Heart Review Answers

1.      The right side of the heart is the ____pulmonary____ circuit; it pumps blood to the ___lungs______. The left side is the ____systemic_____ circuit. The ____atria___ are the receiving chambers, and the ___ventricles______ are the pumping chambers.

2.      The heart is surrounded by a double-walled sac called the pericardium____. Inflammation of this sac is called ____pericarditis____. Accumulation of fluid in the sac is called ___cardiac  tamponade_______.

3.      The heart wall has 3 layers – the visceral pericardium or epicardium__, the muscular _____myocardium___, and the lining called ____endocardium_______.

4.      There are 3 grooves on the heart’s surface: the ___coronary_____ sulcus between the atria and ventricles, the anterior__ atrioventricular_ sulcus on the front surface, and the ____posterior__ _____atrioventricular___ sulcus on the back.

5.      The atria are covered by flaps called ______auricles______. The right atrium receives blood from 3 vessels: the ___SVC___, ___IVC ___, and the ___coronary______ ______sinus____. The left atrium receives blood from the 4 ___pulmonary___ ___veins______.  The atria contain _______pectinate___ muscles.

6.      The ventricles have ridges of muscle called _____carnae____ __trabeculae_ and _____papillary____ muscles that anchor the ___chordae_________ ___tendinae_____, or “heart strings.” The thicker ventricle is on the __left_ side. It pumps blood into the ___aorta___.

7.      Between the atria and ventricles are the ____AV____ valves – the bicuspid (mitral)_valve on the left and the tricuspid valve on the right. The chordae tendinae hold the valves ____closed____ when the ventricles contract. Blood exiting the ventricles travels through the pulmonary and aortic semilunar___ valves.  ____valvular_____ ___stenosis______ is a condition in which the valves have stiff flaps.

8.      Blood from the right atrium flows through the ___right AV______ valve to the right _____ventricle_____. It is pumped through the pulmonary_ semilunar valve to the _____pulmonary_______ artery, to the lungs. It returns in the ____pulmonary______ veins to the left__ ___atrium____ and flows through the left_ ____AV__ valve to the left__ _____ventricle___. It is then pumped through the aortic__ ____semilunar____ valve into the ____aorta____ to the rest of the body. It returns in the superior and inferior ____vena____ _____cavae______ to the right atrium.

9.      Coronary circulation includes the left coronary artery and its branches, the anterior_ interventricular____ ______artery_________ and the __circumflex__ _________artery_____, and the right coronary artery and its branches, the ____posterior______ ____interventricular___ and the ___right___ _____marginal_______ arteries.

10.   The great, middle, and small _____cardiac______ veins merge to form the coronary _______sinus____ which empties into the right atrium.

11.   Chest pain caused by a temporary impairment of blood flow to the myocardium is called ______angina______ _______pectoris__________. A heart attack, or myocardial__ _____infarction______ is due to prolonged loss of blood flow.

12.   Cardiac muscle cells are “striped,” or _____striated_________ with ___single______ ____central_____ nuclei. They have many ___mitochondria________ and undergo ____aerobic______ respiration. They connect to each other via ____intercalated____ disks which consist of _______desmosomes_____to keep cells connected to each other, and gap__ junctions that couple adjacent cells.

13.   Electrical impulses begin in the _____SA______ node, pass to the _____AV_________ node, then to the _____bundle_______ _of_ His to the right and left ___bundle_______ ____branches______ and finally the ___Purkinje_____ fibers.

14.   The SA node sets a rhythm of about 100 bpm___ but this is reduced to ___75___ by extrinsic factors. The AV node has an intrinsic rhythm of ~50__ bpm without input from the SA node, and may take over if the SA node fails. It also delays impulses briefly before passing them into the ventricles.  Purkinje fibers have an intrinsic rare of 30 bpm.

15.   An irregular heart rhythm is called an _____arrhythmia_______. Rapid, irregular contractions is called ___fibrilation_____.

16.   An abnormal pacemaker rhythm is called an ___ectopic_______ focus_____. Excess stimulants like caffeine can cause a high rate and premature contraction called _______extrasystole______.

17.   A defective AV node can cause a heart _____block______ where impulses don’t reach the ventricles. Ventricles set an intrinsic rate too slow for life.

18.   The cardioacceleratory center is controlled by the _____sympathetic_____ branch of the ANS and secretes _____norepinephrine_______. The cardioinhibitory center is controlled by the _____parasympathetic_____ branch and secretes ___acetylcholine________.

19.   ______ECG_______ is a tracing that reflects electrical activity in the heart. It consists of 3 waves: The P wave represents atrial depolarization, the ___QRS____ complex is atrial repolarization and ___ventricular__ ____depolarization_______, and the T_ wave is ventricular _______repolarization_____.

20.   The first heart sound is from the closing of the ___AV_____ valves, which is the beginning of ___systole______, and the 2^nd, the closing of the ___SL___ valves, which is the beginning of ____distole___.

21.   Ventricular filling is mostly passive, with only the last 20% delivered by atrial contraction___. The amount of blood in the ventricles before they contract is called end__ diastolic__ _____volume_____. The amount left after ventricular contraction is called ____end___ _____systolic______ volume__.

22.   Cardiac output = ____heart_____ _____rate_________ x ___stroke___ ___volume____. At rest it is about _____5.25______ L/min.

23.   An abnormally fast heart rate is called _____tachycardia_______; abnormally slow is _____bradycardia_______. If CO is too low to meet circulation needs, it can cause _______congestive_______ _______heart_____ ____failure______ and is due to weak heart muscle.

24.   The fetal heart contains an opening between the atria called the foramen____ ____ovale_____; in an adult this is called the ____fossa___ ___ovalis_____. It also contains the ______ductus___ _____areteriosis_______ that connects the pulmonary trunk and aorta, in an adult this is called the ___ligamentum______ ____arteriosus__________.