What is the outer of heart covering called? What is it's function?
fibrous pericardium
anchors the heart to the mediastinum, also know as a loose fitting sack
Which heart covering is also known as visceral pericardium?
epicardium
What is fibrous pericardium composed of ?
Thick, white fibrous CT
What are the visceral and parietal pericardium composed of?
serous membrane that consist of CT covered by epithelium
What is the delicate inner layer sac that covers the heart called?
epicardium
When the visceral pericardium folds over what covering of the heart is formed? What does the new layer become?
parietal pericardium
The parietal pericardium becomes the inner linning of the fibrous pericardium
Where is the pericardial cavity located? What is it's function?
between the visceral and parietal pericardium
it moistins the opposing surfaces and help movement of the heart in the pericardial sac as it (heart) contracts and pumps
What fluid is located in the pericardial cavity and how much is there?
pericardial fluid
25-35 ml
What are the 3 layers of the heart wall?
Epicardium
Myocardium
Endocardium
Which 2 layers of the heart wall have blood and lymph cappillaries and nerve fibers?
epicardium
myocardium
What is the function of the epicardium?
protective outer covering of the heart
What constitutes the great masses of the heart?
myocardium
What does the myocardium consist of?
cardiac muscle that forms a complex network
What is the function of the myocardium?
contracts and pumps the blood out of the heart
What is the inner lining of the heart?
endocardium
What does endocardium consist of ?
epithelium and CT
What layer of the heart contains purkinje fibers that are involved with the conduction system of the heart?
endocardium
What are purkinje fibers?
specilized cardiac muscle fibers that are involved in the conduction system of the heart
What does endocardium line?
heart chambers, valves, and the great blood vessels that enter and leave the heart
What are blood vessels that carry blood away from the heart called?
arteries
What are blood vessels that carry blood to the heart called?
veins
What are the upper chambers of the heart called?
artia(singular= atrium)
What is the function of the atria?
they serve as resivoirs between contractions
Where do the atria recieve blood from?
veins
What part of the heart has thin muscular walls but is highly expandable?
atria
What are auricles?
earlike, expandable portions of the atria
What seperates the right and left atria?
interatrial septum
What are the lower portions of the heart called?
ventricles
What is the function of the ventricles?
pumps blood out of the heart and into the arteries
What sperarates the right and left ventricle?
interventricular septum
What is the opening between an atrium and it's ventricle?
artioventricular orifice
What guards each orifice?
an AV valve(artioventricular valve)
What are the 2 AV valves? Where are they located?
tricuspid valve, between the right atrium and right ventricle
bicuspid valve, between the left atrium and the left ventricle
What is a cusp?
flaps of fibrous tissue (covered with endothelium), that make up the AV valve and project from the heart wall into the opening btwn the atrium and ventricle
Strong, fibrous strings that attach to cusps on the ventricular side?
Chordae tendineae
Muscles that extend inward from the ventricular wall and attach to chorade tendineae
papillary muscles
What is the function of the papillary muscles and the chordae tendineae?
to prevent cusps from swinging into the atria when the AV valve closes
What veins supply the right atria with blood?
Superior and Inferior Vena Cava
Coronary sinus
What guards the right atriventricular orifice?
tricuspid valve
What is the function of the tricuspid valve?
allows blood to flow from the right atrium to the right ventricle
prevents blood from moving from the right ventricle to the right atrium
What happens to the tricuspid valve when the blood pressure in greater in the right atrium?
It passivly folds out of the way for blood to move to the right ventricle
Where does the right ventricle pump the blood to?
pulmonary trunk which divides into left and right pulmonary arteries
What guards the base of the pulmonary trunk? How many cusps does it contain?
The pulmonary (semilunar) valve
3 cusps
What is the position of the pulmonary valve when the right ventricle contracts?
open
What causes the pulmonary valve to close?
When the ventricular wall relaxes the blood backs up in the pulmonary trunk causing the pulmonary valve to close
Which ventricle has thinner muscle?
the right ventricle
What does a thinner muscular wall create? Why is that necessary?
lower pressure to move the blood a shorter distance to the lungs(pulmonary circuit)
Where does the left atrium recieve blood from?
four pulmonary veins, 2 from the right lung, 2 from the left lung
What guards the left atrioventricular orifice?
The bicuspid valve aka mitral valve
What is the function of the bicuspid valve?
to prevent blood from flowing back into the left atrium from the left ventricle
Where does the left ventricle pump blood to?
the Aorta
What guards the aorta? How many cusps does it contain?
th aortic semilunar valve
3
What is the pulminary circuit?
thin walls in the right ventricle, lower pressure, delivers blood short distance to the lungs
What is the fuction of the aortic valve?
to prevent blood from moving from the aorta into the left ventricle during muscle relaxation
What is the systemic circuit?
thicker muscluar walls of the left ventricle contract with greater force, increasing pressure to ditribute blood throughout the body(systemic circuit)
What does the skeleton of the heart consist of ?
dense fibrous CT rings that enclose the
pulmonary trunk, aorta, and atrioventricular orifices
also cosists of the interventricular septum
What are the 3 functions of the skeleton of the heart?
attachment for heart valves
prevents outlets of the heart chambers from dilating excessively during contraction
physically isolates the atrial and ventricual muscular cells
Where does Deoxygenated blood enter the heart and from where?
the right side of the heart from the superior and inferior vena cava and the coronary sinus
What happens as the right atrium contracts?
blood gets forces through the tricuspid valve to the right ventricle
What happens to the tricuspid valve as the right ventricle contracts?
it closes
After the tricuspid valve closes where does the blood go?End at the lungs
through the pulmonary valve, into the pulmonary trunk, which then divides into the right and left pulmonary arteries leading to the lungs
Where does gas exchange take place?
between the blood in the capillaries and the air in the alevoli(lungs)
What gets removed once the blood is oxygenated in the lungs?
some of the carbon dioxide
Where does the blood go once it has been oxygenated? go through steps to aorta
returns to the left side of the heart through the pulmonary veins, enters the left atrium. as the left atrium contracts blood flows through the mitral vavle to left ventricle, which contracts, sends blood through aortic valve to aorta
What happens to blood after it has reached the aorta? end at right atrium
aorta branches off, blood enters the systemic circuit to deliver oxigenated blood to all cells, body uses oxygen and produces carbon dioxide, the deoxygenated blood returns to right atrium
The cardiac control center of the ________ coordiantes the innervation of the heart
medulla oblongata
The ______ acts to receive from all the veins of the heart
coronary sinus
The point in the conduction system of the heart where the impulse is temporarily delayed
AV node
The blood pressure in the systemic arteries is greatest during
ventricular systole
The hepatic portal system is an unusual vein in that it is transporting
nutrient rich blood
If excessive fluid retention increases blood volume, blood pressure is likely to
increase
The first branches which come off the aorta are the right and left _______ arteries
coronary
During ________, the atrioventricular valves are closed and the semilunar valves are open
ventricular systole
The _______ is also referred to as the pacemaker of the heart
S-A node
The _____ are the last part of the electrical conducting system of the heart
purkinje fibers
What event causes the normal heart sounds?
closing of the valves
What is the sequance of veins returning blood from the stomach?
gastric--, hepatic portal--, liver--, hepatic--, inferior vena cava--, right atrium
What does the p wave of an ECG represent?
atrial depolorization
The amount of blood ejected by the ventricles per beat is termed
stroke volume
The ____ acts to slow action potentials, while the _____ transmits these signals very quickly
A-V nodes; purkinje fibers
Which valve prevents backflow of blood from the left ventricle to the left atrium?
bicuspid atrioventricular
The specilized area of the myocardium that acts to anchor the chordae tendineae is the
papillary muscle
The production and conduction of action potentials in the heart produces a recordable tracing of the electrical activity of the heart is called
EKG
Which tunic of the artert contains endothelium?
tunica intera
The _____ rhythmically forms impulses initating each heartbeat and transmits these impulses to the
