❤️pt. 2 Flashcards
Systemic
Carries blood to and from the body
Blood flow through the ❤️
1) The blood first enters the right atrium from the superior and inferior vena cava.
2) It then flows through the tricuspid valve into the right ventricle.
3) The blood then moves through the pulmonary valve into the pulmonary artery.
4) The pulmonary artery carries blood to the lungs where it takes up oxygen.
5) Oxygenated blood returns to the heart through the pulmonary vein into the left atrium.
6)The blood then moves through the mitral valve into the left ventricle.
7)The left ventricle then pumps the blood through the aortic valve into the aorta.
8)From the aorta, the blood is transported through the network of blood vessels, delivering oxygen and nutrients to tissues and taking carbon dioxide and wastes from tissues.
9)Deoxygenated blood returns to the heart via the superior and inferior vena cava, and the cycle begins again.
Blood follow through the body
1)Oxygenated blood from the left side of the heart gets pumped out of the aorta, the largest vessel of the body. The aorta extends from the left ventricle of the heart down into the abdomen.
2)Blood then flows through arteries that branch off from the aorta. These arteries deliver blood to different areas of the body.
3)Arteries then split into smaller vessels known as arterioles, which then carry blood to the smallest vessels in the body—the capillaries.
4)The capillaries deliver oxygen and nutrients to the tissues of your body and simultaneously remove carbon dioxide to be eliminated in the lungs.
5)Deoxygenated blood from the capillaries then flows back to the heart through small vessels known as venules.
6)The venules then gradually merge to form veins.
7)Blood enters back into the heart via large veins known as the superior and inferior vena cava.
8)Blood is then pumped through the right side of the heart, into the lungs to get oxygen, and back into the left side of the heart.
Right atrium collects blood from
Systemic circuit
Left atrium collects blood from
Pulmonary circuit
Right ventricle pumps blood to
Pulmonary circuit
Left ventricle pumps blood to
Systemic circuit
Right AV valve
■ Also called tricuspid valve
■ Has 3 cusps
AV valves
Between atria and ventricles
■ Blood pressure closes valve cusps during ventricular contraction
■ Papillary muscles tense chordae tendineae:
■ prevent valves from swinging into atria during ventricular contraction
Left AV valve
“Mitral”/“bicuspid valve”
2 cusps
Pulmonary semilunar valve
heart valve that controls the flow of oxygen-poor blood from the right ventricle to the lungs
Opens when pressure in right ventricle greater than pressure in pulmonary artery
Aortic semilunar valve
regulate blood flow from the left ventricle of the heart into the aorta, while preventing blood from flowing backward
-opens when left ventricle contracts
-closes when left ventricle relaxes
Aortic sinuses
-origin of left and right coronary arteries
-blood can only flow into coronary arteries in diastole
-when the aortic valve is closed because valves block off coronary vessels during systoli
Fibrous skeleton
-4 bands around ❤️ valves and bases of pulmonary trunk and aorta
-stabilize valves
-electrically isolate ventricular cells from atrial cells
Cardiac muscle struture
Striated, short, branch, 1 or 2 nuclei per cell
Cardiac muscle: contracts as a unit
Yes, gap junctions create a functional syncytium
Na+ rush from cell to cell via gap junctions➡️enter cell➡️depolarization➡️trigger AP➡️ contraction
T tubules of cardiac muscle
Few and wide
Cardiac muscle: sacroplasmic reticulum
Less elaborate; no terminal cisterns
Cardiac muscle: source of Ca2+ for contraction
Sarcoplasmic reticulum and ECF
Cardiac muscle: Ca2+ binds to troponin?
Yes
Cardiac muscle: pacemaker cells present?
Yes
Cardiac muscle: tetanus possible?
No
Cardiac muscle cell: supply of ATP
Aerobic only
Functions of intercalated discs
-maintain structure
-enhance molecular and electrical connections
-conduct APs
