The Cardiovascular System Flashcards Preview

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Flashcards in The Cardiovascular System Deck (57):
1

Pulmonary Circulation

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

2

Systemic Circulation

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

3

Tricuspid Valve

Right Atrium
--[valve]-->
Right Ventricle

Note: 3 leaflets

4

Pulmonary Valve

Right Ventricle
--[valve]-->
Pulmonary Artery

Note: 3 leaflets

5

Mitral (Bicuspid) Valve

Left Atrium
--[valve]-->
Left Ventricle

Note: 2 leaflets

6

Aortic Valve

Left Ventricle
--[valve]-->
Aorta

Note: 3 leaflets

7

Valves of the Heart

Tricuspid Valve-->
Pulmonary Valve-->
Mitral Valve-->
Aortic Valve

8

Atrioventricular Valves

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

9

Semilunar Valves

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

10

Circulation Pathway

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

11

Electric Conduction of Heart

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

11

Sinoatrial (SA) Node

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

12

Atrioventricular (AV) Node

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.

13

Bundle of His (AV Bundle)

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.

14

Purkinje Fibers

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.

15

Two Phases of the Heartbeat

Systole and Diastole

16

Systole

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

17

Diastole

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

18

Cardiac Output

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

19

Question:

Increase in heart rate and contractility is due to?

The sympathetic nervous system

20

Question:

Decrease in the heart rate and contractility is due to?

The parasympathetic nervous system

21

Vasculature

Consists of arteries, capillaries and veins.

22

Arteries

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

23

Arterioles

Small muscular arteries that control blood flow into capillary beds.

24

Capillaries

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).

25

Venule

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

26

Veins

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.

27

Question:

Transportation of deoxygenated blood back to the heart occurs in?

Veins

28

Question:

Transportation of oxygenated blood away from the heart occurs in?

Arteries

Exceptions: Pulmonary Artery and Umbilical Artery

29

Vasculature Flow

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

30

Question:

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

Endothelial Cells

31

Question:

Do arteries or veins have more smooth muscle?

Arteries

32

Superior Vena Cava

Returns blood from portions of the body above the heart.

33

Inferior Vena Cava

Returns blood from portions of the body below the heart.

34

Portal Venous System

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

35

3 Portal Venous Systems

Hepatic Portal System, Hypophyseal Portal System, Renal Portal System

36

Hepatic Portal System

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.

37

Hypophyseal Portal System

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.

38

Renal Portal System

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.

39

Composition of Blood By Volume

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

40

Plasma

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.

41

3 Major Cellular Components of Blood

Erythrocytes, Leukocytes, and Platelets

42

Formation of Blood Cells

Formed from hematopoietic stem cells located in the bone marrow.

43

Function(s) of Plasma Water

Solvent for carrying other substances

44

Function(s) of Plasma Salts

Osmotic balance, pH buffering, regulation of membrane potential

Ex. Na+, Ka+, Ca+, Mg+, Cl-, HCO3-

45

Function(s) of Plasma Proteins

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

46

Erythrocytes (RBC)

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.

47

Lifespan of Erythrocytes

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

48

Hematocrit

Measurement of how much of a blood sample consists of RBC's, given as a %.

Normal Hematocrit:
-Males = 41%-53%
-Females = 36%-46%

49

Leukocytes

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

50

Granular Leukocytes

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

51

Agranulocytes

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.

52

Platelets (Thrombocytes)

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).

53

Hematopoiesis

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.

54

Hormones involved in Hematopoiesis

Erythropoietin: secreted by the kidney and stimulates RBC development

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

55

Hemoglobin (Hg or Hgb)

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.

56

Question:

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

Answer: Arterioles

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