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CARDIOVASCULAR
Brings O2 and nutrients to all body cells and remove
wastes.
CHAPTER 13
HEART
• Located in the pericardial/thoracic cavity (contains
serous fluid to reduce friction)
• Lined by a serous membrane called the pericardium
• 3 layers
– Epicardium-outer layer that protects heart
– Myocardium-thick middle layer of cardiac muscle that
forces blood out the heart chambers
– Endocardium-inner layer that contains blood vessels
that attach to the heart
• 4 chambers
– Atria: upper 2 chambers that have thin walls and
receive blood returning to heart
– Ventricles: lower 2 chambers that have thick walls
and receive blood from atria then contract to
force blood out of heart
• Interventricular Septum-solid wall that separates the
heart into left and right halves
• Coronary arteries-supply blood to the hearts tissues
(the 1st 2 branches of the aorta)
• Cardiac veins& Coronary sinus: blood returns to the
right atrium through these
• Atrioventricular valves: tricuspid/bicuspid
• Semilunar valves: pulmonary/aortic
PATH OF BLOOD FLOW THROUGH HEART
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Superior & Inferior
vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonary valve
Pulmonary trunk
Pulmonary arteries
Lungs
Pulmonary veins
Left atrium
Bicuspid valve
Left ventricle
Aortic valve
Aorta
Your body
BLOOD VESSELS
Artery
arteriole
(away from heart)
capillary
*site of nutrient,
gas, and waste exchange
venule
vein
(back to heart)
• Closed system of blood circulation
– Pulmonary circuit: sends deoxygenated blood to lungs
– Systemic circuit: sends oxygenated blood and nutrients to all body
cells and removes wastes
• The heart pumps 7,000 liters of blood through the body
each day, contracting some 2.5 billion times in an average
lifetime.
CARDIAC CYCLE
• The events of one complete heart beat (1 contraction
& relaxation) that lasts about .8 sec.
• Both atria contract while ventricles are relaxing.
• Both atria relax while ventricles are contracting.
• Pressure within the chambers rises and falls causes the
valves to open and close.
• When ventricular pressure exceeds atrial pressure, the
AV valves open.
• Papillary muscles contract and pull chordate tendineae
to open and close the valves. They aid in preventing
back flow of blood.
• Heart beat sound: lupp-dupp
• Lupp occurs when the AV valves are closing
• Dupp occurs when the semilunar valves are closing
• Cardiac conduction system coordinates the events of
the cardiac cycle.
• S-A node (sinoatrial node) or pacemaker
• upper right atrium
• generate the hearts rhythmic contractions
• A-V bundle
• Purkinje fibers
• Electrocardiogram (ECG): recording of the
electrical changes that occur in the
myocardium during the cardiac cycle.
ECG cont…
• S-A node triggers a cardiac impulse, atrial
fibers depolarize(contraction), producing an
electrical charge.
• Ventricle walls are thicker causing a greater
electrical charge.
• Adult heart rate 60-100 beats per minute.
Well trained athlete 40-60 bpm.
• Heart rate influences
• Emotional upset, anxiety
• Temperature change
• Ion changes (K+, Ca+2)
BLOOD PRESSURE
• Force blood exerts against the blood vessel walls. Specifically,
pressure in arteries supplied by branches of the aorta.
• Forces blood throughout the body.
• Blood vessels walls are constructed to adequately carry blood
(pg. 358)
• Artery
Highest pressure
arteriole
capillary
venule
vein
Lowest pressure
• Cut an artery, blood squirts out; cut a vein, blood flows out
• Contraction of the human heart creates enough pressure to
squirt blood 30 ft.
Blood Pressure cont..
• Systolic pressure: maximum pressure in the arteries
during ventricular contraction.
• Diastolic pressure: lowest pressure remaining in the
arteries before the next ventricular contraction.
• Average blood pressure 120/80
Arterial Pulse
Temporal
Facial
Carotid
Brachial
radial
femoral
popliteal
posterior tibial
dorsalis pedis
systolic/diastolic
• Factors that influence blood pressure
• Stroke volume: amount of blood discharged from
ventricle with each contraction
• Blood volume: sum of all blood components
• Peripheral resistance: friction b/w the blood and
blood vessel walls
• Viscosity: consistency of blood
CARDIOVASCULAR DISORDERS
• Tachycardia- abnormally fast heart beat – above
100 BPM
• Bradycardia – slow heart beat – below 60 BPM
• Murmur – abnormal heart sound due to incomplete
closure of heart valves
• Idiopathic cardiomyopathy – enlarged heart
• Congenital defects – defect present at birth
• Stenosis – narrowing of an opening
• Myocardial infarction – heart attack
• Angina pectoris – pain in the chest
• Hypertension – high blood pressure (140/90)
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Arrhythmias – abnormal heart rhythms
Atherosclerosis – a build-up of plaque in the arteries
Arteriosclerosis – hardening of the arteries
Coronary bypass – surgery using a vein from the leg or
artery from the chest to correct blocked coronary
arteries
Thrombus – blood clot
Embolus – moving blood clot
Ischemia – lack of blood flow and oxygen to heart
Aneurysm – a permanent weakness in an artery
Angioplasty – a catheter is inserted into an artery in the
leg or arm and fed into a coronary artery
Cardiac output – the amount of blood the heart pumps
each minute