deck_16255153 Flashcards

Question

where does fibrous pericardium also attach

Answer 1

tunica adventitia of great vessels

Answer 2

inflammation of the pericardium

Answer 3

excess accumulation of pericardial fluid

Answer 4

"closure or blockage (as of a wound or body cavity) by or as if by a tampon, especially to stop bleeding" "It's from tampon, a stoppage/plug/etc. With -ade added to make it a new noun."

Answer 5

a. Epicardium b. Myocardium c. Endocardium

Answer 6

External layer Aka visceral layer of the serous pericardium Gives the heart it’s smooth, slippery texture

Answer 7

middle layer that makes up 95% of the heart cardiac muscle tissue; striated & involuntary Responsible for the hearts pumping action

Answer 8

innermost layer Thin layer of endothelium overlying a thin layer of connective tissue Provides a smooth lining for the chambers of the heart and covers the heart valves Continuous with the endothelial lining of the blood vessels attached to the heart Minimizes friction of blood as it passes through the heart

Answer 9

there are 4 chambers altogether 2 atria – superior receiving chambers 2 ventricles – inferior pumping chambers

Answer 10

the 2 superior chambers (right & left) has auricles – “little ears”

Answer 11

located on the anterior surface of each atrium, wrinkled pouch-like structure

Answer 12

helps increase the capacity/volume of the heart

Answer 13

fibrous connective tissue that separates chambers ventricles = interventricular septum atrium = interatrial septum

Answer 14

small grooves on cardiac surface that hold blood vessels & fat Mark the external boundary between two chambers of the heart

Answer 15

i. coronary sulcus - encircles the heart and separates the atrium from the ventricles

Answer 16

separates the 2 ventricles on the anterior side

Answer 17

separates the 2 ventricles on the posterior side

Answer 18

Right atrium receives blood from systemic circuit

Answer 19

Right ventricle pumps blood into pulmonary circuit

Answer 20

Left atrium receives blood from pulmonary circuit

Answer 21

Left ventricle pumps blood into systemic circuit

Answer 22

Forms the right border of the heart

Answer 23

superior vena cava inferior vena cava coronary sinus

Answer 24

Rough due to pectinate muscles

Answer 25

Muscular ridge that extend into the auricle contribute to forceful atrial contractions.

Answer 26

Blood passes from RA to RV through the Right atrioventricular valve (AV valve) aka tricuspid valve

Answer 27

Forms most of the base of the heart

Answer 28

Receives oxygenated blood from the lungs through 4 pulmonary veins

Answer 29

Smooth "Embryologically, the left atrium is also derived from the sinus venosus and a primitive auricle. Similar to the RA, the sinus venosus provides a smooth back wall to the atrium, but, unlike the RA, almost the entire atrial wall is baldly smooth."

Answer 30

Rough due to pectinate muscles

Answer 31

Blood passes from the LA to the LV through the bi-cuspid (mitral) valve aka Left AV- valve

Answer 32

Oval depression in the interatrial septum Remnant of the foramen ovale, an opening in the interatrial septum of the fetal heart

Answer 33

some blood skips pulmonary circuit goes RA to LA --> babies lungs don't oxygenate blood

Answer 34

remnant of ductus arteriosus in the fetal heart Connects pulmonary trunk with aorta

Answer 35

connect pulmonary trunk (artery) to aorta some blood skips pulmonary circuit --> babies lungs don't oxygenate blood

Answer 36

Forms most of the anterior surface of the heart

Answer 37

Receives de-oxygenated blood from the right atrium

Answer 38

Series of ridges formed by raised bundles of cardiac muscle fibers Some help with cardiac conduction system, other are mechanical

Answer 39

Tendon-like cords attach to the cusps of the tricuspid valve and to cone-shaped trabecular carneae called papillary muscles help stabilize and strengthen the cusps and preventing them from everting during forceful ventricle contraction

Answer 40

Word origin: Latin columnae (column) + carneae (flesh) Synonyms: trabeculae carneae. fleshy beams. “small beam”

Answer 41

Each ventricle features large cone-shaped trabeculae carneae known as papillary muscles (these are a specific type of trabeculae carneae)

Answer 42

Blood passes from the RV to the Pulmonary trunk via the pulmonary valve (aka Pulmonary semilunar valve) pulmonary trunk in turn becomes the right and left pulmonary arteries

Answer 43

Forms the apex of the heart

Answer 44

The largest & strongest of the 4 chambers Its myocardium is the thickest and therefore generates the most amount of force during contraction

Answer 45

The left ventricle is the strongest because it has to pump blood out to the entire body.

Answer 46

also has Trabecular carneae and Chordae tendinae anchor down the mitral (BICUSPID, left AV) valve to papillary muscles

Answer 47

Blood passes from the LV to the ascending aorta through the aortic valve (aka aortic semilunar valve)

Answer 48

Coronary arteries branch from the ascending aorta to feed the heart muscle Blood from ascending aorta to the arch of the aorta and thoracic and abdominal aorta then throughout the body

Answer 49

4 dense CT rings that surround the valves of the heart fuse with one another and merge with the interventricular septum Prevent overstretching of valves Point of insertion for bundles of cardiac muscle fibers Acts as an electrical insulator between atria and ventricles (CONTRACT INDEPENDENTLY)

Answer 50

fibrous skeleton/septa

Answer 51

Prevent overstretching of valves (CT rings of fibrous skeleton

Answer 52

fibrous skeleton/setpa/CT rings

Answer 53

inflammation of the muscles of the heart

Answer 54

Usually due to viral infections, rheumatic fever, or chemical or pharmacological agents (drugs)

Answer 55

inflammation of the endocardium usually due to bacterial infections and typically involved the heart valves dangerous, can be fatal

Answer 56

inflammation of the pericardium usually due to viral infections m/c is acute pericarditis that begins suddenly

Answer 57

Can be mistaken for a heart attack due to left shoulder and arm pain as a result of irritation to the pericardium

Answer 58

Can have pericardial friction rub "A pericardial friction rub, also pericardial rub, is an audible medical sign used in the diagnosis of pericarditis. Upon auscultation, this sign is an extra heart sound of to-and-fro character, typically with three components, two systolic and one diastolic."

Answer 59

Gradually and long lasting Build up of pericardial fluid – leads to cardiac tamponade

Answer 60

May be caused by cancer, TB

Answer 61

All 4 valves ensure the one-way flow of blood (note trabeculae carneae and chordae tendinae) Valves open and close in response to pressure changes as the heart contracts and relaxes

Answer 62

Allow only one-way blood flow from atrium into ventricle

Answer 63

at exit from each ventricle; allow only one-way blood flow from ventricle out into aorta or pulmonary trunk

Answer 64

Each has three (tricuspid) or two (mitral/bicuspid) cusps Cusps attach to tendon-like connective tissue bands = chordae tendineae Chordae tendineae anchored to thickened cone-shaped papillary muscles

Answer 65

When pressure is higher in atria than ventricle, AV valves open rounded ends of the cusps project into the ventricle Ventricles relaxed Papillary muscles relaxed, chordae tendineae slack

Answer 66

Yes including papillary muscles / chordae tendinae

Answer 67

When pressure is higher in ventricle than atria, AV valves close Cusps up Ventricles Contracted Pressure of blood in ventricles drives the cusps upwards Papillary muscles contract, chordae tendineae tight ---> (Prevents everting of valves)

Answer 68

Composed of 3 crescent moon-shaped cusps Each cusp is attached to the arterial wall by its convex outer margin The free border of each cusp project into the lumen of the artery

Answer 69

Ventricles contract Pressure builds up within the ventricles Valves open when pressure in the ventricles exceeds the pressure in the arteries

Answer 70

because chordae tendinae & papillary muscles (special trabeculae carnae) contract the cusps of the tricuspid/bicuspid valves to prevent these valves from EVERTING

Answer 71

Ventricles relax pressure gradient changes again

Answer 72

A narrowing of a heart valve opening, artery, or other structure (?) that restricts blood flow

Answer 73

Congenital heart defect Aortic valve calcification Rheumatic fever High blood pressure

Answer 74

The most common cause of mitral stenosis is rheumatic fever — a complication of strep throat. This infection can scar the mitral valve, causing it to thicken with scar tissue and narrow While rheumatic fever is now rare in the United States, it is still common in developing countries.

Answer 75

related to the presence of cardiovascular risk factors such as male sex, arterial hypertension, diabetes mellitus, dyslipidemia, and smoking, sharing many similarities with the process that regulates atherosclerosis

Answer 76

Dyslipidemia refers to abnormal levels of lipids in the bloodstream, which poses a significant risk factor for cardiovascular (CV) diseases. Dysregulation in these lipid levels, whether due to genetic predispositions or lifestyle factors, can lead to atherosclerosis and other CV complications.

Answer 77

An irregular heart sound (heart murmur), palpitations Chest pain (angina) or tightness with activity SOB, faintness, dizziness, fatigue

Answer 78

recall that heart beating sound is blood opening valves, and valves making contact with structures (E.g. Aorta) with stenotic valves (narrowing that restricts blood blow) that sound may be weaker (?) or with different pattern from usual (?)

Answer 79

a type of chest pain caused by reduced blood flow to the heart. Angina is a symptom of coronary artery disease. reduced opening (narrowing) of valves = reduced blood flow to heart

Answer 80

Failure of a valve to close completely

Answer 81

Mitral Valve Prolapse (eversion) --> I.e. papillary muscles and chordae tendinae not functioning appropriately

Answer 82

backflow of blood from LV to LA MOST COMMON VALVE DISORDER

Answer 83

m/c valvular disorder, affects 30% of the population

Answer 84

A racing or irregular heartbeat (arrhythmia) Dizziness or lightheadedness shortness of breath, fatigue

Answer 85

Infectious disease that can damage or destroy heart valves Acute systemic inflammatory disease Usually occurs after a streptococcal infection of the throat AB’s attack connective tissue of joints, valves and other organs Most often damage is to the mitral and aortic valves

Answer 86

Worldwide, incidence ranges from 8 to 51/100,000 (1), with lowest rates (< 10/100,000) in North America and Western Europe Rheumatic fever is rare in Canada, the United States, and Europe. But it was fairly common until the 1950s. Widespread use of antibiotics to treat strep throat has greatly lowered the number of new cases of rheumatic fever.

Answer 87

Systemic circulation the system that brings blood to/from the rest of the body Pulmonary circulation the system that brings blood to/from the lungs coronary circuit (?)

Answer 88

Arteries (carry blood away from the heart) Also called efferent vessels

Answer 89

Arterioles small arteries, very little BP (pulse)

Answer 90

exchange substances between blood and tissues Interconnect smallest arteries and smallest veins

Answer 91

small veins, low pressure, NO pulse

Answer 92

Veins (carry blood to the heart) Also called afferent vessels Very low pressure, no pulse

Answer 93

largest artery, highest amount of BP, oxygenated blood

Answer 94

Ascending Aorta Aortic Arch *Descending Thoracic Aorta *Descending Abdominal Aorta *sometimes/generally referred together as the descending aorta

Answer 95

branches or extensions of the aorta noticeable pulse & BP major systemic arteries: Carotid Vertebral iliac Femoral radial ulnar

Answer 96

smallest of the blood vessels, NO pulse, NO BP site where O2 & CO2 exchange

Answer 97

Inferior Vena Cava (from lower body) Superior Vena Cava (from upper body, head, brain) Pulmonary veins (from lungs ,*oxygenated) coronary sinus (?)

Answer 98

Right Atrium Right Ventricle Pulmonary Arteries Pulmonary Arterioles Pulmonary Capillaries Pulmonary Venules Pulmonary Veins Left Atrium Left Ventricle

Answer 99

Left Atrium Left Ventricle Systemic Arteries (via Aorta) Systemic Arterioles Systemic Capillaries Systemic Venules Systemic Veins Right Atrium Right Ventricle

Answer 100

Continuously supplies cardiac muscle (myocardium) with oxygen/nutrients Left and right coronary arteries arise from ascending aorta; fill when ventricles are relaxed (diastole) Myocardial blood flow may increase to 9 times the resting level during maximal exertion

Answer 101

POSSIBLE THEORY: pressure inside LV exceeds pressure of Aorta causesaortic semilunar valve to open and fills aorta with blood valve stays open until pressure gradient switches back when pressure gradient switches back Left ventricle (ventricles in general) relaxes at that point pressure inside aorta rises and causes blood to flow from area of higher pressure to area of lower pressure (Which includes coronary arteries (Left and right coronary arteries from ascending aorta)

Answer 102

Passes inferior to the left auricle and divides into: A) anterior interventricular branch B) circumflex branch

Answer 103

Passes in the anterior interventricular sulcus supplies blood to both ventricles

Answer 104

lies in coronary sulcus supplies blood to left atrium & ventricles

Answer 105

Supplies small branches to the right atrium and continues inferiorly to the right auricle and divides into: A) posterior interventricular branch B) marginal branch

Answer 106

bending around something else; curved.

Answer 107

follows the posterior interventricular sulcus supplies blood to both ventricles

Answer 108

lies in the coronary sulcus supplies blood to the right ventricle

Answer 109

Deoxygenated blood from the myocardium drains into this large vascular sinus located in the coronary sulcus on the posterior surface of the heart Empties directly into the right atrium

Answer 110

coronary sulcus on the posterior surface of the heart

Answer 111

Great Cardiac Vein Middle Cardiac Vein Small Cardiac Vein Anterior cardiac Vein

Answer 112

Lies in the anterior interventricular sulcus (with left anterior descending) Drains the areas of the heart supplied by they left coronary artery (LV,RV,LA) --> circumflex and LAD branch

Answer 113

Lies in the posterior interventricular sulcus Drains the areas of the heart supplied by the posterior interventricular branch of the RCA (LV,RV) (posterior descending artery)

Answer 114

Lies in coronary sulcus Drains RA and RV

Answer 115

Drains RV and opens directly into RA (??)

Answer 116

ischemia is the lack of blood supply due to partial obstruction of a vessel causes hypoxia or anoxia

Answer 117

angina pectoris myocardial infarction (MI, heart attack)

Answer 118

Inadequate blood supply to the heart mild to severe, crushing chest pain associated with myocardial ischemia usually this pain pattern is referred to the neck, chin, left arm down to elbow

Answer 119

complete obstruction of coronary artery resulting in death of cells & tissue (infarction)

Answer 120

chest pain or discomfort uncomfortable, squeezing pressure over the chest radiating pain to the jaw and over neck region pain in epigastric region nausea or vomiting sweating dizziness shortness of breath

Answer 121

Chest pain in only 30% Unusual fatigue or weakness Sleep Disturbances Indigestion shortness of breath Anxiety Cold sweats Discomfort/pain between shoulder blades Dizziness

Answer 122

You may not even know you've had a silent heart attack until weeks or months after it happens. It's best to know what's normal for your body and get help when something doesn't feel right. Knowing the subtle signs of a silent heart attack can help you identify one. Studies differ, but some suggest that silent heart attacks are more common in women than in men. Women and their physicians may also be more likely to chalk up symptoms of a silent heart attack to stress or anxiety and dismiss them.

Answer 123

a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atherosclerosis. Angioplasty and Stent Placement for the Heart

Answer 124

CABG vein graft sewn to bypass blockage

Answer 125

Shorter in length (card

Answer 126

Less circular in transverse sections

Answer 127

Exhibit branching

Answer 128

One centrally located nucleus (usually)

Answer 129

Specialized intercellular connections Intercalated discs = branching interconnections between cells

Answer 130

Larger and more numerous Mitochondria (cadiac)

Answer 131

transverse tubules are wider and less abundant

Answer 132

Smaller sarcoplasmic reticulum

Answer 133

hows striations alternating bands of light and dark Same striations as skeletal muscle Same arrangement of actin and myosin Same bands, zones, Z discs

Answer 134

considered involuntary no conscious willful control

Answer 135

Intercalated discs Connect neighboring cardiac muscle fibers

Answer 136

i. desmosomes ii. gap junctions

Answer 137

tight cell to cell junctions for lots of stability hold the fibers together

Answer 138

tubular shaped cell to cell junctions that allow for transmission of substances and/or signals between adjacent cells allow muscle action potentials to conduct from one muscle fiber to its neighbor allowing the cardiac muscles to contract in coordinated fashion

Answer 139

Autorhythmicity = cardiac muscle’s ability to contract at its own pace independent of neural or hormonal stimulation

Answer 140

Autorhythmicity = cardiac muscle’s ability to contract at its own pace independent of neural or hormonal stimulation

Answer 141

autorhythmic fibres These specialized cardiac muscle fibers, called autorhythmic fibers, are self-excitable can generate their own action potentials even without nerve attachments.

Answer 142

Only about 1% of the cardiac muscle fibers are autorhythmic fibers

Answer 143

Conducting system = network of specialized cardiac muscle cells (pacemaker and conducting cells) that initiate/distribute a stimulus to contract

Answer 144

A) Sinoatrial node (SA node) B) Internodal pathways C) Atrioventricular node (AV node) D) AV bundle and bundle branches E) Purkinje fibers

Answer 145

concentration of cells that “set the rhythm” for contraction through electrical excitation Under normal functioning conditions, the SA node is the pacemaker

Answer 146

SA NODE (under normal conitions)

Answer 147

Natural pacemaker: sets the fundamental rhythm Nerve impulses from the ANS and blood borne hormones (epinephrine) modify the timing and strength of each heart beat

Answer 148

nerve singals from ANS (vagus nerve?) hormones (e.g. epinephrine)

Answer 149

Each heartbeat begins with action potential generated here In posterior wall of right atrium, near superior vena cava Impulse is initiated here and spreads through adjacent cells Average 60–100 bpm

Answer 150

In posterior wall of right atrium, near superior vena cava

Answer 151

"Pacemaker potential" (?)

Answer 152

Formed by conducting cells Distribute signal through both atria

Answer 153

At junction between atria and ventricles Relays signals from atria to ventricles Has pacemaker cells that can take over pacing if SA node fails AV pacing is slower—40 to 60 bpm

Answer 154

junction between atria and ventricles

Answer 155

Relays signals from atria to ventricles

Answer 156

40 to 60 bpm

Answer 157

60-100 bpm

Answer 158

Conducting cells transmit signal from AV node down through interventricular septum Usually only electrical connection between atria/ ventricles

Answer 159

transmit signal from AV node down through interventricular septum IV SEPTUM

Answer 160

Right and left branches Left bundle branch larger Conducting cells transmit signal to apex of heart, then spreading out in ventricular walls

Answer 161

Radiate upward through ventricular walls Propagate action potentials as fast as myelinated neurons Stimulate ventricular myocardium and trigger contraction

Answer 162

neurons with mylenated axons

Answer 163

Stimulate ventricular myocardium and trigger contraction

Answer 164

If the SA node becomes damaged or diseased an artificial pacemaker may be inserted

Answer 165

Runs on a battery w/ leads into the right atrium, this simulates the firing of the SA node which in turn propagates a signal down the normal conduction system.

Answer 166

New - activity adjusted pacemakers Automatically speed up during exercises

Answer 167

Brief action potential (skeletal) Long action potential (cardiac)

Answer 168

(SKELETAL) Contraction ends when sarcoplasmic reticulum reclaims Ca2+ (CARDIAC) Ca2+ enters cells over prolonged period -->Long contraction (~250 msec)

Answer 169

(SKELETAL) Short refractory period ends before peak tension develops (CARDIAC) Refractory period continues into relaxation

Answer 170

(SKELETAL) Twitches can summate; tetanus can occur (CARDIAC) No tetanic contractions occur (otherwise heart couldn’t pump blood)

Answer 171

by the time cardiac muscle relative refractory period ends, heart muscle is close to fully relaxed by the time absolute refractory period ends, heart muscle is partially relaxed FOR SKELETAL MUSCLE, RELATIVE REFRACTORY PERIOD ENDS BEFORE MUSCLE FIBRE EVEN REACHES MAXIMUM TENSION ABSOLUTE REFRACTORY FOR SKELETAL MUSCLE ENDS ALMOST BEFORE MUSCLE FIBRE EVEN BEGINS CONTRACTING (?)

Answer 172

in skeletal muscle, repolarization occurs @ end of ABSOLUTE REFRATORY PERIOD in cardiac muscle, full repolarization occurs @ end of relative refractory period partial repolarization in cardiac muscle occurs @ end of absolute refractory period

Answer 173

Rapid depolarization Plateau Repolarization

Answer 174

similar to that in skeletal muscle At threshold, voltage-gated fast sodium channels open Massive, rapid Na+ influx Channels open quickly and very briefly

Answer 175

from -90 RMP, to +30 after rapid depolarization leading into PLATEAU is quick dip from +30 to 0mV (where it stays for plateau period)

Answer 176

Fast sodium channels close as potential nears +30 mV, Cell actively pumps Na+ out K+ channels outflow into interstitial fluid ****** Voltage-gated slow calcium channels open— Ca2+ influx Opening of slow Ca2+ channels in sarcolemma increasing Ca2+ in cytosol and triggering a contraction (calcium induced calcium release) ****** So, because Ca2+ positive charge offset Na+ leaving cell (?)

Answer 177

Substances that alter the movement of Ca2+ through slow Ca2+ channels influence the strength of heart contractions (contractility) E.g. Epinephrine: increases Ca2+ = increases contraction force

Answer 178

Slow calcium channels close Slow potassium channels remain open; K+ rushes out; causes rapid repolarization and restores resting potential

Answer 179

Produces little ATP by anaerobic cellular respiration (same as all cells, relatively, but more so here) Relies on aerobic cellular respiration in its numerous mitochondria

Answer 180

AT REST: Oxidation of fatty acids (60%) and glucose (35%)

Answer 181

Use lactic acid

Answer 182

creatine phosphate

Answer 183

Creatine Kinase is the enzyme that catalyzes transfer of a phosphate group from CP to ADP to make ATP

Answer 184

normally is contained in the muscle tissue but will be released in any cardiomyopathy CK is the 1st enzyme in blood they test for in heart attacks.

Answer 185

a recording of the electrical currents generated by action potentials propagating through the heart.

Answer 186

1) If the conduction pathway is abnormal (i.e.. arrhythmias) 2) If the heart is enlarged (?) 3) If certain regions of the heart are damaged (i.e.. MI) 4) Causes of chest pain

Answer 187

An electrocardiogram (ECG) can show if the heart is beating too fast or too slow. A health care provider can look at signal patterns for signs of a thickened heart muscle (hypertrophy).

Answer 188

The most frequently used electrocardiographic criterion for identifying acute myocardial infarction is ST segment elevation in two or more anatomically contiguous leads.

Answer 189

10 electrodes placed in specific positions By comparing electrodes, 12 different trackings are produced (12 leads)

Answer 190

6 limb leads 6 precordial (chest) leads

Answer 191

in front of the heart; involving the precordium. from English precordium ((anatomy) The region of the body over the heart and thorax.)

Answer 192

I, II, III, aVR, aVL, aVF Measure vertical vectors or electrical conduction

Answer 193

V1-V6 Measure horizontal vectors of electrical conduction

Answer 194

Movement towards positive pole gives positive inflection on ECG Movement away from positive pole gives negative inflection on ECG

Answer 195

The electrical axis of the heart is most similar to lead II Therefore, lead II is often used as reference for basic ECG

Answer 196

P wave QRS complex T wave

Answer 197

ATRIAL DEPOLARIZATION

Answer 198

VENTRICULAR DEPOLARIZATION ATRIAL repolarization occurs @ same time as Ventricular depolarization (so it's hidden under QRS complex)

Answer 199

ventricular repolarization

Answer 200

P wave = atrial depolarization Atria begin contracting ~25 msec after P wave starts

Answer 201

QRS complex = ventricular depolarization Larger wave due to larger ventricle muscle mass Ventricles begin contracting shortly after R wave peak Atrial repolarization also occurs now but is masked by QRS

Answer 202

Larger wave due to larger ventricle muscle mass

Answer 203

begin contracting shortly after R wave peak

Answer 204

P-Q interval (sometimes called P-R interval) Q–T interval S–T segment

Answer 205

Period from start of atrial depolarization to start of ventricular depolarization

Answer 206

>200 msec may mean damage to conducting pathways or AV node Possibly from scar tissue d/t previous MI

Answer 207

beginning of the QRS complex to the end of the T-wave. This represents the time from start of ventricular depolarization to the end of ventricular repolarization.

Answer 208

from BEGINNING of ventricular depolarization to END of ventricular repolarization

Answer 209

May be lengthened by electrolyte disturbances, medications, conduction problems (conduction system/NODES/pacemaker cells), coronary ischemia, myocardial damage

Answer 210

end of the QRS complex to the beginning of the T-wave. This represents the interval between ventricular depolarization and repolarization

Answer 211

from END of DEPOLARIZATION to BEGINNING of REPOLARIZATION (interval where there is neither depolarization, nor repolarization -- PLATEAU phase)

Answer 212

The ST segment corresponds to the plateau phase of the ventricular transmembrane action potential. (NEITHER depolarization, nor repolarization) --> actually technically, it is depolarized, and in a continuous state of "

Answer 213

Can see and elevated ST segment in acute MI

Answer 214

ECGs valuable for detecting/and diagnosing arrhythmias

Answer 215

abnormal patterns of cardiac electrical activity

Answer 216

About 5% of healthy people experience a few abnormal heartbeats each day Not a clinical problem unless pumping efficiency is reduced

Answer 217

Average heart rate is between 60 - 100 bpm Tachycardia = fast heart rate (>100 bpm) Bradycardia = slow heart rate (<60 bpm)

Answer 218

some athletes can have lower than 60bpm resting heartbeat

Answer 219

Often occur in healthy people Normal atrial rhythm momentarily interrupted by “surprise” atrial contraction I.e. SOONER THAN EXPECTED Increased incidences caused by stress, caffeine, various drugs that increase permeability of the SA pacemakers Normal ventricular contraction follows the atrial beat

Answer 220

Premature atrial contraction triggers flurry of atrial activity Ventricles keep pace Heart rate jumps to about 180 bpm

Answer 221

Impulses move over atrial surface at up to 500 bpm Atria quiver—not organized contraction Ventricular rate cannot follow, may remain fairly normal Atria nonfunctional, but ventricles still fill passively Person may not realize there is an arrhythmia

Answer 222

Premature atrial contractions (PACs) Paroxysmal atrial tachycardia (PAT) Atrial fibrillation

Answer 223

Premature ventricular contractions (PVCs) Ventricular tachycardia Ventricular fibrillation

Answer 224

Purkinje cell or ventricular myocardial cell depolarizes; triggers premature contraction Cell responsible called an ectopic pacemaker (pacemaker other than the SA node) Single PVCs common, not dangerous Frequency increased by epinephrine, stimulatory drugs, or ionic changes that depolarize cardiac muscle cells

Answer 225

An ectopic pacemaker, also known as ectopic focus or ectopic foci, is an excitable group of cells that causes a premature heart beat outside the normally functioning SA node of the heart. It is thus a cardiac pacemaker that is ectopic, producing an ectopic beat.

Answer 226

in an abnormal place or position. ektopos: out of place ectopia: present of tissue, cells, etc. in an abnormal place

Answer 227

a situation in which an organ or body part is in the wrong position, either from birth or because of an injury

Answer 228

Also known as VT or V-tach Defined as four or more PVCs without intervening normal beats Multiple PVCs and V-tach may indicate serious cardiac problems

Answer 229

Also known as VF or V-fib Responsible for condition known as cardiac arrest Rapidly fatal because ventricles quiver, but cannot pump any blood

Answer 230

Exercise Stress test Continuous ambulatory electrocardiographs Holter monitor

Answer 231

A Holter monitor is a small, wearable device that records the heart's rhythm, usually for 1 to 2 days. It's used to spot irregular heartbeats, also called arrhythmias. A Holter monitor test may be done if a traditional electrocardiogram (ECG or EKG) doesn't provide enough details about the heart's condition.

Answer 232

Two phases: Contraction (systole)—blood leaves the chamber Relaxation (diastole)—chamber refills

Answer 233

Atria contract together first (atrial systole) Push blood into the ventricles Ventricles are relaxed (diastole) and filling

Answer 234

Ventricles contract together next (ventricular systole) Push blood into the pulmonary and systemic circuits Atria are relaxed (diastole) and filling

Answer 235

Typical cardiac cycle lasts 800 msec (0.8 secs) 60s / 0.8 = 75 (BPM)

Answer 236

period between start of one heartbeat and the next (a complete round of systole and diastole)

Answer 237

Contraction (systole)—blood leaves the chamber Relaxation (diastole)—chamber refills

Answer 238

Atria contract together first (atrial systole) Ventricles contract together next (ventricular systole) Typical cardiac cycle lasts 800 msec (0.8 secs)

Answer 239

Push blood into the ventricles Ventricles are relaxed (diastole) and filling

Answer 240

Push blood into the pulmonary and systemic circuits Atria are relaxed (diastole) and filling

Answer 241

heart rate 75 bpm

Answer 242

1) Cardiac cycle begins—all four chambers are relaxed (diastole; ventricles are passively refilling) 2) Atrial systole (100 msec)—atria contract; finish filling ventricles 3) Atrial diastole (270 msec)—continues until start of next cardiac cycle (through ventricular systole) 4) Ventricular systole—first phase. Contracting ventricles push AV valves closed but not enough pressure to open semilunar valves (= isovolumetric contraction—no volume change) 5) Ventricular systole—second phase. Increasing pressure opens semilunar valves; blood leaves ventricle (= ventricular ejection) 6) Ventricular diastole—early. Ventricles relax and their pressure drops; blood in aorta and pulmonary trunk backflows, closes semilunar valves 7) Isovolumetric relaxation. All valves closed; no volume change; blood passively filling atria 8) Ventricular diastole—late. All chambers relaxed; AV valves open; ventricles fill passively to ~70%

Answer 243

SA node fires, causing both atria to contract (atrial systole) Increases pressure within atrium, pressure remains low in ventricles Blood is ejected thru AV valve (tricuspid & mitral) from atrium to ventricles Contributes 25mL to an already 105mL in each ventricle = total of 130mL in the ventricles at the end of atrial systole/ventricle diastole Called the end diastolic volume (EDV)

Answer 244

25mL to 105mL that was already in ventricles 105 from passively filling

Answer 245

END DIASTOLIC VOLUME "diastolic" referring to the end of diastole for the ventricles, before they contract I.e. after atria finish contracting, then immediately ventricles are @ end of diastole I.e. ventricular systole begins exactly when atrial systole ends

Answer 246

during period when both atria and ventricles are in diastole (second phase of ventricular diastole) ---> (about half the entire Cardiac Cycle) (filling passively)

Answer 247

During ventricular systole the atria are relaxed (atrial diastole) (atrial diastole begins precisely when ventricular systole begins)

Answer 248

BOTH SEMILUNAR AND AV valves are CLOSED I.e. Isovolumetric contraction (Iso- "same" -- volume) I.e. volume of ventricle doesn't change during early ventricular contraction UNTIL the pressure in the chamber is enough to EXCEED the pressure in the pulmonary trunk & Aorta (pressure of the semilunar valves). After this pressure is reached, the valves open and blood enters the pulmonary/systemic circuit.

Answer 249

LV pressure > 80mmHg (continue to rise to 120mmHg) RV pressure > 20mmHg (continue to rise to 25-30mmHg)

Answer 250

I.e. how long ventricular systole last (?) 250-270msec (?) notes say 250msec diagram shows 270msec for ventricle systole

Answer 251

END SYSTOLIC VOLUME

Answer 252

about 70mL end systolic volume would be 60mL in this example

Answer 253

about 1/2 cardiac cycle 400msec in example of 800msec cycle

Answer 254

about 500msec / 800

Answer 255

about 700msec / 800

Answer 256

Ventricle pressure decreases and blood in the aorta and pulmonary trunk flows back toward the low pressure ventricles = closing the semilunar valves Aortic valves close at 100mmHg

Answer 257

because as blood from LV flows into aorta, pressure increases from 80 --> 120 (in this example) ??? therefore, when LV pressure decreases to 100, there is not enough pressure to continue flowing into aorta, and backflow closes aortic semilunar valve Why? both pressure simultaneously decrease to 100mmHg, until decrease in LV exceeds decrease in aorta @ 100mmHg, and backflow closes SL valve (?)

Answer 258

Ventricle pressure drops below atrial pressure and the AV valves open and ventricle filling begins (PASSIVE FOR MAJORITY OF FILLING) recall: passively filling for about 400msec / 800 (entire heart diastole) --NOT QUITE --> they fill during SECOND phase of Ventricular DIASTOLE, not the entire duration = 105 / 130 mL last 25mL via atrial systole

Answer 259

Increase in pressure with opening of aortic valve Drop in pressure with closing of aortic valve (because blood moves along aorta and away from the initial segment, causing pressure to decrease gradually

Answer 260

even though pressure gradually decreases with aortic semilunar valve closing, there is a short pressure rise in aorta as ELASTIC WALLS RECOIL phenomenon known as DICROTIC NOTCH in pressure tracing

Answer 261

(dúo, “two”) +‎ κρότος (krótos, “beat”)

Answer 262

Auscultation – the process of listening to sounds in the body (heart, GI, lungs) performed with a stethoscope

Answer 263

The sounds of the heartbeat come from blood turbulence created by closing valves S1 ( “lubb”)—when AV valves close; marks start of ventricular contraction S2 (“dupp”)—when semilunar valves close S3 - —very faint; rarely heard in adults blood flowing into ventricles S4—almost always pathologic (?)

Answer 264

abnormal sounds (whooshing or swishing) that is heard before, between or after normal heart sounds. They may also mask normal heart sounds Tends to be common in children due to developing cardiac structures, but abnormal in adults 2-4 years old Innocent or functional heart murmurs vs. Congenital heart murmurs

Answer 265

2-4 years old

Answer 266

They may mask normal heart sounds

Answer 267

heard before, between or after normal heart sounds

Answer 268

abnormal sounds (whooshing or swishing)

Answer 269

Not always indicative of heart problems (innocent) May indicate valve disorder E.g. Stenosis or valvular insufficiency

Answer 270

the amount/volume of blood that is ejected from the left ventricle each minute Measured in mL/min

Answer 271

Cardiac Output = HR × SV heart rate stroke volume

Answer 272

Heart rate (HR) = # contractions/minute (beats per minute) Stroke volume = volume of blood pumped out of ventricle per contraction

Answer 273

By changing either or both HR and SV, cardiac output is precisely controlled to meet changing needs of tissues.

Answer 274

Right ventricle SV = left ventricle SV Stroke volume depends on the relationship between end-diastolic volume and end-systolic volume

Answer 275

SV = EDV – ESV

Answer 276

70*75 = a bit over 5000mL I.e. entire volume of blood is pumped through entire circuit(s) in 1 minute

Answer 277

any factor icnreasing SV or HR

Answer 278

the difference between the maximum CO & CO at rest

Answer 279

Average person has a CR of 4 to 5 times resting value

Answer 280

Athletes have reserves up 7-8 times their resting Cardiac Output (CO)

Answer 281

almost no reserves = limited ADLs

Answer 282

Important in short-term control of CO and BP Most important regulators of heart rate are: 1) the ANS 2) hormones released by the adrenal medulla note that ANS signals to adrenal medulla, so it's really just the ANS that regulates HR

Answer 283

Varies with age, general health, physical conditioning Normal range is 60–100 bpm Bradycardia Heart rate slower than normal (<60 bpm) Tachycardia Heart rate faster than normal (>100 bpm) *note that certain athletes may have lower than 60bpm but still normal

Answer 284

Pacemaker potential in SA node cells occurs 80–100 times/min Establishes heart rate SA node brings AV nodal cells to threshold before they reach it on their own, thus SA node paces the heart

Answer 285

80–100 times/min

Answer 286

@ cardiovascular center of the medulla oblongata (anterior to cerebellum)

Answer 287

input from sensory receptors and higher brain centers

Answer 288

limbic system, cerebral cortex

Answer 289

directs the divisions of the ANS to increase or decrease frequency of nerve impulses

Answer 290

A) baroreceptors – pressure changes (aorta, carotid aa) B) chemoreceptors – chemical changes in blood C) proprioceptors – sensory from the limbs & extremities

Answer 291

when pressing on carotid, can change BP, activate sensory feedback of baroceptor --> change heartbeat (?) or change BP (?)

Answer 292

sympathetic, parasympathetic

Answer 293

Cardioinhibitory center Cardioacceleratory center

Answer 294

Controls parasympathetic neurons; slows heart rate Parasympathetic supply to heart via vagus nerve (X); synapse in cardiac plexus Postganglionic fibers to SA/AV nodes, atrial musculature

Answer 295

vagus nerve (CN X) to Cardiac Plexus

Answer 296

(???) Postganglionic fibers to SA/AV nodes, ultimately atrial musculature

Answer 297

Controls sympathetic neurons; increases heart rate Sympathetic innervation to heart via postganglionic fibers in cardiac nerves; innervate nodes, conducting system (nodes/branches/bundles), atrial and ventricular myocardium

Answer 298

sympathetics travel thru CARDIAC ACCELERATORY NERVES in the thoracic region of the spinal cord

Answer 299

Releases norepinephrine: ---> Speeds the rate of spontaneous depolarization ---> Enhances calcium entry – increasing contractility

Answer 300

Enhances calcium entry – increasing contractility

Answer 301

parasympathetics travel thru the right and left Vagus Nerve (CN X)

Answer 302

Release acetylcholine: ---> Decreases rate of spontaneous depolarization

Answer 303

Sympathetic stimulation increases heart rate (norepinephrine can also increase BP) Binding of norepinephrine to beta-1 receptors opens ion channels: ---> Increases rate of depolarization ---> Decreases repolarization

Answer 304

NOTE BETA BLOCKERS mechanism: (sympathetic response also affect BP) Beta blockers are medicines that lower blood pressure. They also may be called beta-adrenergic blocking agents. The medicines block the effects of the hormone epinephrine, also known as adrenaline. Beta blockers cause the heart to beat more slowly and with less force. This lowers blood pressure.

Answer 305

Parasympathetic stimulation decreases heart rate ACh from parasympathetic neurons: A) Opens K+ channels in plasma membrane B) Hyperpolarizes membrane (K+ outflow?) C) Slows rate of spontaneous depolarization D) Lengthens repolarization

Answer 306

Electrolyte Imbalances: Ca2+: elevated interstitial levels ↑ strength of contraction and speeds heart rate K+: elevated blood levels will decrease/block AP, thus decreases ↓ muscle contraction and HR

Answer 307

Hormones: (REMEMBER SAME SUBSTANCE CAN BE CONSIDERED EITHER NT OR HORMONE DEPENDING ON HOW IT IS RELEASED. RELEASE FROM GLAND = HORMONE, FROM NEURON = NT) Hormones: epinephrine & norepinephrine will ↑ HR and contractility ---> (From adrenal medulla)

Answer 308

Thyroid hormones: Increase cardiac contraction and increase HR

Answer 309

Age Gender Physical fitness Body temperature

Answer 310

recall that there is always 40-50% of blood volume that remains in the ventricles after full ventricular systole (approx 60 mls)

Answer 311

Preload Contractility Afterload

Answer 312

The degree of stretch on the heart before it contracts, proportional to the END DIASTOLIC VOLUME

Answer 313

akin to a rubber band, the more you stretch it, the more force it will snap back with. Thus, the more blood enters the ventricles, the higher the volume, the more stretch or load on the muscle tissues the greater the contraction. (NOTE THAT TOO MUCH STRESS CAN STILL DECREASE CONTRACTILITY, just like with Skeletal muscle)

Answer 314

The duration of ventricle diastole Venous return (passively filling ventricles)

Answer 315

the strength of contraction of muscle tissue/fibers

Answer 316

positive inotropic agents increase contraction negative inotropic agents decrease contraction

Answer 317

"modifying the force or speed of contraction of muscles." From Ancient Greek ἴς (ís, “sinew, tendon; strength, force”) +‎ -tropic (“affecting, changing”)

Answer 318

sympathetic nervous system (CARDIAC ACCELERATORY NERVES), digitalis (drug), epinephrine (from adrenal medulla?), anything that increases Ca2+ inflow (?)

Answer 319

parasympathetics (E.g. via Vagus Nerves), anoxia, drugs, anything that blocks or inhibits Ca2+ inflow (calcium channel blockers)

Answer 320

the pressure that must be overcome before the semilunar valves (aortic & pulmonary) can open.

Answer 321

Factors that increase the afterload will decrease the SV

Answer 322

increase BP (hypertension) in systemic arteries ex. via Atherosclerosis, Weight gain (??)

Answer 323

increased PRELOAD increased CONTRACTILITY decreased AFTERLOAD ultimately? increased SV --> increased CO

Answer 324

A loss of pumping efficiency by the heart

Answer 325

CAD, congenital defects, high BP, MI, valve disorders

Answer 326

Pumping becomes less effective ---> increase in EDV (preload) ---> heart becomes overstretched ---> contract less forcefully

Answer 327

Left Ventricle more common, leads to pulmonary edema Right Ventricle, leads to peripheral edema

Answer 328

Abnormal rhythm of the heart as a result of a defect in the conduction system of the heart Leads to asynchronous contractions & therefore abnormal blood pumping

Answer 329

conduction system

Answer 330

nodes, branches, bundles, fibres, etc

Answer 331

leads to asynchronous contractions & therefore abnormal blood pumping

Answer 332

chest pain, shortness of breath, lightheadedness, dizziness, fainting

Answer 333

stress, caffeine, alcohol, cocaine, nicotine, CAD, MI, HTN (many) HTN = hypertension (?)

Answer 334

Bradycardia (below 50beats/min) (60?) Tachycardia (above 100beat/min) Fibrillation (rapid, uncoordinated heartbeats)

Answer 335

Results from the effects of the accumulation of atherosclerotic plaques in coronary arteries, which leads to a reduction in blood flow to the myocardium

Answer 336

accumulation of atherosclerotic plaques in coronary arteries

Answer 337

Smoking, high BP, DM, high cholesterol, obesity, sedentary lifestyle, family Hx Males > females, > after 70 years of age

Answer 338

dependent on severity (chest pain, dyspnea, etc.) can have complications: angina pectoris MI

Answer 339

Cardiovascular disease is the leading cause of death

Answer 340

athero - meaning gruel or paste and sclerosis meaning hardness Arteriosclerosis: Thickening of artery walls and loss of elasticity Atherosclerosis One form of arteriosclerosis

Answer 341

Progressive disease characterized by the formation of lesions called atherosclerotic plaques in the walls of large and medium sized arteries These plaques are cholesterol or fatty acid molecules that accumulate too much, too fast, too often

Answer 342

Coarctation of the aorta Patent ductus arteriosus Septal defect (patent foramen ovale) Tetralogy of Fallot

Answer 343

A segment of the aorta is narrowed Resulting in reduced oxygenated blood flow Sx: Depend on severity Pale, sweating, dyspnea Tx: catheterization and low BP medications

Answer 344

The ductus arteriosus remains open rather than closing shortly after birth Aortic blood flows into the lower pressure pulmonary trunk Tx depends on severity, some are never recognized

Answer 345

MEDICINE (of a vessel, duct, or aperture) open and unobstructed; failing to close.

Answer 346

Atrial: The fetal foramen ovale fails to close (patent foramen ovale) Ventricular: Incomplete development of the septum Oxygenated and deoxygenated blood mix

Answer 347

Combination of 4 defects: 1) Ventricular septal defect 2) Aorta that emerges from both ventricles (overriding aorta) 3) Pulmonary valve stenosis 4) Right ventricular hypertrophy (note that if pulmonary SL valve is stenosed, RV requires more force to push blood into pulmonary circuit --> i.e. RV hypertrophy)

Answer 348

MEDICINE a set of four related symptoms or abnormalities frequently occurring together.

Answer 349

Results in a decreased blood flow to lungs and a mixing of oxygenated and deoxygenated blood can lead to cyanosis, “blue baby”

Answer 350

"An overriding aorta is a congenital heart defect where the aorta is positioned directly over a ventricular septal defect, instead of over the left ventricle" I.e. septal defect is directly related to overriding aorta

Answer 351

A clinical term meaning cessation of an effective heartbeat Can be spontaneous (SCA) or due to trauma (TCA) Causes: Arrhythmia Coronary artery disease Cardiomyopathy or CHF Penetrating wound or blunt trauma (commotio cordis)

Answer 352

Penetrating wound or blunt trauma sudden arrhythmic death caused by a low/mild chest wall impact About 59% of people who experience it survive. You're most likely to survive if you receive CPR right away.

Answer 353

With commotio cordis (Latin for “agitation of the heart”), the impulse from the object disrupts the normal heart rhythm and leads to sudden cardiac arrest. How common is commotio cordis? Cases of commotio cordis are extremely rare. There are fewer than 30 cases each year. "struck in the chest at a specific time in the heart rhythm cycle"

Answer 354

A period of rapid heartbeats that begins and ends suddenly

Answer 355

SSx: dyspnea, arrhythmia, edema Causes: MI, valve disease, cardiomyopathy, hypertension, anemia, etc.

Answer 356

A term referring to right-sided heart failure from disorders that bring about HTN into the pulmonary circulation Causes: Left-sided heart failure, COPD, cystic fibrosis, and more

Answer 357

The heart is the first functional organ One of the first systems to form in an embryo (heart and brain) Begins its development from mesoderm on day 18/19 following fertilization Develops from a group of mesodermal cells called the cardiogenic area Most development occurs between weeks 5 and 9

Answer 358

a rescue technique in which an unconscious, pulseless person is assisted in maintaining heart rate (cardio) and breathing (pulmonary) CPR keeps oxygenated blood circulating until the heart can be restarted

Answer 359

When in doubt – chest compressions, chest compressions, chest compressions 2007 Japanese study found that in lay-person rescue, chest compressions alone are equally as effective as traditional CPR with ventilation Place the heel of your hand on the centre of the person's chest, then place the palm of your other hand on top and press down by 5 to 6cm (2 to 2.5 inches) at a steady rate of 100 to 120 compressions a minute.