Cardiovascular System: Heart Flashcards
Hearts Location
. Located between the right and left lungs in the lower portion of the mediastinum
. Protected by the sternum anteriorly and by the bodies of the thoracic vertebrae posteriorly
. Apex (blunt point) is at the lower left edge, lying on the diaphragm
Apical beat (heart sound at the apex)
heard best between the 5th and 6th rib (5th intercostal space) left midclavicular line
The Atria (Latin “atrium” – central court or main room)
small, upper chambers
thin, less muscular walls
“receiving chambers” - receive blood from the veins
Atrium’s
Right Atrium – receives unoxygenated blood (blood devoid of oxygen) from the biggest veins– the inferior
and superior vena cavae
Left Atrium – receives oxygenated blood (blood with oxygen) coming from the lungs through the pulmonary veins
The Ventricles (Latin “ventriculus”- stomach)
large, lower chambers
thicker, more muscular walls
“discharging chambers”- pump blood into arteries
Ventricle’s
Right Ventricle – pumps unoxygenated blood to the lungs through the pulmonary artery
Left Ventricle – pumps oxygenated blood to the different parts of the body, through the aorta
Interatrial Septum (Latin “saeptum” – a fence)
- separates the 2 atria
Interventricular
Septum
- separates the 2 ventricles
The septa prevent what?
a mixture of oxygenated
and unoxygenated blood
LAYERS OF THE HEART
. Endocardium - lines the inside of the chambers of the heart, being constantly bathed in blood
. Myocardium - the thick layer of heart muscle itself that pumps blood out of the heart
. Pericardium – the lining and covering of the heart which is composed of 2 layers:
1. visceral pericardium/epicardium – adherent to the heart
2. parietal pericardium – outer layer that acts like a loose-fitting sack, allowing enough room for the heart to beat
Pericardium is composed of 2 layers:
- visceral pericardium/epicardium – adherent to the heart
- parietal pericardium – outer layer that acts like a loose-fitting sack, allowing enough room for the heart to beat
Pericardial Fluid
– lubricant fluid between the visceral and parietal pericardia
HEART VALVES- the “Doors” of the Heart
Atrioventricular valves – the valves between the atria and ventricles that prevent the back flow of blood into the atria when the ventricles contract
1. tricuspid valve
2. mitral valve/bicuspid valve
Semilunar valves – between the ventricles and the arteries that carry blood away from the heart; prevent back flow of
blood into the ventricles
1. pulmonic/pulmonary valve
2. aortic valve
Atrioventricular valves includes what 2 valves?
- tricuspid valve – between the right atrium and right ventricle (Latin “cuspis” – cusps)
- mitral valve/bicuspid valve – between the left atrium and left ventricle (Latin “mitre” – headdress of a bishop)
Semilunar valves includes what 2 valves?
- pulmonic/pulmonary valve – at the root of the pulmonary artery, prevents blood from flowing back to the right ventricle
- aortic valve –at the root of the aorta, prevents blood from flowing back to the left ventricle
First heart sound (“lub”)
– caused by the closure of the atrioventricular valves during contraction of the ventricles
Second heart sound (“dup”)
– caused by closure of the
semilunar valves as the ventricles undergo diastole
What is a Heart Murmur
A sound made by blood flowing with turbulence through the heart
May be normal or abnormal
What is considered a Normal or “innocent” murmur?
are not associated
with signs and symptoms referable to a heart problem
What is considered an Abnormal murmur?
are often caused by defective valves, shunting of blood through septal defects or obstruction to flow of blood
- often accompanied by signs and symptoms of heart disease
Systole
- contraction of the heart
Diastole
- relaxation of the heart
Atrial systole
always comes first before ventricular systole.
Cardiac cycle
- one complete heartbeat which includes one contraction (systole) and one relaxation (diastole
Stroke Volume
What is the Normal stroke volume among adults?
– the quantity of blood that leaves the heart at every beat
. Normal stroke volume among adults is 60-100 ml/beat
Cardiac Output
– the amount of blood pumped by the heart in one minute
. Normal Cardiac Output among adults 4.5-6 liters/min
BLOOD FLOW THROUGH THE HEART
Superior & Inferior Vena Cava deliver blood devoid of oxygen -> Right Atrium -> Tricuspid valve -> Right Ventricle -> Pulmonary valve -> Pulmonary Artery -> Lungs where CO2 is released and O2 is taken up -> Pulmonary Veins carrying oxygenated blood -> Left Atrium -> Mitral valve
-> Left Ventricle -> Aortic valve -> Aorta -> to the whole body -> back to the Superior & Inferior Vena Cava
Pulmonary circulation
- movement of blood from right ventricle to the lungs and back to the left atrium
Systemic circulation
- movement of blood from left ventricle to the whole body & back to the right atrium
Circulation of Blood
Systemic circulation begins in the left ventricle -> aorta
-> arteries -> arterioles
-> capillaries in tissues where exchange of gases and substances occur -> venules -> veins -> superior and inferior vena cavae -> right atrium
pulmonary circulation begins in the right ventricle -> pulmonary valve -> left & right artery -> lungs -> left & right pulmonary veins -> left atrium
BLOOD SUPPLY TO THE CARDIAC MUSCLES
The myocardium must have constant supply of nutrients and oxygen to function effectively.
Coronary circulation – the delivery of oxygen and nutrient rich blood to the heart muscle and the return of un-oxygenated blood from the myocardium to the veins
. Coronary arteries
. Cardiac veins
Coronary circulation consist of arteries & veins. List what do they do?
. Coronary arteries - from the aorta, deliver oxygenated blood to the cardiac muscles
. Cardiac veins - deliver oxygen-poor blood back from the myocardium to the right atrium through the coronary sinus
Coronary Heart Disease
Narrowing of the coronary vessels caused by the build-up of plaque resulting in slowing down (ischemia)
or cessation of blood flow to the heart
Symptoms:
.chest pain or chest
.discomfort (angina)
.fatigue
.shortness of breath
.general weakness
what does Angina mean?
chest pain or chest