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Flashcards in Cardiology I & II Deck (82):
1

Components of the cardiovascular system

Heart
Arteries
Veins
Capillaries
Lymphatic vessels

2

Layers of the heart

Epicardium
Myocardium
Endocardium

3

Components of Epicardium

Mesothelial lining
Connective Tissue Underlying the mesothelium

4

Mesothelial Lining of the epicardium

covers the external surface of the heart

5

Connective tissue underlying mesothelium of the epicardium

Loose connective tissue, adipose tissue
Nerves pass through this layer
Blood vessels travel to the myocardium through this layer

6

Principle component of heart wall

Myocardium (thickest layer)

7

Thickness of myocardium in the atria vs ventricles

Thicker in the ventricles

8

Most internal layer of the heart

Endocardium

9

Components of endocardium

endothelium
subendothelial connective tissue
impulse conducting system

10

Describe the internal skeleton of the heart

Four fibrous rings that surround the valve orifeces

All within the atrioventricular plane (one continuous sheet)

11

Purpose of a trigone

to connect fibrous tissue rings surrounding valves together

12

left atrioventricular rings surrounds what valve

Mitral valve

13

Right atrioventricular ring surrounds what valve

Tricuspid

14

Left trigone connects what?

left atrioventricular ring (mitral) and aortic fibrous rings

15

Right trigone connects what?

left (mitral) and right (tricuspid) atrioventricular rings

16

Membranous Part of the interventricular septum

Devoid of cardiac muscle
Composed of dense irregular connective tissue
Contains part of the AV bundle

17

Where dies Ventricular Septal Defect occur

in the membranous portion of the IV septum

18

layers of valves

1: Fibrosa
2: Spongiosa
3: Atrialis

19

Fibrosa

formed of DICT connected to corresponding fibrous ring

Extends form the base along the ventricular side of atrioventricular valves

20

Which layer of the valve faces the ventricular side of the atrioventricular valve

fibrosa

21

Spongiosa

Formed of loose connective tissue

large amounts of elastic fibers

Most prominent on free edges of the valve

22

Where do you find the spongiosa layer of the valve, what is the purpose of this layer

most prominent on the free edges

Purpose: shock absorption (dampens vibrations as the valve closes)

23

Atrialis

covers the atrial aspect of spongiosa
Rich in proteoglycans
Contains elastic fibers and occasional smooth muscle cells

24

What layers of the valve contain elastic fibers

Spongiosa
Atrialis

25

Which layer(s) of the valve (may) contains some smooth muscle cells?

Atrialis

26

Mirtal Valve stenosis

inflammation of valve leaflets that promotes angiogenesis leading to formation of fibrotic tissue resulting in stenosis of the valve

Rheumatic fever can be a cause

27

Describe the ANS and heartbeat

ANS can REGULATE the heart beat but it does not INITIATE heartbeat

28

Parasympathetic - HR

Decrease HR

29

Sympathetic- HR

Increases HR

30

Effect of hormones and other substances on HR

can change the rate and force of contraction

ex: Epinephrine, thyroid hormones, caffeine

31

What are cardiac conducting cells called

Purkinje Fibers

32

Describe Purkinje fibers

modified cardiac myocyte (modified to conduct electrical impulses)

contain a lot of glycogen
can transmit faster than myocytes
still have intercalated discs

33

What do Purkinje fibers form

Nodes and bundles

including the sinoatrial and atreoventricular node and bindle of His

34

Myocardial infaction

caused by obstruction of coronary arteries and loss of blood supply to the cardiac muscle for more than 20 minutes

35

Is MI reversible? Why

No- Nuclei get spit out (cell death)

myocytes are unable to regenerate/ proliferate and get replaced by a scar

36

Atherosclerosis involves what layer of the vessel

Tunica intima thickening- narrows the lumen eventually causing rupture- clot will form due to exposed collagen

37

Most common benign tumor of the heart

Myxoma (bunch of loose connective tissue)

Commonly found in the left atrium

38

Angiosarcoma

rare tumor that originates in the heart (1/3 of all tumors that originate in the heart)

39

One of the most common tumors to spread to the heart

Metastatic Melanoma

40

Layers of blood vessels

Tunica intima
Tunica media
Tunica Adventitia

41

Components of tunica intima

endothelium
subendthelial connective tissue
internal elastic lamina

42

What lines the luminal surface

Endothelium of the tunica intima

43

Functions of Endothelium

1: Selective permeability (transcellular, paracellular, fenestrations)

2: Non-Thrombogenic factor

3: Modulation of blood flow

4: Regulation/Modulation of Immune Responses

5: Hormonal Synthesis

6: Metabolic activity

44

Endothelium

Transcellular pathway

allows active transport across the plasma membrane

Clatherin- independent pathway is used to transport material from blood into the cell

Clatherin- DEpenent pathway is used to transport LDL and cholesterol

45

Endothelium

Paracellular Pathway

Passive transport across zonula occuludens

Normally blocked by zonula occludens but in the case of inflammation the immune cells need to get out of the blood(causes edema and allows extravagation)

46

Endothelium

Fenestrations

Endothelial cells have holes in them that allow for the passage of fairly large molecules

(kidney and endocrine glands)

47

Endothelium

Non-Thrombogenic Barrier

Produce/ Secrete
- Anticoagulants (thrombomodulin)
- Antithrombogenic substances

In situations when the endothelium becomes damaged it secretes Thrombogenic agensts such as von Willebrand factor (triggers the clotting cascade)

48

Endothelium

Modulation of blood flow

Vasoconstrictors
- ACE (increase BP through Angiotensin)
- Endothelian
- Thromboxane

Vasodialators
- NO
- Prostacyclin

49

Endothelium

Regulation/Modulation of Immune Responses

control of leukocyte adhesion (movement of wbc into blood)

Secretion of interleukins and cytokines (IL-1, IL-6, IL-8)

50

Endothelium

Hormonal synthesis

Growth factors
- Colony stimulating factor (CSF)
- Fibroblast growth factor (FGF)
- Platelet derived growth factor (PDGF)

Growth factor inhibitors
- Tranforming growth factor B (TGF-B)

51

Endothelium

Metabolic activity

Angiotensin I --> Angiotensin II

through ACE to increase blood pressure

52

Subendothelial layer of tunica intima

Loose connective tissue

53

Internal Elastic Lamina of tunica intima

flattened fenestered sheet of elastin

separates tunica intima from tunica media

54

Tunica Media

middle layer of blood vessels

mostly smooth muscle (circularly arranged)

External elastic lamina

55

Where is external elastic lamina located

tunica media

56

where is internal elastic lamina located

tunica intima

57

What is the purpose of tunica media

maintain the architecture of the vessel

58

Tunica Adventitia

Most external layer
composed of mostly connective tissue
smooth muscle fibers (longitudinally arranged)
Small blood vessesl (vasa vasorum)
small nerves (nervi vasorum)

59

Which layer of blood vessels contains longitudinally arranged smooth muscle?

Tunica adventitia

60

Which layer of blood vessels contain circularly arranged smooth muscle?

Tunica media

61

Which blood vessel layer contains small blood vessels and veins

Tunica media

62

Three major types of arteries

Large elastic (conducting)
Muscular arteries
Small arteries and arterioles

63

Which type of arteries controls resistance

Small arteries and arterioles

64

Purpose of Arterioles

control blood flow to capillary network

Contracting smooth muscle cells

Depending on the type of activity the arterioles direct the blood to the organs that need it most

65

Do capillaries contain three tunics in their walls?

No- walls are made up of single layer of epithelium and their basal lamina

66

Types of capillaries

Continuous Capillaries
Fenestrated Capillaries
Discontinuous Capillaries

67

Continuous Capillaries

Continuous basal lamina
tight occluding junctions

68

Where are continuous capillaries found

muscles, lungs, CNS

69

Fenestrated capillaries

small holes in the endothelial cells (10-100 mm)

** basal lamina remains intact (acts as a filter)

70

Where are fenestrated capillaries found

in tissues where there is substantial fluid transport

intestinal villi, choroid plexus, renal glomeruli, endocrine organs

71

Discontinuous capillaries

endothelial cells separated by larger gaps (150-175 mm)
** holes extend into the basal lamina

72

Where are discontinuous capillaries found

Liver (sinusoids), spleen, bone marrow

73

Three major types of veins

Small veins (venules)
Medium veins (less than 1 cm)
Large veins (greater than 1 cm)

74

Divisions of small veins

Postcapillary venules
Muscular venules

75

Postcapillary venules

receive blood from capillaries

76

What layer is missing in postcapillary venules

tunic media

77

Principle site of immigration of WBC

Postcapillary venules - High endothelial venules

78

High endothelial venules

postcapillary venules of lymph organs
have columnar endothelium

79

Muscular Venules

collect blood from postcapillary venules

have a tunica media - VERY thin

80

order of venous blood flow

1: Post capillary venule
2: Muscular venules
3: Medium veins
4: Large veins
5: Heart

81

purpose of venous and lymphatic valves

ensure unidirectional flow

82

Permeability of lymphatic capillaries compared to blood capillaries

Greater permeability of lymphatic capillaries