ANATOMY & PHYSIOLOGY II CHAPTER 13
Terms
undefined, object
copy deck
- Where is the heart located?
- The heart is located between the lungs in the lower portion of the mediastinum.
- Describe what a heart looks like.
- The heart is often described as a triangular organ, shaped and sized roughly like a closed fist.
- Where is the heart positioned?
- The heart is positioned in the thoracic cavity between the sternum in front and the bodies of the thoracic vertebrae behind.
- Identify the heart chambers.
- The heart contains four cavities or hollows chambers. The 2 upper chambers are called atria (smaller). The 2 lower chambers are called ventricles. (thinner and less muscular).
- What do the heart chambers do?
- Atria are often called the receiving chambers because blood enters the heart through veins that open into these upper cavities. Blood is then pumped from the heart into arteries that exit from the ventricles; therefore the ventricles are sometimes referred to as the discharging chambers of the heart.
- What is myocardium?
- The WALL of each heart chamber is composed of cardiac muscle tissue referred to as the myocardium.
- What is endocardium?
- Each chamber of the heart is lined by a thin layer of very smooth tissue called the endocardium.
- What is endocarditis?
- Inflammation of the endocardium (lining in the heart chamber).
- What is thrombus?
- A blood clot.
- The heart has a covering and a lining. What is the name of its covering?
- Its covering, called the pericardium consists of 2 layers of fibrous tissue with a small space in between.
- Describe the 2 layers of the pericardium.
- The inner layer of the pericardium is called the visceral pericardium. It covers the heart the way an apple skin covers an apple. The outer layer is called the parietal pericardium. It fits around the heart like a loose fitting sack allowing enough room for the heart to beat.
- What is pericarditis?
- Inflammation of the pericardium.
-
Complete the sentence.
Contraction of the heart is called _____________. - systole
- Relaxation of the heart is called _____________.
- diastole.
- Name the four heart valves.
- Four valves keep blood flowing through the heart;prevent backflow (2 atrioventricular, or AV, and 2 semilunar valves). Tricuspid, Bicuspid, Pulmonary semilunar, Aortic semilunar.
- Where are the four heart valves located?
-
Tricuspid-opening of the right atrium into the ventricle.
Bicuspid- at the opening of the left atrium into the ventricle.
Pulmonary semilunar-at the beginning of the pulmonary artery.
aortic semilunar-at the beginning of the aorta. - What are the different types of valve disorders?
-
Rheumatic heart disease-cardiac damage resulting from a delayed inflammatory response to streptococcal infection.
Mitral valve prolapse-incompetence of mitral valve because its edges extend into the left atrium when the left ventricle contracts. - The heart makes rhythmical and repetitive sounds that are often described as lub dup. Describe what happens when the heart is making this sound.
- The first, or lub, sound is caused by the vibration and abrupt closure of the AV valves as the ventricles contract. Closure of the AV valves prevents blood from rushing back up into the atria during contraction of the ventricles. The second heart sound is caused by the closing of both the semilunar valves.
- The heart acts as two separate pumps. Describe the blood flow through the heart.
- Blood enters right atrium through 2 large veins called superior and inferior vena cava. After entering the right atrium, the blood is pumped through the tricuspid valve and enters the right ventricle. The ventricles contract and blood in the right ventricle is pumped into the pulmonary semilunar valve into the pulmonary artery and eventually into the lungs where oxygen is added and carbon dioxide is lost. Blood rich in oxygen RETURNS to the left atrium through the 4 pulmonary veins. It then passes throught the bicuspid valve into the left ventricle. When the left ventricle contracts, blood is forced through the aortic semilunar valve into the aorta and is distributed to the body as a whole.
- What is coronary circulation?
- The delivery of oxygen and nutrient rich arterial blood to cardiac muscle tissue and the return of oxygen poor blood from this active tissue to the venous system.
- What is myocardial infarction?
- Blockage of blood flow through the coronary arteries (heart attack or tissue death)
- What is a cardiac cycle?
- Each heartbeat is called a cardiac cycle and includes the contraction (systole) and relaxation (diastole) of atria and ventricles. Each cycle takes about 0.8 seconds to complete if the heart is beating at an average rate of about 72 beats per minute.
-
Complete sentence.
The ________________is the pacemaker of the heart and begins the contraction of the atria. - SA (sinoatrial) node
-
Complete sentence.
The __________________are extensions of the atrioventricular fibers and cause the contracton of the ventricles. - Purkinje fibers
- The ECG tracing that occurs when the ventricles are depolarizing is called______________.
- QRS Complex
- The ECG tracing that occurs when the atria is depolarizing is called ______________.
- P wave.
- Name the major types of cardiac dysrhythmia.
-
Heart block
Bradycardia
Tachycardia
Sinus dysrhythmia
Premature contraction
Fibrillation.