Ch 20 The Heart Flashcards
How many times does the heart beat each day and per lifetime?
It beats 100,000 times per day
It beats 2.5 billion times per lifetime
How much blood does the heart pump per year in gallons
1.3 million gallons of blood
What is cardiology
It studies the function and diseases of the heart
What are the dimensions of the heart and what does it weigh?
It is 5 in Long
3 and 1/2 in wide
2 and 1/2 in thick
It weighs 8 to 10 oz and it’s larger in males
Where does the heart lie
It lies in the mediastenim of the thorax
What is the Apex of the heart formed by?
It is formed by the left ventricle
One side is flat because it rests on the diaphragm
What are the two layers of the serous membrane and what do they secrete
It is a mesothelium tissue
It is composed of the parietal layer which is fused to the fibrous layer of the pericardium
The visceral layer which covers the surface of the heart
Both layers secrete serous fluid which in the heart is called pericardial fluid
What is the base of the heart
It is the superior portion of the heart where the great vessels exit
The great vessels are the aorta and pulmonary trunk
What are the features of the fibrous tissue of the pericardium
It is made of dense irregular tissue( all collagen)
It is a tough tissue so it prevents overstretching and anchors in place
What is the epicardium and what is the other name? It is called when referred to as a covering
It is the outermost layer of the heart
It is very thin and made of mesothelium( simple squamous) plus areolar
If it is referred to as a covering. It is called the visceral pericardium
What is the myocardium and what does it consist of?
It is 95% of the heart
It has fascicles that are spiral in their arrangement and they twist as the heart contracts(think of wringing out a wet rag)
Each cell is covered by endomysium and and each fascicle is covered by a paramysium
What tissue makes up the endocardium and what are its features
It is endothelium( simple squamous lining the heart and blood vessels) and areolar
It is the inner layer of the heart
It is very thin
And it continues into the great vessels
What are the Atria of the heart
They are the two Superior Chambers
Their job is to receive blood
What are the ventricles of the heart?
The two inferior Chambers
Their job is to pump blood out
What are the auricles?
External pouches (ear shaped)
Their job is to hold blood for the Atria
What are sulci?
They are shallow grooves filled with blood vessels and adipose
They are the vessels that get clogged and cause heart attacks
What are the vessels that most often get clogged in the heart?
The sulci
Where is the coronary sulcus?
It encircles the entire top of the heart and is filled with blood vessels and adipose
Where is the anterior interventricular sulcus
It descends between the right and left ventricles and it is an external structure
What is the posterior interventricular sulcus
It descends between the right and left ventricles on the posterior side of the heart. It is an external structure
What is the right atrium receive flood from
The superior vena cava( SVC)
The inferior vena cava (IVC)
The coronary sinus
What type of blood does the SVC, the ivc and the coronary sinus carry
Deoxygenated blood
What are pectinate muscles
Muscle ridges in the right atrium that extend into the auricle
What is the interatrial septum
Wall between the Atria very thin
What is the fossa ovalis versus Foreman ovale
The fossa ovalis is the depression in the interatrial septum which is the remnant of a hole that was there when you were a fetus
The hole is the foramen ovale that is there when you were a fetus
What does the right atrioventricular valve or tricuspid valve control?
The RAV controls blood flow into the right ventricle
What is the trabeculae carneae?
Muscle ridges near the apex of the heart
What is the chordae tendineae
Quarts or strings of connective tissue anchored to the papillary muscles
Their job is to prevent eversion
What is the intraventricular septum?
The thick layer that is a wall between the ventricles
It pumps deoxygenated blood into the pulmonary trunk
Exits at the base
Divides into right and left pulmonary arteries
And to the lungs
What does the left atrium receive blood from and what type of blood is it?
The four pulmonary veins carrying oxygenated blood
What is collateral circulation
Were the two sulcas join near the Apex? If one gets clogged to the other can go around and provide blood
What is AA VV
The plural form of arteries or veins
What is the direction of blood moving in the arteries versus the veins?
Artery blood direction is leaving the heart
Vein direction is moving towards the heart
Where are the pectinate muscles in the left atrium?
They are in the left atrium only, not in the left auricle
What is the left atrioventricular valve also known as the bicuspid or mitral valve?
The lav controls the blood flow in the left ventricle
It has two cusps
The size of the left ventricle versus the right ventricle
The left ventricle is three times thicker than the right
Where does the left ventricle pump blood to
To the aorta and then to the entire body
What is the ductus arteriosus?
It is part of fetal circulation
A tiny vessel that connects the a order to the pulmonary trunk
It allows blood to bypass the fetal lungs
It collapses once born
The remnant is now called the ligamentum arteriosum
What is fiber skeleton made of
Dense regular connective tissue
What does fiber skeletons surround in the heart?
The openings of the four valves
Merges in the interventricular septum
What are the four functions of the fiber skeleton in the heart
Structural foundation for valves
Prevents overstretching of valves
Electrical insulator
Point of insertion for muscle cells, giving them something to pull against
What do cusps and cords equal
A valve
What are the two atrioventricular valves?
The tricuspid valve in the bicuspid valve
Where is the tricuspid valve located and what is it made of?
It separates the right atrium from the right ventricle
And is made of three cusps and chords
Where is the bicuspid valve and what is it made of?
It separates the left atrium from the left ventricle
It is made of two cusps and chords
What happens when the bicuspid valve is open
The cusps project into the veins
Papillary muscles relax
Cords are slack
The ventricles are relaxed and blood is flowing into the ventricles
What happens when the ventricle is contract
The force of the blood forces cusps closed and cords prevent eversion
When cusps, flip up into the Atria cords prevent eversion
What happened if valves are damaged?
The blood will regurgitate back into the Atria when the ventricles contract
What are the semilunar valves and where are they located
They are located in the aorta and pulmonary trunk
They have three cusps and no cords
What happens to semilunar valves when the ventricles contract
The cusps are forced open and the blood passes through into the vessels
What happens to the semilunar valves when the ventricles relax?
Blood falls and valves close preventing backflow into the veins
What is the path of systemic circulation?
It is controlled by the left side of the heart
The left artery receives oxygenated blood from four vessels
Blood passes through the left AV valve
The left ventricle
The aorta
And to the body
What is the path of pulmonary circulation
It is on the right side of the heart
Blood travels from the right ventricle
To the pulmonary trunk
To the pulmonary semilunar valve
Divides into right and left pulmonary arteries
To the lungs
What is corner circulation composed of
Anterior and posterior interventricular sulcus
These cause heart attacks
Implies the outer wall of the heart
Where does coronary circulation start?
The coronary arteries Branch from the ascending aorta and surround the heart
Left coronary artery location and what does it supply
It lays interior to the left auricle
The anterior intraventricular artery supplies what and where is it located?
The walls of both ventricles and it lays in the anterior interventricular sulcus
The left coronary artery has a circumflex. What does it supply and where is it?
It supplies the walls of the left ventricle and left atrium
It is found in the coronary sulcus
Where is the right coronary artery?
It lays inferior to the right auricle
Where is the posterior interventricular artery and what does it supply?
IT supplies the walls of both veins
It lays in posterior interventricular sulcus
