Download Outline11 Heart - Napa Valley College

Biology 218 – Human Anatomy
Cardiovascular System: The Heart
Clemens
Text: Chapter 13
Learning Objectives
1. Describe the organization of the pericardium and the heart wall.
2. Describe the features of the atria and the ventricles.
3. Identify the great vessels and heart valves associated with each heart chamber.
4. Describe the functions of the heart valves.
5. Trace the path of blood flow through the pulmonary and systemic circulations.
A. Introduction to the Heart
location: anterior thoracic cavity, in the mediastinum
orientation: apex - inferior, points leftward, under 5th rib
base - superior, tilts rightward, under sternum
B. Pericardium and Heart Wall
fibrous pericardium
parietal layer of serous pericardium
visceral layer of serous pericardium = epicardium
myocardium - cardiac muscle
endocardium - endothelium
C. Chambers of the Heart
atria - receiving chambers (RA, LA)
ventricles - pumping chambers (RV, LV)
surface features: auricles
coronary sulcus
anterior interventricular sulcus
posterior interventricular sulcus
coronary arteries
1. Right Atrium ← superior and inferior vena cavae and coronary sinus
(deoxygenated blood)
internal features:* pectinate muscles
interatrial septum
*both R and L atria
fossa ovalis
2. Right Ventricle → pulmonary trunk (deoxygenated blood)
- pulmonary pump
internal features:* trabeculae carneae
chordae tendineae
*both R and L ventricles
papillary muscles
interventricular septum
3. Left Atrium ← pulmonary veins (oxygenated blood)
4. Left Ventricle → aorta (oxygenated blood)
- systemic pump
thickest walls, highest blood pressure
Fibrous skeleton of the heart
- dense CT between atria and ventricles
- forms rings around heart valves
Biology 218 – Human Anatomy
Clemens
D. Heart Valves
1. atrioventricular (AV) valves
a. tricuspid valve - RA } RV
b. bicuspid (mitral) valve - LA } LV
- AV valves prevent backflow of blood into the atria when the ventricles are contracting (systole)
- closing of AV valves produces the first heart sound (“lub”)
2. semilunar valves
a. pulmonary valve - RV } pulmonary trunk
b. aortic valve - LV } aorta
- semilunar valves prevent backflow into the ventricles when ventricles are relaxed (diastole)
- closing of semilunar valves produces the second heart sound (“dupp”)
- blood is ejected from the heart between “lub” and “dupp”
3. Heart murmurs
- turbulent sounds resulting from abnormal valve function
insufficiency - incomplete closure of a valve (e.g., mitral valve prolapse)
stenosis - narrowing of valve opening (e.g., aortic stenosis)
E. Circulation of Blood
pulmonary circuit: RA → RV → pulmonary trunk → lungs → pulmonary veins
systemic circuit : LA → LV → aorta → body → vena cavae
(coronary circulation: coronary arteries → heart → cardiac veins → coronary sinus)
F. Cardiac Conduction System
1. sinoatrial (SA) node - primary “pacemaker”, sets the heart rhythm
2. atrioventricular (AV) node - slight delay between the atria and ventricles
3. atrioventricular bundle
4. right and left bundle branches rapid conduction to the apex
5. Purkinje fibers
and through the ventricles
Study Questions
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What is the specific location of the heart in the thoracic cavity and in relation to
other structures of the thorax (e.g., lungs, mediastinum, esophagus, diaphragm)?
Describe the layers of the pericardium and the heart wall. What structure is
considered to be part of both the pericardium and the heart wall?
Match the four chambers of the heart with their associated great vessels.
Compare and contrast the general structure of the atria and the ventricles.
Which specific chamber of the heart has the thickest walls, and why?
Know the names and locations of the atrioventricular valves and semilunar valves.
Which valves are open and which are closed when the heart is relaxed (in diastole)?
Which valves are open and which are closed when the ventricles are contracting and
ejecting blood (in systole)? How does this relate to the heart sounds (“lub-dupp”)?
What is the function of the chordae tendineae and the papillary muscles?
Summarize the conduction system of the heart. What structure serves as the
primary “pacemaker” where cardiac excitation begins?
Trace the flow of blood through the heart and through the pulmonary and systemic
circulations. Identify the heart chambers, great vessels and valves at each point,
and identify which chambers and vessels contain oxygenated blood and which
contain deoxygenated blood.