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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.
Fibrous Pericardium encloses the heart (like
a bag) and has 2 layers
• visceral pericardium (inner)
• and parietal pericardium (outer, attached
to diaphragm, sternum and vertebrae)
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. Circulation
is a double circuit: Pulmonary (lungs
only) and systemic (rest of the body)
• Heart has 4 chambers:
• 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) & 2
Semilunar valves)
• Left Atrioventricular valve – also called
the bicuspid valve or mitral valve.
Between left atrium and ventricle
• Right Atrioventricular valve – also called
the tricuspid valve. Between right atrium
and ventricle
– Aortic Semilunar – or just aortic valve.
Between the left ventricle and the aorta
– Pulmonary Semilunar, or just pulmonary
valve. Between the right ventricle and the
pulmonary artery
Path of Blood Flow
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.
The cusps (flaps) of the bicuspid and tricuspid
valves are anchored to the ventricle walls by fibrous
“cords” called chordae tendineae, which attach to
the wall by papillary muscles. This prevents the
valves from being pushed up into the atria during
ventricular systole.
ECG – electrocardiogram – a recording of
the electrical events (changes) during a cardiac cycle (heartbeat).
• 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
Analyze an ECG
Each one of the figures represents
an ECG pattern displaying three
types of abnormal rhythms:
Tachycardia, Bradycardia, and
Arrhymthmia. Identify each.
Cardiac Conduction
S-A Node
Junctional Fibers
A-V Node
A-V Bundle
Perkinje Fibers
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)
BLOOD
Blood transports substances and maintains
homeostasis in the body
Three Types of
Blood Cells
red blood cells
(erythrocytes)
white blood cells
(leukocytes)
platelets
(thrombocytes)
HEMATOPOEISIS – formation of
blood cells (bone marrow)
Liver & Spleen - phagocytosis
Elements Critical to RBC
Production
• Folic Acid
• Vitamin B12
• Iron
• Too few RBC = anemia
Oxygen Levels
Oxyhemoglobin = plenty of oxygen;
bright red
Deoxyhemoglobin = low in O2,
“bluish red”
WHITE BLOOD CELLS
(Leukocytes)
• General function is to protect the body
against disease
• There are several different kinds of WBCs
Granulocytes (granular cytoplasm)
Neutrophils, Eosinophils, Basophils
Agranulocytes (lacking granular cytoplasm)
Monocytes, Lymphocytes
Neutrophil
(nucleus has several lobes)
Active phagocytes
60% of WBC
Present in the pus of
wounds
Basophil
Produces
Heparin and
Histamines
Important in
Inflammatory
Reaction
1% WBC
Eosinophil
Mainly
attack
parasites
2% WBC
Monocyte
(larger cell, horseshoe shaped nucleus)
Become
macrophages
Lymphocyte
(nucleus is dark and takes up almost
whole cell; almost no cytoplasm seen)
Defense
against
invaders
Yield
Antibodies
30% WBC
Platelets (thrombocytes)
Blood clots and vessel
repair
Plasma Proteins
• Albumins – blood pressure
• Globulins (alpha, beta, gamma) – transport
lipids and antibodies for immunity
• Fibrinogen – important for blood clotting
Fibrogen • Fibrin
HEMOSTASIS
The process of stopping bleeding
Involves the coagulation and clotting of the
blood to seal the site of damage
• THROMBUS –
blood clot
(abnormal)
• EMBOLUS –
when the clot
moves to another
place.
ANEMIA
• Iron-Deficiency Anemia (most common)
• Aplastic Anemia – bone marrow does not
produce enough RBC
• Hemorrhagic anemia – due to extreme blood
loss
• Pernicious anemia – B12 deficiency
• Sickle Cell Anemia (genetic)
Leukemia
• Type of cancer
• Overproduction of immature white blood cells
• They take the place of RBCs
• Treatable with bone marrow transplants, chemothemotherapy,
radiation
Infectious mononucleosis
sometimes called "mono"
or "the kissing disease," is
an infection usually
caused by the EpsteinBarr virus (EBV).
EBV is very common, and
many people have been
exposed to the virus at
some time in childhood.
Blood poisoning - Septicemia
• An infection enters the blood stream
• Can be deadly
• Treated with antibiotics
Thrombocytopenia
• Low production of Platelets
• Causing bleeding or bruising
Jaundice
• In newborns, caused by the liver not
functioning fully
• Secretes bilirubin into the blood causing
the yellow color
• Exposure to flourescent lights (bili lights)
will break down the substance
SICKLE CELL ANEMIA
• Genetic
Disorder
• Abnormally
shaped blood
cells
• Parents can be
carriers
(asymptomatic)
Complications
1.Pain
2.Lethargy
3.Lifelong anemia
(low red blood count)
4.Organ failure
5.Stroke
HEMOPHILIA
This disorder causes a failure of the blood to
clot
Patients can be treated with blood
transfusions that include clotting agents.
Blood Type is Controlled by 3 Alleles
4 Possible Blood Types
Alleles: A, B, O
A & B are codominant
O is recessive
Genotypes
Rh Factor
A person can either be Rh + or Rh –
(positive is dominant)