Unit 2: heart Flashcards
Where is the human heart located?
In the mediastinum, extending from the second rib to the fifth intercostal space.
What encloses the human heart?
The pericardium.
What are the three layers of the pericardium?
- Outer fibrous pericardium
- Visceral pericardium
- Parietal pericardium
What is the visceral pericardium?
It lies on the surface of the heart and is considered part of the heart wall.
What does the parietal pericardium adhere to?
The inner surface of the fibrous pericardium.
What is found in the pericardial cavity?
Serous fluid.
What are the three layers of the heart wall?
- Epicardium (visceral pericardium)
- Myocardium
- Endocardium
What type of tissue makes up the epicardium?
Thin serous membrane made of simple squamous epithelium.
What composes the myocardium?
Cardiac muscle.
What type of tissue lines the heart chambers and valves?
Simple squamous epithelial tissue (endocardium).
What are the two thin-walled superior chambers of the heart called?
Atria
Atria are responsible for receiving blood returning to the heart.
What are auricles in relation to the heart?
Externally located earlike flaps at the anterior edge of each atrium
Auricles increase the capacity of the atria.
What are the two relatively thick-walled inferior chambers of the heart known as?
Ventricles
Ventricles pump blood out of the heart.
What is the function of the bicuspid (mitral) valve?
Prevents backflow from the left ventricle to the left atrium
This is an atrioventricular (AV) valve.
What does the tricuspid valve do?
Prevents backflow from the right ventricle to the right atrium
This is also an atrioventricular (AV) valve.
What is the role of the pulmonary valve?
Prevents backflow from the pulmonary trunk into the right ventricle
This valve is classified as a semilunar (SL) valve.
What does the aortic valve prevent?
Prevents backflow from the aorta into the left ventricle
This valve is also a semilunar (SL) valve.
What is the purpose of the pulmonary trunk?
Transporting deoxygenated blood from the right ventricle to the lungs
It branches into the left and right pulmonary arteries.
What do the pulmonary arteries do?
Transport deoxygenated blood to the lungs
They branch from the pulmonary trunk.
What is the function of the pulmonary veins?
Return oxygenated blood to the left atrium from the lungs
There are typically four pulmonary veins.
What is the aorta responsible for?
Transporting oxygenated blood from the left ventricle to the systemic circuit
It is the largest artery in the body.
What does the superior vena cava do?
Returns deoxygenated blood to the right atrium from areas located superior to the heart
It collects blood from the upper body.
What is the function of the inferior vena cava?
Returns deoxygenated blood to the right atrium from areas located inferior to the heart
It collects blood from the lower body.
What are chordae tendineae?
Cordlike tendons that connect the papillary muscles to the AV valves
They play a critical role in valve function.
