Download pulmonary valve

Cardiovascular System
heart and blood vessels
Systemic
Circulation –
delivers blood to
all body cells and
carries away
waste
Pulmonary
Circulation –
eliminates carbon
dioxide and
oxygenates blood
(lung pathway)
Structure of the Heart
Heart Size – about 14
cm x 9 cm (the size of a
fist).
Located in the
mediastinum (space
between lungs,
backbone, sternum),
between the 2nd rib and
the 5th intercostal
space.
The distal end of the
heart is called the apex.
Pericardium encloses the heart (like a bag)
and has 2 layers
Pericardial cavity – contains fluid for the
heart to float in, reducing friction
Wall of the Heart
Epicardium – outer layer, reduces friction
Myocardium – middle layer, mostly cardiac muscle
Endocardium – thin inner lining, within chambers of
the heart
Heart Chambers & Valves
• Your heart is a double pump/loop.
Circulation is a double circuit: Pulmonary
(lungs only) and systemic (rest of the
body)
• Heart has 4 chambers:
o
o
2 Atria – thin upper chambers that receive blood
returning to the heart through veins.. Right and Left
Atrium
2 Ventricles – thick, muscular lower chambers.
Receive blood from the atria above them. Force
(pump) blood out of the heart through arteries. Right
and left ventricle.
• Septum – separates the right and left sides of
the heart
• Valves of the Heart – allow one-way flow of
blood.
4 total
• (2 Atrioventricular Valves (AV)
o
Right Atrioventricular valve – also called the
tricuspid valve. Between right atrium and
ventricle
Left Atrioventricular valve – also called the bicuspid
valve or mitral valve. Between left atrium and
ventricle
• Superior Vena Cava: vein that carries
deoxygenated blood from the upper half
of the body to the heart's right atrium.
• Inferior Vena Cava: vein that carries deoxygenated blood from the lower half of
the body into the right atrium of the
heart.
• Coronary Sinus collection of veins joined
together to form a large vessel that
collects blood from the myocardium of
the heart. It delivers deoxygenated blood
to the Right atrium in conjunction with
the superior and inferior vena cava.
• Chordae tendinae/ Papillary muscles
also known as the heart strings, are
cord-like tendons that connect the
papillary muscles to the tricuspid valve
and the mitral valve in the heart.
• Pulmonary Trunk/arteries: Carries
deoxygenated blood from the heart to
the lungs. They are the only arteries
(other than umbilical arteries in the fetus)
that carry deoxygenated blood.
• Begins at the base of the right ventricle
then branches into two pulmonary
arteries (left and right), which deliver deoxygenated blood to the corresponding
lung.
• Pulmonary Semilunar, or just pulmonary
valve. Between the left ventricle and the
aorta
• Pulmonary Veins: Large blood vessel that
carries oxygenated blood from the lungs to
the left atrium of the heart. In humans there
are four pulmonary veins, two from each
lung
13
• Aorta- is the largest artery in the body
•
which orginates from the left ventricle.
Distributes oxygenated blood to the
body.
Aortic Semilunar – or just aortic valve.
Between the left ventricle and the aorta
Mitral = bicuspid (left side)
Tricuspid (right side)
Aortic and Pulmonary are
both semilunar valves
Path of Blood Flow
*This is a good time to watch some of
the heart animations and tutorials.
Label the heart
diagram on your
notes!
Check your labels!
1 Pulmonary Valve
2 Tricuspid Valve
3 Mitral (Bicuspid)
Valve
4 Aortic Valve
5 Heart Apex
Heart Actions
• Cardiac Cycle: One complete heartbeat.
The contraction of a heart chamber is called
systole and the relaxation of a chamber is
called diastole.
Regulation of Cardiac Cycle
controlled by the cardiac center within the
medulla oblongata. The cardiac center
signals heart to increase or decrease its rate
according to many factors that the brain
constantly monitors.
Muscle Activity
Body Temperature
Blood ion levels (potassium & calcium)
ECG – electrocardiogram – a recording of
the electrical events (changes) during a cardiac cycle
• P Wave – depolarization of
the atria (atrial contraction
– systole)
• QRS Complex –
depolarization of the
ventricles (ventricular
contraction, systole)
• T Wave – Repolarization of
the ventricles
Heart Sounds – opening and
closing of the valves, flow of
blood into and out of the
chambers, vibrations in
muscle
SADS = (Sudden Arrhythmia Death
Syndromes or Sudden Adult Death
Syndrome)
Routine ECG Screening may help prevent
deaths in young people
Heart Sounds - Opening and Closing of Valves,
"Lub Dub"
Stethoscope - instrument to
listen and measure heart
sounds
Interpreting ECGs
An ECG is printed on paper covered with a
grid of squares.
Notice that five small squares on the paper
form a larger square. The width of a single
small square on ECG paper represents 0.04
seconds.
A common length of an ECG printout is 6
seconds; this is known as a "six second
strip."
Analyze an ECG
Each one of the figures represents an
ECG pattern displaying three types of
abnormal rhythms: Tachycardia,
Bradycardia, and Arrhymthmia.
Identify each.
Factors affecting blood pressure:
Average is
120/80 (higher number is the systolic pressure)
1.
Cardiac Output
2.
Blood volume (5 liters for avg adult)
3.
Blood Viscosity
4.
Peripheral Resistance
Control of Blood Flow:
Precapillary sphincters – circular, valve-like muscle at
arteriole-capillary junction.
Vasoconstriction – narrowing blood vessel’s lumen
(“passageway”)
Vasodilation – explanding blood vessel’s lumen
Blood flow through veins – not
very efficient. Slow, weak
“pushing” by arterial blood
pressure is not much of a
factor at all. Important factors
include:
1. Contraction of the
diaphragm.
2. Pumping action of the
skeletal muscles.
3. Valves in the veins.
13.4 BLOOD VESSELS
Blood Vessels: arteries, veins, capillaries
Arteries : strong elastic vessels which carry blood
moving away from the heart. Smallest ones are
arterioles which connect to capillaries.
VEINS - Thinner, less muscular vessels carrying blood
toward the heart.
Smallest ones are called venules which connect to
capillaries. Contain valves.
Capillaries: Penetrate nearly all tissues. Walls are
composed of a single layer of squamous cells – very
thin. Critical function: allows exchange of materials
(oxygen, nutrients) between blood and tissues.
Disorders of the Circulatory System
1. MVP - mitral valve prolapse, the mitral valve does not
close all the way; this creates a clicking sound at the end of
a contraction.
2. Heart Murmurs – valves do not close completely, causing
an (often) harmless murmur sound. Sometimes holes can
occur in the septum f the heart which can also cause a
murmur
3. Myocardial Infarction (MI) - a blood clot obstructs a
coronary artery, commonly called a “heart attack”
4. Atherosclerosis – deposits of fatty materials such as cholesterol form a
“plaque” in the arteries which reduces blood flow. Advanced forms are
called arteriosclerosis. Treatment: Angioplasty, where a catheter is
inserted into the artery and a balloon is used to stretch the walls open. A
bypass can also treat clogged arteries, a vein is used to replace a
clogged artery. Coronary bypass refers to a procedure where the
coronary artery is bypassed to supply blood to the heart. (The phrase
“quadruple bypass” means that 4 arteries were bypassed.)
Video Showing a Stent and Angioplasty (Mayo Clinic)
5. Hypertension – high blood pressure, the force within the arteries is too
high. A sphygmomanometer can be used to diagnose hypertension