bsc 182 exam 2- achy breaky heart

parasympathetic nervous system opposes sympathetic effects- ach results in slower hr and will have no effect on contractility. heart at rest exhibits vagal tone, which is parasympathetic dominant influence

(autonomic nervous system regulation): talk about what the parasympathetic nervous system does

sympathetic nervous system activated by emotional or physical stressors- noepi causes pacemaker to fire more rapidly and increases contractility, which results in faster relaxation and filling. also increases hr

(autonomic nervous system regulation): talk about what the sympathetic nervous system does

delivered when heart is relaxed, and left ventricle receives most blood supply

(coronary circulation)- functional blood supply to heart): when is it delivered, and which receives most blood supply?

anterior interventricular artery; circumflex artery; supplies interventricular septum, anterior ventricular walls, left atrium, and posterior wall of left ventricle

(coronary circulation- arteries): arteries arise from base of aorta, js. but what 2 things make up the left coronary artery branches; and what 4 things does it supply?

right marginal artery; posterior interventricular artery; supplies right atrium and most of the right ventricle

(coronary circulation- ateries): what 2 things make up the right coronary artery branches?; and what does the right coronary artery branches mainly supply to

provides additional routes for blood delivery, and cant compensate for coronary artery occlusion

(coronary circulation- contains anastomoses): what does it provide, and it cant compensate what?

collect blood from capillary beds

(coronary circulation- veins): what do cardiac veins collect?

empty directly into right atrium anteriorly

(coronary circulation- veins): where do the anterior cardiac veins empty

empties into right atrium; formed by merging cardiac veins- great cardiac vein of anterior interventricular sulcus, middle cardiac vein in posterior interventricular sulcus, and small cardiac vein from inferior margin

(coronary circulation- veins): where does the coronary sinus empty, and list the 3 things where it empties to

cardiac veins, coronary sinus, anterior cardiac veins

(coronary circulation- veins):what 3 things are a part of the veins?

1. most common birth defect; treated with surgery 2. two types- mixing of o2 poor and o2 rich blood, or narrowed valves or vessels 3. tetralogy of fallot- both types of disorders are present

(developmental aspects of the heart- congenital heart defects): what are the 3 characteristics?

1. foramen ovale connects the 2 atria- remnant is fossa ovalis in adult 2. ductus arteriosus connects pulmonary trunk to aorta- remnant of ligamentum arteriosum in adult 3. closes at birth

(developmental aspects of the heart- fetal heart structures that bypass pulmonary circulation): what are the 3 characteristics? 1. what does it connect, and what is the remnant? 2. what does it connect, and remnant? 3. when does it close?

composite of all action potentials generated by nodal and contractile cells at given time; p wave- depolarisation of sa node into the atria; qrs complex- ventricular depolarisation and atrial repolarisation; t wave- ventricular repolarisation

(electrocardiography): an ekg is a composite of what? and what are the 3 waves, and explain what da hell dey do

heartbeat modified by ans via cardiac centres in medulla oblongata. involves the sympathetic, parasympathetic, cardioacceleratory centre, cardioinhibitory centre

(extrinsic innervation of the heart): the heartbeat is modified by what via what? and what 4 components are involved?

sympathetic increases rate and force; parasympathetic decreases rate; cardioacceleratory centre is sympathetic, and affects sa, av nodes, heart muscle, and coronary arteries; cardioinhibitory centre is parasympathetic, and inhibits sa and av nodes via vagus nerve

(extrinsic innervation of the heart): what does sympathetic increase?; parasympathetic decreases?; cardioacceleratory sympathetic or parasympathetic, and affects what 4 things?; cardioinhibitory sympathetic or parasympathetic, and inhibits what 2 things via what?

heart depolarises and contracts without nervous system stimulation- rhythm can be altered by ans

(heart physiology): what is the heart's electrical events?

1. in superior interventricular septum 2. this is the only electrical connection between atria and ventricles bc the atria and ventricles aren't connected via gap junctions

(heart physiology- sequence of excitation): talk about the atrioventricular (av) bundle. 1. where is it located? 2. this is the only what, and why?

1. in inferior interatrial septum 2. delays impulse .1 sec bc fibres are smaller in diametre with fewer gap junctions, and allows atrial contraction prior to ventricular contraction 3. inherent rate of 50x/ min in absence of sa node input

(heart physiology- sequence of excitation): talk about the atrioventricular (av) node. 1. where is it located? 2. what does it delay, and why does it delay? 3. inherent rate?

2 pathways in interventricular septum; carry impulses toward apex of the heart

(heart physiology- sequence of excitation): talk about the right and left bundle branches. what are they the 2 pathways of?; and where does impulse go to?

1. pacemaker of the heart in right atrial wall. this depolarises faster than the rest of the myocardium 2. generates impulses 75x/ min (sinus rhythm). this is an inherent rate of 100x/ min tempered by extrinsic factors 3. impulse spreads across atria and av node

(heart physiology- sequence of excitation): talk about the sinoatrial (sa) node. 1. what is it, and what does it do faster than the rest of the myocardium? 2. generating impulses? the inherent rate? 3. impulse spreads?

1. complete pathway thru interventricular septum into apex and ventricular walls 2. more elaborate on left side of heart 3. av bundle and subendocardial conducting network depolarise 30x/ min in absence of av node input 4. ventricular contraction follows from apex toward atria

(heart physiology- sequence of excitation): talk about the subendocardial conducting network (purkinje fibres). 1. pathway of and thru what? 2. left side? 3. depolarisation, and in absence of what? 4. ventricular contraction follows?

1. gap junctions 2. intrinsic cardiac conduction system: network of non- contractile cells, initiates and distributes impulses which leads depolarisation and contraction of heart

(heart physiology- setting the basic rhythm): what 2 things show that coordinated heartbeat is a function? and with the 2nd thing, what is it a network of, and what does it do with impulses?

closing of heart valve- as av node closes, it begins the systole. as sl valve closes, it begins the ventricular diastole. pauses indicate heart relaxation; heart murmur is abn heart sound that indicates incompetent/ stenotic valves

(heart sounds): what are the 2 sounds (lub- dup) associated with?. what begins as the av node closes?. what begins as sl valve closes?. a pause indicates what?. what is a heart murmur?

pulmonary congestion- left side fails lead to blood backed up in lungs; peripheral congestion- right side fails lead to blood pools in body organs (edema); failure of either side weakens the other; treated by removing fluid, reducing afterload, increasing contractility

(homeostatic imbalance): pulmonary congestion? peripheral congestion? if either side fails? treated by?

arrhythmias- irregular heart rhythms and uncoordinated atrial and ventricular contractions; fibrillation- rapid, irregular contractions that are useless for pumping blood. when circulation ceases, it causes brain death. defibrillation to treat

(homeostatic imbalances): defects in intrinsic conduction system can cause what 2 things? for the first thing, what is irregular, and uncoordinated? for the second thing, contractions?

visceral layer of serous pericardium

(layers of the heart wall): explain the epicardium

it is continuous with endothelial lining of blood vessels. it also lines the heart chambers and covers cardiac skeleton of valves

(layers of the heart): talk about the endothelium

contractile cardiac muscle; cardiac skeleton- ct, anchors cardiac muscle fibres, supports great vessels and valves, and limits spread of action potentials to specific paths

(layers of the heart): what are the 2 things of the myocardium

cardiac cycle: blood flows thru the heart during one complete heartbeat; atrial systole and diastole is followed by ventricular systole and diastole; systole- contraction; diastole- relaxation; series of pressure and blood volume changes

(mechanical events- cardiac cycle): what 4 overviews happen during the cardiac cycle?

left atrium to mitral valve to left ventricle to aortic semilunar valve to aorta to systemic circulation

(pathways of blood thru the heart): what aare the 6 routes of the systemic valve after it goes thru the pulmonary circuit?

right atrium to tricuspid valve to right ventricle to pulmonary semilunar valve to pulmonary arteries to lungs to pulmonary veins to left atrium

(pathways of blood thru the heart): what is the 10 routes of the pulmonary circuit?

ventricles relax. atria is relaxed and filling; backflow of blood in aorta and pulmonary trunk closes the semilunar valves. ventricles are closed chambers; when the atrial pressure exceeds that in the ventricles, the av valves open and the cycle begins again

(phases of the cardiac cycle): what 3 things occur during isovolumetric relaxation? ventricles and atria? backflow? atrial pressure?

takes place in mid to late diastole; av valves are open and pressure is low; 80% of blood passively flows into ventricles; atrial systole occurs and delivering remaining 20%

(phases of the cardiac cycle): what 4 things occur during the ventricular filling?where does it take place? Av valves? blood flowing?delivering?

atria relaxes and ventricles begin to contract; rising ventricular pressure leads to closing of av valves; isovolumetric contraction phase is when all valves are closed; in ejection phase, ventricular pressure exceeds pressure in large arteries, forcing semilunar valves to open

(phases of the cardiac cycle): what 4 things occur during the ventricular systole? atria and ventricles? pressure? valves? ejection phase?

degree of stretch of cardiac muscle cells before they contract; most important factor stretching cardiac muscle is amount of blood returning to the heart (venous return); slow heartbeat and exercise increases venous return; increased venous return stretches ventricles and increases contraction force

(regulation of stroke volume): what are the 4 things of the preload?degree of stretch? most important factor? slow...? increased...?

pressure ventricles must overcome to eject blood

(regulation of stroke volume): what is afterload?

contractile strength at given muscle length

(regulation of stroke volume): what is contractility?

right side- receives deoxygenated blood from tissues, and pumps to lungs thru the pulmonary circuit/ left side receives oxygenated blood from lungs- pumps to body tissues thru the systemic circuit

(the pulmonary and systemic circuits- heart is transport system; two side by side pumps): talk about what the right side and what it receives and what it pumps to/ as well as the left side

right ventricle pumps blood thru pulmonary circuit; left ventricle pumps blood thru systemic circuit

(the pulmonary and systemic circuits- pumping chambers of heart): what are the 2 pumping chambers of the heart, and where would it pump blood to?

right atrium receives blood returning from systemic circuit/ left atrium receives blood returning from pulmonary circuit

(the pulmonary and systemic circuits- receiving chambers of the heart): what are 2 receiving chambers, and what exactly do they receive?

hypocalcemia

not enough calcium; depresses hr

thicker walls than atria; actual pumps of the heart; right ventricle pumps blood into pulmonary trunk; left ventricle pumps blood into aorta, which is the largest artery in the body

part 2: what are the 4 things about the discharging chambers of the ventricles?

aortic valve

sounds are heard in 2nd ics at right sternal margin

pulmonary valve

sounds heard in 2nd ics at left sternal margin

mitral valve

sounds heard over the heart apex (in 5th ics) in line with middle of clavicle

tricuspid valve

sounds typically heard in right sternal margin of 5th ics

a part of the aorta is narrowed, increasing the workload of the left ventricle

talk about coarctation of the aorta- what happens to the aorta, and what will this increase?

progressive condition; cardiac output is so low that blood circulation is inadequate; reflects weakened myocardium caused by coronary atherosclerosis, persistent high bp, multiple heart attacks, and dilated cardiomyopathy

talk about congestive heart failure

pulmonary trunk and valve and too narrow, resulting in hypertrophied right ventricle, ventricular septal defect, and aorta opening from both ventricles

talk about tetralogy of fallot- what is too narrow, which results in what 3 things?

1. superior part of the interventricular septum fails to form, allowing blood to mix between the 2 ventricles 2. more blood is shunted from left to right bc the left ventricle is stronger

talk about ventricular septal defect- what fails to form, and what will happen to the blood? blood shunted?

hypokalemia

too enough potassium; feeble heartbeat; arrhythmias

hypercalcemia

too much calcium; increases hr and contractility

hyperkalemia

too much potassium; alters electrical activity, which leads to heart block and cardiac arrest

1. auricles- appendages that increase atrial volume 2. right atrium- pectinate muscles, and posterior and anterior regions are separated by crista terminalis 3. left atrium- pectinate muscles are only in auricles

what 3 things are in the receiving chambers of the atria?

ventricular septal defect, coarctation of the aorta, tetralogy of fallot

what are 3 examples of congenital heart defects?

fetal heart structures that bypass pulmonary circulation and congenital heart defects

what are the 2 developmental aspects of the heart?

angina pectoris- thoracic pain caused by fleeting deficiency in blood delivery to myocardium. cells are weakened. myocardial infarction (heart attack) which is prolonged coronary blockage, and areas of cell death are repaired with non- contractile scar tissue

what are the 2 homeostatic imbalances of the coronary shit i talked about?

incompetent valve- blood backflows so the heart repumps the same blood over again; valvular stenosis- stiff flaps will constrict the opening and will lead to the heart exerting more force to pump blood/ mechanical, animal, or cadaver valve

what are the 2 homeostatic imbalances?/ what are the 3 ways a valve can be replaced?

1. functional blood supply to heart muscle 2. contains anatomoses (junctions)

what are the 2 things about coronary circulation?

ectopic focus- abn pacemaker; av node may take over and sets a junctional rhythm (40-60 beats/ min); extrasystole (premature contraction)- the ectopic focus sets a high rate, and can be from excess caffeine or nicotine

what are the 3 homeostatic imbalances of a defective sa node?

epicardium, myocardium, endocardium

what are the 3 layers of the heart wall?

preload, contractility, afterload

what are the 3 main factors that affect stroke volume?

1. ventricular filling 2. ventricular systole 3. isovolumetric relaxation

what are the 3 phases of the cardiac cycle?

1. coronary sulcus- encircles junction of atria and ventricles 2. anterior interventricular sulcus- anterior position of interventricular septum 3. posterior interventricular sulcus- landmark on posterioroinferior surface

what are the 3 portions of the chambers and associated great vessels?

1. four chambers- two superior atria, two inferior atria 2. interatrial septum- separates atria and contains fossa ovalis, which is a remnant ovale of fetal heart 3. interventricular septum- separates ventricles

what are the 3 portions of the chambers?

1. heart is transport system; two side by side pumps 2. receiving chambers of the heart 3. pumping chambers of heart

what are the 3 pulmonary and systemic circuits?

1. size of fist 2. located in mediastinum between second rib and fifth intercostal space; on superior surface of diaphragm; anterior to vertebral column, posterior to sternum 3. base (posterior surface) leans toward right shoulder 4. apex points toward left hip- apical impulse is palpated between fifth and sixth ribs, just below left nipple

what are the 4 characteristics of heart anatomy

1. ensures uni- directional blood flow thru the heart 2. opens and closes in response to pressure changes 3. two atrioventricular valves- tricuspid and mitral. it prevents backflow into atria when ventricles contract, and the chordae tendinae anchors the cusps to papillary muscles that will hold the valve flaps in closed position 4. two semilunar valves- aortic and pulmonary semilunar valves. it prevents backflow into ventriles when ventricles relax, and opens and closes in response to pressure changes

what are the 4 characteristics of heart valves? 1. what does it ensure? 2. when does it open and close in response to? 3. what will it prevent and anchor? 4. what will it prevent and open/close to?

1. equal volumes of blood are pumped to pulmonary and systemic circuits 2. pulmonary circuit is short, low pressure circulation 3. systemic circuit is long, high friction circulation 4. anatomy of ventricles reflect differences- left ventricle walls are 3x thicker than right bc it pumps with greater pressure

what are the 4 characteristics of the pathway of blood thru the heart? 1. equal volumes of what? 2, circulation of pulmonary circuit? 3. circulation of systemic circuit? 4. anatomy of _ reflects...?

small, thin walled; contributes little to propulsion of blood; 3 veins empty into right atrium- superior vena cava, inferior vena cava, and coronary sinus; 4 pulmonary veins empty into left atrium

what are the 4 characteristics of the receiving chambers of the atria?

hypocalcemia, hypercalcemia, hypokalemia, hyperkalemia

what are the 4 homeostatic imbalances of hr?

sclerosis and thickening of valve flaps; decline in cardiac reserve; fibrosis of cardiac muscle; atherosclerosis

what are the 4 tings of age- related changes affecting the heart?

most of the volume of the heart; right ventricle is most of the anterior surface; left ventricle is the posterioroinferior surface; trabeculae carnae are the irregular ridges of muscle on walls; papillary muscles anchor the chordae tendinae

what are the 5 ventricles of the discharging chambers, and kinda where they are each located at

sinoatrial to atrioventricular node to atrioventricular bundle to right and left bundle branches to subendocardial conducting network (purkinje fibres)

what are the order of the sequence of excitation (5 stages)?

hr slower than 60 beats/ min. may result in inadequate blood circulation in non- athletes. may be desirable result of endurance training

what is bradycardia?

volume of blood pumped by each ventricle in one minute; CO- hr x sv (stroke volume); hr= number of beats per minute; sv= volume of blood pumped out by one ventricle with each beat; normal is 5.25 L/min

what is cardiac output (co)? co? hr? sv? normal?

abn fast hr. exceeds 100 beats/ min; if persistent, it could lead to fibrillation

what is tachycardia?

hormones- epi from adrenal medulla increases hr and increases contractility; thyroxine increases hr and enhances effects of noepi and epi

what is the chemical regulation of hr, and what are the 2 things?

heart block- few (partial block) or no (total block) impulses reach ventricles, and artificial pacemakers can treat it

what is the homeostatic imbalance of a defective av node? js, but to reach the ventricles, impulse must pass thru av node

age, gender, exercise, body temp

what other 4 factors influence hr?