Chapter 15 - Cardiovascular system Flashcards
How much blood is pumped through the body each day?
7000 liters
How many times does the heart contract in an average lifetime?
2.5 billion times
What makes up the cardiovascular system?
heart and blood vessels
Name the 2 circuits of the blood vessels:
- pulmonary circuit
- systemic circuit
Describe the heart:
hollow, cone-shaped, muscular pump
Name the 4 chambers of the heart:
2 atria , 2 ventricles
What do the atria do?
blood storage
What do the ventricles do?
pump blood
Does the heart change with body size?
varies with body size
What cavity does the heart lie in?
thoracic cavity
Where does the heart lie in terms of the diaphragm?
above
The base of the heart is which part of the heart? Top of bottom anatomically?
top
Where does the base lie?
beneath the 2nd rib
Where is the apex of the heart?
5th intercostal space
What is the covering of the heart called?
pericardium
Name the layers of the pericardium:
- Fibrous
- Visceral
- Parietal
Name the layers of the wall of the heart:
- epicardium
- myocardium
- endocardium
What does cardiac muscle have that is special?
striated, branched, intercalated discs, single nucleus
Describe the epicardium:
connective tissue, serous membrane - outer cover, secretes serous fluid
Describe the Myocardium
cardiac muscle tissue, contracts to pump blood from the heart chambers
Describe the Endocardium
membrane of epithelial that forms a protective inner lining of the chambers and valves
Where does blood enter the heart?
right atrium
Where does the heart receive blood (to be pumped to the body) from, what structures/vessels?
- inferior vena cava
- superior vena cava
- coronary sinus
Where does the heart tissue get blood for nourishment (not pump)?
- coronary arteries, branch of aorta
What is a heart attack?
MI, interruption of blood supply to the heart from a clot, death of cardiac cells,
What is a natural protection from heart attacks?
arterial anastomoses which provide alternate route of blood flow (collateral circulation)
What is chest pain from partial obstruction of coronary blood flow?
angina pectoris - ischemia of heart muscle, myocardium shifts to anaerobic fermentation, producing lactic acid and thus stimulating pain
Where does blood get sent in the pulmonary circuit?
oxygen-poor blood is sent to the lungs to get oxygen and unload co2
Can the heart be considered 1 or 2 pumps?
2 pumps
Where does the right side of the heart pump blood?
lungs (pulmonary circuit)
Where does the left side of the heart pump blood?
body (systemic circuit)
Where is the heart located in the thorax?
in the mediastinum, above the diaphragm
Where can you feel the apical heartbeat?
5th and 6th ribs to the left of the midline
What encloses the heart?
pericardium
What is the double layer serous membrane that covers the heart?
parietal and visceral pericardium
What is the fibrous pericardium made of?
dense connective tissue
What structures does the fibrous pericardium attach to?
sternum, vertebral column, diaphragm, heart blood vessels
What is the space between the parietal and visceral serous layers?
pericardial cavity
What is contained in the pericardial cavity?
serous fluid
What is the function of the serous fluid?
reduce friction between the pericardial membranes as the heart moves within them