cardiovascular system the heartcf.linnbenton.edu/...15_cardiovascular_system_part...the...

2/20/2016

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Part 1

The Cardiovascular System

• Blood

• Heart

• Blood vessels

Cardiovascular System

• Functions

–Transport gases, wastes, food, hormones, blood cells

• Systems affected

–Respiratory

–Urinary

–Digestive

–Musculoskeletal

–Immune system

Cardiovascular System

• Four separate chambers in humans

– Also other mammals, birds

• Double pump � two closed circuits

• 5 L/minute

The Heart

Figure 18.5

Oxygen-rich,

CO2-poor blood

Oxygen-poor,

CO2-rich blood

Capillary beds

of lungs where

gas exchange

occurs

Capillary beds of all

body tissues where

gas exchange occurs

Pulmonary veinsPulmonary arteries

Pulmonary

Circuit

Systemic

Circuit

Aorta and branches

Left atrium

Heart

Left ventricleRight atrium

Right ventricle

Venae cavae

• Symmetrical in design, but not in position

– 2/3 of mass to the left of midline

– 1/3 to right

The Heart

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Figure 18.1a

Point of

maximal

intensity

(PMI)

Diaphragm

(a)

Sternum

2nd rib

Midsternal line

Located within mediastinum

Figure 18.1c

(c)

Superior

vena cava

Left lung

Aorta

Parietalpleura (cut)

Pericardium(cut)

Pulmonary

trunk

Diaphragm

Apex of

heart

–Membrane surrounding and protecting the heart

• Confines while still allowing free movement

Pericardium

–Double walled organ

• Fibrous pericardium

• Serous pericardium

Pericardium



–Fibrous connective tissue

–Prevents overstretching, protection, anchorage


Pericardium




–Serous epithelium

–Double layer

» Parietal layer

* Epithelial cells

* Secrete serous fluid (thin mucus)

* Fused to fibrous pericardium

» Visceral layer (epicardium)

* Thin connective tissue

* Forms surface of heart

Pericardium

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• Pericardial cavity

–Between visceral and parietal serous pericardium

–Scant amount of serous fluid – accumulation may cause…

• Pericarditis

– Inflammation of pericardium

–Sharp, stabbing chest pain

–May be caused by viral

infection, heart attack

–Begins suddenly but

resolves quickly

Pericardium

Figure 18.2

Fibrous pericardium

Parietal layer of

serous pericardium

Pericardial cavity

Epicardium

(visceral layer

of serous

pericardium)Myocardium

Endocardium

Pulmonary

trunk

Heart chamber

Heart

wall

Pericardium

Myocardium

• Three layers

–Epicardium

• Also called the…

–Myocardium

–Endocardium

Muscular Wall of the Heart

Figure 18.2

Fibrous pericardium

Parietal layer of

serous pericardium

Pericardial cavity

Epicardium

(visceral layer

of serous

pericardium)Myocardium

Endocardium

Pulmonary

trunk

Heart chamber

Heart

wall

Pericardium

Myocardium

• Epicardium

– Serous membrane

– Typicially infiltrated

with fat in the elderly

Muscular wall of the heart

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• Myocardium

–Primarily cardiac muscle

–Bulk of heart

–Variable thickness

• Ventricles thicker than atria

• Left ventricle thicker than right

– Inner surface raised into finger-

like projections

• Papillary muscles


• Myocardium

–Branching cardiac muscle cells

–Connected to one another by crisscrossing connective tissue

fibers

• Non-excitable – limits the spread of action potentials to specific

pathways in the heart

–Arranged in spiral or circular bundles

–Bundles interlace and effectively link all parts of the heart

together


Figure 18.3

Cardiac

muscle

bundles

Myocardium

• Endocardium

–Squamous epithelium

• Smooth, white

–Continuous with

endothelial linings

of large blood

vessels

entering/exiting

the heart


• Endocardium

–Endocarditis – inflammation of the endocardium

–Common in IV drug users

–Leads to valve damage, emboli


• Chambers

Anatomy of the Heart

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• Chambers

–Right and left atria

• Separated by interatrial septum

• Coronary sulcus (atrioventricular groove) encircles the junction of the

atria and ventricles

– Blood vessels that supply the myocardium rest inside

• Auricles

– Atrial appendages

– Increase atrial volume


• Chambers

–Right and left ventricles

• Separated by interventricular septum


Figure 18.6

Right

ventricle

Left

ventricle

Interventricular

septum

• Ventricular septal

defect (VSD)


• Numerous blood vessels are associated with the

heart…

Major Vessels of the Heart

Figure 18.4b

(b) Anterior view

Brachiocephalic trunk

Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium

Right coronary artery

(in coronary sulcus)

Anterior cardiac vein

Right ventricle

Right marginal artery

Small cardiac vein

Inferior vena cava

Left common carotid

arteryLeft subclavian artery

Ligamentum arteriosum

Left pulmonary artery

Left pulmonary veins

Circumflex artery

Left coronary artery


Left ventricle

Great cardiac vein

Anterior interventricular

artery (in anterior

interventricular sulcus)

Apex

Aortic arch

Auricle of

left atrium


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• Vessels entering right atrium

–Superior vena cava

– Inferior vena cava

–Coronary sinus

• Vessels entering left atrium

–Right and left pulmonary veins

AtriaThe Receiving Chambers

Figure 18.4b

(b) Anterior view


Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium




Right ventricle


Small cardiac vein

Inferior vena cava

Left common carotid





Circumflex artery



Left ventricle

Great cardiac vein


artery (in anterior


Apex

Aortic arch

Auricle of

left atrium

Major Vessels of the Heart – Entering Right Atrium

Figure 18.4d

(d) Posterior surface view

Aorta

Left pulmonaryartery

Left pulmonaryveins

Auricle of leftatrium

Left atrium

Great cardiacvein

Posterior veinof left ventricle

Left ventricle

Apex

Superior vena cava

Right pulmonary artery

Right pulmonary veins

Right atrium

Inferior vena cava

Right coronary artery(in coronary sulcus)

Coronary sinus

Posteriorinterventricularartery (in posteriorinterventricular sulcus)

Middle cardiac vein

Right ventricle


Figure 18.4e

Aorta

Left pulmonary

arteryLeft atrium

Left pulmonary

veins

Mitral (bicuspid)

valve

Aortic valve

Pulmonary valveLeft ventricle

Papillary muscle

Interventricularseptum

EpicardiumMyocardium

Endocardium

(e) Frontal section

Superior vena cava

Right pulmonaryarteryPulmonary trunk

Right atrium

Right pulmonaryveinsFossa ovalis

Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava


Figure 18.4b

(b) Anterior view


Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium




Right ventricle


Small cardiac vein

Inferior vena cava

Left common carotid





Circumflex artery



Left ventricle

Great cardiac vein


artery (in anterior


Apex

Aortic arch

Auricle of

left atrium

Major Vessels of the Heart – Entering Left Atrium

Figure 18.4e

Aorta

Left pulmonary

arteryLeft atrium

Left pulmonary

veins

Mitral (bicuspid)

valve

Aortic valve


Papillary muscle



Endocardium

(e) Frontal section

Superior vena cava


Right atrium


Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava

Major Vessels of the Heart – Entering Left Atrium

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• Vessel leaving the right ventricle

–Pulmonary trunk → right and le> pulmonary arteries

• Vessel leaving the left ventricle

–Aorta

Ventricles The Discharging Chambers

Figure 18.4b

(b) Anterior view


Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium




Right ventricle


Small cardiac vein

Inferior vena cava

Left common carotid





Circumflex artery



Left ventricle

Great cardiac vein


artery (in anterior


Apex

Aortic arch

Auricle of

left atrium

Major Vessels of the Heart – Exiting Right Ventricle

Figure 18.4b

(b) Anterior view


Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium




Right ventricle


Small cardiac vein

Inferior vena cava

Left common carotid





Circumflex artery



Left ventricle

Great cardiac vein


artery (in anterior


Apex

Aortic arch

Auricle of

left atrium


Figure 18.4e

Aorta

Left pulmonary

arteryLeft atrium

Left pulmonary

veins

Mitral (bicuspid)

valve

Aortic valve


Papillary muscle



Endocardium

(e) Frontal section

Superior vena cava


Right atrium


Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava


Figure 18.4b

(b) Anterior view


Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium




Right ventricle


Small cardiac vein

Inferior vena cava

Left common carotid





Circumflex artery



Left ventricle

Great cardiac vein


artery (in anterior


Apex

Aortic arch

Auricle of

left atrium

Major Vessels of the Heart – Exiting Left Ventricle

Figure 18.4e

Aorta

Left pulmonary

arteryLeft atrium

Left pulmonary

veins

Mitral (bicuspid)

valve

Aortic valve


Papillary muscle



Endocardium

(e) Frontal section

Superior vena cava


Right atrium


Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava

Major Vessels of the Heart – Exiting Left Ventricle

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• Supply blood to the heart wall itself

Coronary Arteries

Figure 18.4b

(b) Anterior view


Superior vena cava

Right pulmonary

artery

Ascending aorta

Pulmonary trunk

Right pulmonary

veins

Right atrium




Right ventricle


Small cardiac vein

Inferior vena cava

Left common carotid





Circumflex artery



Left ventricle

Great cardiac vein


artery (in anterior


Apex

Aortic arch

Auricle of

left atrium


• Atrioventricular (AV) valves

–Prevent backflow into the atria when ventricles contract

–Chordae tendineae (“heart strings”) anchor AV valve cusps to

papillary muscles

• Semilunar valves

–Prevent backflow into the ventricles when ventricles relax

Unidirectional blood flow through the heart

Heart Valves

Figure 18.8c

Pulmonary

valve

Aortic

valve

Area of

cutaway

Mitral

valve

Tricuspid

valve

Chordae tendineae

attached to tricuspid valve flap

Papillary

muscle(c)

• Atrioventricular

–Separate atria from ventricles

• Tricuspid

– Right side

• Mitral (bicuspid)

– Left side

• Semilunar

–Separate ventricles from great arteries

• Pulmonary semilunar

• Aortic semilunar

Heart Valves

Figure 18.4e

Aorta

Left pulmonary

arteryLeft atrium

Left pulmonary

veins

Mitral (bicuspid)

valve

Aortic valve


Papillary muscle



Endocardium

(e) Frontal section

Superior vena cava


Right atrium


Pectinate muscles

Tricuspid valve

Right ventricle

Chordae tendineae

Trabeculae carneae

Inferior vena cava

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Figure 18.8a

Pulmonary valveAortic valve

Area of cutaway

Mitral valveTricuspid valve

Myocardium

Tricuspid

(right atrioventricular)

valve

Mitral

(left atrioventricular)

valve

Aortic

valve

Pulmonary

valve

(b)

Pulmonary valveAortic valve

Area of cutaway

Mitral valve

Tricuspid valveMyocardium

Tricuspid

(right atrioventricular)

valve

(a)

Mitral

(left atrioventricular)

valveAortic valve

Pulmonary

valveFibrous

skeleton

Anterior

• The heart is two side-by-side pumps

–Right side = pulmonary circuit

• Vessels that carry blood to and from the lungs

–Left side = systemic circuit

• Vessels that carry the blood to and from all body tissues

Cardiac Circulation

Figure 18.5

Oxygen-rich,

CO2-poor blood

Oxygen-poor,

CO2-rich blood

Capillary beds

of lungs where

gas exchange

occurs

Capillary beds of all

body tissues where

gas exchange occurs

Pulmonary veinsPulmonary arteries

Pulmonary

Circuit

Systemic

Circuit

Aorta and branches

Left atrium

Heart

Left ventricleRight atrium

Right ventricle

Venae cavae

Right atrium (via vena cava)

Tricuspid valve

Right ventricle

Pulmonary semilunar valve

Pulmonary trunk

Pulmonary arteries

Lungs

Pathway of Blood Through the Heart

Lungs

Pulmonary veins

Left atrium

Bicuspid valve

Left ventricle

Aortic semilunar valve

Aorta

Systemic circulation

Figure 18.9

1 Blood returning to the

heart fills atria, puttingpressure against

atrioventricular valves;

atrioventricular valves areforced open.

1 Ventricles contract, forcing

blood against atrioventricularvalve cusps.

2 As ventricles fill,

atrioventricular valve flapshang limply into ventricles.

2 Atrioventricular valves

close.

3 Atria contract, forcing

additional blood into ventricles.

3 Papillary muscles

contract and chordaetendineae tighten,

preventing valve flaps

from everting into atria.

(a) AV valves open; atrial pressure greater than ventricular pressure

(b) AV valves closed; atrial pressure less than ventricular pressure

Direction of

blood flow

Atrium

Ventricle

Cusp of

atrioventricularvalve (open)

Chordae

tendineae

Papillary

muscle

Atrium

Blood in

ventricle

Cusps of

atrioventricularvalve (closed)

Figure 18.10

As ventriclescontract andintraventricularpressure rises,blood is pushed upagainst semilunarvalves, forcing themopen.

As ventricles relaxand intraventricularpressure falls, bloodflows back fromarteries, filling thecusps of semilunarvalves and forcingthem to close.

(a) Semilunar valves open

(b) Semilunar valves closed

Aorta

Pulmonarytrunk

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• “lub-dup”

Heart Sounds

• Blood from the chambers cannot serve as a functional blood

supply to the heart

• Heart muscle has its own blood supply

– Coronary circulation

Coronary (Cardiac) Circulation

• Arteries

– Right and left coronary arteries

– Branch off base of the aorta

– Extensive branching throughout epicardium

• Common for branches from right and left coronary arteries to unite

– Anastomoses

• Cardiac veins feed into coronary sinus directly into right atrium

Coronary (Cardiac) Circulation

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Figure 18.7a

Rightventricle

Rightcoronaryartery

Rightatrium

Rightmarginalartery

Posteriorinterventricularartery

Anteriorinterventricularartery

Circumflexartery

Leftcoronaryartery

Aorta

Anastomosis(junction ofvessels)

Leftventricle

Superiorvena cava

(a) The major coronary arteries

Left atrium

Pulmonarytrunk

Figure 18.4d

(d) Posterior surface view

Aorta

Left pulmonaryartery

Left pulmonaryveins

Auricle of leftatrium

Left atrium

Great cardiacvein

Posterior veinof left ventricle

Left ventricle

Apex

Superior vena cava

Right pulmonary artery

Right pulmonary veins

Right atrium

Inferior vena cava

Right coronary artery(in coronary sulcus)

Coronary sinus

Posteriorinterventricularartery (in posteriorinterventricular sulcus)

Middle cardiac vein

Right ventricle

Figure 18.7b

Superiorvena cava

Anteriorcardiacveins

Small cardiac vein

Middle cardiac vein

Greatcardiacvein

Coronarysinus

(b) The major cardiac veins

Coronary sinus drains into right atrium

• Benefits of anastomoses

• Provides additional route of blood flow

• Older heart attack patients are more likely to survive

than younger ones

– Sudden clot formation vs gradual

Collateral Circulation

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