The Heart

Question 1

What makes up the looser connective tissue layer of the endocardium?

Answer 1

Fibroelastic connective tissue

Question 2

What types of tissues and fibers make up the dense irregular connective tissue layer of the endocardium?

Answer 2

More collagen I and elastic fibers and some smooth muscles (for support not contraction)

Question 3

What is a term used to describe the looser connective tissue layer and dense irregular layers of the endocardium?

Answer 3

Sub-endothelium connective tissue layer

Question 4

What makes up the sub-endocardial layer of the endocardium?

Answer 4

Looser connective tissue with blood vessels, nerves

Question 5

Where are the Purkinje fibers located in the endocardium?

Answer 5

Within the sub-endocardium

Question 6

What are Purkinje fibers?

Answer 6

Modified cardiac myocytes

Question 7

What substance is stored in the Purkinje fibers?

Answer 7

Glycogen

Question 8

How are Purkinje fibers attached?

Answer 8

Gap junctions and desmosomes

Question 9

What is the function of the Purkinje fibers?

Answer 9

To conduct contraction impulse rapidly

Question 10

What chambers of the heart have less muscle and more elastic fibers?

Answer 10

Atria

Question 11

What chambers of the heart have well-developed cardiac muscle layer?

Answer 11

Ventricles

Question 12

What portion of the intercalated discs are the risers of the stairs?

Answer 12

Transverse

Question 13

What portion of the intercalated discs are the steps of the stairs?

Answer 13

Longitudinal portion

Question 14

What cell junctions make up the transverse portion of the intercalated discs?

Answer 14

Macula adherens and fascia adherens

Question 15

What portion of the intercalated discs have large gap junctions which enable the flow of ions for contraction?

Answer 15

Longitudinal portion

Question 16

What is the function of the macula adherens in the transverse portion of the intercalated discs?

Answer 16

Attach cardiomyocytes in a row

Question 17

What is the function of fascia adherens in the transverse portion of the intercalated discs?

Answer 17

Attach and stabilize myofibrils

Question 18

What are the three functions of the intercalated discs?

Answer 18

Arrange cardiac myocytes in a row, attach and stabilize myofibrils, cell to cell communication/transfer of ions

Question 19

What is the effect of the sympathetic nervous system on heart rate and contraction force?

Answer 19

Increased

Question 20

What is the effect of the parasympathetic nervous system on heartbeat and contraction strength?

Answer 20

Slowed and decreased

Question 21

What are the specialized cardiac cells that have an endocrine function in the atria and interventricular septum?

Answer 21

Myoendocrine cells

Question 22

What are the endocrine functions of the myoendocrine cells and what organs or structures do they target?

Answer 22

Fluid and electrolyte balance (target the kidneys)

Decrease blood pressure (target the small arteries and arterioles)

Question 23

What is another name for the epicardium?

Answer 23

Visceral pericardium

Question 24

What is another name for the pericardium?

Answer 24

Serous pericardium

Question 25

What makes up the sub-epicardial fibroelastic connective tissue layer of the visceral pericardium?

Answer 25

Coronary vessels, nerves, sometimes adipose

Question 26

What part of the epicardium secretes a serious lubricating fluid?

Answer 26

Mesothelium

Question 27

What are the two parts of the parietal pericardium?

Answer 27

Mesothelium and a layer of fibroelastic connective tissue

Question 28

What type of cells make up the endothelium of the endocardium of the heart?

Answer 28

Simple squamous cells

Question 29

What layers make up the pericardial sac?

Answer 29

Parietal pericardium and fibrous pericardium

Question 30

What is the volume of the pericardial cavity?

Answer 30

About 15-50 milliliters

Question 31

The pericardial cavity is located in between what layers?

Answer 31

Parietal pericardium and visceral pericardium

Question 32

What is the general valve histology of the heart?

Answer 32

Endothelium with dense irregular tissue below made of collagen I and elastic fibers (almost avascular)

Question 33

What type of connective tissue primarily makes up the cardiac skeleton?

Answer 33

Dense irregular connective tissue

Question 34

What are the three main components of the cardiac skeleton?

Answer 34

Annuli fibrosi, trigonum fibrosum, septum membranaceum

Question 35

Where is the annuli fibrosi located in the cardiac skeleton?

Answer 35

Around the base of the aorta, pulmonary arteries, and openings to the chambers

Question 36

Where can the trigonum fibrosum of the cardiac skeleton be found?

Answer 36

By cusps of aortic valve

Question 37

Where can the septum membranaceum of the cardiac skeleton be found?

Answer 37

Upper portion of interventricular septum

Question 38

What is the function of the septum membranaceum?

Answer 38

Origin and insertion of cardiac myocytes

Question 39

What type of connective tissue is associated with chordae tendinae?

Answer 39

Dense regular connective tissue (because it's tendon-like)

Question 40

What is the overall function of the cardiac skeleton?

Answer 40

Isolates atrial and ventricular myocardia to ensure individual chamber contractions

Question 41

What is angina?

Answer 41

Chest pain usually brought on by exertion

Question 42

What is the cause of angina?

Answer 42

Slow progressive narrowing of the coronary vessels (therefore less oxygen)

Question 43

What is dysrhythmia of the heart?

Answer 43

Abnormal heart rhythms

Question 44

What is the cause of dysrhythmia?

Answer 44

Damage or death occurs to Purkinje fibers and other conducting tissues

Question 45

What is pericarditis?

Answer 45

Inflammation of the pericardial cavity and therefore inflammation of the serous pericardium