CH 21: The Heart Flashcards
The heart keeps blood in what?
It beats — per minute
Motion
70 beats per minute
What are the four chambers of the heart?
Right and left atria(top)
Right and left ventricles (bottom)
What are the two circuits the heart pumps blood into?
Pulmonary circuit
Systemic circuit
What is the pulmonary circuit?
The right side of the heart (right atrium and right ventricle) receive and then pump blood to the lungs. Right side pumps to lungs and then back to the left and that is called “pulmonary circuit”
What is the systemic circuit?
The left side receives the blood in the left atrium, and then the left ventricle pumps the blood out to the entire rest of the body (exclusion of the lungs). Left ventricle pumps to the entire body, then flows back to the right side which is called “systemic circuit”
Each of the circuit involves?
Arteries
Veins
Capillaries
What do arteries do?
Transports blood “away” from the heart
What do veins do?
Transport blood “toward” the heart
What do capillaries do?
What happens here?
They are vessels that interconnect arteries and veins
This is where gas exchange happens
What is the pericardium?
What are the two layers?
Pericardium is the serous membrane lining the pericardial cavity
The two layers are visceral and parietal pericardium
— visceral and parietal are the same membrane folded in on itself
What is cardiac tamponade?
This is when there’s excessive fluid in the pericardial cavity which increases pressure on the heart
What are the three layers of the heart walls?
Epicardium- external surface it’s right on top of the heart
Myocardium - consist of cardiac muscle cells ( big, beefy, part of the heart)
Endocardium - internal surface made of simple squamous epithelium
What are intercalated discs made of?
Desmosomes - intercellular junctions that provide strong adhesion between cells
Gap junctions - in the heart it mediates intercellular communication
What surrounds all four valves and what is its function?
Fibrous skeleton
It anchors valve cusps, prevents overdilation of valve openings, gives the muscle leverage(something to pull on), and blocks direct spread of electrical impulses (acts as an insulator)
Where does the apex of the heart rotate toward?
The left side, and that is why the left lung has the cardiac notch to accommodate the apex of the heart
Why is the myocardium twisted (spiraled) within the heart?
The twisting and spiraling of the myocardium allows the heart as it squeezes to twist so the blood can be moved out of the chambers efficiently, which helps each heartbeat.
What is the purpose of the interatrial grove?
It’s separates the left and right atria
What is the purpose of the coronary sulcus?
It separates the atria and the ventricles
What is the purpose of the anterior and posterior interventricular sulcus?
It separates the left and right ventricles
What kind of blood does the right atrium receive?
It receives deoxygenated blood (depleted of oxygen) via the superior vena cava, inferior vena cava, and coronary sinus