Question | Answer |
What structures prevent prolapse of atrioventricular valves? | Chordae tendineae |
Where is the Bundle of HIS located? | Interventricular septum |
The lub-dub heart sounds heard during auscultation of the heart are associated with? | The heart valves closing |
Blood flow during ventricular filling is most dependent upon what? | pressure changes |
This valve is found between the right atrium and the right ventricle | Tricuspid |
During which part of the cardiac cycle would pressure in the ventricle be at its lowest? | mid-diastole |
Arial repolarization occurs during this period of time, seen on an EKG | QRS complex |
Blood is prevented from flowing back into the left ventricle by the: | aortic semilunar valve |
This area is known as the pacemaker of the heart | SA node |
Structures in the ventricles | trabeculae carneae, papillary muscles, and chordae tendineae |
The most important factor for stretching cardiac muscle is: | End diastolic volume |
The greatest decrease in ventricular pressure occurs at this time | Isovolumetric relaxation |
Blood being pumped out of the left ventricle enters the | aorta |
Deoxygenated blood from the myocardium enters the right atrium through the | coronary sinus |
Nerve impulses directly supplied to the papillary muscles by the | Purkinje fibers |
The entire ventricular myocardium is depolarized during this time on an EKG | S-T segment |
All oxygenated blood returns to the heart via the | pulmonary veins |
Blood is carried to the heart by these vessels | Veins |
The parasympathetic nervous system decreases heart rate by | opening potassium gates |
An increase in end diastolic volume would have which effect on cardiac output? | increase |
The anterior surface of the heart consists mostly of this chamber | right ventricle |
All four heart valves are closed during this time | Isovolumetic contractions |
Cardiac muscle tissue is found in which layer of the heart? | myocardium |
The amount of blood pumped out of each ventricle in one minute is called | cardiac output |
The renin-angiotensin mechanism stimulates the release of which hormone? | aldosterone |
Long-term mechanisms control blood pressure by | regulating blood volume |
If you have a blood pressure of 120/80mmHg, what is your diastolic pressure? | 80 |
If you have a blood pressure of 110/80mmHg, what is your pulse pressure? | 30 |
Gaining weight may increase blood pressure because increased adipose tissues cause an increase in | blood vessel length |
These vessels also serve as a blood reservoir | veins |
Types of capillaries | fenestrated, sinusoidal, continuous |
These arteries supply 80% of the cerebrum | internal carotids |
Which of the following blood vessel types have the greatest effect on peripheral resistance? | arterioles |
An increase in peripheral resistance would have what effect on blood pressure? | increase |
Sinusoids are a highly modified form of these vessels | capillaries |
Found in large arteries | elastic tissue, smooth muscle, endothelium |
Venules unite to form | veins |
These vessels are able to constrict | arterioles |
The aortic reflex sends | inhibitory impulses to the vasomotor center |
In which of the following tissues would low oxygen levels cause vasoconstriction? | lungs |
Baroreceptors in our arteries respond to | an increase in blood pressure |
The exchange between blood vessels and cells occurs here | capillaries |
The first portion of the aorta is called the | ascending aorta |
This is the muscular layer of blood vessels | Tunica media |
These are the smallest blood vessels in our body | capillaries |
These vessels carry blood toward the heart | venules |
This part of the nervous system is responsible for vasomotor tone | sympathetic |
Branches off the arch of aorta | left common carotid artery, brachiocephalic artery, left subclavian artery |
A series of vessels that connect to capillary beds is a(n) | portal system |
What are the layers of the heart? | epicardium, myocardium, endocardium |
What is the location of the heart? | in the mediastinum between second rib and fifth intercostal space |
What is the heart enclosed in? | Pericardium |
How many chambers are in the heart? | 4 (2 atria-right and left and 2 ventricles) |
The right side of the heart is the pump for what circuit? and the vessels carry blood _________ | pulmonary
to and from the lungs |
The left side of the heart is the pump for what circuit? and the vessels carry blood_______ | systemic
to and from all body tissues |
Major branches of coronary circulation: arteries and veins | arteries: right and left coronary, marginal, circumflex, and anterior interventricular arteries
veins: small cardiac, anterior cardiac, and great cardiac veins |
Atrioventricular valves (AV) | Prevent backflow into the atria when ventricles contract
tricuspid valve:right and mitral valve:left |
Semilunar valves (SL) | Prevent backflow into the ventricles when ventricles relax
Aortic semilunar valve and pulmonary semilunar valve |
Cardiac muscles | striated, short, fat, branched and interconnected
numerous large mitochondria
intercalated discs: junctions between cells anchor cardiac cells |
Arrhythmias | irregular heart rhythms |
Fibrillation | rapid, irregular contractions, useless for pumping blood (can lead to clots) |
Defective SA node may result in | Ectopic focus: abnormal pacemaker takes over |
Defective AV node may result in | Partial or total heart block
Few or no impulses from SA node reach the ventricles |
Where are cardiac centers located? | Medulla oblongata |
Electrocardiogram (EKG or ECG) | a composite of all the action potentials generated by nodal and contractile cells at a given time |
What are the 3 electrocardiography waves | P wave, QRS complex, T wave |
P wave | depolarization of SA node |
QRS complex | ventricular depolarization |
T wave | ventricular repolarization |
What are heart murmurs | abnormal heart sounds most often indicative of valve problems |
Heart sounds: how does the first sound occur? | AV valves close and signifies beginning of systole |
Heart sounds: how does the second sound occur? | SL valves close at the beginning of ventricular diastole |
What is the cardiac cycle? | all events associated with blood flow through the heart during one complete heartbeat |
Systole | contraction |
Diastole | relaxation |
What are the phases of cardiac cycle? | Ventricular filling, ventricular systole, and isovolumetric relaxation |
How do you find cardiac output? | heart rate x stroke volume |
What 3 main factors affect stroke volume? | preload, contractility, and afterload |
What factors influence heart rate? | age, gender, exercise, body temperature |
What is tachycardia? | abnormally fast heart beat |
What is bradycardia? | heart rate is slower than 60bpm |
Arteries | carry blood away from the heart |
Capillaries | contact tissue cells and directly serve cellular needs (allow nutrients and gases to diffuse) |
Veins | carry blood toward the heart |
Structure of blood vessel walls: arteries and veins | tunica intima, tunica media, and tunica externa |
Structure of blood vessel walls: Lumen | central blood-containing space |
Structure of blood vessel walls: Capillaries | endothelium with sparse basal lamina |
Tunica intima | endothelium lines the walls (squamous cells) |
Tunic media | smooth muscle and sheets of elastin fibers |
Tunica externa | collagen fibers protect and reinforce |
Arterioles | smallest arteries- lead to capillary beds-control flow into capillary beds via vasodilation and vasoconstriction |
Capillaries are in all tissues except: | cartilage, epithelia, cornea and lens of eye |
Functions of capillaries | exchange of gases, nutrients, wastes, hormones, etc. |
What are the 3 structural types of capillaries | Continuous, fenestrated, and sinusoidal |
Continuous capillaries | abundant in the skin and muscles |
Fenestrated capillaries | Function in absorption or filtrate formation (small intestines, endocrine glands, and kidneys, filters urine) |
Sinusoidal capillaries | allow large molecules and blood cells to pass between the blood and surrounding tissues- found in liver, bone marrow and spleen |
Capillary beds consist of two types of vessels: | Vascular shunt and true capillaries |
Capillary beds-Vascular shunt: | directly connects the terminal arteriole and a post capillary venule |
Capillary beds- True capillaries | branch off the metarteriole or terminal arteriole |
What regulates blood flow into true capillaries? | precapillary sphincters |
Capillary beds consist of two types of vessels: | Vascular shunt and true capillaries |
Capillary beds-Vascular shunt: | directly connects the terminal arteriole and a post capillary venule |
Capillary beds- True capillaries | branch off the metarteriole or terminal arteriole |
Relationship of blood flow and blood pressure | If blood pressure increases, blood flow speeds up |
What regulates blood flow into true capillaries? | precapillary sphincters |
Relationship of blood flow and peripheral resistance | Blood flow is inversely proportional to peripheral resistance---if resistance increases, blood flow decreases (flow=pressure X resistance) |
How is the blood flow regulated through capillary beds? | local chemical conditions and vasomotor nerves |
What generates blood flow? | pumping action of the heart |
Venules | formed when capillary beds unite- very pourous- allow fluids and WBCs into tissues |
Relationship of blood flow and blood pressure | If blood pressure increases, blood flow speeds up |
Relationship of blood flow and peripheral resistance | Blood flow is inversely proportional to peripheral resistance---if resistance increases, blood flow decreases (flow=pressure X resistance) |
What generates blood flow? | pumping action of the heart |
Pressure results from? | the flow being opposed by resistance |
Systolic pressure | pressure exerted during ventricular contraction |
Diastolic pressure | lowest level of arterial pressure |
How do you calculate pulse pressure? | systolic-diastolic |
Mean arterial pressure (MAP) | pressure that propels the blood to the tissues |
MAP formula | diastolic pressure + 1/3 pulse pressure |
What factors influence blood pressure? | cardiac output, peripheral resistance, blood volume |
How does the body regulate blood pressure? | Changes in one variable (cardiac output, peripheral resistance, or blood volume) are quickly compensated for by changes in the other variables |