Download Cardiovascular_System - walker2015

Cardiovascular System
Chapter 11
Anatomy of the Heart

Location and Size



The size of the heart is slightly larger than a
person’s fist
Apex – the pointed end of the heart
Base – the broad portion of the heart
Base
Apex
Anatomy of the Heart (cont.)

Coverings

Pericardium – a double sac
of serous membranes that
surrounds the heart



Visceral (epicardium) – tightly
hugs the external surface of
the heart
Parietal – the outer layer that
anchors the heart to the
diaphragm and sternum
Serous fluid located inside the pericardium used
to prevent friction
Anatomy of the Heart (cont.)

Walls



Epicardium – the outermost layer of the heart
Myocardium – the middle layer (a muscle) that
actually contracts
Endocardium – the innermost layer that lines the
heart’s chambers
Anatomy of the Heart (cont.)

Flow of blood through vessels

Artery




Arteriole - small artery
Capillary




Carries blood away from the heart
Thickest blood vessel
smallest blood vessel
A couple of cell layers thick
Venule – small vein
Vein

Carries blood towards the heart
Color of Blood and Blood Vessels


Common misconception: blood is blue in the
body
Truth: blood is always a shade of red




Oxygenated blood is a bright-red color
Deoxygenated blood is a dark-red, maroon color
In books and diagrams, oxygenated blood is
depicted red & deoxygenated blood is blue
Blood vessels are colorless without blood
https://www.msu.edu/~kalinkat/professionalpages/TechMatrixMaterials/documentarybloodmisconceptions.htm
Anatomy of the Heart (cont.)

Chambers and Vessels

http://science.nationalgeographic.com/science/he
alth-and-human-body/human-body/heartarticle.html
Flow of Blood Through Heart

1. Superior vena cava – carries
deoxygenated blood from the head, neck,
and arms into the right atrium
Flow of Blood Through Heart

1. Inferior vena cava – carries deoxygenated
blood from the legs and other lower parts of
the body into the right atrium
Flow of Blood Through Heart

2. Right atrium – Hollow, receiving chamber
that collects deoxygenated blood from the
vena cavae before sending it to the right
ventricle
Flow of Blood Through Heart

3. Tricuspid valve - valve with three cusps;
situated between the right atrium and the
right ventricle
Flow of Blood Through Heart

4. Right ventricle – muscular, hollow chamber
that collects deoxygenated blood from the
right atrium before sending it to the
pulmonary artery
Flow of Blood Through Heart

5. Pulmonary semilunar valve – a valve
between the right ventricle and the pulmonary
artery; prevents blood from flowing from the
artery back into the heart
Flow of Blood Through Heart

6. Pulmonary artery – carries deoxygenated
blood from the right ventricle to the lungs
Flow of Blood Through Heart

7. Lungs – Location where deoxygenated
blood becomes oxygenated
Flow of Blood Through Heart

8. Pulmonary vein – carries oxygenated
blood from the lungs into the left atrium
Flow of Blood Through Heart

9. Left atrium – Hollow, receiving chamber
that collects oxygenated blood from the
pulmonary vein before sending it to the left
ventricle
Flow of Blood Through Heart

10. Bicuspid valve (or mitral valve) - Permits
blood to flow from the left atrium into the left
ventricle
Flow of Blood Through Heart

10. Bicuspid valve (or mitral valve)

This valve is called the mitral valve because it has
two flaps (cusps) and looks like a bishop's miter or
headdress
Flow of Blood Through Heart

11. Left ventricle – muscular, hollow chamber
that collects oxygenated blood from the left
atrium before sending it to the aorta
Flow of Blood Through Heart

12. Aortic semilunar valve – a valve between
the left ventricle and the aorta; prevents
blood from flowing from the artery back into
the heart
Flow of Blood Through Heart

13. Aorta – Large artery that distributes
oxygenated blood from the heart to the rest of
the body
Exterior Structures

Coronary arteries – vessels that provide the
heart muscle with the oxygenated blood it
needs to keep tissues healthy
Coronary Artery Disease
Internal Structures

Septum – a dividing wall or partition
Internal Structures

Papillary muscles – the
rounded muscular
projections attached to
the chordae tendineae
in the ventricles of the
heart
Internal Structures

Chordae tendineae (or
heart strings) – cordlike tendons that
connect the papillary
muscles to the tricuspid
valve and bicuspid
valve
Chordae tendineae
Pulmonary
Semilunar Valve
Bicuspid valve
Aortic Semilunar
Valve
Chordae tendineae
Septum
Differences in Right and Left Ventricles
(Bicuspid Valve)
Pulmonary
Semilunar Valve
Aortic Semilunar
Valve
Left
Blood Flow Through the Heart

http://www.youtube.co
m/watch?v=mH0QTWz
U-xI
Valves

There are two sounds heard during each
heart beat. These are called Lub-Dub noises.

When atrioventricular (AV) valves close, a "lub"
sound is heard.


The first sound heard in the heart
When the semilunar valves close, a "dub" sound
is heard followed by a longer pause Lub-DubLubDub.

The second sound heard in the heart
Murmurs


If the valves do not close properly and leak,
the sound will not be clear but blurred.
This sound is more of a Lub-Shhh-Dub or
Lub-Dub Rumble.
Varicose Veins



A.K.A “spider veins”
Varicose veins are gnarled, enlarged veins.
Caused by valves in blood vessels not
closing properly and pooling of blood causes
the veins to swell
Cardiac Circulation

Pulmonary circulation




Pulmonary - lungs
Located on the right side of the heart
Deoxygenated side
Systemic circulation



Systemic - body
Located on the left side of the heart
Oxygenated side
Physiology of the Heart

Intrinsic conduction system – the system that
conducts heartbeats




Sinoatrial (SA) node – The pacemaker that sends
electrical signals in the right atrium
Atrioventricular (AV) node – Located between the
right atrium and right ventricle
AV bundle – Found in the septum
Purkinje fibers – Found along the sides of the
heart
Heart Attack and Treatments

http://science.nationalgeographic.com/scienc
e/health-and-human-body/human-body/heartarticle.html
Cardiac Output


Cardiac output (CO) – Amount of blood pumped by
each ventricle of the heart in one minute
Stroke volume (SV) – Volume of blood pumped by
each ventricle in one contraction (each heartbeat)



About 70 mL of blood is pumped out of the left ventricle
with each heartbeat
Usually remains relatively constant
Heart rate (HR) – Typically 75 beats per minute
Cardiac Output

CO = HR  SV




Cardiac output = heart rate x stroke volume
CO = HR (75 beats/min)  SV (70 mL/beat)
CO = 5250 mL/min
Changing heart rate is the most common way
to change cardiac output
Blood Pressure

Measurements by health professionals are
made on the pressure in large arteries




Systolic—pressure at the peak of ventricular
contraction
Diastolic—pressure when ventricles relax
Write systolic pressure first and diastolic last
(120/80 mm Hg)
mm Hg (millimeters of mercury) – unit of pressure
Category
Normal
Diastolic
(bottom
number)
Systolic
(top number)
Less than 120
And
Less than 80
120–139
Or
80–89
Stage 1
140–159
Or
90–99
Stage 2
160 or higher
Or
100 or higher
Prehypertension
High blood pressure
Variations in Blood Pressure

Normal human range is variable

Normal



Hypotension



140–110 mm Hg systolic
80–75 mm Hg diastolic
Low systolic (below 110 mm Hg)
Often associated with illness
Hypertension


High systolic (above 140 mm Hg)
Can be dangerous if it is chronic
Comparison of Blood Pressures
in Different Vessels

Pressure in blood
vessels decreases as
distance from the heart
increases
Measuring Arterial Blood Pressure
Measuring Arterial Blood Pressure
Blood Pressure: Effects of Factors

Temperature

Heat has a vasodilating effect




Cold has a vasoconstricting effect
Chemicals


Vaso – blood vessel
Dilation – relaxation
Various substances can increase or decrease
blood pressure
Diet
Pulse



Pulse – Pressure wave of blood
Monitored at “pressure points” in arteries
where pulse is easily palpated
Pulse averages 70–76 beats per minute at
rest