Chapter 22: Heart
(Int. Ana: Right Atrium) Which major vessels empty into the right atrium?
(1) The superior vena cava drains blood from the head, neck, upper limbs, and superior regions of the trunk; (2) the inferior vena cava drains blood from the lower limbs and trunk; and (3) the coronary sinus drains blood from the heart wall.
What is the APEX of the heart?
-The inferior, conical end -It projects slightly anteroinferiorly toward the left side of the body
serous pericardium
-The inner portion is a thin, double- layered serous membrane -divided into: parietal layer and visceral layer (aka epicardium)
Pericardial cavity
-The thin space between the parietal and visceral layers of the serous pericardium -into which serous fluid is secreted to lubricate the serous membranes and facilitate the almost frictionless, continuous movement of the heart when it beats
Friction
-a crackling or scraping sound heard with a stethoscope that is caused by the movement of the inflamed pericardial layers against each other. The inflammation results in the loss of the lubricating action of the serous membranes. -helps identify pericarditis
Systemic Circulation
-consists of the chambers on the left side of the heart (left atrium and left ventricle), along with all the other named blood vessels. -carries blood to all the peripheral organs and tissues of the body
pulmonary circulation
-consists of the chambers on the right side of the heart (right atrium and right ven- tricle) as well as the pulmonary arteries and veins
Heart's 3 Characteristics and Functions
-unidirectional flow -delivery of blood to lungs for gas exchange -delivery of blood to body tissues for nutrients and respiratory gas delivery
Where does gas exchange with tissues happen?
Capillaries
Arteries
Carries blood away from the heart -all are high in oxygen (except for pulmonary arteries)
Veins
Carries blood back to the heart -all are low in oxygen (except for pulmonary arteries)
Capillaries
Gas is exchanged with tissues from the body's smallest vessels
The heart is located left of the body midline posterior to the sternum in the ___
Mediastinum
Blood that is high in oxygen (oxygenated) from the left side of the heart is pumped into the aorta, the largest systemic artery in the body, and then into smaller systemic arteries.
Note: largest artery --> smallest arteries
The pericardial cavity is a potential space with just a thin lining of serous fluid. However, it may become a real space. This would result in what condition?
Pericarditis is an inflammation of the pericardium typically caused by viruses, bacteria, or fungi. Whatever the cause of pericarditis, the pericardium is inflamed. The inflammation causes an increase in capillary permeability. Thus, the capillaries become more "leaky," resulting in fluid accumulation in the pericardial cavity. At this point, the potential space of the pericardial cav- ity becomes a real space as it fills with fluid and pus.
What is cardiac output?
The amount of blood pumped from one ventricle per minute (about 5.25 liters at rest)
Great Vessels
The arteries and veins entering and leaving the heart are called the great vessels because of their relatively large diameter Includes: superior and inferior vena cava, pulmonary artery, pulmonary vein, and aorta (systemic artery)
The heart is contained within the ___
The heart is contained within the pericardium
Unidirectional flow
The heart's anatomy ensures the unidirectional flow of blood through it. Backflow of blood is prevented by valves within the heart.
In which heart layer do heart attacks occur?
The myocardial layer is where myocardial infarctions (heart attacks) occur because the arrangement of cardiac muscle in the heart wall permits the compression necessary to pump large volumes of blood out of the heart.
fibrous pericardium
The outer portion is a tough, dense connective tissue layer of the pericardium
Function of the pericardium?
The pericardium restricts the heart's movements so that it doesn't bounce and move about in the thoracic cavity, and prevents the heart from overfilling with blood.
What does the BASE of the heart consist of?
The posterosuperior surface of the heart, formed primarily by the left atrium
(Ext. Ana) T/F: Both ventricles pump the same volume of blood per minute
True
T/F: As we age, more fat is deposited in the epicardium, and so this layer becomes thicker and more fatty
True
T/F: The heart is slightly rotated such that its right side or right border (primarily formed by the right atrium and ventricle) is located more anteriorly, while its left side or left border (primarily formed by the left atrium and ventricle) is located more posteriorly.
True
T/F: certain diseases may cause heart size to increase dramatically.
True
(Int. Ana) ___ are the tapering projection of a cardiac valve, also called flaps or leaflets.
Valve cusps; When the flaps of the valves are forced closed during the cardiac cycle, they produce sounds: "lubb-dupp" heart sounds.
(Ext. Ana) All sulci house blood vessels packed in ___ connective tissue. These vessels supply and drain the heart
adipose
Where does systemic circulation carry blood?
all the peripheral organs and tissues of the body
(Ext. Ana) The ___ conducts blood from the left ventricle into the systemic circu- lation.
aorta
What is the largest systemic artery in the body?
aorta
(Ext. Ana) These anterior and posterior inter-ventricular sulci extend inferiorly from the coronary sulcus toward the heart ___.
apex
The endocardium is composed of a simple squamous epithelium, called an endothelium, and a layer of ___ connective tissue.
areolar
The epicardium is composed of a serous membrane and ___ connective tissue.
areolar
Pulmonary circulation conveys blood to the lungs via pulmonary ___ to reduce carbon dioxide and replenish oxygen levels in the blood before returning to the heart in pulmonary ___.
arteries; veins
The superior border is formed by the great arterial trunks ___ and ___ and which vena cava?
ascending aorta and pulmonary trunk; superior
(Int. Ana: Right Ventricle) The right ventricle receives deoxygenated venous blood from the right ___
atrium
(Ext. Ana) The anterior part of each atrium is a wrinkled, flaplike extension, called an ___ because it resembles an ear.
auricle
The heart develops ___ through alternate cycles of heart wall contraction and relaxation
blood pressure
Pulmonary circulation conveys blood to the lungs via pulmonary arteries to reduce ___ and replenish ___ levels in the blood before returning to the heart in pulmonary veins.
carbon dioxide; oxygen
The myocardium is the middle layer of the heart wall and is composed of ___ muscle tissue
cardiac
(Ext. Ana) The atria are separated from the ventricles externally by a relatively deep ___ (or atrioventricular sulcus) that extends around the circumference of the heart.
coronary sulcus
Pericardium: The outer portion is a tough, ___ connective tissue layer called the fibrous pericardium.
dense
(Int. Ana: Right Atrium) ____ venous blood flows from the right atrium, through the right atrioventricular opening when the valve is open, into the right ventricle
deoxygenated
Outer layer is attached to both the ___ and the base of the great vessels.
diaphragm
What covers the internal surface of the heart and the external surfaces of the heart valves?
endocardium
The endocardium is composed of a simple squamous epithelium, called an ___, and a layer of areolar connective tissue.
endothelium
The endocardium is composed of a simple squamous ___, called an endothelium, and a layer of areolar connective tissue.
epithelium
(Int. Ana) What are valves and what is their importance?
epithelium-lined dense connective tissue cusps that permit the passage of blood in one direction and prevent its backflow
Checkpoint: Contrast the pulmonary and systemic circulations
explain to group
Checkpoint: What is the basic distinction between arteries and veins?
explain to group
Checkpoint: What is the difference between the base of the heart and its apex
explain to group
Checkpoint: Identify the layers of the pericardium. Why is the pericardial cavity described as a potential space?
explain to group layers: Fibrous pericardium Parietal layer of serous pericardium Pericardial cavity Visceral layer of serous pericardium (epicardium) Myocardium Endocardium
The heart wall consists of what three distinctive layers
external epicardium, a middle myocardium, and an internal endocardium
(Int. Ana: F. Skeleton) The___ of the heart is located between the atria and the ventricles, and is formed from dense regular connective tissue
fibrous skeleton
When the body is more active, and the cells need oxygen and nutrients delivered at a faster pace, the heart can increase its output up to ______.
five- or six-fold
(Int. Ana: Right Atrium) Inspection of the interatrial septum reveals an oval depression called the ___
fossa ovalis, also called the oval fossa
(Int. Ana: Right Atrium) what occupies the former location of the fetal foramen ovale, which shunted blood from the right atrium to the left atrium during fetal life?
fossa ovalis, also called the oval fossa
(Ext. Ana) The heart is composed of ___ hollow chambers: ___ smaller atria and ___ larger ventricles
four; two; two
From where does the blood then enter pulmonary circulation?
from the right atrium in Systemic Circulation
Cardiac tamponade
heart is unable to pump blood = heart failure and death
Blood that is __ in oxygen from the left side of the heart is pumped into the aorta
high
(Ext. Ana) The left and right ventricles are the ___.
inferior chambers
The serous pericardium may be subdivided into (1) a parietal layer of serous pericardium that lines the ___ surface of the fibrous pericardium, and (2) a visceral layer of serous pericardium (also called the epicardium) that covers the ___ of the heart.
inner; outside
(Int. Ana: Right Atrium) What is the thin wall between the right and left atria?
intertribal septum
(Int. Ana: Right Ventricle) An ___ forms a thick wall between the right and left ventricles.
interventricular septum
In pulmonary circulation: Blood returns to the ___ side of the heart, where it then enters the systemic circulation
left
The pulmonary veins that enter the ___ atrium border the BASE
left
Systemic veins then carry blood that is ___ in oxygen and ___ in carbon dioxide and waste products back to the heart
low, high
A ___ blood pressure is essential for pushing blood through the blood vessels.
minimum
Which is the thickest of the 3 heart wall layers?
myocardium
(Int. Ana: Right Atrium) The posterior atrial wall is smooth, but the auricle and anterior wall exhibit obvious muscular ridges, called ___muscles.
pectinate The structural differences in the anterior and posterior walls occur because the two walls formed from separate structures during embryonic development.
Left border of the heart consists of ___ and located ___
primarily formed by the left atrium and ventricle; posteriorly
Right border of the heart consists of ___ and located ___
primarily formed by the right atrium and ventricle; anteriorly
(Ext. Ana) Two large arteries, the ___ and the ___ , exit the heart at its superior border.
pulmonary trunk; aorta
The parietal and visceral layers ___ along the great vessels, where these layers become continuous with one another.
reflect (or fold back)
(Int. Ana: Right Atrium) The ___ atrium receives venous blood from the systemic circulation and the heart muscle itself.
right
(Int. Ana: Right Atrium) The right AV valve is forced closed when the right ventricle begins to contract, pre- venting blood from flowing back into the ___ atrium
right
The inferior border is formed by the ___ ventricle
right
superior and inferior venae cavae drain blood into the ___ atrium
right
(Int. Ana: Right Atrium) Separating the right atrium from the right ventricle is the ___
right atrioventricular opening
(Ext. Ana) Blood that enters an atrium is passed to the ventricle on the ___ side of the heart
same
The heart acts like two side-by-side pumps that work at the ____ rate and pump the ____ volume of blood
same
The endocardium is composed of a ___ squamous epithelium, called an endothelium, and a layer of areolar connective tissue.
simple
(Ext. Ana) The left and right atria are thin-walled chambers located ___.
superiorly
(Ext. Ana) The atria receive blood returning to the heart through both circulations: The right atrium receives blood from the ___ circulation, and the left atrium receives blood from the ___ circulation.
systemic; pulmonary
Blood pressure
the force of the blood pushing against the inside walls of the vessels.
The cardiovascular system consists of two circulations:
the pulmonary circulation and the systemic circulation
(Int. Ana) Name the four heart chambers
the right atrium, right ven- tricle, left atrium, and left ventricle
Most veins merge and drain where?
the superior and inferior venae cavae
(Int. Ana: Right Ventricle) The right ventricle typically has ___ cone-shaped, muscular projections called papillary muscles, which anchor numerous thin strands of collagen fibers called chordae tendineae
three
(Int. Ana: Right Ventricle) The internal wall surface of each ventricle displays characteristic large, smooth, irregular muscular ridges, called the ___
trabeculae carneae
(Int. Ana: Right Atrium) the right atrioventricular opening is covered by a right atrioventricular (AV) valve (also called the ___, since it has three triangular cusps)
tricuspid valve
The pericardium is composed of ___ parts
two
(Ext. Ana) The pulmonary trunk carries blood from the right ___ into the pulmonary circulation
ventricle
The epicardium is the outermost heart layer and is also known as the ___ layer of the serous pericardium.
visceral
(Int. Ana: F. Skeleton) Functions of the fibrous skeleton
■ Separates the atria and ventricles. ■ Anchors heart valves by forming supportive rings at their attachment points. ■ Provides electrical insulation between atria and ventricles. This insulation ensures that muscle impulses are not spread randomly throughout the heart, and thus prevents all of the heart chambers from beating at the same time. ■ Provides a rigid framework for the attachment of cardiac muscle tissue.
