Help study for your blood and heart test, try some of these sites!!

http://web.buddyproject.org/web019/web019/heart.html Diagraph of heart

http://www.linkpublishing.com/cgi-bin/ie.cgi?exam=chap26.exm Exam

http://www.linkpublishing.com/cgi-bin/ie.cgi?exam=chap26p.exm More Exams over the heart

http://www.gwc.maricopa.edu/class/bio202/cyberheart/hartint0.htm Way cool heart diagraph interactive

http://www.pbs.org/wgbh/nova/heart/heartmap.html trace the path of blood through the heart

HEART Parts to know:

pericardium

Right atrium
Left atrium

 septum
 Pectinate muscle
 Right auricle
 Left auricle
 Right ventricle
 Left ventricle
. Moderator band - muscle bundle between the ventricular wall and the interventricular septum; serves as an internal brace.
Apex 
 Trachea

 Superior vena cava
 Inferior vena cava 
 Tricuspid valve
 Pulmonary semilunar valve
 Pulmonary trunk
Right pulmonary artery
Left pulmonary artery
 Right pulmonary veins
 Left pulmonary veins
 Bicuspid (mitral) valve

 Chordae tendineae
Papillary muscles
 Aortic semilunar valve
 Ascending aorta
 Aortic arch
 Descending aorta
 Coronary arteries (in general)
Coronary (cardiac) veins (in general)

HEART CHECKLIST:

1. Paracardium

12. Left auricle

coronary arteries

 

13. Tricuspid valve

 Ascending aorta

 

14. Chordae tendineae

 

4. Right atrium

15. Papillary muscle

septum

5. Left atrium

16. Moderator band

 

 

 

28. Apex

 

18. Pulmonary semilunar valve

 

8. Pectinate muscle

19. Pulmonary trunk

30. Superior vena cava

9. Right ventricle

20. Pulmonary veins

31. Inferior vena cava

10. Left ventricle

21. Bicuspid (mitral) valve

 

11. Right auricle

22. Aortic semilunar valve

 

 

Stethoscope - instrument used to detect heart sounds.
 Heart Murmurs - "extra" heart sounds caused by leaking valves.
 Pulse - wave of pressure that can be palpated (felt) in the arteries; due to left ventricular contraction.
 Pulse rate - the number of pulses per minute; average is 72-80 beats/min.
 Tachycardia - a rapid pulse rate; usually above 100 beats per minute.
Bradycardia - a slow pulse rate; usually below 60 beats per minute.
 Radial pulse - palpation of the radial artery at the wrist.
Carotid pulse - palpation of the common carotid artery in the neck.
.Electrocardiogram (ECG) - recording of the electrical changes of each cardiac cycle.
Electrocardiograph - the instrument used to record the electrical changes of the heart.
P wave - atrial depolarization.
QRS complex - ventricular depolarization; (atrial depolarization also occurs during this time, but is masked)
T wave - ventricular depolarization.
. Electrodes - "leads" which sense electrical activity at the surface of the skin and send information to the electrocardiograph.
Sphygmomanometer - instrument used for taking blood pressure.
Systolic pressure - force of blood in the major arteries during ventricular contraction.
Diastolic pressure - force of blood that persists in the major arteries during ventricular relaxation.
Korotkoff sounds - the sounds of the brachial artery wall collapsing heard while taking a blood pressure.

 



1. Identify the structures traversed in sequence of blood flow. Relate the anatomy of the heart to its basic physiological function.

This is one of those cases when a picture is definitely worth "a thousand words":

The basic physiological function of the heart is to mechanically pump blood through both of the body's circulatory loops. The human heart is really two different pumps - one for each circuit. The atria are like miniature "priming pumps", whose job it is to help fill the ventricles. The ventricles, then, are the "main pumps" that move blood around the body.

One key point relates to the origin/attachment of the myocardium (heart muscle) to the fibrous skeleton. The myocardium, in a way, forms loops around each chamber, starting and ending at the fibrous skeleton. Therefore, when the muscle contracts, the chambers get smaller, squeezing the blood out of the heart.

2. Identify the structures found in each of the four chambers and consider their significance.

·         Right Atrium:

o        sinus venarum: thin-walled posterior part, where vena cava empty (Latin, sinus = fold, hollow)

o        pectinate muscle: muscular anterior part (Latin, pecten = comb)

o        right AV (tricuspid) valve - superior surface: opens into right ventricle

o        sulcus terminalis: external demarcation of separation of sinus venarum and pectinate muscle

o        crista terminalis: internal demarcation of separation of sinus venarum and pectinate muscle

o        opening of coronary sinus: this venous trunk drains most of the heart and dumps right into the right atrium

o        fossa ovalis: remnant of foramen ovale, an opening in the interatrial septum in fetus

·         Right Ventricle:

o        conus arteriosis: smooth portion leading to pulmonary valve and trunk

o        trabeculae carnae: ridged muscular wall

o        right AV (tricuspid) valve - inferior surface: opens from right atrium

o        chordae tendinae: attach to cusps of AV valve, preventing both separation and prolapse (valves being pushed back into atrium) (Note: the chordae tendinae and papillary muscles do not "pull" the valves open.)

o        papillary muscles: contraction during systole (ventricular contraction) helps prevent valve prolapse and regurgitation of blood

o        pulmonary valve: leads to pulmonary trunk. Semilunar cusps prevent regurgitation of blood from pulmonary trunk during diastole (ventricular relaxation).

·         Left Atrium:

o        smooth-walled portion: no specific name, as in right atrium, but serves similar purpose - site of emptying of the four pulmonary veins

o        pectinate muscle: muscular anterior part, near auricle

o        interatrial septum: opening (closed at the other end by the fossa ovalis) to the right atrium

o        left AV (mitral) valve - superior surface: opens to left ventricle

·         Left Ventricle:

o        trabeculae carnae: ridged muscular wall

o        left AV (mitral, bicuspid) valve - inferior surface: opens from left atrium

o        chordae tendinae: attach to cusps of AV valve, preventing both separation and prolapse (valves being pushed back into atrium) (Note: the chordae tendinae and papillary muscles do not "pull" the valves open.)

o        papillary muscles: contraction during systole (ventricular contraction) helps prevent valve prolapse and regurgitation of blood

o        aortic valve: leads to aortic arch. Semilunar cusps prevent regurgitation of blood from pulmonary trunk during diastole (ventricular relaxation).

Compare and contrast the anatomical characteristics of the right and left sides of the heart.

The right and left sides of the heart are very similar in terms of structural components. Both contain an AV valve, a semilunar outflow valve, smooth and muscular parts, etc. The primary difference between the right and left sides of the heart is size. The muscle of the left ventricle is 2-3 times thicker than that of the right, although the size of the cavity itself is about the same as the right. Both ventricles pump the same amount of blood, but the left ventricle must be much more powerful in order to perfuse the entire body, as opposed to the right ventricle that only has to perfuse the lungs. The systemic resistance to flow, which must be overcome by the left ventricle, is much higher than the pulmonary resistance to flow.

Identify the arterial supply and venous drainage of the heart. Describe the electrical conduction system.

Arterial Supply:

Electrical conduction:

The SA node is the "pacemaker" of the heart. It is located in the crista terminalis. It can generate signals independent of any CNS input, or it can be regulated by the autonomic nervous system.

The electrical signal travels from the SA node through the atrial myocardium, causing atrial contraction.

The signal then reaches the AV node, which is surrounded by the insulating fibrous skeleton. There is a significant delay here, to allow the ventricles to fill before they contract.

The signal leaves the AV node via the AV bundle, which splits at first into two branches, then into multiple branches to supply the ventricular myocardium. This splitting and quick conduction by the specialized cells of the bundle allow for all parts of the ventricle to contract together.

 

 Check out these sections from the 1918 version of Gray's Anatomy of the Human Body! Some of the terms are out-of-date, but the illustrations are timeless.

The Heart - The Aorta - Surface Anatomy of the Thorax - Surface Markings of the Thorax


 

 Examine the right atrioventricular (tricuspid) valve. Define the cusps.

There are three cusps. The two larger ones are the anterior and the septal cusps. The smaller one is the posterior cusp.

Define chamber walls: interventricular (or interatrial), anterior and posterior.

Right atrium: thin-walled sinus venarum posteriorly, more muscular anteriorly (including a muscular auricle), with interatrial septum between it and the left atrium

Left atrium: thin-walled portion posteriorly, muscular auricle more anteriorly, with interatrial septum between it and the right atrium

Right ventricle: lateral and anterior walls are muscular, while the posterior portion is mostly composed of interventricular septum

Left ventricle: interventricular septum is more anterior, rest of wall is muscular

 In the right atrium, define papillary muscles, chordae tendinae, and tricuspid valve cusps.

The right ventricle usually has only two papillary muscles (anterior and posterior); occasionally there is one or more small septal papillary muscles. They are muscular projections from the ventricular wall which have tendinous cords (chordae tendinae) extending to the tricuspid valve cusps. The anterior muscle is the largest and has tendinous cords attaching to the anterior and posterior cusps. The smaller posterior muscle, which may consist of several parts, has cords attaching to the posterior and septal cusps. The septal muscle, when there is one, has cords attaching to the anterior and septal cusps. If there is no septal muscle, chordae tendinae arise directly from ventricle's septal wall.

. Do you find a septomarginal trabecula?

The septomarginal trabecula (moderator band), when present, is a muscular ridge of myocardium extending from the right ventricle's septal wall to the base of the anterior papillary muscle.

. Name the semilunar cusps of the pulmonary valve.

The pulmonary valve's three semilunar cusps are named according to their orientations: right, left and anterior.

 Does the left atrioventricular (mitral, bicuspid) valve have any commissural cusps? Note relation of anterior cusp to aortic wall.

Commissural cusps are small accessory cusps occurring between the named cusps (anterior and posterior). The anterior cusp of the mitral valve abuts and curves around the base of the aorta.

. What is the relationship of the heart's fibrous skeleton to its conduction system? Why is this important?

The fibrous skeleton provides attachment for heart's myocardium and valves. Additionally, it serves as an electrical insulator between the atria and ventricles penetrated only by the conduction system. This ensures that there is a pause between the contraction of the atria (leading to ventricular filling) and the contraction of the ventricles (ventricular ejection or emptying).