The Cardiovascular System

Question 1

Pulmonary Circulation

Answer 1

Portion of cardiovascular system that carries deoxygenated blood away from the heart, to the lungs, and returns blood back to the heart.

Question 2

Systemic Circulation

Answer 2

Portion of the cardiovascular system that carries oxygenated blood from the heart, to the body, and returns deoxygenated blood back to the heart.

Question 3

Tricuspid Valve

Answer 3

Right Atrium
–[valve]–>
Right Ventricle

Note: 3 leaflets

Question 4

Pulmonary Valve

Answer 4

Right Ventricle
–[valve]–>
Pulmonary Artery

Note: 3 leaflets

Question 5

Mitral (Bicuspid) Valve

Answer 5

Left Atrium
–[valve]–>
Left Ventricle

Note: 2 leaflets

Question 6

Aortic Valve

Answer 6

Left Ventricle
–[valve]–>
Aorta

Note: 3 leaflets

Question 7

Valves of the Heart

Answer 7

Tricuspid Valve–>
Pulmonary Valve–>
Mitral Valve–>
Aortic Valve

Question 8

Atrioventricular Valves

Answer 8

Consists of 2 valves which separate the atria from the ventricles and includes the:

• Tricuspid Valve = right atrium/right ventricle
• Mitral Valve = left atrium/left ventricle

Note: Mitral valve is also known as the bicuspid valve

Question 9

Semilunar Valves

Answer 9

Consists of 2 valves which separate the ventricles from the vasculature and includes the:

• Pulmonary Valve = right ventricle/pulmonary artery
• Aortic Valve = left ventricle/aorta

Question 10

Circulation Pathway

Answer 10

Right Atrium-(TV)->Right Ventricle->(PV)->Pulmonary Artery->Lungs->Pulmonary Veins->Left Atrium->[MV]->Left Ventricle->[AV]->Aorta-> Arteries->Arterioles->Capillaries->Venules->Veins->Venae Cavae->Right Atrium

Question 11

Electric Conduction of Heart

Answer 11

Sinoatrial (SA) Node–>
Atrioventricular (AV) Node–>
Bundle of His–>
Purkinje Fibers

Question 11

Sinoatrial (SA) Node

Answer 11

Small collection of cells, located in the right atrium, capable of self-depolarization (automaticity). Depolarization cascades thru the bedmann’s bundle to left atrium and thru internodal tracts to AV Node.

Note: The SA Node is the pacemaker of the cell and initiates impulse; 60-100 signals per minute w/o neural input

Question 12

Atrioventricular (AV) Node

Answer 12

Located at the junction of the atria and ventricles. It is here that the signal from the SA node is delayed, allowing ventricles to fill completely before contraction. The atria and ventricles contract 100 milliseconds (0.1) apart.

Question 13

Bundle of His (AV Bundle)

Answer 13

The collection of muscle cells embedded in the interventricular septum, specialized for electrical conduction that transmits electrical impulses from the AV node to the point of apex of the fascicular branches via the bundle branches, which then lead to the Purkinje fibers.

Question 14

Purkinje Fibers

Answer 14

Specialized conducting fibers located in the inner ventricular walls of the heart in a space called the subendocardium. Receives electrical impulses from the Bundle of His and creates synchronized contractions of the ventricles. Responsible for heart rhythm.

Question 15

Two Phases of the Heartbeat

Answer 15

Systole and Diastole

Question 16

Systole

Answer 16

Ventricular contraction and closure of the AV valves occurs and blood is pumped out of the ventricles.

Question 17

Diastole

Answer 17

Ventricular relaxation and closure of the semilunar valves allow blood from the atria to fill the ventricles.

Question 18

Cardiac Output

Answer 18

The total blood volume pumped by a ventricle in 1 minute. Cardiac output is the product of:

• heart rate (HR, beats per minute)
• stroke volume (SV, volume of blood pumped per beat)

Note: Human cardiac output = 5 liters per minute

Question 19

Question:

Increase in heart rate and contractility is due to?

Answer 19

The sympathetic nervous system

Question 20

Question:

Decrease in the heart rate and contractility is due to?

Answer 20

The parasympathetic nervous system

Question 21

Vasculature

Answer 21

Consists of arteries, capillaries and veins.

Question 22

Arteries

Answer 22

Thick, highly muscular structure with an elastic quality. This allows for recoil and helps to propel blood forward within the system.

Question 23

Arterioles

Answer 23

Small muscular arteries that control blood flow into capillary beds.

Question 24

Capillaries

Answer 24

Narrow structures that make up microcirculation. Their endothelial linings are one cell layer thick, making them permeable to both gas and solute exchange (e.g. H2O, O2, CO2, nutrients and waste).

Question 25

Venule

Answer 25

Small blood vessel in the microcirculation that allows blood to return from the capillary bed to drain into the larger blood vessels, the veins.

Question 26

Veins

Answer 26

Inelastic, thin-walled structures that transport blood to the heart. They obtain the ability to stretch in order to accommodate large volumes of blood but do not recoil. Veins are compressed by surrounding skeletal muscle and have valves to prevent backflow.

Question 27

Question: Transportation of deoxygenated blood back to the heart occurs in?

Answer 27

Veins

Question 28

Question: Transportation of oxygenated blood away from the heart occurs in?

Answer 28

Arteries Exceptions: Pulmonary Artery and Umbilical Artery

Question 29

Vasculature Flow

Answer 29

``` Arteries--> Arterioles--> Capillaries--> Venules--> Veins--> Superior and Inferior Venae Cavae ```

Question 30

Question: What is the main cell type that comprises all vasculature vessels?

Answer 30

Endothelial Cells

Question 31

Question: Do arteries or veins have more smooth muscle?

Answer 31

Arteries

Question 32

Superior Vena Cava

Answer 32

Returns blood from portions of the body above the heart.

Question 33

Inferior Vena Cava

Answer 33

Returns blood from portions of the body below the heart.

Question 34

Portal Venous System

Answer 34

Occurs when a capillary bed pools into another capillary bed through veins, before returning to the heart.

Question 35

3 Portal Venous Systems

Answer 35

Hepatic Portal System, Hypophyseal Portal System, Renal Portal System

Question 36

Hepatic Portal System

Answer 36

The part of the venous portal system in which blood leaves capillary beds in the walls of the gastrointestinal tract and passes through the hepatic portal vein before reaching the capillary beds in the liver.

Question 37

Hypophyseal Portal System

Answer 37

The part of the venous portal system in which blood leaves the capillary beds in the hypothalamus and travels to a capillary bed in the anterior pituitary allowing for paracrine secretion of releasing hormones.

Question 38

Renal Portal System

Answer 38

The portion of the venous portal system in which blood leaves the glomerus and travels through the efferent arterioles before surrounding the nephron in a capillary network called the vasa recta.

Question 39

Composition of Blood By Volume

Answer 39

55% Plasma and 45% Cells (e.g. erythrocytes, leukocytes, platelets)

Question 40

Plasma

Answer 40

The liquid portion of blood that holds blood cells in suspension; this makes plasma the extracellular matrix of blood cells. It is the intravascular fluid part of the extracellular fluid. It is an aqueous mixture of water, nutrients, salts, respiratory gases, hormones, and blood proteins.

Question 41

3 Major Cellular Components of Blood

Answer 41

Erythrocytes, Leukocytes, and Platelets

Question 42

Formation of Blood Cells

Answer 42

Formed from hematopoietic stem cells located in the bone marrow.

Question 43

Function(s) of Plasma Water

Answer 43

Solvent for carrying other substances

Question 44

Function(s) of Plasma Salts

Answer 44

Osmotic balance, pH buffering, regulation of membrane potential Ex. Na+, Ka+, Ca+, Mg+, Cl-, HCO3-

Question 45

Function(s) of Plasma Proteins

Answer 45

Osmotic balance, pH buffering, clotting, defense (antibodies)

Question 46

Erythrocytes (RBC)

Answer 46

Lack mitochondria, a nucleus, and organelles in order to make room for hemoglobin, a protein that carries oxygen. Main functions are to transport O2 and help to transport CO2. Note: RBC's rely entirely on glycolysis for the production of ATP, with lactic acid as the main byproduct.

Question 47

Lifespan of Erythrocytes

Answer 47

Red blood cells can live for 120 days in the bloodstream before being recycled in the liver and spleen.

Question 48

Hematocrit

Answer 48

Measurement of how much of a blood sample consists of RBC's, given as a %. Normal Hematocrit: - Males = 41%-53% - Females = 36%-46%

Question 49

Leukocytes

Answer 49

Formed in the bone marrow and are a crucial part of the immune system. Two major subdivisions: - Granular Leukocytes - Agranulocytes

Question 50

Granular Leukocytes

Answer 50

The class of leukocytes that includes neutrophils, eosinophils, basophils all of which play a role in nonspecific immunity.

Question 51

Agranulocytes

Answer 51

The class of leukocytes that includes lymphocytes and monocytes both of which play a role in immunity, with lymphocytes playing a larger role in specific immunity.

Question 52

Platelets (Thrombocytes)

Answer 52

The cell fragments released from cells in the bone marrow known as megakaryocytes. They are present in high concentrations in the blood and are required for coagulation (blood clotting).

Question 53

Hematopoiesis

Answer 53

The production of blood cells and platelets from hematopoietic stem cells in the bone marrow. Production of blood cells is stimulated by hormones, growth factors, and cytokines.

Question 54

Hormones involved in Hematopoiesis

Answer 54

Erythropoietin: secreted by the kidney and stimulates RBC development Thrombopoietin: secreted by the liver and kidney and stimulates thrombocyte development

Question 55

Hemoglobin (Hg or Hgb)

Answer 55

Fe-containing O2-containing metalloprotein in RBC's. Carries oxygen from the lungs to body tissues where it is released and permits aerobic respiration to provide energy to power the functions of the organism in a process called metabolism.

Question 56

Question: The largest drop in blood pressure occurs in which type of vasculature?

Answer 56

Answer: Arterioles Reason: Capillaries are thin-walled and unable to withstand the pressure of the arterial side of the vasculature.