Histo Exam 2-Heart study guide

Question 1

What is the bulk of the heart muscle?

Answer 1

myocardium

Question 2

What is the layer that lines the chambers of the heart?

Answer 2

endocardium

Question 3

What are the outermost layers of the heart?

Answer 3

pericardium

Question 4

What is direectly attached to the surface of the myocardium?

Answer 4

epicardium

Question 5

What is the endothelium?

Answer 5

simple squamous epithelium with a thin continuous basal lamina

Question 6

Where is this endothelium found?

Answer 6

contacts blood within the chambers of the heart

Question 7

What is subendothelium?

Answer 7

loose connective tissue layer with abundant elastic fibers and some smooth muscle bundles

Question 8

What is subendothelium comparable to?

Answer 8

lamina propia

Question 9

What is subendocardium?

Answer 9

layer of loose connective tissue

Question 10

What does the subendocardium contain?

Answer 10

small vessels, nerves, bundle branches and purkinje fibers

Question 11

Where is the subendocardium found?

Answer 11

connected to myocardium

Question 12

Why is there collagen and elastin in the endocardium?

Answer 12

lots of collagen and elastin to allow for expansion and contraction of heart, allows for flexibility

Question 13

Why are there smooth muscle bundles in the endocardium?

Answer 13

smooth muscle helps endocardium contract back to normal size

Question 14

What does the myocardium consist of?

Answer 14

consists of cardiac muscle fibers, part of the cardiac skeleton, and the impulse-conduction system of the heart

Question 15

What surrounds each cardiac muscle cell?

Answer 15

surrounded by endomysium

Question 16

What are groups of cardiac cells surrounded by?

Answer 16

perimysium

Question 17

What are characteristics of cardiac muscle?

Answer 17

striated, branched, single central round nucleus, intercalated disks

Question 18

What are intercalated disks?

Answer 18

gap junctions and fascia adherens

Question 19

What do you look for in cross sections of cardiac muscle?

Answer 19

look for central nuclei and bundled myofilaments

Question 20

What is atrial cardiac muscle made of?

Answer 20

overlapping network of woven fibers with collagen and elastin interspersed

Question 21

What do atrial cardiac cells synthesize?

Answer 21

the hormone atrial natriuretic factor

Question 22

Atrial cardiac muscle conducts impulses_________ and contract ________rhythmically than ventricular cardiac muscle cells.

Answer 22

faster, more

Question 23

Does atrial have more or less gap junctions than ventricular cardiac muscle cells?

Answer 23

more gap junctions

Question 24

What are the characteristics of the endocardium and myocardium in atrial cardiac muscle?

Answer 24

thicker endocardium and thinner myocardium

Question 25

Specifically where is more ANF synthesized?

Answer 25

in the right atrium

Question 26

What is the purpose of ANF?

Answer 26

targets the kidneys and stimulates sodium and water loss and reduces blood pressure

Question 27

What is a characteristic of ventricular cardiac muscle?

Answer 27

thicker myocardium than atria, larger less granular cardiac myosites, less elastic fibers

Question 28

How are cells positioned in ventricular cardiac muscle?

Answer 28

helically around the cavity

Question 29

Why are ventricular cardiac cells winding helically around the cavity?

Answer 29

to aid in "wringing out" the heart during contraction

Question 30

What is another name for epicardium?

Answer 30

visceral pericardium

Question 31

What is epicardium made of?

Answer 31

outer single smooth layer of squamous mesothelial cells with thin basal lamina

Question 32

What is the subepicardial laer made of?

Answer 32

loose connective tissue binds epicardium to myocardium

Question 33

What is also found in the epicardium?

Answer 33

contains variable amounts of adipose, within which coronary vessels are embedded

Question 34

What is the cardiac skeleton?

Answer 34

dense connective tissue scaffolding into which cardiac muscle fibers insert and from which cardiac valves extend

Question 35

What is the annuli fibrosae?

Answer 35

dense connective tissue rings that surround and reinforce valve openings

Question 36

What is trigona fibrosae?

Answer 36

two triangular dense CT masses lying between the two groups of annuli fibrosae

Question 37

What is the septum membranaceum?

Answer 37

dense fibrous plate forming the top of the muscular interventricular septum

Question 38

What can happen to the cardiac skelton with age?

Answer 38

it may calcify

Question 39

All four rings of this are associated with the 4 major heart valves?

Answer 39

annuli fibrosae

Question 40

What are cardiac valves?

Answer 40

folds of endocardium enclosing a core of dense fibrous CT

Question 41

What are the cardiac valves rich in?

Answer 41

rich in collagen and elastin

Question 42

The bases of cardiac valves are anchored to?

Answer 42

stong fibrous rings of the annuli fibrosae

Question 43

Where is the mitral valve located?

Answer 43

between the left atrium and left ventricle

Question 44

What is another name for mitral valve?

Answer 44

bicuspid

Question 45

What are the characteristics of the bicuspid valve?

Answer 45

has 2 cusps or flaps

Question 46

What are the flaps anchored to?

Answer 46

papillary muscles

Question 47

What holds the flaps to the papillary muscle?

Answer 47

chordae tendinae

Question 48

What does the chordae tendinae insert into?

Answer 48

a fibrous cap in the myocardium

Question 49

Where is the AV valve located?

Answer 49

located between the right atrium and ventricle

Question 50

What is another name for AV valve?

Answer 50

tricuspid valve

Question 51

How many flaps are on the tricuspid valvee?

Answer 51

3 cusps or flaps

Question 52

What are the semilunar valves?

Answer 52

the aortic valve and the pulmonary valve

Question 53

How many cusps are on the seminlunar valves?

Answer 53

3 cusps or flaps

Question 54

What is unique to the semilunar valves?

Answer 54

no chordae tendinae and each cusp has a thickened nodule at the center of its free edge

Question 55

What are the 3 distinct layers of the aortic cusp?

Answer 55

fibrosa, spongiosum, ventricularis

Question 56

What is the fibrosa?

Answer 56

densely packed collagen

Question 57

What is spongiosum?

Answer 57

proteoglycan and GAG matric with loosely arranged collagen

Question 58

What is ventricularis?

Answer 58

abundant elastic fibers

Question 59

What does the conduction system of the heart consist of?

Answer 59

consists of specialized cardiac muscle cells that are able to initiate and conduct electrochemical impulses

Question 60

What does the conduction system include?

Answer 60

the sinoatrial node, the atrioventricular node, the bundle of His(av bundle), bundle branches and purkinje fibers

Question 61

What are purkinje fibers?

Answer 61

conducting myofibrs

Question 62

What is the SA node?

Answer 62

small mass of specialized cells found in the right atrium's median wall adjacent to the opening of the superior vena cava within the terminal groove

Question 63

Why do SA node cells serve as the pacemaker?

Answer 63

they have the fasted intrinsic rythym of contraction

Question 64

What is the rate of contraction influenced by?

Answer 64

autonomic input

Question 65

What are characteristics of cells of the conducting system?

Answer 65

large, pale cells, rich in glycogen with sparse myofibrils

Question 66

What are purkinje fibers?

Answer 66

specialized impulse conducting cells

Question 67

Where are purkinje fibers found?

Answer 67

in the subendocardium and myocardium

Question 68

How do you differentiate purkinje fibers from typical cardiac myocytes?

Answer 68

larger and paler, with 1-2 central nuclei, intercalated disks and sparse myofilaments

Question 69

What will be seen histologically with an acute myocardial infarction?

Answer 69

leukocytes and eosinophilic necrotic cardiac myocytes

Question 70

What is seen histologically with older myocaridial infarcts?

Answer 70

dense connective tissue scar