Circulatory

Question 1

How many fibrous rings (annulus fibrosus) are there?

Answer 1

4

Base of aorta and pulmonary trunk and openings between left and right atria and ventricles

Question 2

What are the fibrous rings made of?

Answer 2

Dense irregular CT

Question 3

The ___ attach to the fibrous rings.

Answer 3

Valves

Question 4

The ___ connect the fibrous rings.

Answer 4

2 fibrous trigones

Question 5

The membraneous part of the interventricular and interatrial septums is ___.

Answer 5

Fibrous

Question 6

The right and left coronary arteries originate from the ___.

Answer 6

Ascending aorta

Question 7

The cardiac veins drain into the ___ which drains into the ___.

Answer 7

Coronary sinus, right atrium

Question 8

What are the 3 structures in the fibrous skeleton?

Answer 8

4 fibrous rings, 2 fibrous trigones, membraneous parts of inter-ventricular/atrial septa

Question 9

What is the most common type of heart disease?

Answer 9

Coronary heart disease

Question 10

Coronary heart disease is caused by?

Answer 10

Plaque buildup in walls of coronary arteries, leads to ischemia and MI

Question 11

Features of MI repair

Answer 11

Day 1: Coagulation necrosis (cell outlines, due to blood loss), wavy fibers, edema

Days 2-3: Neutrophil infiltration

Day 7-10: Macrophage remove necrotic fibers, start of granulation tissue (fibroblasts invade, made of loose CT w/ capillaries)

2 months: Dense collagenous scar

Question 12

Where is the heart located?

Answer 12

Middle mediastinum

Question 13

The epicardium is also known as ___.

Answer 13

Visceral layer of serous pericardium

Question 14

Characteristics of epicardium

Answer 14

• -Single layer of mesothelial cells (simple squamous endothelial)
• -CT
• -Adipose tissue
• -Blood vessels, nerves, lymphatic vessels

Question 15

The pericardial cavity contains ___ and is lined by ___.

Answer 15

Serous (pericardial fluid)

Single layer of mesothelial cells

Question 16

Both the parietal serous pericardium and epicardium have a layer of simple squamous cells. T/F

Answer 16

True, both line the pericardial cavity which is lined by mesothelial cells

Question 17

Pericarditis

Answer 17

Inflammation of the pericardium

Question 18

Cardiac tamponade

Answer 18

Excess fluid in pericardial sac, causes pressure

Question 19

The myocardium of the ventricles is ___ than the atria.

Answer 19

Thicker

Question 20

The myocaridum of the left ventricle is ___ than the right ventricle.

Answer 20

Thicker

Question 21

The myocytes of the atria are ___ compared to the ventricular myocytes.

Answer 21

Smaller in diameter

Question 22

What secretes the serous fluid that fills the pericardial cavity?

Answer 22

The mesothelial cells lining the parietal and visceral serous pericardium

Question 23

The ventricular myocytes have more T-tubules and gap junctions than atrial myocytes. T/F

Answer 23

False, atrial myocytes can lack T-tubules, but have more gap junctions

Question 24

Why can atrial myocytes lack T-tubules?

Answer 24

The atrial myocytes are smaller, thus ions/molecules can move easier via gap junctions and T-tubules aren’t needed

Question 25

What is a unique feature of atrial myocytes?

Answer 25

Atrial granules containing diuretic hormones (ANF/BNF)

Question 26

Features of atrial myocardium

Answer 26

- -Myocytes smaller in diameter - -May lack T-tubules - -More gap junctions - -Specific atrial granules

Question 27

The myocardium and endocardium is thicker in the ventricles than in the atria. T/F

Answer 27

False, the endocardium of the atria is thicker

Question 28

The endocardium in the atria is ___ compared to the ventricles.

Answer 28

Thicker

Question 29

Order the layers of the endocardium from inner to outer

Answer 29

Endothelium, subendothelial CT, middle layer, subendocardium

Question 30

Describe the layers of the endocardium

Answer 30

Endothelium - simple squamous epithelium lining chambers and valves Subendothelial layer - dense elastic and collagen fibers Middle layer - elastic and collagen fibers and smooth muscle Subendocardium - continuous with CT of myocardium with blood vessels and nerves, has Purkinje fibers in ventricles

Question 31

What layer is the purkinje fibers found?

Answer 31

Subendocardium in ventricles

Question 32

Smooth muscle is found in the ___ of the endocardium.

Answer 32

Middle layer

Question 33

The interventricular septum is ___ than the interatrial septum.

Answer 33

Thicker

Question 34

___ lines each surface of both septums.

Answer 34

Endocardium

Question 35

What are the septa composed of?

Answer 35

Cardiac muscle with a membraneous portion of dense CT Interventricular septum has AV bundle

Question 36

The valves attach to the ___.

Answer 36

Annulus fibrosa (dense irregular CT of fibrous rings)

Question 37

Are valves cusps vascular or avascular?

Answer 37

Avascular

Question 38

Describe the layers of the heart valves

Answer 38

Spongiosa - Loose CT, elastic fibers, proteoglycans (associates with water, cushions/dampens vibrations) Fibrosa - dense irregular CT (extensions of annulus fibrosa) Ventricularis - dense irregular CT, elastic fibers, covered by endothelium, becomes chordae tendinaea (in AV valves)

Question 39

Which layer of the heart valves functions to dampen vibrations?

Answer 39

Spongiosa (proteoglycans associated with water, act as cushion)

Question 40

The ___ of the heart valves is continuous with the chordae tendineae.

Answer 40

Ventricularis

Question 41

The core of the heart valves is made of what tissue?

Answer 41

Dense irregular CT (extension of fibrous rings)

Question 42

The ventricularis of the heart valves is composed of what tissue?

Answer 42

Dense irregular CT and elastic fibers, covered by endothelium

Question 43

The spongiosa is referred to as the ___ in the aortic / pulmonary valves and ___ in the mitral / tricuspid valves.

Answer 43

Arterialis, auricularis

Question 44

Regurgitation

Answer 44

Backflow from valve not closing tightly

Question 45

Regurgitation is most often due to ___, which mainly affects the ___ valve.

Answer 45

Prolapse, mitral valve

Question 46

Prolapse

Answer 46

Valve bulges/opens back into upper heart chamber during systole, causes regurgitation

Question 47

Stenosis

Answer 47

Flaps of valve stiffen / fuse, preventing the valve from fully opening, decreases blood flow through valve

Question 48

The transverse portion of ICD contains ___ while the longitudinal portion contains ___.

Answer 48

Fascia adherens, desmosomes, gap junctions

Question 49

How are the intercalated discs arranged?

Answer 49

Step-like with fascia adherens and desmosomes in transverse portion and gap junctions in longitudinal portion

Question 50

Nodal cardiac muscle cells are ___ than the atrial cardiac muscle cells. Why?

Answer 50

Smaller, few myofibrils, no ICDs, not for contraction (still have gap junctions)

Question 51

Nodal cardiac muscle cells vs. atrial cardiac muscle cells

Answer 51

- -Smaller - -Fewer myofibrils - -No ICDs

Question 52

The conduction system of the heart is composed of modified cardiac muscle cells. T/F

Answer 52

True

Question 53

Ventricular muscle cells are ___ than cardiac muscle cells of the AV bundle, bundle branches, and Purkinje fibers.

Answer 53

Smaller

Question 54

Where are purkinje fibers located?

Answer 54

Subendocardium of ventricles

Question 55

Purkinje fibers are ___ than ventricular muscle cells. Why?

Answer 55

Larger, have large amounts of glycogen and larger nucleus

Question 56

Features of purkinje fibers

Answer 56

- -Myofibrils in periphery of cells - -Have ICDs (vary in look/#) - -Have lots of glycogen - -Larger than ventricular muscle cells, larger nuclei, more resistant to hypoxia

Question 57

Purkinje fibers vs. ventricular myocytes

Answer 57

Purkinje are larger, have large nuclei, lots of glycogen, more resistant to hypoxia

Question 58

The purkinje fibers are more resistant to hypoxia/fatigue than ventricular myocytes. Why?

Answer 58

They contain lots of glycogen, which acts as energy source

Question 59

Sympathetic innervation on the heart functions to...?

Answer 59

Increase HR, force of contraction, dilates coronary arteries

Question 60

Parasympathetic innervation of the heart functions to...?

Answer 60

Decrease HR and constricts coronary arteries

Question 61

What are the substances that cause a positive chronotropic and inotropic effect on heart?

Answer 61

NoEP/EP (SNS), NoEP (medulla), caffeine, thyroid hormones, theophylline, digoxin,

Question 62

What are the substances that cause a negative chronotropic and inotropic effect on heart?

Answer 62

ACh (PSNS), propranolol, calcium channel blockers

Question 63

Baroreceptors are located in the ___ and ___.

Answer 63

Carotid sinus, aortic arch

Question 64

Baroreceptor function

Answer 64

Detect arterial blood pressure

Question 65

Chemoreceptors consist of ___ bodies located in the ___ and ___ bodies located in the ___.

Answer 65

Carotid bodies, bifurcation of common carotid arteries | Aortic bodies, aortic arch and right subclavian artery

Question 66

Chemoreceptor function

Answer 66

Detect changes in oxygen, CO2, and pH, function in neuronal reflexes that adjusts cardiac output and respiratory rate

Question 67

What structures have both chemoreceptors and baroreceptors?

Answer 67

Carotid sinus and aortic arch

Question 68

Volume receptors are located in the ___.

Answer 68

Walls of atria and ventricles

Question 69

Volume receptor function

Answer 69

Detect cardiac distension, relay to CNS

Question 70

What are the carotid/aortic bodies of chemoreceptors composed of?

Answer 70

Modified epithelial cells with both afferent and efferent nerve fibers

Question 71

Why is it important for the chemoreceptors to have both afferent and efferent nerve fibers?

Answer 71

For the neuronal reflex that adjusts cardiac output and respiratory rate