Lecture 22: Heart Gross Anatomy Flashcards Preview

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Flashcards in Lecture 22: Heart Gross Anatomy Deck (82):
1

Mediastinum

Space between the pleural cavities

2

Phrenic nerve: Fiber type, roots, trajectory

GSE; C3, 4, 5; Through middle mediastinum, to the diaphragm

3

What vessels supply the diaphragm and pericardium?

Pericardiacophrenic arteries and veins

Artery is a branch of the internal thoracic artery

Vein drains into internal thoracic vein

4

What are the sacs of the pericardium?

There are 2:

1. Outer fibrous sac (composed of fibrous pericaridum)

2. Inner serous sac (composed of serous pericardium, with parietal and visceral layers, with a pericardial cavity in between)

5

components of inner serous sac

Serous pericardium of the 2 pericardium sacs; composed of an outer parietal layer, middle pericardial cavity, and inner visceral layer, which is aka epicaridum

6

What's another name for the visceral layer of the pericardium's inner serous sac?

Epicardium

7

3 layers of the wall of the heart

epicardium, myocardium (cardiac muscle), endocardium

8

What are sulci, where do you see them, what are they composed of?

A component of the epicardium that are grooves of adipose tissue on the surface of the heart (aka FAT!)

Demarcate the chambers of the heart on the heart's surface

9

What do the (anterior/posterior) coronary sulci (sing: sulcus) demarcate?

2 atria from 2 ventricles

10

What do the anterior/posterior interventricular sulci (sing: sulcus) demarcate?

Right ventricle from Left ventricle

11

What are the coronary arteries/veins embedded?

In the adipose tissue of the sulci

12

What do coronary arteries do?

Supply myocardium with oxygen; their occlusion results in a heart attack

13

Major branches of the Right Coronary Artery

1. Sinuatrial nodal branch (supplies the SA node)
2. Marginal branch
3. Atrioventricular nodal artery (supplies the AV node)
4. Posterior interventricular branch

14

Major branches of the Left Coronary Artery

1. Anterior interventricular branch (aka LAD, Left anterior descending artery)
2. Circumflex branch

15

What is the first branch of the aorta?

Coronary arteries

16

What does left anterior descending artery (LAD) run along?

Anterior interventricular sulcus
It is known as the Interventricular branch, the Widow Maker because where heart attacks occur most often

17

Location/path of the Right coronary artery

Originates from right aortic sinus of the ascending aorta; descends in the coronary sulcus between RA and RV

Travels in the coronary sulcus to reach posterior surface of the heart; there it anastomoses with circumflex branch of left coronary artery

18

What runs within the coronary sulcus?

Right coronary artery, small cardiac vein, coronary sinus, circumflex branch of the left coronary artery

19

What is the right atrial branch?

Branch of the RCA

Supplies the SA node

20

Where does sinuatrial nodal branch supply come from?

60% from Right coronary artery; 40% from Left coronary artery

21

Atrioventricular nodal artery supply?

Branch of the posterior interventricular branch of the RCA; 80% supply to AV nodal artery from the RCA, 20% from the LCA

22

Wheres does the LAD run?

Anterior interoventricular sulcus

23

What does the Right coronary artery supply?

Right atrium
Right ventricle
Posterior part of the Left ventricle
Posterior part of the interventricular sulcus

24

What does the Left coronary artery supply?

Left atrium
Left ventricle
Variable amount of Right ventricle
Most of the interventricular sulcus

25

Right coronary artery dominance

Normal distribution pattern of the coronary arteries means a right dominant coronary artery (supplies to 70% of heart) because the posterior interventricular branch arises from the RCA, and it supplies much of the posterior wall of the LV

26

Left coronary artery dominance

Normally, LCA supplies only 15% of the heart

In hearts with left dominant coronary artery, posterior interventricular branch arises from enlarged circumflex branch --> supplies most of posterior wall of LV

27

What do coronary arteries do?

Supply myocardium with oxygen

28

What do cardiac veins do?

Remove metabolic waste products from the metabolic activity of the myocardium

29

What are the branches of the cardiac veins of the heart?

1. Coronary sinus
2. Great cardiac vein
3. Middle cardiac vein
4. Small cardiac vein
5. Anterior cardiac vein
6. Venae cordis minimae

30

What cardiac vein(s) drain into the coronary sinus / RA?

Great cardiac vein
Middle cardiac vein
Small cardiac vein

31

What cardiac vein(s) drain into the RA?

Anterior cardiac vein

32

What cardiac vein(s) drain into the RA chamber?

Venae cordis minimae

33

Companion vessel for LAD?

Great cardiac vein

34

What is the pericardial cavity?

POTENTIAL SPACE! between the parietal seroues and visceral serous layers of the pericardium

35

When do the coronary arteries fill with blood?

Diastoli

36

Where does the coronary sinus drain to?

RA

37

Paths of cardiac veins

Listed from R to L/smallest to biggest:

Small cardiac vein (runs w/ R branch of RCA)
Middle cardiac vein (runs w/ posterior interventricular branch of LCA/RCA)
Great cardiac vein (runs w/ anterior interventricular a. and then circumflex branch of LCA)

38

Where does great cardiac vein begin?

Coronary sinus (posterior side of heart)

39

Where does middle cardiac vein begin?

Bottom of coronary sulcus

40

What do arteries give off?

arterioles and then capillaries

41

Do all arteries end in capillaries?

no

42

Do arteries/their branches sometimes anastomose?

yes

43

What forms the basis for collateral circulation?

Arterial anastomoses, which allow for collateral circulation if narrowing/occlusion of artery

44

Examples of arteries with anastomoses

1. Posterior intercostal arteries anastomose w/ anterior intercostal arteries

2. Superior epigastric arteries anastomose with inferior epigastric arteries

45

What are end-arteries?

Vessels without anastomoses; their occlusion results in necrosis of the tissue supplied by the occluded vessel

46

Example of end-arteries?

Central artery of the Retina; branches of the coronary arteries

47

Do coronary arteries have anastomoses?

Yes, but usually insufficient to provide adequate collateral circulation.

Anastomoses occur:
1. between interventricular branch of RCA and circumflex branch of LCA
2. between posterior interventricular branch of RCA and LAD

See anastomoses in the interventricular sulci

48

Why are coronary arteries called "functional end-arteries?

Because they are end-arteries ONLY in terms of physiology; NOT in terms of anatomy (since they do anastomose)

49

What does coronary occlusion lead to?

myocardial infarction/necrosis of the myocardium, aka heart attack

50

What does coronary insufficiency lead to?

myocardial ischemia, aka angina pectoris (cardiac pain; chest pain)

51

3 most common locations of coronary occlusion

Proximal end of RCA
Proximal end of LAD
Proximal end of circumflex branch of RCA

52

Where might cardiac pain be felt?

Pain arising from T1-T5 dermatomes

Typical: substernal; upper left chest; medial aspect of left upper extremity

Atypical: shoulder; neck; jaw; ear

Less common: both sides/right side of these areas

Uncommon: back between scapulae

53

What does MAK call the heart?

A muscular pump
An electrical organ
An endocrine gland
Has its own blood supply

54

Thickness of heart walls?

Related to workload/pressure flow of heart chambers

LV: thickest
RV: moderate
Atria: thinnest

55

Myocardium made of?

Cardiac muscle

56

Histo composition of epicardium?

Thickest epicardium along sulcus

Single layer of squamous cells along mesothelium; produces pericardial fluid, which invades pericardial cavity

Mostly is fat, elastic fiber

Also have lymphatic vessels, nerves

57

Composition of endocardium (facing atrium)?

Thicker than portion on ventricle

Endo: covered by single layer of endothelium cells; beneath endo, have layer of subendothelial tissue- CT with collagen and elastic fibers, fibroblasts, and some SM cells

Also have subendocarium

58

Composition of endocardium (facing ventricle)?

Thinner than portion on atrium

Endo: covered by single layer of endothelium cells; beneath endo, have layer of subendothelial tissue- CT with collagen and elastic fibers, fibroblasts, and some SM cells

Also have subendocarium layer

59

Myocardium made of

cardiac muscle cells, cardiac myoctyes or cardio cytes, contractile cells, myoendocrine cells (atrial myocytes), and conducting cells (nodal cells, bundle branches, purkinje fibers)

60

What are cardiac myocytes?

Contractile cells; endocrine cells that form exclusively in the atrium- not in the ventricle!

Conduct impulses

Made up cells of SA and AV nodes, bundle branches, and purkinje fibers

61

Direction of cardiac muscle fiber in myocardium

Spiral around ventricles and atria

62

Perimysium

separate cardiac myocytes into bundles/fascicles

63

How cardiac myocytes work?

Contract; leads to squeezing/twisting of ventricle to expel blood out of ventricle, wrings it out (like wet towel)

64

Fibers of cardiac myocytes?

Actin and myosin filaments

65

Intercalated disc

specialized intercellular junctions that draw together 2 cardiomyocytes

66

How many capillaries around each cardiac myocyte cell/why?

5 capillaries
b/c very metabolic/active tissue, need lots of blood supply, nutrients from capillaries

67

Lipofuscin pigment

Cardiac myocytes become yellow/brown pigment as age; are very long-lived cell

68

Can cardiac myocytes regenerate?

No

69

structure of intercalated disc

desmosome: 2 filaments that bind the 2 cardiac myocyte cells together

fascia adherentes: actin filaments for contractility

gap junction: lie on longitudinal portion; site of electrical and chemical transmission rapdily

70

extracellular matrix of heart structure

made of collagen fiber bundles, extends from extracellular matrix to myocardium

basal lamina form weave surrounding cardiocytes; elastic fiber bundles wrap around them; collagen fibrils insert into basal lamina; collagen fiber bundles form collagen struts btwn neighboring cardiocytes

71

atrial monocytes

smaller than ventricular monocytes
have granules which contain hormones
have fewer transverse-tubules than ventricular myocytes

72

is the heart endocrine/exocrine organ?

endocrine because atrial myocytes synthesize atrial natriuretic peptide (ANP) - a peptide hormone that is stored in its granules

73

What is ANP/what does it do?

when atrial wall stretches, it's secreted by exocytosis into blood circulation

blocks sodium resportion in renal tubules, thereby promoting sodium excretion and urine excretion

74

What conducts heart?

Cardiac muscle cells, NOT NERVOUS TISSUE!

75

What are cardiac muscle cells specialized for?

Initiating normal heart beat
Conducting impulses rapidly through the heart
Coordinating contraction of the 4 heart chambers

76

Components of heart's conducting system

SA node
AV node
AV bundle (Bundle of His) - right and left bundle branches
Purkinje fibers (in subendocardium)

77

SA node location?

sulcus terminales

cannot see it superficially

located at landmark btwn entrance of SVC to RA

78

What does SA nodal artery supply?

RA and SA node

79

SA node characteristics

modified atrial monocytes
small in size
few myofibrils
unorganized striations
gap junctions and desmosomes
irregular meshwork
embedded in fibrous tissue
autonomic nerves/blood vessels

80

purkinje fiber characteristics

in subendocardium
stain pale b/c of glycogen
large in size
have fewer myofibrils
lack t-tubules
no typical ICD
have desmosomes, gap junctions

81

Are there blood vessels w/in valve?

no

82

What are heart valves made of?

Leaflets of fibroelastic tissue, covered by endothelium continuous with that of the lining of the heart chambers and great vessels

On ventricular side, dense plate of collagneous tissue, lamina fibrosa; toward atrial side, elastic fibers

No blood vessels are present in the valves.