Heart Flashcards
Where is the heart located in the chest specifically?
• Located posterior to sternum in the mediastinum • Goes 2nd to 5th intercostal space • Slightly tilted so the tip (apex) projects to the left
What are the 3 different layers of the pericardium?
- Fibrous pericardium
- Visceral pericardium
- Parietal pericardium
Heart receives mostly _________ blood via ______.
Unoxygenated blood via veins
Heart sends mostly __________ blood out via ________.
oxygenated blood out via arteries.
_________ circulation carries deoxygenated blood to the lungs and back to heart for distribution
Pulmonary
________ circulation moves oxygenated blood to
body.
Systemic
What are the 3 layers of the heart wall?
- Epicardium
- Myocardium
- Endocardium
Which heart wall layer?
Most superficial
• visceral pericardium - epithelium
• Adipose tissue
Epicardium
Which heart wall layer?
Middle thick muscular layer
• Forms bulk of heart wall
• Contains fibrous skeleton
Myocardium
Which heart wall layer? Deepest layer • Areolar connective tissue • Endothelium – smooth epithelium that lines chambers and heart valves
Endocardium
What is myocarditis?
inflammation of the myocardium
• Usually due to a viral infection
What is endocarditis?
inflammation of the endocardium and typically also involves the heart valves
• Usually caused by a bacterial infection
What is the function of the atria?
Atria are receiving chambers that pump
blood into ventricles.
From where does each atrium receive its blood?
Right atrium receives blood from superior and inferior vena cava, and coronary sinus.
Left atrium receives blood from pulmonary veins.
What are the differences between right and left atrium?
Right atrium receives deoxygenated blood while left atrium receives oxygenated blood.
A normal part of fetal blood circulation. All babies are born with this opening between the aorta and the pulmonary artery. But it usually closes on its own shortly after birth.
Ductess Arteriosus
What is the adult structure of ductess arteriosus?
Ligamentum Arteriosum
What is the adult remnant structure of the foramen ovale in infants?
Fossa Ovalis
As pericardium becomes inflamed the capillaries become leakier resulting in fluid accumulation in the pericardial cavity called \_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_\_ • In severe cases it can stop the heart from filling adequately • This leads to the heart being unable to pump blood and could lead to heart failure
Cardiac Tamponade
What do the ventricles do?
Pump blood into the pulmonary
and systemic circulation.
• Small opening in interatrial septum • When the fossa ovale doesn’t seal all of the way and blood can go between the atria • Occurs in 15-25% of people • Leads to hypertrophy of right atria and ventricle and dilation of pulmonary trunk
Atrial Septal Defect
- Separates right and left ventricle
- Thicker than interatrial septum due to more pressure in ventricles
- Composed mostly of myocardium inferiorly
- Small portion superiorly is fibrous connective tissue
Interventricular Septum
When the interventricular septum fails to form completely
• Blood from the left ventricle is shunted into the right
ventricle
• More blood forced into the pulmonary circulation
• Pulmonary hypertension
Ventricular Septal Defect
- Septum between atria and ventricles
- Has 4 openings that allow blood to move into and out
- Each opening has a valve
- Valves weaken the septum so it is heavily reinforced with dense connective tissue called the fibrous skeleton
Atrioventricular Septum
- Network of collagen and elastin
- Provides structural support
- Forms fibrous rings for valves to attach
- Provides a framework for cardiac muscle attachment
- Acts as an electrical insulator
Fibrous Skeleton
What are the coverings of the heart and the layers of the walls starting with the most superficial?
- Fibrous Pericardium
- Parietal Pericardium
- Visceral Pericardium
- Epicardium
- Myocardium
- Endocardium
The visceral layer of the serous
pericardium:
a. Is fused to the fibrous pericardium
b. Is the fluid that offers protection to the heart
c. Is the outer layer of the heart
d. Is a tough, inelastic layer that anchors the heart in the mediastinum
e. Is also called the pericardial cavity
c. Is the outer layer of the heart
Which is not true of the fibrous
skeleton of the heart?
a. It acts as an electrical insulator
b. It connects with the interatrial septum
c. It consists of four connective tissue rings
d. It prevents overstretching of the valves
e. All the above are not true
b. It connects with the interatrial septum
_________ contract prior to the other regions of the ventricle, which tightens the chordae tendineae, and closes the tricuspid valve. This stops the blood from re-entering the right atrium during ventricular contraction.
Papillary Muscles
The _______ _________ make up the leaflet suspension system that ultimately determine and maintain the position and tension on the valve leaflets at end of systole.
Chordae Tendineae
Muscular ridges that crisscross and project from the inner walls of the heart ventricles. Their structure is important to their role. Had the inner surface of heart ventricles been flat, suction could occur and this would impair the heart’s ability to pump efficiently.
Trabeculae Carneae
- Open during ventricular contraction (atrial relaxation)
- Closed during ventricular relaxation
- Made up of 3 little cusps/cups
- When ventricles contract the pressure inside the ventricles is greater than in the pulmonary trunk so blood flows into pulmonary trunk
- When ventricles relax, blood begins to flow back filling the cusps and closing the valve
Pulmonary Semilunar Valve
• Also known as mitral valve • Separates the left atrium from the left ventricle • Composed of 2 leaflets connected to papillary muscle via chordeae tendinae • Open during ventricular relaxation • Closes during ventricular contraction
Bicuspid Valve
What opens and closes the bicuspid valve?
The chordae tendineae and papillary muscles keep the leaflets stable to prevent blood from flowing backward.
• Found between the left ventricle and aorta • Made up of three cusps • As ventricles relax, cusps fill with blood and close valve effectively preventing backflow
Aortic Semilunar Valve
What opens and closes the Aortic Semilunar Valve?
Pressure of blood flow
- Ensures blood flows from right atria to ventricle without backflow
- Open during ventricular rest (atrial contraction)
- Closed during ventricular contraction (atrial relaxation)
- Backflow of blood pushes it closed
- Made up of 3 flaps attached to chordae tendineae
- Chordae tendineae are attached to papillary muscles
- Contract and pull the “heart strings” to prevent valves from prolapsing
Tricuspid Valve
What opens and closes the tricuspid valve?
Papillary muscle contracts and chordae tendinae open valve
