chapter 22 218... · 2015-06-08 · histological organization of blood vessels •characteristics...

Lecture Presentation by

Steven Bassett

Southeast Community College

Chapter 22

The Cardiovascular

System

Vessels and

Circulation

© 2015 Pearson Education, Inc.

Introduction

• There are two groups of blood vessels

• Pulmonary circuit

• Blood goes to and from the lungs

• Systemic circuit

• Blood goes to the rest of the body and back to the

heart

• Blood goes to both circuits at the same time with

each heartbeat


Histological Organization of Blood Vessels

• The walls of the vessels consist of three layers

• The layered walls give the vessels tremendous

strength

• The vessel walls are thick

• The walls themselves are supplied with blood

• These blood vessels are called vasa vasorum



• Characteristics of the Three Layers

• Intima (innermost layer)

• Also called tunica intima

• Makes up the endothelium of the vessel

• Media (middle layer)

• Also called tunica media

• Consists of smooth muscle

• Involved in vasoconstriction and vasodilation

• Adventitia (outermost layer)

• Also called tunica adventitia

• Fibers of the adventitia anchor the blood vessels


Figure 22.1 The Structure of Blood Vessels (4 of 8)


Lumenofartery

Endothelium

Adventitia

Smooth

muscle

Media

Intima

Lumen

of vein

Adventitia

Media

Intima

Endothelium

ARTERY VEIN

LM × 60Artery and Vein

Histological Comparison of Arteries and Veins

AV bundle

The internal elastic

membrane is a network of

elastic fibers located between

the intima and the media.

The media is separated fromthe adventitia by the external

elastic membrane, a band

of elastic tissue.

Elastic fiber

Smooth muscle


• Distinguishing Arteries from Veins

• Most arteries and veins run parallel to each other

• Arteries carry blood away from the heart

• Veins carry blood toward the heart

• Walls of arteries are thicker than veins

• Arteries maintain their circular shape and veins

typically collapse when cut

• Endothelial lining of arteries have pleated folds—

endothelial lining of veins do not




Large veins include the superior and inferior

venae cavae (also termed the great veins) and

their tributaries within the abdominopelvic

and thoracic cavities.

Structural Differences between Arteries and Veins

VEINS ARTERIES Start

Large Vein7

Adventitia

Media

Endothelium

Intima

Medium-sized veins, such as the radial and ulnar

veins, range from 2 to 9 mm in internal diameter and

correspond in general size to muscular arteries. In

these veins the media is thin,

and it contains relatively few

smooth muscle cells.

Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima

Venules, the smallest veins, collect blood from

capillaries. They vary widely in diameter and

character, and the small venules are both

innumerable and unnamed. The smallest

venules resemble expanded capillaries,

and venules smaller than 50 m in

total diameter lack a media

altogether.

Venule5

Adventitia

Endothelium

Capillaries4

Fenestrated capillaries are

capillaries that contain

“windows,” or pores in

their walls, due to an

incomplete or

perforated endothelial

lining.

Fenestrated Capillary

Pores

Endothelial

cells

Basal lamina

Elastic Artery 1

The walls of elastic arteries, such as the aorta and

brachiocephalic arteries, are not very thick relative to the

vessel diameter, but they are extremely

resilient. The media of these vessels

contains relatively few smooth

muscle cells and a high density

of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2

A typical muscular artery has a diameter of

approximately 4 mm (0.15 in.). Muscular arteries, such

as the radial and ulnar arteries, have a thicker media

with a greater percentage of smooth

muscle cells than elastic arteries.

Adventitia

Media

Endothelium

Intima

Arteriole 3

Arterioles have an average diameter of about 30 m. They

are considerably smaller than muscular arteries, and they

are both innumerable and unnamed. Arterioles have a

poorly defined adventitia, and the media

consists of scattered smooth muscle cells that

may not form a complete layer.

Smooth muscle cells

Endothelium

Basal lamina

Continuous Capillary Continuous capillaries are found

in most regions of the body. In

these capillaries the endothelium

is a complete lining, and the

endothelial cells are connected by

tight junctions and desmosomes.

Endothelial

cells

Basal lamina


• Arteries

• As blood leaves the heart, it travels through:

• Elastic arteries

• Muscular arteries

• Arterioles



• Elastic Arteries

• Large vessels up to 2.5 cm in diameter

• Very resilient

• Examples are:

• Aorta

• Brachiocephalic

• Pulmonary trunk

• Common carotid

• Subclavian

• Common iliac










Large Vein7

Adventitia

Media

Endothelium

Intima







Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima








altogether.

Venule5

Adventitia

Endothelium

Capillaries4





incomplete or


lining.


Pores

Endothelial

cells

Basal lamina

Elastic Artery 1







of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2






Adventitia

Media

Endothelium

Intima

Arteriole 3







Smooth muscle cells

Endothelium

Basal lamina







Endothelial

cells

Basal lamina


• Muscular Arteries

• Medium-sized arteries up to 0.4 cm diameter

• Examples are:

• Radial and ulnar

• External carotid

• Brachial

• Femoral

• Mesenteric










Large Vein7

Adventitia

Media

Endothelium

Intima







Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima








altogether.

Venule5

Adventitia

Endothelium

Capillaries4





incomplete or


lining.


Pores

Endothelial

cells

Basal lamina

Elastic Artery 1







of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2






Adventitia

Media

Endothelium

Intima

Arteriole 3







Smooth muscle cells

Endothelium

Basal lamina







Endothelial

cells

Basal lamina


• Arterioles

• Small arteries around 30 microns in diameter

• Poorly defined adventitia

• Control blood flow between arteries and capillaries










Large Vein7

Adventitia

Media

Endothelium

Intima







Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima








altogether.

Venule5

Adventitia

Endothelium

Capillaries4





incomplete or


lining.


Pores

Endothelial

cells

Basal lamina

Elastic Artery 1







of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2






Adventitia

Media

Endothelium

Intima

Arteriole 3







Smooth muscle cells

Endothelium

Basal lamina







Endothelial

cells

Basal lamina


• Capillaries

• Smallest of all vessels

• Most delicate of all vessels

• Walls are thin enough to permit exchange of

gases between the blood and the interstitial fluid

• The diameter is about 8 microns

• A red blood cell diameter is also about 8 microns



• Types of Capillaries

• Continuous

• Endothelial lining is complete

• Fenestrated

• Endothelial lining is not complete

• These capillaries have pores in their lining


Figure 22.2ab Structure of Capillaries and Sinusoids


Basal lamina

Fenestrations,

or pores

Nucleus

Endosomes

Endosomes

Boundary

between

endothelial

cells

Boundary

between

endothelial

cells

This diagrammatic view of a fenestrated

capillary details the structure of the wall.This diagrammatic view of a continuous

capillary shows the structure of its wall.

Basal

lamina

Basal

lamina

Endothelial cell

a b


• Capillaries (continued)

• There are four mechanisms regarding the

passage of material across the walls of capillaries

• Material can diffuse across the endothelial lining

• Material can diffuse through gaps between

adjacent cells of the lining

• Material can diffuse through pores

• Material can move via endocytosis



• Capillary Beds

• Capillaries do not function as individual units

• Capillaries form an interconnected network of

capillaries (capillary beds)

• The capillary bed consists of vessels connecting

arterioles with venules

• There are precapillary sphincters involved in

regulating blood flow through the capillaries


Figure 22.3a Organization of a Capillary Bed


Collateral

arteries

Arteriole

Smooth

muscle cells

Metarterioles

Vein

Venule

Arteriovenous

anastomosis

Precapillary

sphincters

Thoroughfare

channel

Consistent

blood flow

Variable

blood flow

KEY

Basic organization of a typical capillary bed. The

pattern of blood flow changes continually in response

to regional alterations in tissue oxygen demand.

Small

venule

Section of

precapillary

sphincter

Capillaries

a


• Capillary Beds (continued)

• In areas such as the brain, heart, and stomach, a

continuous, rich flow of blood is required

• In these areas, more than one artery supplies a

specific area

• These arteries (collateral arteries) typically fuse

forming an arterial anastomosis

• If one arteriole is blocked, the other one will supply

blood to the capillary bed



• Capillary Beds (continued)

• In areas such as the joints or visceral organs,

blood flow through some vessels may be

hindered due to body movement

• In order to accommodate this, there must be a

direct connection between arterioles and venules

• This direct connection is called an arteriovenous

anastomosis


Figure 22.3a Organization of a Capillary Bed


Collateral

arteries

Arteriole

Smooth

muscle cells

Metarterioles

Vein

Venule

Arteriovenous

anastomosis

Precapillary

sphincters

Thoroughfare

channel

Consistent

blood flow

Variable

blood flow

KEY

Basic organization of a typical capillary bed. The

pattern of blood flow changes continually in response

to regional alterations in tissue oxygen demand.

Small

venule

Section of

precapillary

sphincter

Capillaries

a


• Veins

• Veins collect blood from tissues and return the

blood to the heart

• As blood leaves the tissue and travels to the heart,

it travels through the following vessels:

• Capillary beds

• Capillaries

• Venules

• Medium-sized veins

• Large veins



• Venules

• Smallest of the veins

• Collect blood from the capillaries

• Lack or have thin tunica media










Large Vein7

Adventitia

Media

Endothelium

Intima







Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima








altogether.

Venule5

Adventitia

Endothelium

Capillaries4





incomplete or


lining.


Pores

Endothelial

cells

Basal lamina

Elastic Artery 1







of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2






Adventitia

Media

Endothelium

Intima

Arteriole 3







Smooth muscle cells

Endothelium

Basal lamina







Endothelial

cells

Basal lamina


• Medium-Sized Veins

• The adventitia (tunica externa) is the largest of the

layers

• Contains elastic fibers










Large Vein7

Adventitia

Media

Endothelium

Intima







Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima








altogether.

Venule5

Adventitia

Endothelium

Capillaries4





incomplete or


lining.


Pores

Endothelial

cells

Basal lamina

Elastic Artery 1







of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2






Adventitia

Media

Endothelium

Intima

Arteriole 3







Smooth muscle cells

Endothelium

Basal lamina







Endothelial

cells

Basal lamina


• Large Veins

• All three layers are relatively thick

• Examples of large veins are:

• Superior vena cava

• Inferior vena cava










Large Vein7

Adventitia

Media

Endothelium

Intima







Medium-Sized Vein6

Adventitia

Media

Endothelium

Intima








altogether.

Venule5

Adventitia

Endothelium

Capillaries4





incomplete or


lining.


Pores

Endothelial

cells

Basal lamina

Elastic Artery 1







of elastic fibers.

Internal elastic

layer

Endothelium

Media

Adventitia

Intima

Muscular Artery 2






Adventitia

Media

Endothelium

Intima

Arteriole 3







Smooth muscle cells

Endothelium

Basal lamina







Endothelial

cells

Basal lamina


• Venous Valves

• Blood in the veins returning to the heart from the

lower extremities has to go against gravity

• To assist in this process, many veins have valves

(venous valves)

• These valves compartmentalize the blood in the

veins thus acting as one-way valves

• Valves prevent backflow of blood


Figure 22.4 Function of Valves in the Venous System


Valve

closed

Valve opens above

contracting muscle

Valve closes below

contracting muscle

Valve

closed


• Blood in the veins from the lower extremities has

to ascend to the heart

• Blood in the veins returning to the heart from the

lower extremities has to go against gravity

• The skeletal muscles of the legs help to propel the

blood back to the heart

• Changes in thoracic pressure helps to move the

blood through the venae cavae back to the heart


The Distribution of Blood

• The total blood volume is distributed unevenly

within the vessels of the body

• Arteries and capillaries contain 30–35 percent of

the volume

• Veins contain 65–70 percent of the volume

• Veins are more distensible than arteries

• Based on blood pressure, a vein can expand about

8 times as much as a parallel artery


Figure 22.5 The Distribution of Blood in the Cardiovascular System


Large veins

18%

Large venous

networks (liver,

bone marrow, skin)

21%

Venules and

medium-sized veins

25%

Blood Vessel Distribution

• Blood vessels can be divided into two circuits

• Pulmonary circuit

• Composed of arteries and veins that transport

blood between the heart and the lungs

• Arteries and veins travel relatively short distances

• Systemic circuit

• Composed of arteries and veins that transport

oxygenated blood between the heart and all other

tissues

• Arteries and veins travel longer distances


Blood Vessel Distribution

• There are functional and structural differences

between the vessels in the two circuits

• Blood pressure in the pulmonary circuit is lower

than in the systemic circuit

• Walls of the pulmonary arteries are thinner than

the walls of systemic arteries


Blood Vessel Distribution Vessel Distribution

• Functional patterns of the pulmonary and

systemic circuits

• The distribution of arteries and veins is the same

on the left side of the body as it is on the right side

of the body except for the venae cavae and the

aorta

• A single vessel will have different names

according to specific anatomical boundaries

• Arteries and veins often anastomose


The Pulmonary Circuit

• Blood on the right side of the heart is on its way

through the pulmonary circuit

• Deoxygenated blood leaves the heart by passing

through the pulmonary valve

• Enters the pulmonary trunk

• Enters the left and right pulmonary arteries

• Blood arrives at the lungs to drop off carbon

dioxide and pick up oxygen

• Oxygenated blood returns to the heart via the

pulmonary veins

• Blood enters the left atrium of the heart


Figure 22.6 An Overview of the General Pattern of Circulation


RA

LA

Brain

Pulmonary

circuit

(arteries)

Pulmonary

circuit

(veins)

Lungs

Systemic

circuit

(arteries)

Systemic

circuit

(veins)

Left

ventricleRight

ventricle

Lower limbs

Upper limbs

Kidneys

Spleen

Digestive

organs

Liver

Gonads

Figure 22.7a The Pulmonary Circuit


Right lung

Trachea

Left lung

Superior vena cava

Ascending aorta

Right pulmonary

arteries

Inferior vena cava

CO2

O2

Left pulmonary veins

Left pulmonary arteries

Pulmonary trunk

Aortic arch

Anatomy of the pulmonary circuit. Blue arrows indicate the flow of

oxygen-poor blood; red arrows indicate the flow of oxygen-rich blood. The

breakout shows the alveoli of the lung and the routes of gas diffusion into

and out of the bloodstream across the walls of the alveolar capillaries.

Right pulmonary

veins

Alveolus

Capillary

Descending aorta

a

Systemic Arteries

• Blood on the left side of the heart is on its way

through the system circulation

• Oxygenated blood leaves the heart by passing

through the aortic valve

• Enters the ascending aorta

• At the base of the ascending aorta are the

branches of the coronary vessels

• Enters the aortic arch

• From the aortic arch, blood branches into

numerous vessels


Figure 22.6 An Overview of the General Pattern of Circulation


RA

LA

Brain

Pulmonary

circuit

(arteries)

Pulmonary

circuit

(veins)

Lungs

Systemic

circuit

(arteries)

Systemic

circuit

(veins)

Left

ventricleRight

ventricle

Lower limbs

Upper limbs

Kidneys

Spleen

Digestive

organs

Liver

Gonads

Systemic Arteries

• Blood in the aortic arch branches into the

following vessels:

• Brachiocephalic trunk

• Then the right common carotid and right

subclavian arteries

• Left common carotid artery

• Left subclavian artery

• Descending aorta


Figure 22.8 An Overview of the Systemic Arterial System


Radial

Ulnar

Palmar

arches

External

iliac

Femoral

Deep

femoral

Descending

genicular

Vertebral

Right subclavian

Brachiocephalic

trunk

Celiac trunk

Brachial

Aortic arch

Popliteal

Ascending

aorta

Right common carotid

Left common carotid

Left subclavian

Axillary

Pulmonary trunk

Descending aorta

Diaphragm

Renal

Superior mesenteric

Gonadal

Inferior mesenteric

Common iliac

Internal iliac

Dorsalis pedis

Posterior tibial

Anterior tibial

Fibular

Plantar arch

Systemic Arteries

• The Ascending Aorta

• Begins at the aortic valve

• Left and right coronary arteries branch off the

base of the ascending aorta

• Aortic arch

• Forms an arch going toward the left and posterior

side of the heart

• Branching off the aortic arch are three elastic

arteries


Systemic Arteries

• Branches of the Aortic Arch

• Brachiocephalic trunk

• Gives rise to the right common carotid artery

• And gives rise to the right subclavian artery, which

supplies blood to the right side of the head and

brain and to the right subclavian artery (supplies

blood to the right arm)

• Left common carotid artery

• Supplies blood to the left side of the head and brain

• Left subclavian artery

• Supplies blood to the left arm


Figure 22.9 Aortic Angiogram


Right common

carotid artery

Left common

carotid artery

Left subclavian

artery

Aortic arch

Descending

aorta

Internal thoracic

artery

Ascending aorta

Brachiocephalic

trunk

Thyrocervical trunk

Right subclavian

artery

Systemic Arteries

• The Subclavian Arteries

• The subclavian arteries

• Continue to form the axillary arteries

• Prior to forming the axillary arteries, the

subclavians form three branches:

• Thyrocervical trunk

• Supplies muscles of the neck, head, and upper back

• Internal thoracic artery

• Supplies the pericardium and anterior wall of the

chest

• Vertebral artery

• Supplies the brain and spinal cord


Figure 22.19a Major Veins of the Head and Neck


Facial

Internal thoracic

Right brachiocephalic

Superior vena cava

Internal jugular

Vertebral

External

jugular

Axillary

Sigmoid

sinus

Right

subclavian

Straight sinus

Great cerebral

Petrosal sinuses

Superior

sagittal sinus

Superficial

cerebral veins

Clavicle

An oblique lateral view of the head and neck

showing the major superficial and deep veins.

Inferior

sagittal sinus

Temporal

Deep cerebral

Cavernous sinus

Maxillary

Right

transverse sinus

Occipital sinus

Occipital

Left brachiocephalic

a

Systemic Arteries

• The Flow of Blood from the Subclavians to the

Arms

• Axillary artery

• Brachial artery

• Radial and ulnar arteries

• Arteries anastomose at the wrist forming the

superficial palmar arch and deep palmar arch


Figure 22.10a Arteries of the Chest and Upper Limb


Thoracoacromial

Subscapular

Inferior ulnar collateral

Anterior ulnar recurrent

Abdominal aorta

Left common

carotid

Rightthyrocervical

trunk

Right

vertebral

Right

common

carotid

Thoracic aorta

Left subclavian

Right vertebral

Left ventricle

Ascending aorta

Aortic arch

Brachiocephalic

trunk

Right common

carotidLeft

common

carotid

Left

subclavian

Right subclavian

Right axillary

Right brachial

Right

radial

Right

ulnar

Right thyrocervical trunk

Right internal thoracic

See Figure 22.12

Anterior view of the

arteries of the chest

and upper limb

Lateral thoracic

Anterior

humeral circumflex

Posterior humeral

circumflex

Deep brachial

Intercostals

Superior

ulnar

collateral

Posterior ulnar recurrent

Anterior

interosseous

Deep palmar

arch

Superficial

palmar arch

Digital arteries

a

Figure 22.10bc Arteries of the Chest and Upper Limb


Posterior cord

of brachial plexus

Axillary artery

Deep brachial

artery

Biceps brachii muscle

Brachial artery

Median nerve

Serratus anterior

muscle

Pectoralis major muscle

(cut and reflected)

Subscapular artery

Right subclavian artery

Medial trunk of

brachial plexus

Clavicle

(cut and removed)

Ulnar artery

Biceps brachii

muscle Brachial artery

Superficial palmar arch

Ulnar artery

Flexor carpi

radialis muscle

Brachioradialis

muscle

Anterior view of the

right axillary region

dissected to show

blood vessels and

nerves in this region

Anterior view of the right

forearm dissected to

show the main arteries

Brachial

artery

Inferior ulnar

collateral artery

Radial artery

b

c

Systemic Arteries

• The Carotid Arteries and the Blood Supply to the

Brain

• The common carotids ascend the neck

• Divide to form the internal carotids and external

carotids

• The carotid sinus is at the base of the internal

carotid artery consisting of baroreceptors and

chemoreceptors


Figure 22.12a Arteries of the Neck and Head


Maxillary

Anterior cerebral

Ophthalmic

Middle cerebral

Superficial temporal

Posterior cerebral

Carotid canal

Occipital

Basilar

Internal carotid

Brachiocephalic

trunk

Common carotid

Carotid sinus

External carotid

General circulation pattern of arteries supplying the neck and superficial

structures of the head; this is an oblique lateral view from the right side.

Cerebral arterial circle

Vertebral

Inferior thyroid

Thyrocervical trunk

Transverse cervical

Suprascapular

Subclavian

Axillary

Internal thoracic

Second rib

Facial

a

Lingual

Systemic Arteries

• The Internal and External Carotid Arteries

• External carotids

• Supply the neck and outside of the skull

• Branches to form:

• Lingual artery

• Facial artery

• Occipital artery

• Superficial temporal artery


Figure 22.12a Arteries of the Neck and Head


Maxillary

Anterior cerebral

Ophthalmic

Middle cerebral

Superficial temporal

Posterior cerebral

Carotid canal

Occipital

Basilar

Internal carotid

Brachiocephalic

trunk

Common carotid

Carotid sinus

External carotid

General circulation pattern of arteries supplying the neck and superficial

structures of the head; this is an oblique lateral view from the right side.

Cerebral arterial circle

Vertebral

Inferior thyroid

Thyrocervical trunk

Transverse cervical

Suprascapular

Subclavian

Axillary

Internal thoracic

Second rib

Facial

a

Lingual

Systemic Arteries

• The Internal and External Carotid Arteries

• Internal carotids

• Enter the skull to deliver blood to the brain


• Ophthalmic artery (supplies the eyes)

• Anterior cerebral artery (supplies frontal and

parietal lobes of the brain)

• Middle cerebral artery (supplies the midbrain and

lateral surfaces of the brain)


Systemic Arteries

• Blood Supply to the Brain

• Blood in the vertebral arteries reaches the brain

via:

• Left and right vertebral arteries fuse to form the

basilar artery

• Basilar artery branches many times in the area of

the pons

• Basilar artery eventually forms the vessels of the

cerebral arterial circle (circle of Willis)




Facial

Internal thoracic


Superior vena cava

Internal jugular

Vertebral

External

jugular

Axillary

Sigmoid

sinus

Right

subclavian

Straight sinus

Great cerebral

Petrosal sinuses

Superior

sagittal sinus

Superficial

cerebral veins

Clavicle



Inferior

sagittal sinus

Temporal

Deep cerebral

Cavernous sinus

Maxillary

Right

transverse sinus

Occipital sinus

Occipital


a

Figure 22.19b Major Veins of the Head and Neck


Superior

sagittal sinus (cut)

Roots of superior

cerebral

Occipital sinus

Straight sinus

Inferior

cerebellars

Cavernous

sinus

Internal

jugular

Petrosal sinuses

Inferior cerebrals

Sigmoid sinus

Transverse sinus

Middle cerebral

An inferior view of the brain showing the major veins.

Compare with the arterial supply to the brain shown in

Figure 22.13a.

Confluence of sinuses

b

Pontal

Systemic Arteries

• The Descending Aorta

• A continuation of the aortic arch

• Divided into thoracic aorta and abdominal aorta at

the diaphragm area


Figure 22.14 Major Arteries of the Trunk


Esophageal

Internal thoracic

Diaphragm

Common hepatic

Lumbar

External iliac

Internal iliac

Common carotid

Axillary

Bronchial

Mediastinal

Intercostal

Inferior mesenteric

Terminal segment

of the aorta

THORACIC AORTA

Right common iliac

Left subclavian

Vertebral

Thyrocervical trunk

Brachiocephalic trunk

Aortic arch

Pericardial

Inferior phrenic

Left gastric

Superior phrenic

Renal

Suprarenal

Median sacral

Celiac trunk

Splenic

Superior

mesenteric

ABDOMINAL

AORTA

Gonadal

Systemic Arteries

• The Thoracic Aorta

• Branches to form the following vessels:

• Bronchial arteries

• Pericardial arteries

• Mediastinal arteries

• Esophageal arteries

• Intercostal arteries

• Superior phrenic arteries




Esophageal

Internal thoracic

Diaphragm

Common hepatic

Lumbar

External iliac

Internal iliac

Common carotid

Axillary

Bronchial

Mediastinal

Intercostal

Inferior mesenteric

Terminal segment

of the aorta

THORACIC AORTA

Right common iliac

Left subclavian

Vertebral

Thyrocervical trunk


Aortic arch

Pericardial

Inferior phrenic

Left gastric

Superior phrenic

Renal

Suprarenal

Median sacral

Celiac trunk

Splenic

Superior

mesenteric

ABDOMINAL

AORTA

Gonadal

Systemic Arteries

• The Abdominal Aorta

• Branches to form the following vessels:

• Celiac trunk

• Superior mesenteric artery

• Inferior mesenteric artery

• Inferior phrenic arteries

• Suprarenal arteries

• Renal arteries

• Gonadal arteries

• Lumbar arteries

• Right and left common iliac arteries




Esophageal

Internal thoracic

Diaphragm

Common hepatic

Lumbar

External iliac

Internal iliac

Common carotid

Axillary

Bronchial

Mediastinal

Intercostal

Inferior mesenteric

Terminal segment

of the aorta

THORACIC AORTA

Right common iliac

Left subclavian

Vertebral

Thyrocervical trunk


Aortic arch

Pericardial

Inferior phrenic

Left gastric

Superior phrenic

Renal

Suprarenal

Median sacral

Celiac trunk

Splenic

Superior

mesenteric

ABDOMINAL

AORTA

Gonadal

Systemic Arteries

• The Celiac Trunk

• Supplies the following organs:

• Liver

• Stomach

• Esophagus

• Gallbladder

• Duodenum

• Pancreas

• Spleen


Systemic Arteries


• Branches to form the left gastric artery

• Supplies the stomach

• Branches to form the splenic artery

• Supplies the spleen

• Branches to form the left gastroepiploic artery to

supply the stomach

• Branches to form the pancreatic arteries to supply

the pancreas


Systemic Arteries


• Branches to form the common hepatic artery


• Hepatic artery proper

• Supplies the liver

• Right gastric artery

• Supplies the stomach

• Cystic artery

• Supplies the gallbladder

• Gastroduodenal artery

• Supplies the duodenum


Figure 22.15a Arteries of the Abdomen


LiverCeliac trunk

Right gastric

Ileocolic

Left common iliac

Rectal

Sigmoid colon

Rectum

Right external iliac

Inferior

pancreaticoduodenal

Inferior vena cava

Left gastric

Right gastroepiploic Left gastroepiploic

PancreaticPancreas

Sigmoid

Small intestine

Ascending colon

Superior mesenteric

Inferior mesenteric

Stomach

Superior

pancreaticoduodenal

ABDOMINAL AORTA

Duodenal

Right internal iliac

Major arteries supplying the abdominal viscera

THORACIC AORTA

Splenic

Spleen

Left colic

Common hepatic

Hepatic artery proper

Cystic

Gastroduodenal

Middle colic (cut)

Right colic

Intestinal

a

Systemic Arteries

• Superior Mesenteric Artery

• Branches to supply

• Pancreas

• Inferior pancreaticoduodenal artery

• Duodenum

• Inferior pancreaticoduodenal artery

• Small intestine

• Intestinal arteries

• Large intestine

• Right colic artery

• Middle colic artery

• Ileocolic arteries




LiverCeliac trunk

Right gastric

Ileocolic

Left common iliac

Rectal

Sigmoid colon

Rectum


Inferior

pancreaticoduodenal

Inferior vena cava

Left gastric


PancreaticPancreas

Sigmoid

Small intestine

Ascending colon

Superior mesenteric

Inferior mesenteric

Stomach

Superior

pancreaticoduodenal

ABDOMINAL AORTA

Duodenal



THORACIC AORTA

Splenic

Spleen

Left colic

Common hepatic


Cystic

Gastroduodenal

Middle colic (cut)

Right colic

Intestinal

a

Systemic Arteries

• Inferior Mesenteric Artery

• Branches to supply

• Terminal portion of the large intestine

• Left colic artery

• Sigmoid arteries

• Rectum

• Rectal arteries




LiverCeliac trunk

Right gastric

Ileocolic

Left common iliac

Rectal

Sigmoid colon

Rectum


Inferior

pancreaticoduodenal

Inferior vena cava

Left gastric


PancreaticPancreas

Sigmoid

Small intestine

Ascending colon

Superior mesenteric

Inferior mesenteric

Stomach

Superior

pancreaticoduodenal

ABDOMINAL AORTA

Duodenal



THORACIC AORTA

Splenic

Spleen

Left colic

Common hepatic


Cystic

Gastroduodenal

Middle colic (cut)

Right colic

Intestinal

a

Systemic Arteries

• Five paired arteries branch off the descending

aorta



• Renal arteries


• Lumbar arteries


Systemic Arteries

• The five paired arteries supply:


• Supply inferior portion of esophagus and

diaphragm


• Supply the suprarenal glands

• Renal arteries

• Supply the right and left kidneys


Systemic Arteries

• The five paired arteries supply (continued)


• Supply testes, scrotum, ovaries, uterine tubes,

uterus

• Lumbar arteries

• Supply vertebrae, spinal cord, abdominal wall




Esophageal

Internal thoracic

Diaphragm

Common hepatic

Lumbar

External iliac

Internal iliac

Common carotid

Axillary

Bronchial

Mediastinal

Intercostal

Inferior mesenteric

Terminal segment

of the aorta

THORACIC AORTA

Right common iliac

Left subclavian

Vertebral

Thyrocervical trunk


Aortic arch

Pericardial

Inferior phrenic

Left gastric

Superior phrenic

Renal

Suprarenal

Median sacral

Celiac trunk

Splenic

Superior

mesenteric

ABDOMINAL

AORTA

Gonadal

Systemic Arteries

• Arteries of the Pelvis and Lower Limbs

• The descending aorta branches to form:

• The common iliac arteries branch to form:

• The internal iliac artery (supplies the urinary

bladder, walls of the pelvis, external genitalia, and

the medial side of the thigh)

• The external iliac artery (supplies blood to the

legs)


Figure 22.8 An Overview of the Systemic Arterial System


Radial

Ulnar

Palmar

arches

External

iliac

Femoral

Deep

femoral

Descending

genicular

Vertebral

Right subclavian

Brachiocephalic

trunk

Celiac trunk

Brachial

Aortic arch

Popliteal

Ascending

aorta

Right common carotid

Left common carotid

Left subclavian

Axillary

Pulmonary trunk

Descending aorta

Diaphragm

Renal

Superior mesenteric

Gonadal

Inferior mesenteric

Common iliac

Internal iliac

Dorsalis pedis

Posterior tibial

Anterior tibial

Fibular

Plantar arch

Systemic Arteries

• Arteries of the Thigh and Leg

• External iliac arteries form the:

• Deep femoral artery

• Femoral artery

• Continues to form the popliteal artery

• The popliteal bifurcates to form anterior tibial and

posterior tibial arteries

• The posterior tibial artery gives rise the fibular

artery


Figure 22.16a Major Arteries of the Lower Limb, Part I


Deep femoral

Superior gluteal

Popliteal

Anterior tibial

Fibular

Iliolumbar

Femoral

Descending

genicular

Posterior tibial

Medial plantar

Dorsal archPlantar arch

Dorsalis pedis

Lateral plantar

Lateral femoral

circumflex

Anterior view of the arteries supplying

the right lower limb

Common iliac

Internal iliac

External iliac

Lateral sacral

Internal pudendal

Obturator

Medial femoral

circumflex

a

Inguinal ligament

Figure 22.17 Major Arteries of the Lower Limb, Part II


Superior gluteal

Medial femoral

circumflex

Lateral

femoral

circumflex

Fibular

Adductor and

obturator

muscles, hip joint

Quadriceps

muscles, hip

and knee

joints

Posterior view of the arteries supplying the right lower limb


(see Fig. 22.15)

Femoral

(see Fig. 22.16)

Thigh

Deep femoral

(see Fig. 22.16)

Hip joint, femoral head,

deep muscles of the thigh

Descending genicular

Skin of leg; knee joint

Popliteal

Leg and foot

Posterior

tibial

Anterior

tibial

Connected by anastomoses

of dorsalis pedis, dorsal

arch, and plantar arch,

which supply distal portions

of the foot and the toes

Systemic Arteries

• Arteries of the Foot

• The anterior tibial artery forms:

• Dorsalis pedis artery

• The posterior tibial artery forms:

• Medial and lateral plantar arteries


Systemic Veins

• Systemic Veins

• Veins collect blood from the body tissues and

return it to the heart

• Blood returns to the heart from the lower

extremities

• Via the inferior vena cava to the right atrium

• Blood returns to the heart from the upper

extremities

• Via the superior vena cava to the right atrium

• Blood returns to the heart from the lungs

• Via the pulmonary veins to the left atrium


Figure 22.7a The Pulmonary Circuit


Right lung

Trachea

Left lung

Superior vena cava

Ascending aorta

Right pulmonary

arteries

Inferior vena cava

CO2

O2

Left pulmonary veins

Left pulmonary arteries

Pulmonary trunk

Aortic arch

Anatomy of the pulmonary circuit. Blue arrows indicate the flow of

oxygen-poor blood; red arrows indicate the flow of oxygen-rich blood. The

breakout shows the alveoli of the lung and the routes of gas diffusion into

and out of the bloodstream across the walls of the alveolar capillaries.

Right pulmonary

veins

Alveolus

Capillary

Descending aorta

a

Figure 22.18 An Overview of the Systemic Venous System


Median cubital

Palmar venous arches

Great saphenous

Popliteal

Small saphenous

Fibular

Dorsal venous arch

Posterior tibial

Femoral

Deep

femoral

Left and right

common iliac

Lumbar

Superior vena cava

Ulnar

Digital

Brachiocephalic

Superficial veins

Internal jugular

Vertebral

External jugular

Subclavian

Axillary

Cephalic

Brachial

Basilic

Hepatic

Radial

Median antebrachial

Intercostal

Inferior vena cava

Renal

Gonadal

External iliac

Internal iliac

Anterior tibial

Plantar venous arch

KEY

Deep veins

Systemic Veins

• The Superior Vena Cava

• All veins drain into the superior vena cava and the

inferior vena cava except:

• Cardiac veins

• Superior vena cava receives blood from:

• The head

• The neck

• The chest

• The shoulders

• The upper limbs


Systemic Veins

• Venous Return from the Cranium

• The superficial cerebral veins drain into:

• Superior and inferior sagittal sinuses

• Petrosal sinuses

• Occipital sinus

• Left and right transverse sinuses

• Straight sinus

• Venous blood from the cranium drains into the

internal jugular veins, which drain into the

brachiocephalic veins




Facial

Internal thoracic


Superior vena cava

Internal jugular

Vertebral

External

jugular

Axillary

Sigmoid

sinus

Right

subclavian

Straight sinus

Great cerebral

Petrosal sinuses

Superior

sagittal sinus

Superficial

cerebral veins

Clavicle



Inferior

sagittal sinus

Temporal

Deep cerebral

Cavernous sinus

Maxillary

Right

transverse sinus

Occipital sinus

Occipital


a

Systemic Veins

• Venous Return from the Cranium (continued)

• Venous blood from the posterior skull and the

cervical spinal cord drain into:

• The vertebral veins

• Drain into brachiocephalic veins


Figure 22.19b Major Veins of the Head and Neck


Superior

sagittal sinus (cut)

Roots of superior

cerebral

Occipital sinus

Straight sinus

Inferior

cerebellars

Cavernous

sinus

Internal

jugular

Petrosal sinuses

Inferior cerebrals

Sigmoid sinus

Transverse sinus

Middle cerebral

An inferior view of the brain showing the major veins.

Compare with the arterial supply to the brain shown in

Figure 22.13a.

Confluence of sinuses

b

Pontal

Systemic Veins

• Superficial Veins of the Head and Neck

• Veins from the head converge to form the:

• Temporal vein

• Drains into the external jugular vein then into the

subclavian vein

• Maxillary veins

• Drain into the external jugular vein then into the

subclavian veins

• Facial vein

• Drains into the internal jugular vein then into the

subclavian veins




Facial

Internal thoracic


Superior vena cava

Internal jugular

Vertebral

External

jugular

Axillary

Sigmoid

sinus

Right

subclavian

Straight sinus

Great cerebral

Petrosal sinuses

Superior

sagittal sinus

Superficial

cerebral veins

Clavicle



Inferior

sagittal sinus

Temporal

Deep cerebral

Cavernous sinus

Maxillary

Right

transverse sinus

Occipital sinus

Occipital


a

Systemic Veins

• Venous Return from the Upper Limb

• Blood returns to the heart from the hands in the

following sequence

• Digital veins

• Superficial and deep palmar veins

• The superficial palmar veins drain into the

cephalic vein

• Subclavian vein

• Brachiocephalic vein


• Right atrium


Figure 22.20 The Venous Drainage of the Trunk and Upper Limb


Radial

Renal

Lumbar

Vertebral

Phrenic

Median cubital

Cephalic

Median antebrachial

Anterior

interosseous

Palmar venous

arches

Ulnar

Basilic

SUPERIOR

VENA CAVA

Mediastinal

Azygos

Gonadal

Internal iliac

Esophageal

Median

sacral

KEY

Internal jugular

External jugular

Subclavian

Highest intercostal

Brachiocephalic

Axillary

Cephalic

Accessory hemiazygos

Hemiazygos

Brachial

Intercostal

INFERIOR VENA CAVA

HepaticBasilic

Suprarenal

Internal

thoracic

Common

iliac

External iliac

Superficial veins

Deep veins

Digital

Systemic Veins


• Blood can also return to the heart from the hands

in the following sequence

• The superficial palmar veins drain into the

cephalic vein

• Median cubital vein

• Basilic vein

• Axillary vein

• Subclavian vein



• Right atrium




Radial

Renal

Lumbar

Vertebral

Phrenic

Median cubital

Cephalic

Median antebrachial

Anterior

interosseous

Palmar venous

arches

Ulnar

Basilic

SUPERIOR

VENA CAVA

Mediastinal

Azygos

Gonadal

Internal iliac

Esophageal

Median

sacral

KEY

Internal jugular

External jugular

Subclavian

Highest intercostal

Brachiocephalic

Axillary

Cephalic


Hemiazygos

Brachial

Intercostal

INFERIOR VENA CAVA

HepaticBasilic

Suprarenal

Internal

thoracic

Common

iliac

External iliac

Superficial veins

Deep veins

Digital

Systemic Veins




• The superficial palmar veins drain into the basilic

vein

• Axillary vein

• Subclavian vein



• Right atrium




Radial

Renal

Lumbar

Vertebral

Phrenic

Median cubital

Cephalic

Median antebrachial

Anterior

interosseous

Palmar venous

arches

Ulnar

Basilic

SUPERIOR

VENA CAVA

Mediastinal

Azygos

Gonadal

Internal iliac

Esophageal

Median

sacral

KEY

Internal jugular

External jugular

Subclavian

Highest intercostal

Brachiocephalic

Axillary

Cephalic


Hemiazygos

Brachial

Intercostal

INFERIOR VENA CAVA

HepaticBasilic

Suprarenal

Internal

thoracic

Common

iliac

External iliac

Superficial veins

Deep veins

Digital

Systemic Veins




• The deep palmar veins drain into the radial and

ulnar veins

• Those veins will unite to form the brachial vein

• Axillary vein

• Subclavian vein



• Right atrium




Radial

Renal

Lumbar

Vertebral

Phrenic

Median cubital

Cephalic

Median antebrachial

Anterior

interosseous

Palmar venous

arches

Ulnar

Basilic

SUPERIOR

VENA CAVA

Mediastinal

Azygos

Gonadal

Internal iliac

Esophageal

Median

sacral

KEY

Internal jugular

External jugular

Subclavian

Highest intercostal

Brachiocephalic

Axillary

Cephalic


Hemiazygos

Brachial

Intercostal

INFERIOR VENA CAVA

HepaticBasilic

Suprarenal

Internal

thoracic

Common

iliac

External iliac

Superficial veins

Deep veins

Digital

Systemic Veins

• The Formation of the Superior Vena Cava

• The following veins drain into the superior vena

cava, which then drains into the right atrium

• Azygos veins

• Brachiocephalic veins

• Subclavian veins drain into the brachiocephalic

veins

• Internal thoracic veins drain into the

brachiocephalic veins




Radial

Renal

Lumbar

Vertebral

Phrenic

Median cubital

Cephalic

Median antebrachial

Anterior

interosseous

Palmar venous

arches

Ulnar

Basilic

SUPERIOR

VENA CAVA

Mediastinal

Azygos

Gonadal

Internal iliac

Esophageal

Median

sacral

KEY

Internal jugular

External jugular

Subclavian

Highest intercostal

Brachiocephalic

Axillary

Cephalic


Hemiazygos

Brachial

Intercostal

INFERIOR VENA CAVA

HepaticBasilic

Suprarenal

Internal

thoracic

Common

iliac

External iliac

Superficial veins

Deep veins

Digital

Systemic Veins

• The Inferior Vena Cava

• The following veins drain into the inferior vena

cava, which drains into the right atrium

• Common iliac veins

• Lumbar veins

• Gonadal veins:

• The right gonadal vein drains into the inferior vena

cava, the left gonadal vein drains into the left renal

vein and then into the inferior vena cava

• Hepatic veins




Median cubital


Great saphenous

Popliteal

Small saphenous

Fibular

Dorsal venous arch

Posterior tibial

Femoral

Deep

femoral

Left and right

common iliac

Lumbar

Superior vena cava

Ulnar

Digital

Brachiocephalic

Superficial veins

Internal jugular

Vertebral

External jugular

Subclavian

Axillary

Cephalic

Brachial

Basilic

Hepatic

Radial

Median antebrachial

Intercostal

Inferior vena cava

Renal

Gonadal

External iliac

Internal iliac

Anterior tibial

Plantar venous arch

KEY

Deep veins

Systemic Veins

• Veins Draining the Pelvis

• The following veins drain into the internal iliac and

then into the common iliac and then into the IVC

• Gluteal veins

• Internal pudendal veins

• Obturator veins

• Lateral sacral veins

• Median sacral veins drain into the left common iliac


Figure 22.21a The Venous Drainage of the Lower Limb


Right common

iliac

Superior gluteal


Femoral circumflex

Femoral

Great saphenous

Small saphenous

Fibular

Internal iliac

Inferior gluteal

Internal pudendal

Lateral sacral

Obturator

Deep femoral

Collects blood

from the thigh

External Iliac

Femoral

Small saphenous

Collects blood from

superficial veins of

the leg and foot

Popliteal

Posterior tibial

Anterior tibial Fibular

The dorsal and plantar venous

arches collect blood from the

foot and toes

Dorsal venous arch

Plantar venous arch

Digital

Anterior view showing the

veins of the right lower limb

a

KEY

Superficial veins

Deep veins

Figure 22.21b The Venous Drainage of the Lower Limb


External Iliac

Femoral

Popliteal

Posterior tibial

Fibular



foot and toes

Dorsal venous arch

Plantar venous arch

Digital

Posterior view showing the


Internal pudendal

Superior gluteal

Inferior gluteal

Obturator

Femoral

circumflex

Deep femoral

Femoral

Great saphenous

Collects blood from

the superficial veins

of the lower limb

Small

saphenous

Anterior tibial

KEY

Superficial veins

Deep veins

b

Anterior tibial

Systemic Veins

• Veins Draining the Abdomen

• The abdominal portion of the inferior vena cava

collects blood from:

• Lumbar veins

• Gonadal veins

• Hepatic veins

• Renal veins

• Suprarenal veins

• Phrenic veins




Median cubital


Great saphenous

Popliteal

Small saphenous

Fibular

Dorsal venous arch

Posterior tibial

Femoral

Deep

femoral

Left and right

common iliac

Lumbar

Superior vena cava

Ulnar

Digital

Brachiocephalic

Superficial veins

Internal jugular

Vertebral

External jugular

Subclavian

Axillary

Cephalic

Brachial

Basilic

Hepatic

Radial

Median antebrachial

Intercostal

Inferior vena cava

Renal

Gonadal

External iliac

Internal iliac

Anterior tibial

Plantar venous arch

KEY

Deep veins

Systemic Veins

• Veins Draining the Lower Limb

• Blood returns to the heart from the feet in the

following sequence

• Plantar veins

• Drain into the anterior tibial, posterior tibial, and

fibular veins

• Popliteal vein

• Femoral vein

• External iliac vein

• Common iliac vein


• Right atrium




Median cubital


Great saphenous

Popliteal

Small saphenous

Fibular

Dorsal venous arch

Posterior tibial

Femoral

Deep

femoral

Left and right

common iliac

Lumbar

Superior vena cava

Ulnar

Digital

Brachiocephalic

Superficial veins

Internal jugular

Vertebral

External jugular

Subclavian

Axillary

Cephalic

Brachial

Basilic

Hepatic

Radial

Median antebrachial

Intercostal

Inferior vena cava

Renal

Gonadal

External iliac

Internal iliac

Anterior tibial

Plantar venous arch

KEY

Deep veins

Systemic Veins

• Veins Draining the Lower Limb

• Blood also leaves the foot and returns to the heart

via the following veins

• Dorsal venous arch

• Great saphenous vein

• Femoral vein

• External iliac vein

• Common iliac vein


• Right atrium


Figure 22.21a The Venous Drainage of the Lower Limb


Right common

iliac

Superior gluteal


Femoral circumflex

Femoral

Great saphenous

Small saphenous

Fibular

Internal iliac

Inferior gluteal

Internal pudendal

Lateral sacral

Obturator

Deep femoral

Collects blood

from the thigh

External Iliac

Femoral

Small saphenous

Collects blood from

superficial veins of

the leg and foot

Popliteal

Posterior tibial

Anterior tibial Fibular



foot and toes

Dorsal venous arch

Plantar venous arch

Digital

Anterior view showing the


a

KEY

Superficial veins

Deep veins

Figure 22.21b The Venous Drainage of the Lower Limb


External Iliac

Femoral

Popliteal

Posterior tibial

Fibular



foot and toes

Dorsal venous arch

Plantar venous arch

Digital

Posterior view showing the


Internal pudendal

Superior gluteal

Inferior gluteal

Obturator

Femoral

circumflex

Deep femoral

Femoral

Great saphenous

Collects blood from

the superficial veins

of the lower limb

Small

saphenous

Anterior tibial

KEY

Superficial veins

Deep veins

b

Anterior tibial

Systemic Veins

• The Hepatic Portal System

• Blood from the small intestine, large intestine,

stomach, and pancreas flows into the hepatic

portal system

• Inferior mesenteric vein drains a portion of the

large intestine

• Splenic vein drains the spleen, lateral border of

the stomach, and the pancreas

• Superior mesenteric vein drains a portion of the

stomach, small intestine, and a portion of the large

intestine


Systemic Veins

• The Hepatic Portal System

• From the hepatic portal veins, venous blood

enters into:

• Liver sinusoids

• Hepatic veins


• Right atrium


Figure 22.22 The Hepatic Portal System


Inferior vena cava

Hepatic

Hepatic portal

Cystic

Liver

Superior mesenteric

Pancreaticoduodenal

Ascending colon

Pancreas

Left colic

Middle colic

(from transverse colon)

Spleen

Left gastroepiploic

Right gastroepiploic

Stomach

Esophagus

Ileocolic

Splenic

Intestinal

Descending colon

Sigmoid

Pancreatic

Left gastric

Right gastric

Aorta

Inferior mesentericRight colic

Small intestine

Superior rectal

Cardiovascular Changes at Birth

• The fetal cardiovascular system differs from the

adult cardiovascular system

• The fetal lungs are nonfunctional

• The fetal digestive system is nonfunctional

• All fetal nutritional and respiratory needs are

provided by diffusion across the placenta

• Blood in the fetal internal iliacs enters the

umbilical arteries

• Enters the umbilical cord

• Enters the placenta



• All fetal nutritional and respiratory needs are

provided by diffusion across the placenta

• Blood leaves the placenta

• Enters the umbilical vein

• Enters the ductus venosus

• Enters the fetal liver

• Enters the inferior vena cava

• Enters the fetal right atrium



• Fetal heart circulation uses two “short circuits” to

the lungs

• Blood in the right atrium can enter into the left

atrium via the foramen ovale

• Blood in the pulmonary trunk can enter into the

aortic arch via the ductus arteriosus


Figure 22.23a Changes in Fetal Circulation at Birth


Foramen ovale (open)

Umbilical vein

Liver

Placenta

Umbilical

cord

Circulation pathways in a full-term fetus.

Red indicates oxygen-rich blood, blue

indicates oxygen-poor blood, and violet

indicates a mixture of oxygen-rich and

oxygen-poor blood.

Aorta

Inferior vena cava

Ductus

arteriosus

(open)

Pulmonary

trunk

Umbilical

arteries

Ductus venosus

a

Figure 22.23b Changes in Fetal Circulation at Birth


Ductus arteriosus

(closed)

Pulmonary

trunk

Foramen ovale

(closed)

Right

atrium

Inferior

vena cava

Right ventricle

Left

atrium

Left

ventricle

Blood flow through the

heart of the newborn.

b

Figure 22.23c Changes in Fetal Circulation at Birth


Superior vena cava General systemic circulation

Right ventricle

Right atrium Left atriumForamen ovale

An opening in the

interatrial septum

that permits some

blood to flow directly

into the left atrium Left ventricle

FETAL HEART

Ductus arteriosus

A vessel that shunts blood

from the pulmonary trunk,

away from the pulmonary

circuit, into the aortic arch

Lungs

Minimal

blood flow

General systemic circulation Aorta

Umbilical arteries Internal iliac arteries

Flowchart for circulatory patterns in the fetus and newborn infant.

PLACENTA

Umbilical vein

Transports oxygen-rich,

nutrient-rich blood from

placenta to fetal liver

Ductus venosus

A shunt that permits most

blood to bypass the fetal

liver so as to directly enter

the inferior vena cava and

then the right atrium

Inferior vena cava

c

KEY

Oxygen-rich blood

Mixed blood

Oxygen-poor blood


• Upon birth:

• Smooth muscles of the ductus arteriosus contract

forming the ligamentum arteriosum found in the

adult heart

• Pressure in the left atrium increases, thus closing

the valvular flap of the foramen ovale, forming the

fossa ovalis found in the adult heart


Aging and the Cardiovascular System

• Age-related changes in the cardiovascular system

• Blood changes

• Decreased hematocrit

• Thrombi and emboli form more easily

• Pooling of blood in veins of the leg

• Heart changes

• Reduced efficiency and elasticity

• Atherosclerosis of coronary vessels

• Scar tissue forms

• Blood vessel changes

• Loss of elasticity

• Calcium deposits damage vessel walls


chapter 22 218... · 2015-06-08 · histological organization of blood vessels •characteristics...

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