CARDIOVASCULAR SYSTEM Flashcards
- A closed system of the heart and blood vessels
*The heart pumps blood
*Blood vessels allow blood to circulate to all
parts of the body
*is to deliver oxygen and nutrients and to remove
carbon dioxide and other waste products
CARDIOVASCULAR SYSTEM
- Thorax between the lungs
- Pointed apex directed toward left hip
- About the size of your fist
- Less than 1
Heart
a double serous membrane
Pericardium
Pericardium Next to heart
Visceral pericardium
Pericardium Outside layer
Parietal pericardium
fills the space between the layers of pericardium
Serous fluid
Three layers of heart wall
- Epicardium
- Myocardium
- Endocardium
*Outside layer
*This layer is the parietal pericardium
*Connective tissue layer
Epicardium
*Middle layer
*Mostly cardiac muscle
Myocardium
- Inner layer
*Endothelium
Endocardium
Covers the heart and attaches to the
pericardium
Epicardium
Contracts to pump blood into the arteries
Myocardium
Lines the interior chambers and valves
Endocardium
Thin, serous(watery) membrane that is
continuous with the lining of the pericardium
Epicardium
Thick layer of cardiac muscle
Myocardium
Thin layer of epithelial cells that is continuous
with the lining of the blood vessels
Endocardium
Right and left side act as separate pumps
HEART CHAMBERS
- Four chambers
- Right Atrium
- Right Ventricle
- Left Atrium
- Left Ventricle
*Receiving chambers
* Right atrium
* Left atrium
Atria
- Discharging chambers
- Right ventricle
- Left ventricle
Ventricles
Upper right chamber
Right Atrium
Lower right chamber
Right Ventricle
Upper left chamber
Left Atrium
Lower left chamber
Left Ventricle
Receives deoxygenated blood from the body via both the Superior(upper) vena cava and inferior (lower) vena cava and pumps into the right ventricle
Right Atrium
Receives blood from the right atrium and pumps it into the pulmonary artery, which carries it to the lungs to be oxygenated.
Right Ventricle
Receives oxygenated blood from the lungs via the
pulmonary veins and pumps it into the left ventricle.
Left Atrium
Receives blood from the left atrium and pumps it into the aorta. The cell walls of the left ventricle are nearly three times as thick as those of the right ventricle owing to the force required to pump the blood into the arterial system
Left Ventricle
Allow blood to flow in only one direction
Valves
Four valves
- Right AV valve or tricuspid valve
- Left valve or Bicuspid or mitral valve
- Right semilunar valve or pulmonic/ pulmonary valve
- Left semilunar valve or aortic valve
Between the right atrium and right ventricle
Right AV valve or tricuspid valve
Between the left atrium and left ventricle
Left valve or Bicuspid or mitral valve
At the entrance to the pulmonary artery
Right semilunar valve or pulmonic/ pulmonary valve
At the entrance to the aorta
Left semilunar valve or aortic valve
Has three cusps hence the name tricuspid
Right AV valve or tricuspid valve
Has two cusps, hence the name bicuspid
Left valve or Bicuspid or mitral valve
Has three half-moon shaped cusps
Right semilunar valve or pulmonic/ pulmonary valve
Has three half shaped cusps
Left semilunar valve or aortic valve
Closes when the right vent. Contracts and prevents blood from flowing back into the right atrium
Right AV valve or tricuspid valve
Closes when the left vent. Contracts and prevents blood from flowing back into the left atrium
Left valve or Bicuspid or mitral valve
Closes when the right vent. Relaxes and prevents blood from flowing back into right ventricle
Right semilunar valve or pulmonic/ pulmonary valve
Closes when the left ventricle relaxes and prevents blood from flowing back into the left ventricle
Left semilunar valve or aortic valve
backflow and repump
Incompetent valve
stiff= heart workload increased
Stenosis
Valve Pathology
- Incompetent valve = backflow and repump
- Stenosis = stiff= heart workload increased
- May be replaced
- Lup Dub Heart Sound
The Heart: Associated Great Vessels
- Aorta
- Pulmonary arteries
- Vena cava
- Pulmonary veins (four)
- Leaves left ventricle
Aorta
- Leave right ventricle
Pulmonary arteries
- Enters right atrium
Vena cava
- Enter left atrium
Pulmonary veins (four)
Rapid heart beat
- = Inadequate blood
- = Angina Pectoris
- Blood in the heart chambers does not nourish the myocardium
- The heart has its own nourishing circulatory system
*Coronary arteries
*Cardiac veins
*Blood empties into the right atrium via the coronary sinus
CORONARY CIRCULATION
Heart muscle cells contract, without nerve impulses, in a regular, continuous way
Intrinsic conduction system (nodal system)
“Pacemaker”
Sinoatrial node
junction of right and left atria and ventricles
Atrioventricular node
Bundle of His
Atrioventricular bundle
Special tissue sets the pace
- Sinoatrial node
- Atrioventricular node
- Atrioventricular bundle
- Bundle branches
- Purkinje fibers
impulse across atria
P wave
spread of impulse down septum, around ventricles
in Purkinje fibers
QRS complex
end of electrical activity in ventricles
T wave
= release of ventricles from control
Damage to AV node
= lack of blood flow to the heart
Fibrillation
= more than 100 beats/min
Tachycardia
= less than 60 beats/min
Bradychardia
= slower heart beat
- Slower heart beat can lead to fibrillation
- Atria contract simultaneously
- Atria relax, then ventricles contract
CARDIAC CYCLE
contraction
Systole
relaxation
Diastole
- Amount of blood pumped by each side of the
heart in one minute
Cardiac output (CO)
(heart rate [HR]) x (stroke volume [SV])
= CO
- Volume of blood pumped by each ventricle in
one contraction
Stroke volume
CO =
= HR x SV
Stroke volume usually remains relatively
constant
REGULATION OF HEART RATE
the more that the cardiac muscle is stretched, the stronger the contraction
Starling’s law of the heart
Increased heart rate
- Sympathetic nervous system
- Hormones
- Exercise
- Decreased blood volume
*Crisis
*Low blood pressure
Sympathetic nervous system
*Epinephrine
*Thyroxine
Hormones
*Parasympathetic nervous system
* High blood pressure or blood volume
* Dereased venous return
* In Congestive Heart Failure the heart is worn out and pumps weakly. Digitalis works to provide a slow, steady, but stronger beat
Decreased heart rate
- Decline in pumping efficiency of heart
- Inadequate circulation
- Progressive, also coronary atherosclerosis, high blood pressure and history of multiple Myocardial Infarctions
CONGESTIVE HEART FAILURE (CHF)
pulmonary congestion and suffocation
Left side fails
peripheral congestion and edema
Right side fails
