
– Large-diameter lumens offer little resistance
– Venous valves prevent backflow of blood
• Most abundant in veins of limbs
– Venous sinuses: flattened veins with
extremely thin walls (e.g., coronary sinus of
the heart and dural sinuses of the brain)
© 2013 Pearson Education, Inc.
Table 19.1 Summary of Blood Vessel Anatomy (2 of 2)
© 2013 Pearson Education, Inc.
Figure 19.1a Generalized structure of arteries, veins, and capillaries.
Artery
Vein
© 2013 Pearson Education, Inc.
Vascular Anastomoses
• Interconnections of blood vessels
• Arterial anastomoses provide alternate
pathways (collateral channels) to given
body region
– Common at joints, in abdominal organs, brain,
and heart; none in retina, kidneys, spleen
• Vascular shunts of capillaries are
examples of arteriovenous anastomoses
• Venous anastomoses are common
© 2013 Pearson Education, Inc.
Physiology of Circulation: Definition of
Terms
• Blood flow
– Volume of blood flowing through vessel,
organ, or entire circulation in given period
• Measured as ml/min
• Equivalent to cardiac output (CO) for entire
vascular system
• Relatively constant when at rest
• Varies widely through individual organs, based on
needs
© 2013 Pearson Education, Inc.
Physiology of Circulation: Definition of
Terms
• Blood pressure (BP)
– Force per unit area exerted on wall of blood
vessel by blood
• Expressed in mm Hg
• Measured as systemic arterial BP in large arteries
near heart
– Pressure gradient provides driving force that
keeps blood moving from higher to lower
pressure areas
© 2013 Pearson Education, Inc.
Physiology of Circulation: Definition of
Terms
• Resistance (peripheral resistance)
– Opposition to flow
– Measure of amount of friction blood
encounters with vessel walls, generally in
peripheral (systemic) circulation
• Three important sources of resistance
– Blood viscosity
– Total blood vessel length
– Blood vessel diameter
© 2013 Pearson Education, Inc.
Resistance
• Factors that remain relatively constant:
– Blood viscosity
• The "stickiness" of blood due to formed elements
and plasma proteins
• Increased viscosity = increased resistance
– Blood vessel length
• Longer vessel = greater resistance encountered
© 2013 Pearson Education, Inc.
Resistance
• Blood vessel diameter
– Greatest influence on resistance
• Frequent changes alter peripheral
resistance
• Varies inversely with fourth power of
vessel radius
– E.g., if radius is doubled, the resistance is
1/16 as much
– E.g., Vasoconstriction  increased resistance
© 2013 Pearson Education, Inc.
Resistance
• Small-diameter arterioles major
determinants of peripheral resistance
• Abrupt changes in diameter or fatty
plaques from atherosclerosis dramatically
increase resistance
– Disrupt laminar flow and cause turbulent flow
• Irregular fluid motion  increased resistance
© 2013 Pearson Education, Inc.
Relationship Between Blood Flow, Blood
Pressure, and Resistance
• Blood flow (F) directly proportional to
blood pressure gradient ( P)
– If  P increases, blood flow speeds up
• Blood flow inversely proportional to
peripheral resistance (R)
– If R increases, blood flow decreases:
F =  P/R
• R more important in influencing local blood
flow because easily changed by altering
blood vessel diameter
© 2013 Pearson Education, Inc.
Systemic Blood Pressure
• Pumping action of heart generates blood
flow
• Pressure results when flow is opposed by
resistance
• Systemic pressure
– Highest in aorta
– Declines throughout pathway
– 0 mm Hg in right atrium
• Steepest drop occurs in arterioles
© 2013 Pearson Education, Inc.
Figure 19.6 Blood pressure in various blood vessels of the systemic circulation.
120
Systolic pressure
100
Mean pressure
80
60
40
Diastolic
pressure
20
0
© 2013 Pearson Education, Inc.
Arterial Blood Pressure
• Reflects two factors of arteries close to
heart
– Elasticity (compliance or distensibility)
– Volume of blood forced into them at any time
• Blood pressure near heart is pulsatile
© 2013 Pearson Education, Inc.
Arterial Blood Pressure
• Systolic pressure: pressure exerted in
aorta during ventricular contraction
– Averages 120 mm Hg in normal adult
• Diastolic pressure: lowest level of aortic
pressure
• Pulse pressure = difference between
systolic and diastolic pressure
– Throbbing of arteries (pulse)
© 2013 Pearson Education, Inc.
Arterial Blood Pressure
• Mean arterial pressure (MAP): pressure
that propels blood to tissues
• MAP = diastolic pressure + 1/3 pulse
pressure
• Pulse pressure and MAP both decline with
increasing distance from heart
• Ex. BP = 120/80; MAP = 93 mm Hg
© 2013 Pearson Education, Inc.
Capillary Blood Pressure
• Ranges from 17 to 35 mm Hg
• Low capillary pressure is desirable
– High BP would rupture fragile, thin-walled
capillaries
– Most very permeable, so low pressure forces
filtrate into interstitial spaces
© 2013 Pearson Education, Inc.
Venous Blood Pressure
• Changes little during cardiac cycle
• Small pressure gradient; about 15 mm Hg
• Low pressure due to cumulative effects of
peripheral resistance
– Energy of blood pressure lost as heat during
each circuit
© 2013 Pearson Education, Inc.
Factors Aiding Venous Return
1. Muscular pump: contraction of skeletal
muscles "milks" blood toward heart;
valves prevent backflow
2. Respiratory pump: pressure changes
during breathing move blood toward
heart by squeezing abdominal veins as
thoracic veins expand
3. Venoconstriction under sympathetic
control pushes blood toward heart
© 2013 Pearson Education, Inc.
Figure 19.7 The muscular pump.
Venous valve (open)
Contracted skeletal
muscle
Venous valve
(closed)
Vein
Direction of blood flow
© 2013 Pearson Education, Inc.
Maintaining Blood Pressure
• Requires
– Cooperation of heart, blood vessels, and
kidneys
– Supervision by brain
• Main factors influencing blood pressure
– Cardiac output (CO)
– Peripheral resistance (PR)
– Blood volume
© 2013 Pearson Education, Inc.
Maintaining Blood Pressure
• F =  P/R; CO =  P/R;  P = CO × R
• Blood pressure = CO × PR (and CO
depends on blood volume)
• Blood pressure varies directly with CO,
PR, and blood volume
• Changes in one variable quickly
compensated for by changes in other
variables
© 2013 Pearson Education, Inc.
Cardiac Output (CO)
• CO = SV × HR; normal = 5.0-5.5 L/min
• Determined by venous return, and neural
and hormonal controls
• Resting heart rate maintained by
cardioinhibitory center via parasympathetic
vagus nerves
• Stroke volume controlled by venous return
(EDV)
© 2013 Pearson Education, Inc.
Cardiac Output (CO)
• During stress, cardioacceleratory center
increases heart rate and stroke volume via
sympathetic stimulation
– ESV decreases and MAP increases
© 2013 Pearson Education, Inc.
Figure 19.8 Major factors enhancing cardiac output.
Exercise
BP activates cardiac centers in medulla
Activity of respiratory pump
(ventral body cavity pressure)
Sympathetic activity
Parasympathetic activity
Activity of muscular pump
(skeletal muscles)
Epinephrine in blood
Sympathetic venoconstriction
Venous return
Contractility of cardiac muscle
ESV
EDV
Stroke volume (SV)
Heart rate (HR)
Initial stimulus
Physiological response
Result
© 2013 Pearson Education, Inc.
Cardiac output (CO = SV x HR)
Control of Blood Pressure
• Short-term neural and hormonal controls
– Counteract fluctuations in blood pressure by
altering peripheral resistance and CO
• Long-term renal regulation
– Counteracts fluctuations in blood pressure by
altering blood volume
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Neural Controls
• Neural controls of peripheral resistance
– Maintain MAP by altering blood vessel
diameter
• If low blood volume all vessels constricted except
those to heart and brain
– Alter blood distribution to organs in response
to specific demands
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Neural Controls
• Neural controls operate via reflex arcs
that involve
– Baroreceptors
– Cardiovascular center of medulla
– Vasomotor fibers to heart and vascular
smooth muscle
– Sometimes input from chemoreceptors and
higher brain centers
© 2013 Pearson Education, Inc.
The Cardiovascular Center
• Clusters of sympathetic neurons in medulla
oversee changes in CO and blood vessel
diameter
• Consists of cardiac centers and vasomotor
center
• Vasomotor center sends steady impulses via
sympathetic efferents to blood vessels 
moderate constriction called vasomotor tone
• Receives inputs from baroreceptors,
chemoreceptors, and higher brain centers
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Baroreceptor
Reflexes
• Baroreceptors located in
– Carotid sinuses
– Aortic arch
– Walls of large arteries of neck and thorax
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Baroreceptor
Reflexes
• Increased blood pressure stimulates
baroreceptors to increase input to
vasomotor center
– Inhibits vasomotor and cardioacceleratory
centers, causing arteriolar dilation and
venodilation
– Stimulates cardioinhibitory center
–  decreased blood pressure
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Baroreceptor
Reflexes
• Decrease in blood pressure due to
– Arteriolar vasodilation
– Venodilation
– Decreased cardiac output
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Baroreceptor
Reflexes
• If MAP low
–  Reflex vasoconstriction  increased CO 
increased blood pressure
– Ex. Upon standing baroreceptors of carotid
sinus reflex protect blood to brain; in
systemic circuit as whole aortic reflex
maintains blood pressure
• Baroreceptors ineffective if altered blood
pressure sustained
© 2013 Pearson Education, Inc.
Figure 19.9 Baroreceptor reflexes that help maintain blood pressure homeostasis.
3
Impulses from baroreceptors
stimulate cardioinhibitory center
(and inhibit cardioacceleratory
center) and inhibit vasomotor
center.
4a
Sympathetic
impulses to heart
cause HR,
contractility, and
CO.
2 Baroreceptors
in carotid sinuses
and aortic arch
are stimulated.
4b
Rate of
vasomotor impulses
allows vasodilation,
causing R.
1 Stimulus:
Blood pressure
(arterial blood
pressure rises
above normal
range).
5 CO and R
return blood
pressure to
homeostatic range.
1 Stimulus:
5 CO and R return
blood pressure to
homeostatic range.
Blood pressure
(arterial blood
pressure falls below
normal range).
4b Vasomotor
fibers stimulate
vasoconstriction,
causing R.
2 Baroreceptors
in carotid sinuses
and aortic arch
are inhibited.
4a
Sympathetic
impulses to heart
cause HR,
contractility, and
CO.
© 2013 Pearson Education, Inc.
3 Impulses from baroreceptors
activate cardioacceleratory center
(and inhibit cardioinhibitory center)
and stimulate vasomotor center.
Slide 1
Short-term Mechanisms: Chemoreceptor
Reflexes
• Chemoreceptors in aortic arch and large
arteries of neck detect increase in CO2, or
drop in pH or O2
• Cause increased blood pressure by
– Signaling cardioacceleratory center 
increase CO
– Signaling vasomotor center  increase
vasoconstriction
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Influence of Higher
Brain Centers
• Reflexes in medulla
• Hypothalamus and cerebral cortex can
modify arterial pressure via relays to
medulla
• Hypothalamus increases blood pressure
during stress
• Hypothalamus mediates redistribution of
blood flow during exercise and changes in
body temperature
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Hormonal Controls
• Short term regulation via changes in
peripheral resistance
• Long term regulation via changes in blood
volume
© 2013 Pearson Education, Inc.
Short-term Mechanisms: Hormonal Controls
• Cause increased blood pressure
– Epinephrine and norepinephrine from adrenal
gland  increased CO and vasoconstriction
– Angiotensin II stimulates vasoconstriction
– High ADH levels cause vasoconstriction
• Cause lowered blood pressure
– Atrial natriuretic peptide causes decreased
blood volume by antagonizing aldosterone
© 2013 Pearson Education, Inc.
Figure 19.10 Direct and indirect (hormonal) mechanisms for renal control of blood pressure.
Direct renal mechanism
Arterial pressure
Indirect renal mechanism (renin-angiotensin-aldosterone)
Initial stimulus
Arterial pressure
Physiological response
Result
Inhibits baroreceptors
Sympathetic nervous
system activity
Filtration by kidneys
Angiotensinogen
Renin release
from kidneys
Angiotensin I
Angiotensin converting
enzyme (ACE)
Angiotensin II
Urine formation
Adrenal cortex
ADH release by
posterior pituitary
Thirst via
hypothalamus
Secretes
Aldosterone
Blood volume
Sodium reabsorption
by kidneys
Water reabsorption
by kidneys
Water intake
Blood volume
Mean arterial pressure
© 2013 Pearson Education, Inc.
Mean arterial pressure
Vasoconstriction;
peripheral resistance
Long-term Mechanisms: Renal Regulation
•
•
•
Baroreceptors quickly adapt to chronic
high or low BP so are ineffective
Long-term mechanisms control BP by
altering blood volume via kidneys
Kidneys regulate arterial blood pressure
1. Direct renal mechanism
2. Indirect renal (renin-angiotensin-aldosterone)
mechanism
© 2013 Pearson Education, Inc.
Direct Renal Mechanism
• Alters blood volume independently of
hormones
– Increased BP or blood volume causes
elimination of more urine, thus reducing BP
– Decreased BP or blood volume causes
kidneys to conserve water, and BP rises
© 2013 Pearson Education, Inc.
Indirect Mechanism
• The renin-angiotensin-aldosterone
mechanism
–  Arterial blood pressure  release of renin
– Renin catalyzes conversion of
angiotensinogen from liver to angiotensin I
– Angiotensin converting enzyme, especially
from lungs, converts angiotensin I to
angiotensin II
© 2013 Pearson Education, Inc.
Functions of Angiotensin II
• Increases blood volume
– Stimulates aldosterone secretion
– Causes ADH release
– Triggers hypothalamic thirst center
• Causes vasoconstriction directly
increasing blood pressure
© 2013 Pearson Education, Inc.
Figure 19.10 Direct and indirect (hormonal) mechanisms for renal control of blood pressure.
Direct renal mechanism
Arterial pressure
Indirect renal mechanism (renin-angiotensin-aldosterone)
Initial stimulus
Arterial pressure
Physiological response
Result
Inhibits baroreceptors
Sympathetic nervous
system activity
Filtration by kidneys
Angiotensinogen
Renin release
from kidneys
Angiotensin I
Angiotensin converting
enzyme (ACE)
Angiotensin II
Urine formation
Adrenal cortex
ADH release by
posterior pituitary
Thirst via
hypothalamus
Secretes
Aldosterone
Blood volume
Sodium reabsorption
by kidneys
Water reabsorption
by kidneys
Water intake
Blood volume
Mean arterial pressure
© 2013 Pearson Education, Inc.
Mean arterial pressure
Vasoconstriction;
peripheral resistance
Figure 19.11 Factors that increase MAP.
Activity of
muscular
pump and
respiratory
pump
Release
of ANP
Fluid loss from
hemorrhage,
excessive
sweating
Crisis stressors:
exercise, trauma,
body
temperature
Conservation
of Na+ and
water by kidneys
Blood volume
Blood pressure
Blood pH
O2
CO2
Blood
volume
Baroreceptors
Chemoreceptors
Venous
return
Activation of vasomotor and cardioacceleratory centers in brain stem
Stroke
volume
Heart
rate
Vasomotor tone;
bloodborne
chemicals
(epinephrine,
NE, ADH,
angiotensin II)
Diameter of
blood vessels
Cardiac output
Physiological response
© 2013 Pearson Education, Inc.
Blood
viscosity
Body size
Blood vessel
length
Peripheral resistance
Initial stimulus
Result
Dehydration,
high hematocrit
Mean arterial pressure (MAP)
Monitoring Circulatory Efficiency
• Vital signs: pulse and blood pressure,
along with respiratory rate and body
temperature
• Pulse: pressure wave caused by
expansion and recoil of arteries
• Radial pulse (taken at the wrist) routinely
used
• Pressure points where arteries close to
body surface
– Can be compressed to stop blood flow
© 2013 Pearson Education, Inc.
Figure 19.12 Body sites where the pulse is most easily palpated.
Superficial temporal artery
Facial artery
Common carotid artery
Brachial artery
Radial artery
Femoral artery
Popliteal artery
Posterior tibial
artery
© 2013 Pearson Education, Inc.
Dorsalis pedis
artery
Measuring Blood Pressure
• Systemic arterial BP
– Measured indirectly by auscultatory method
using a sphygmomanometer
– Pressure increased in cuff until it exceeds
systolic pressure in brachial artery
– Pressure released slowly and examiner
listens for sounds of Korotkoff with a
stethoscope
© 2013 Pearson Education, Inc.
Measuring Blood Pressure
• Systolic pressure, normally less than 120
mm Hg, is pressure when sounds first
occur as blood starts to spurt through
artery
• Diastolic pressure, normally less than 80
mm Hg, is pressure when sounds
disappear because artery no longer
constricted; blood flowing freely
© 2013 Pearson Education, Inc.
Variations in Blood Pressure
• Transient elevations occur during changes
in posture, physical exertion, emotional
upset, fever.
• Age, sex, weight, race, mood, and posture
may cause BP to vary
© 2013 Pearson Education, Inc.
Alterations in Blood Pressure
• Hypertension: high blood pressure
– Sustained elevated arterial pressure of 140/90
or higher
– Prehypertension if values elevated but not
yet in hypertension range
• May be transient adaptations during fever, physical
exertion, and emotional upset
• Often persistent in obese people
© 2013 Pearson Education, Inc.
Homeostatic Imbalance: Hypertension
• Prolonged hypertension major cause of
heart failure, vascular disease, renal
failure, and stroke
– Heart must work harder  myocardium
enlarges, weakens, becomes flabby
– Also accelerates atherosclerosis
© 2013 Pearson Education, Inc.
Primary or Essential Hypertension
• 90% of hypertensive conditions
• No underlying cause identified
– Risk factors include heredity, diet, obesity,
age, diabetes mellitus, stress, and smoking
• No cure but can be controlled
– Restrict salt, fat, cholesterol intake
– Increase exercise, lose weight, stop smoking
– Antihypertensive drugs
© 2013 Pearson Education, Inc.
Homeostatic Imbalance: Hypertension
• Secondary hypertension less common
– Due to identifiable disorders including
obstructed renal arteries, kidney disease, and
endocrine disorders such as hyperthyroidism
and Cushing's syndrome
– Treatment focuses on correcting underlying
cause
© 2013 Pearson Education, Inc.
Alterations in Blood Pressure
• Hypotension: low blood pressure
– Blood pressure below 90/60 mm Hg
– Usually not a concern
• Only if leads to inadequate blood flow to tissues
– Often associated with long life and lack of
cardiovascular illness
© 2013 Pearson Education, Inc.
Homeostatic Imbalance: Hypotension
• Orthostatic hypotension: temporary low
BP and dizziness when suddenly rising
from sitting or reclining position
• Chronic hypotension: hint of poor
nutrition and warning sign for Addison's
disease or hypothyroidism
• Acute hypotension: important sign of
circulatory shock; threat for surgical
patients and those in ICU
© 2013 Pearson Education, Inc.
Blood Flow Through Body Tissues
• Tissue perfusion involved in
– Delivery of O2 and nutrients to, and removal of
wastes from, tissue cells
– Gas exchange (lungs)
– Absorption of nutrients (digestive tract)
– Urine formation (kidneys)
• Rate of flow is precisely right amount to
provide proper function
© 2013 Pearson Education, Inc.
Figure 19.13 Distribution of blood flow at rest and during strenuous exercise.
750
750
Brain
750
Heart
250
12,500
1200
Skeletal
muscles
500
Skin
Kidneys
1100
Abdomen
1400
1900
Other
600
Total blood
flow at rest
5800 ml/min
600
600
400
© 2013 Pearson Education, Inc.
Total blood flow during
strenuous exercise
17,500 ml/min
Velocity of Blood Flow
• Changes as travels through systemic
circulation
• Inversely related to total cross-sectional
area
• Fastest in aorta; slowest in capillaries;
increases in veins
• Slow capillary flow allows adequate time
for exchange between blood and tissues
© 2013 Pearson Education, Inc.
Figure 19.14 Blood flow velocity and total cross-sectional area of vessels.
Relative crosssectional area of
different vessels
of the vascular bed
5000
4000
Total area
(cm2) of the 3000
vascular
2000
bed
1000
0
Velocity of
blood flow
(cm/s)
© 2013 Pearson Education, Inc.
50
40
30
20
10
0
Autoregulation
• Automatic adjustment of blood flow to
each tissue relative to its varying
requirements
• Controlled intrinsically by modifying
diameter of local arterioles feeding
capillaries
– Independent of MAP, which is controlled as
needed to maintain constant pressure
• Organs regulate own blood flow by varying
resistance of own arterioles
© 2013 Pearson Education, Inc.
Autoregulation
• Two types of autoregulation
– Metabolic controls
– Myogenic controls
• Both determine final autoregulatory
response
© 2013 Pearson Education, Inc.
Metabolic Controls
• Vasodilation of arterioles and relaxation of
precapillary sphincters occur in response
to
– Declining tissue O2
– Substances from metabolically active tissues
(H+, K+, adenosine, and prostaglandins) and
inflammatory chemicals
© 2013 Pearson Education, Inc.
Metabolic Controls
• Effects
– Relaxation of vascular smooth muscle
– Release of NO (powerful vasodilator) by
endothelial cells
• Endothelins released from endothelium
are potent vasoconstrictors
• NO and endothelins balanced unless
blood flow inadequate, then NO wins
• Inflammatory chemicals also cause
vasodilation
© 2013 Pearson Education, Inc.
Myogenic Controls
• Myogenic responses keep tissue perfusion
constant despite most fluctuations in
systemic pressure
• Vascular smooth muscle responds to
stretch
– Passive stretch (increased intravascular
pressure) promotes increased tone and
vasoconstriction
– Reduced stretch promotes vasodilation and
increases blood flow to the tissue
© 2013 Pearson Education, Inc.
Figure 19.15 Intrinsic and extrinsic control of arteriolar smooth muscle in the systemic circulation.
Vasodilators
Metabolic
O2
CO2
H+
K+
• Prostaglandins
• Adenosine
• Nitric oxide
Neuronal
Sympathetic tone
Hormonal
• Atrial natriuretic
peptide
Extrinsic mechanisms
Intrinsic mechanisms
(autoregulation)
Vasoconstrictors
• Metabolic or myogenic controls
• Distribute blood flow to individual
organs and tissues as needed
Myogenic
• Stretch
© 2013 Pearson Education, Inc.
Neuronal
Sympathetic tone
Metabolic
Hormonal
• Endothelins
• Angiotensin II
• Antidiuretic hormone
• Epinephrine
• Norepinephrine
• Neuronal or hormonal controls
• Maintain mean arterial pressure
(MAP)
• Redistribute blood during exercise
and thermoregulation
Long-term Autoregulation
• Occurs when short-term autoregulation
cannot meet tissue nutrient requirements
• Angiogenesis
– Number of vessels to region increases and
existing vessels enlarge
– Common in heart when coronary vessel
occluded, or throughout body in people in
high-altitude areas
© 2013 Pearson Education, Inc.
Blood Flow: Skeletal Muscles
• Varies with fiber type and activity
– At rest, myogenic and general neural
mechanisms predominate - maintain ~ 1L
/minute
– During muscle activity
• Active or exercise hyperemia - blood flow
increases in direct proportion to metabolic activity
• Local controls override sympathetic
vasoconstriction
• Muscle blood flow can increase 10
© 2013 Pearson Education, Inc.
Blood Flow: Brain
• Blood flow to brain constant as neurons
intolerant of ischemia; averages 750
ml/min
• Metabolic controls
– Decreased pH of increased carbon dioxide
cause marked vasodilation
• Myogenic controls
– Decreased MAP causes cerebral vessels to
dilate
– Increased MAP causes cerebral vessels to
constrict
© 2013 Pearson Education, Inc.
Blood Flow: Brain
• Brain vulnerable under extreme systemic
pressure changes
– MAP below 60 mm Hg can cause syncope
(fainting)
– MAP above 160 can result in cerebral edema
© 2013 Pearson Education, Inc.
Blood Flow: Skin
• Blood flow through skin
– Supplies nutrients to cells (autoregulation in
response to O2 need)
– Helps regulate body temperature (neurally
controlled) – primary function
– Provides a blood reservoir (neurally
controlled)
© 2013 Pearson Education, Inc.
Blood Flow: Skin
• Blood flow to venous plexuses below skin
surface regulates body temperature
– Varies from 50 ml/min to 2500 ml/min,
depending on body temperature
– Controlled by sympathetic nervous system
reflexes initiated by temperature receptors
and central nervous system
© 2013 Pearson Education, Inc.
Temperature Regulation
• As temperature rises (e.g., heat exposure,
fever, vigorous exercise)
– Hypothalamic signals reduce vasomotor
stimulation of skin vessels 
– Warm blood flushes into capillary beds 
– Heat radiates from skin
© 2013 Pearson Education, Inc.
Temperature Regulation
• Sweat also causes vasodilation via
bradykinin in perspiration
– Bradykinin stimulates NO release
• As temperature decreases, blood is
shunted to deeper, more vital organs
© 2013 Pearson Education, Inc.
Blood Flow: Lungs
• Pulmonary circuit unusual
– Pathway short
– Arteries/arterioles more like veins/venules
(thin walled, with large lumens)
– Arterial resistance and pressure are low
(24/10 mm Hg)
© 2013 Pearson Education, Inc.
Blood Flow: Lungs
• Autoregulatory mechanism opposite that in
most tissues
– Low O2 levels cause vasoconstriction; high
levels promote vasodilation
• Allows blood flow to O2-rich areas of lung
© 2013 Pearson Education, Inc.
Blood Flow: Heart
• During ventricular systole
– Coronary vessels are compressed
• Myocardial blood flow ceases
• Stored myoglobin supplies sufficient oxygen
• During diastole high aortic pressure forces
blood through coronary circulation
• At rest ~ 250 ml/min; control probably
myogenic
© 2013 Pearson Education, Inc.
Blood Flow: Heart
• During strenuous exercise
– Coronary vessels dilate in response to local
accumulation of vasodilators
– Blood flow may increase three to four times
• Important–cardiac cells use 65% of O2 delivered
so increased blood flow provides more O2
© 2013 Pearson Education, Inc.
Blood Flow Through Capillaries
• Vasomotion
– Slow, intermittent flow
– Reflects on/off opening and closing of
precapillary sphincters
© 2013 Pearson Education, Inc.
Capillary Exchange of Respiratory Gases
and Nutrients
• Diffusion down concentration gradients
– O2 and nutrients from blood to tissues
– CO2 and metabolic wastes from tissues to blood
• Lipid-soluble molecules diffuse directly through
endothelial membranes
• Water-soluble solutes pass through clefts and
fenestrations
• Larger molecules, such as proteins, are actively
transported in pinocytotic vesicles or caveolae
© 2013 Pearson Education, Inc.
Figure 19.16 Capillary transport mechanisms. (1 of 2)
Pinocytotic
vesicles
Red blood
cell in lumen
Endothelial
cell
Fenestration
(pore)
Endothelial
cell nucleus
Basement
membrane
© 2013 Pearson Education, Inc.
Tight
junction
Intercellular
cleft
Figure 19.16 Capillary transport mechanisms. (2 of 2)
Lumen
Caveolae
Pinocytotic
vesicles
Intercellular
cleft
Endothelial
fenestration
(pore)
Basement
membrane
1 Diffusion
through
membrane
(lipid-soluble
substances)
© 2013 Pearson Education, Inc.
2 Movement
through
intercellular
clefts (watersoluble
substances)
4 Transport
via vesicles
or caveolae
(large
substances)
3 Movement
through
fenestrations
(water-soluble
substances)
Fluid Movements: Bulk Flow
• Fluid leaves capillaries at arterial end;
most returns to blood at venous end
– Extremely important in determining relative
fluid volumes in blood and interstitial space
• Direction and amount of fluid flow depend
on two opposing forces: hydrostatic and
colloid osmotic pressures
© 2013 Pearson Education, Inc.
Hydrostatic Pressures
• Capillary hydrostatic pressure (HPc)
(capillary blood pressure)
– Tends to force fluids through capillary walls
– Greater at arterial end (35 mm Hg) of bed
than at venule end (17 mm Hg)
• Interstitial fluid hydrostatic pressure
(HPif)
– Pressure that would push fluid into vessel
– Usually assumed to be zero because of
lymphatic vessels
© 2013 Pearson Education, Inc.
Colloid Osmotic Pressures
• Capillary colloid osmotic pressure
(oncotic pressure) (OPc)
– Created by nondiffusible plasma proteins,
which draw water toward themselves
– ~26 mm Hg
• Interstitial fluid osmotic pressure (OPif)
– Low (~1 mm Hg) due to low protein content
© 2013 Pearson Education, Inc.
Hydrostatic-osmotic Pressure Interactions:
Net Filtration Pressure (NFP)
• NFP—comprises all forces acting on
capillary bed
– NFP = (HPc + OPif) – (HPif + OPc)
• Net fluid flow out at arterial end
• Net fluid flow in at venous end
• More leaves than is returned
– Excess fluid returned to blood via lymphatic
system
© 2013 Pearson Education, Inc.
Figure 19.17 Bulk fluid flow across capillary walls causes continuous mixing of fluid between the plasma and the
interstitial fluid compartments, and maintains the interstitial environment. (1 of 5)
The big picture
Fluid filters from capillaries at their arteriolar
end and flows through the interstitial space.
Most is reabsorbed at the venous end.
Arteriole
Fluid moves through
the interstitial space.
For all capillary beds,
20 L of fluid is filtered
out per day—almost 7
times the total plasma
volume!
Net filtration pressure (NFP) determines the
direction of fluid movement. Two kinds of
pressure drive fluid flow:
Hydrostatic pressure (HP)
• Due to fluid pressing against a
boundary
• HP “pushes” fluid across the
boundary
• In blood vessels, is due to blood
pressure
Osmotic pressure (OP)
• Due to nondiffusible solutes that
cannot cross the boundary
• OP “pulls” fluid across the
boundary
• In blood vessels, is due to
plasma proteins
Piston
Boundary
“Pushes”
Solute
molecules
(proteins)
17 L of fluid per
day is reabsorbed
into the capillaries
at the venous end.
Boundary
“Pulls”
Venule
© 2013 Pearson Education, Inc.
About 3 L per day
of fluid (and any
leaked proteins) are
removed by the
lymphatic system
(see Chapter 20).
Lymphatic
capillary
Figure 19.17 Bulk fluid flow across capillary walls causes continuous mixing of fluid between the plasma and the
interstitial fluid compartments, and maintains the interstitial environment. (3 of 5)
Net filtration pressure (NFP) determines the
direction of fluid movement. Two kinds of
pressure drive fluid flow:
Hydrostatic pressure (HP)
Osmotic pressure (OP)
• Due to fluid pressing against a
boundary
• HP “pushes” fluid across the
boundary
• In blood vessels, is due to blood
pressure
• Due to nondiffusible solutes that
cannot cross the boundary
• OP “pulls” fluid across the
boundary
• In blood vessels, is due to
plasma proteins
Piston
Solute
molecules
(proteins)
Boundary
“Pushes”
© 2013 Pearson Education, Inc.
“Pulls”
Boundary
Figure 19.17 Bulk fluid flow across capillary walls causes continuous mixing of fluid between the plasma and the
interstitial fluid compartments, and maintains the interstitial environment. (4 of 5)
How do the pressures drive fluid flow across a capillary?
Net filtration occurs at the arteriolar end of a capillary.
Capillary
Hydrostatic pressure
in capillary “pushes”
fluid out of capillary.
Osmotic pressure in
capillary “pulls” fluid
into capillary.
Boundary
(capillary wall)
HPc = 35 mm Hg
OPc = 26 mm Hg
HPif = 0 mm Hg
OPif = 1 mm Hg
NFP = 10 mm Hg
© 2013 Pearson Education, Inc.
Interstitial fluid
Hydrostatic
pressure in
interstitial fluid
“pushes” fluid
into capillary.
Osmotic pressure
in interstitial fluid
“pulls” fluid out
of capillary.
To determine the pressure driving
the fluid out of the capillary at any
given point, we calculate the net
filtration pressure (NFP)––the
outward pressures (HPc and OPif)
minus the inward pressures
(HPif and OPc). So,
NFP = (HPc + OPif) – (HPif + OPc)
= (35 + 1) – (0 + 26)
= 10 mm Hg (net outward
pressure)
As a result, fluid moves from the
capillary into the interstitial space.
Figure 19.17 Bulk fluid flow across capillary walls causes continuous mixing of fluid between the plasma and the
interstitial fluid compartments, and maintains the interstitial environment. (5 of 5)
Net reabsorption occurs at the venous end of a capillary.
Boundary
(capillary wall)
Capillary
Interstitial fluid
Hydrostatic pressure in capillary
HPc = 17 mm Hg
“pushes” fluid out of capillary.
The pressure has dropped
because of resistance encountered
along the capillaries.
Osmotic pressure in capillary
“pulls” fluid into capillary.
OPc = 26 mm Hg
HPif = 0 mm Hg
Hydrostatic pressure in
interstitial fluid “pushes”
fluid into capillary.
OPif = 1 mm Hg
Osmotic pressure in
interstitial fluid “pulls”
fluid out of capillary.
NFP= –8 mm Hg
© 2013 Pearson Education, Inc.
Again, we calculate the NFP:
NFP = (HPc + OPif) – (HPif + OPc)
= (17 + 1) – (0 + 26)
= –8 mm Hg (net inward
pressure)
Notice that the NFP at the venous
end is a negative number. This
means that reabsorption, not
filtration, is occurring and so fluid
moves from the interstitial space
into the capillary.
Circulatory Shock
• Any condition in which
– Blood vessels inadequately filled
– Blood cannot circulate normally
• Results in inadequate blood flow to meet
tissue needs
© 2013 Pearson Education, Inc.
Circulatory Shock
• Hypovolemic shock: results from largescale blood loss
• Vascular shock: results from extreme
vasodilation and decreased peripheral
resistance
• Cardiogenic shock results when an
inefficient heart cannot sustain adequate
circulation
© 2013 Pearson Education, Inc.
Figure 19.18 Events and signs of hypovolemic shock.
Acute bleeding (or other events that reduce
blood volume) leads to:
1. Inadequate tissue perfusion
resulting in O2 and nutrients to cells
Initial stimulus
Physiological response
Signs and symptoms
Result
2. Anaerobic metabolism by cells, so lactic
acid accumulates
3. Movement of interstitial fluid into blood,
so tissues dehydrate
Chemoreceptors activated
(by in blood pH)
Baroreceptor firing reduced
(by blood volume and pressure)
Hypothalamus activated
(by blood pressure)
Brain
Minor effect
Major effect
Respiratory centers
activated
Cardioacceleratory and
vasomotor centers activated
Heart rate
Sympathetic nervous
system activated
ADH
released
Neurons
depressed
by pH
Intense vasoconstriction
(only heart and brain spared)
Central
nervous system
depressed
Kidneys
Renal blood flow
Adrenal
cortex
Renin released
Angiotensin II
produced in blood
Aldosterone
released
Rate and
depth of
breathing
CO2 blown
off; blood
pH rises
© 2013 Pearson Education, Inc.
Tachycardia;
weak, thready
pulse
Kidneys retain
salt and water
Skin becomes
cold, clammy,
and cyanotic
Blood pressure maintained;
if fluid volume continues to
decrease, BP ultimately
drops. BP is a late sign.
Water
retention
Urine output
Thirst
Restlessness
(early sign)
Coma
(late sign)
Circulatory Pathways: Blood Vessels of the
Body
• Two main circulations
– Pulmonary circulation: short loop that runs
from heart to lungs and back to heart
– Systemic circulation: long loop to all parts of
body and back to heart
© 2013 Pearson Education, Inc.
Figure 19.19a Pulmonary circulation.
Pulmonary
capillaries
of the
R. lung
R. pulmonary
artery
Pulmonary
capillaries
of the
L. lung
L. pulmonary
artery
To
systemic
circulation
Pulmonary
trunk
R. pulmonary veins
From
systemic
circulation
LA
RA
L. pulmonary
veins
RV
© 2013 Pearson Education, Inc.
Schematic flowchart.
LV
Figure 19.19 Pulmonary circulation.
Pulmonary
capillaries
of the
R. lung
Pulmonary
capillaries
of the
L. lung
R. pulmonary L. pulmonary
artery
artery
To
systemic
circulation
Pulmonary
trunk
R. pulmonary veins
From
systemic
circulation
RA
LA
RV
LV
L. pulmonary
veins
Schematic flowchart.
Left pulmonary
artery
Air-filled
alveolus
of lung
Aortic arch
Pulmonary trunk
Right pulmonary
artery
Three lobar arteries
to right lung
Pulmonary
capillary
Gas exchange
Two lobar arteries
to left lung
Pulmonary
veins
Pulmonary
veins
Right
atrium
Left atrium
Right
ventricle
Left
ventricle
Illustration. The pulmonary arterial system is shown in blue to indicate that the blood it carries is oxygen-poor.
The pulmonary venous drainage is shown in red to indicate that the blood it transports is oxygen-rich.
© 2013 Pearson Education, Inc.
Figure 19.20 Schematic flowchart showing an overview of the systemic circulation.
Common
carotid arteries
to head and
subclavian
arteries to
upper limbs
Capillary beds of
head and
upper limbs
Superior
vena cava
Aortic
arch
Aorta
RA
LA
RV LV
Azygos
system
Venous
drainage
Inferior
vena
cava
Thoracic
aorta
Arterial
blood
Capillary beds of
mediastinal structures
and thorax walls
Diaphragm
Abdominal
aorta
Inferior
vena
cava
© 2013 Pearson Education, Inc.
Capillary beds of
digestive viscera,
spleen, pancreas,
kidneys
Capillary beds of
gonads, pelvis, and
lower limbs
Differences Between Arteries and Veins
Arteries
Veins
Delivery
Blood pumped into single
systemic artery—the aorta
Blood returns via
superior and interior
venae cavae and the
coronary sinus
Location
Deep, and protected by tissues
Both deep and superficial
Pathways
Fairly distinct
Numerous
interconnections
Supply/drainage
Predictable supply
Usually similar to
arteries, except dural
sinuses and hepatic
portal circulation
© 2013 Pearson Education, Inc.
Developmental Aspects
• Endothelial lining arises from mesodermal
cells in blood islands
• Blood islands form rudimentary vascular
tubes, guided by cues
• Vascular endothelial growth factor
determines whether vessel becomes
artery or vein
• The heart pumps blood by the 4th week of
development
© 2013 Pearson Education, Inc.
Developmental Aspects
• Fetal shunts (foramen ovale and ductus
arteriosus) bypass nonfunctional lungs
• Ductus venosus bypasses liver
• Umbilical vein and arteries circulate blood
to and from placenta
• Congenital vascular problems rare
© 2013 Pearson Education, Inc.
Developmental Aspects
• Vessel formation occurs
– To support body growth
– For wound healing
– To rebuild vessels lost during menstrual
cycles
• With aging, varicose veins,
atherosclerosis, and increased blood
pressure may arise
© 2013 Pearson Education, Inc.
Figure 19.21a Major arteries of the systemic circulation.
R. internal
carotid artery
R. external
carotid artery
R. common carotid
– right side of head and neck
R. vertebral
R. axillary
R. subclavian
– neck and
R. upper limb
Brachiocephalic
– head, neck, and
R. upper limb
Arteries of
R. upper
limb
L. external
carotid artery
L. internal
carotid artery
L. common carotid
– left side of head and neck
L. vertebral
L. subclavian
– neck and L.
upper limb
Aortic arch
L. axillary
Arteries of
L. upper
limb
Ascending aorta
– L. ventricle to sternal angle
Thoracic aorta T5–T12 (diaphragm)
L. and R. coronary
arteries
L. ventricle of heart
Visceral branches
Mediastinal
– posterior
mediastinum
Esophageal
– esophagus
Bronchial
– lungs and
bronchi
Parietal branches
Pericardial
– pericardium
Posterior intercostals
– intercostal muscles, spinal
cord, vertebrae, pleurae, skin
Superior phrenics
– posterior and superior
diaphragm
Diaphragm
Abdominal aorta T12 (diaphragm)–L4
Visceral branches
Gonadal
– testes or
ovaries
Suprarenal
– adrenal
glands
and
Renal
– kidneys
Superior
and inferior
mesenterics
– small
intestine
– colon
Parietal branches
Celiac trunk
– liver
– gallbladder
– spleen
– stomach
– esophagus
– duodenum
R. common iliac
– pelvis and R. lower limb
Arteries of R. lower limb
Schematic flowchart
© 2013 Pearson Education, Inc.
Inferior phrenics
– inferior diaphragm
Lumbars
– posterior
abdominal
wall
Median sacral
– sacrum
– coccyx
L. common iliac
– pelvis and L. lower limb
Arteries of L. lower limb
Figure 19.21b Major arteries of the systemic circulation.
Arteries of the head and trunk
Internal carotid artery
External carotid artery
Common carotid arteries
Vertebral artery
Subclavian artery
Brachiocephalic trunk
Arteries that supply the upper limb
Subclavian artery
Axillary artery
Brachial artery
Aortic arch
Ascending aorta
Coronary artery
Celiac trunk
Abdominal aorta
Superior mesenteric
artery
Renal artery
Gonadal artery
Radial artery
Ulnar artery
Deep palmar arch
Superficial palmar arch
Digital arteries
Arteries that supply the lower
limb
External iliac artery
Inferior mesenteric artery
Femoral artery
Common iliac artery
Popliteal artery
Internal iliac artery
Anterior tibial artery
Posterior tibial artery
Illustration, anterior view
© 2013 Pearson Education, Inc.
Arcuate artery
Figure 19.22a Arteries of the head, neck, and brain.
R. and L. anterior
cerebral arteries
R. Middle
cerebral
artery
Anterior
communicating artery
Cerebral arterial circle
R. and L.
Posterior
communicating arteries
Ophthalmic artery
Superficial
temporal
artery
R. posterior
cerebral
artery
Basilar
artery
R. and L.
vertebral
arteries
Maxillary
artery
Occipital
artery
R. and L.
internal
carotid
arteries
Facial
artery
Lingual
artery
R. and L.
external
carotid
arteries
Superior
thyroid
artery
R. and L.
common
carotid
arteries
R. and L.
subclavian
arteries
Brachiocephalic trunk
Aortic arch
© 2013 Pearson Education, Inc.
Schematic flowchart
Figure 19.22b Arteries of the head, neck, and brain.
Ophthalmic artery
Basilar artery
Vertebral
artery
Internal
carotid artery
External
carotid artery
Common
carotid artery
Thyrocervical
trunk
Costocervical
trunk
Subclavian
artery
Axillary
artery
Arteries of the head and neck, right aspect
© 2013 Pearson Education, Inc.
Branches of
the external
carotid artery
• Superficial
temporal artery
• Maxillary artery
• Occipital artery
• Facial artery
• Lingual artery
• Superior thyroid
artery
Larynx
Thyroid gland
(overlying trachea)
Clavicle (cut)
Brachiocephalic
trunk
Internal thoracic
artery
Figure 19.22c Arteries of the head, neck, and brain.
© 2013 Pearson Education, Inc.
Colorized arteriograph of the arterial supply
of the brain
Figure 19.22d Arteries of the head, neck, and brain.
Anterior
Cerebral arterial
circle
(circle of Willis)
Frontal lobe
Optic chiasma
• Anterior
communicating
artery
Middle
cerebral
artery
• Anterior
cerebral artery
Internal
carotid
artery
• Posterior
communicating
artery
Mammillary
body
• Posterior
cerebral artery
Basilar artery
Temporal
lobe
Vertebral artery
Pons
Occipital lobe
Cerebellum
Posterior
Major arteries serving the brain (inferior view, right side
of cerebellum and part of right temporal lobe removed)
© 2013 Pearson Education, Inc.
Figure 19.23a Arteries of the right upper limb and thorax.
R. vertebral artery
R. common
carotid
artery
L. common carotid
artery
Thyrocervical trunk
L. vertebral artery
L. subclavian
artery
Suprascapular artery
R. subclavian artery.
Axillary artery
Thoracoacromial
artery
Thoracoacromial
artery
(pectoral
branch)
Aortic arch
Anterior
and posterior
circumflex
humeral
arteries
Brachial
artery
Deep
artery
of arm
Brachiocephalic
trunk
Internal
thoracic
artery
Anterior
intercostal
arteries
Lateral
thoracic
artery
Subscapular
artery
Anastomosis
Common
interosseus
artery
Radial
artery
Deep
palmar
arch
Ulnar artery
Metacarpal arteries
Superficial palmar arch
Digital arteries
© 2013 Pearson Education, Inc.
Schematic flowchart
Costocervical
trunk
Thoracic
aorta
Posterior
intercostal
arteries
Figure 19.23b Arteries of the right upper limb and thorax.
Vertebral artery
Thyrocervical trunk
Costocervical trunk
Suprascapular artery
Thoracoacromial artery
Axillary artery
Subscapular artery
Posterior circumflex
humeral artery
Anterior circumflex
humeral artery
Common carotid arteries
Right subclavian artery
Left subclavian artery
Brachiocephalic trunk
Posterior
intercostal arteries
Anterior intercostal artery
Internal thoracic artery
Brachial artery
Deep artery of arm
Lateral thoracic artery
Thoracic aorta
Common
interosseous artery
Radial artery
Ulnar artery
Deep palmar arch
Superficial palmar arch
Digital arteries
Illustration, anterior view
© 2013 Pearson Education, Inc.
Figure 19.24a Arteries of the abdomen.
Diaphragm
Abdominal
aorta
Inferior
phrenic
arteries
L. gastric artery
R. gastric
artery
Common
hepatic
artery
Hepatic
artery
proper
L
Splenic
artery
Gastroduodenal
artery
R
Celiac
trunk
R. gastroepiploic
artery
Middle
suprarenal
arteries
L. gastroepiploic artery
Intestinal arteries
Middle colic
artery
Superior
mesenteric
artery
R. colic
artery
Renal
arteries
Gonadal
arteries
Ileocolic artery
Sigmoidal
arteries
Inferior
mesenteric
artery
Lumbar
arteries
L. colic
artery
Superior rectal
artery
Median sacral artery
Common iliac arteries
Schematic flowchart.
© 2013 Pearson Education, Inc.
Figure 19.24b Arteries of the abdomen.
Liver (cut)
Inferior vena cava
Celiac trunk
Common
hepatic artery
Hepatic
artery proper
Gastroduodenal
artery
Right
gastric artery
Diaphragm
Esophagus
Left gastric artery
Stomach
Splenic artery
Left gastroepiploic
artery
Spleen
Gallbladder
Pancreas
(major portion lies
posterior to stomach)
Right gastroepiploic
artery
Duodenum
Abdominal aorta
Superior mesenteric
artery
The celiac trunk and its major branches. The left half of the liver has been removed.
© 2013 Pearson Education, Inc.
Figure 19.24c Arteries of the abdomen.
Hiatus (opening)
for inferior vena cava
Hiatus (opening)
for esophagus
Diaphragm
Inferior
phrenic artery
Adrenal
(suprarenal) gland
Middle
suprarenal artery
Celiac trunk
Renal artery
Kidney
Superior
mesenteric artery
Abdominal aorta
Lumbar arteries
Ureter
Median
sacral artery
Major branches of the abdominal aorta.
© 2013 Pearson Education, Inc.
Gonadal
(testicular
or ovarian) artery
Inferior
mesenteric artery
Common
iliac artery
Figure 19.24d Arteries of the abdomen.
Celiac trunk
Superior mesenteric
artery
Branches of
the superior
mesenteric artery
• Middle colic artery
• Intestinal arteries
• Right colic artery
• Ileocolic artery
Ascending colon
Right common iliac
artery
Ileum
Transverse colon
Aorta
Inferior mesenteric
artery
Branches of
the inferior
mesenteric artery
• Left colic artery
• Sigmoidal arteries
• Superior rectal
artery
Descending colon
Cecum
Appendix
Distribution of the superior and inferior mesenteric arteries.
The transverse colon has been pulled superiorly.
© 2013 Pearson Education, Inc.
Sigmoid colon
Rectum
Figure 19.25a Arteries of the right pelvis and lower limb.
Abdominal
aorta
Superior
gluteal
artery
Internal
iliac
artery
Inferior
gluteal
artery
Internal
pudendal
Common
iliac
artery
Obturator
artery
Deep artery
of thigh
Medial
circumflex
femoral
artery
Lateral
circumflex
femoral
artery
External
iliac
artery
Femoral
artery
Adductor
hiatus
Arterial
anastomosis
Popliteal
artery
Anterior
tibial
artery
Posterior tibial
artery
Fibular
(peroneal)
artery
Dorsalis
pedis
artery
Lateral
plantar
artery
Lateral
plantar
artery
Medial
plantar
artery
Arcuate
artery
Plantar arch
Dorsal
metatarsal
arteries
Schematic flowchart
© 2013 Pearson Education, Inc.
Plantar
metatarsal
arteries
Figure 19.25b Arteries of the right pelvis and lower limb.
Common iliac artery
Internal iliac artery
Superior gluteal artery
External iliac artery
Deep artery of thigh
Lateral circumflex
femoral artery
Medial circumflex
femoral artery
Obturator artery
Femoral artery
Adductor hiatus
Popliteal artery
Anterior tibial artery
Posterior tibial artery
Fibular artery
Dorsalis pedis artery
Arcuate artery
Dorsal metatarsal
arteries
© 2013 Pearson Education, Inc.
Anterior view
Figure 19.25c Arteries of the right pelvis and lower limb.
Popliteal artery
Anterior tibial
artery
Posterior tibial
artery
Lateral plantar
artery
Medial plantar
artery
© 2013 Pearson Education, Inc.
Posterior view
Fibular artery
Dorsalis pedis
artery (from top
of foot)
Plantar arch
Figure 19.26a Major veins of the systemic circulation.
Veins of
R. upper
limb
R. axillary
R. external
jugular
– superficial
head and neck
R. vertebral
– cervical spinal
cord and
vertebrae
Intracranial
dural venous sinuses
R. internal jugular
– dural venous
sinuses of the brain
R. subclavian
– R. head, neck,
and upper
limb
Same as R. brachiocephalic
R. brachiocephalic
– R. side of head and R. upper limb
L. brachiocephalic
– L. side of head and L. upper limb
Superior vena cava
– runs from union of brachiocephalic
veins behind manubrium to R. atrium
Azygos system
– drains much of
thorax
R. atrium of heart
Diaphragm
Inferior vena cava
– runs from junction of common iliac
veins at L5 to R. atrium of heart
R. suprarenal
(L. suprarenal drains
into L. renal vein)
– adrenal glands
R. gonadal
(L. gonadal drains
into L. renal vein)
– testis or ovary
R. common iliac
– pelvis and R. lower
limb
Veins of
R. lower limb
© 2013 Pearson Education, Inc.
Schematic flowchart.
L., R., and middle
hepatic veins
– liver
L. and R. renal veins
– kidneys
Lumbar veins
(several pairs)
– posterior abdominal
wall
L. common iliac
– pelvis and L. lower
limb
Veins of
L. lower limb
Figure 19.26b Major veins of the systemic circulation.
Veins of the head and trunk
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
Superior mesenteric vein
Inferior mesenteric vein
Inferior vena cava
Common iliac vein
Internal iliac 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
External iliac vein
Femoral vein
Great saphenous vein
Popliteal vein
Posterior tibial vein
Anterior tibial vein
Small saphenous vein
Dorsal venous arch
Dorsal metatarsal veins
Illustration, anterior view. The vessels of the pulmonary circulation are not shown.
© 2013 Pearson Education, Inc.
Figure 19.27a Venous drainage of the head, neck, and brain.
Superior sagittal sinus
Inferior sagittal sinus
Occipital
vein
Superficial
temporal vein
Straight
sinus
Transverse
sinus
Ophthalmic
vein
Cavernous
sinus
Facial vein
Posterior auricular
vein
Sigmoid sinus
Internal jugular vein
External jugular
vein
Superior thyroid vein
Vertebral vein
Middle thyroid vein
Brachiocephalic veins
Subclavian vein
Superior vena cava
Schematic flowchart
© 2013 Pearson Education, Inc.
Figure 19.27b Venous drainage of the head, neck, and brain.
Ophthalmic vein
Superficial
temporal vein
Facial vein
Occipital vein
Posterior
auricular vein
External
jugular vein
Vertebral vein
Internal
jugular vein
Superior and
middle thyroid veins
Brachiocephalic
vein
Subclavian vein
Superior
vena cava
Veins of the head and neck, right superficial aspect
© 2013 Pearson Education, Inc.
Figure 19.27c Venous drainage of the head, neck, and brain.
Superior sagittal sinus
Falx cerebri
Inferior sagittal sinus
Straight sinus
Cavernous sinus
Transverse sinuses
Sigmoid sinus
Jugular foramen
Right internal jugular vein
Dural venous sinuses of the brain
© 2013 Pearson Education, Inc.
Figure 19.28a Veins of the thorax and right upper limb.
Internal
Subclavian
jugular vein
vein
External
Brachiocephalic
jugular vein veins
Axillary
vein
Superior
vena cava
Accessory
hemiazygos
vein
Median
cubital
vein
Azygos
vein
Brachial
vein
Hemiazygos
vein
Right and left posterior
intercostal veins
Cephalic
vein
Median
antebrachial
vein
Radial
vein
Basilic
vein
Ulnar
vein
Deep venous
palmar arch
Metacarpal veins
Superficial venous
palmar arch
Digital veins
Schematic flowchart
© 2013 Pearson Education, Inc.
Figure 19.28b Veins of the thorax and right upper limb.
Brachiocephalic veins
Right subclavian vein
Axillary vein
Brachial vein
Cephalic vein
Basilic vein
Internal jugular vein
External jugular vein
Left subclavian vein
Superior vena cava
Azygos vein
Accessory hemiazygos
vein
Hemiazygos vein
Posterior intercostals
Inferior vena cava
Ascending lumbar vein
Median cubital
vein
Median
antebrachial vein
Cephalic vein
Radial vein
Anterior view
© 2013 Pearson Education, Inc.
Basilic vein
Ulnar vein
Deep venous
palmar arch
Superficial venous
palmar arch
Digital veins
Figure 19.29a Veins of the abdomen.
Inferior vena cava
Cystic vein
Hepatic
portal
system
Inferior phrenic veins
Hepatic veins
Hepatic portal vein
Superior mesenteric vein
Splenic vein
Suprarenal veins
Renal veins
Inferior
mesenteric
vein
Gonadal veins
Lumbar veins
R. ascending
lumbar vein
L. ascending
lumbar vein
Common iliac veins
External iliac vein
Internal iliac veins
Schematic flowchart.
© 2013 Pearson Education, Inc.
Figure 19.29b Veins of the abdomen.
Hepatic veins
Inferior phrenic
vein
Inferior vena cava
Right suprarenal
vein
Left suprarenal
vein
Renal veins
Right gonadal
vein
External iliac
vein
Left ascending
lumbar vein
Lumbar veins
Left gonadal
vein
Common iliac
vein
Internal iliac
vein
Tributaries of the inferior vena cava.
Venous drainage of abdominal organs not drained by the hepatic portal vein.
© 2013 Pearson Education, Inc.
Figure 19.29c Veins of the abdomen.
Hepatic veins
Liver
Hepatic portal
vein
Gastric veins
Spleen
Inferior vena cava
Splenic vein
Right
gastroepiploic vein
Inferior
mesenteric vein
Superior
mesenteric vein
Small intestine
Large intestine
Rectum
The hepatic portal circulation.
© 2013 Pearson Education, Inc.
Figure 19.30a Veins of the right lower limb.
Internal
iliac
vein
Inferior
vena cava
Common iliac vein
External iliac vein
Femoral
vein
Great
saphenous
vein
Femoral
vein
Popliteal
vein
Small
saphenous
vein
Small
saphenous
vein
Anterior
tibial
vein
Fibular
(peroneal)
vein
Fibular
(peroneal)
vein
Posterior
tibial
vein
Plantar
veins
Dorsalis
pedis
vein
Dorsal
venous
arch
Deep
plantar arch
Dorsal
metatarsal
veins
Digital
veins
Anterior
Posterior
Schematic flowchart of the anterior and posterior veins
© 2013 Pearson Education, Inc.
Figure 19.30b Veins of the right lower limb.
Common iliac vein
Internal iliac vein
External iliac vein
Inguinal ligament
Femoral vein
Great saphenous
vein (superficial)
Popliteal vein
Small
saphenous vein
Fibular vein
Anterior
tibial vein
Dorsalis
pedis vein
Dorsal
venous arch
Dorsal
metatarsal veins
© 2013 Pearson Education, Inc.
Anterior view
Figure 19.30c Veins of the right lower limb.
Great
saphenous
vein
Popliteal
vein
Anterior
tibial vein
Fibular
vein
Small
saphenous
vein
(superficial)
Posterior
tibial
vein
Plantar
veins
Deep
plantar arch
Digital veins
© 2013 Pearson Education, Inc.
Posterior view