Unit 2 Flashcards
What is the position of the heart in the thoracic cavity?
The heart is located in the mediastinum, slightly left of the midsagittal line, with most of its right side resting superior to the diaphragm.
What are the great vessels associated with the heart?
The great vessels include:
* Superior vena cava
* Inferior vena cava
* Pulmonary trunk
* Aorta
What is the function of the superior vena cava?
The superior vena cava drains blood from the upper body into the right atrium.
What is the function of the inferior vena cava?
The inferior vena cava drains blood from the lower body into the right atrium.
What is the apex of the heart?
The apex is the inferior portion of the left ventricle, pointing towards the left hip.
What is the base of the heart?
The base is the superior part of the heart where the atria and great blood vessels reside.
What are the coverings of the heart?
The coverings of the heart include:
* Fibrous pericardium
* Parietal pericardium
* Visceral pericardium
What is the pericardial cavity?
The pericardial cavity is the space between the parietal and visceral pericardial layers containing serous fluid.
What are the three layers of the heart wall?
The three layers of the heart wall are:
* Epicardium
* Myocardium
* Endocardium
What is the myocardium?
The myocardium is the thick middle layer of the heart wall composed mainly of cardiac muscle cells.
What is the histological structure of cardiac muscle?
Cardiac muscle features:
* Short, branched cells
* Striations
* Intercalated discs with desmosomes and gap junctions
What is the function of the endocardium?
The endocardium is the innermost layer of the heart, composed of simple squamous epithelium, lining its chambers and covering the heart valves. Its primary function is to provide a smooth surface for blood flow within the heart, minimizing resistance and preventing blood clot formation.
How many chambers does the heart have?
The heart has four chambers: two atria and two ventricles.
What is the role of the atria in the heart?
The atria receive blood from veins.
What is the role of the ventricles in the heart?
The ventricles push blood into arteries.
What separates the right and left sides of the heart?
The septum, including the interatrial septum and interventricular septum.
What is the function of heart valves?
Heart valves prevent backward movement of blood, ensuring one-way flow.
What are the two types of heart valves?
The two types of heart valves are:
* Atrioventricular valves
* Semilunar valves
What is another name for the right atrioventricular valve?
The right atrioventricular valve is also known as the tricuspid valve.
What is another name for the left atrioventricular valve?
The left atrioventricular valve is also known as the bicuspid valve or mitral valve.
What are chordae tendineae?
Chordae tendineae are dense connective tissue that anchor the atrioventricular valves to the ventricles.
What is the function of papillary muscles?
Papillary muscles prevent the atrioventricular valves from prolapsing into the atria.
What are the two semilunar valves?
The two semilunar valves are:
* Pulmonary semilunar valve
* Aortic semilunar valve
What is the role of the pulmonary trunk?
The pulmonary trunk carries deoxygenated blood from the right ventricle to the lungs.
What major artery carries oxygenated blood from the heart to the body?
The aorta carries oxygenated blood from the left ventricle to the rest of the body.
What is the ligamentum arteriosum?
The ligamentum arteriosum is a small ligament that is the remnant of the ductus arteriosus, a fetal blood vessel connecting the pulmonary trunk to the aorta. During fetal development, the ductus arteriosus allows blood to bypass the non-functioning lungs by connecting the pulmonary artery directly to the descending aorta. After birth, as the newborn begins to breathe air, the ductus arteriosus closes and eventually forms the ligamentum arteriosum.
True or False: Cardiac muscle cells are amitotic.
True
Fill in the blank: The heart pumps about _______ liters of blood every minute.
[five]
What is the function of the pulmonary semilunar valve?
Lies between the right ventricle and the pulmonary trunk
What is the function of the aortic semilunar valve?
Located between the left ventricle and the aorta
Trace the pathway of blood through the heart starting with the superior and inferior vena cava.
Blood enters the right atrium, passes through the tricuspid valve to the right ventricle, then through the pulmonary semilunar valve into the pulmonary trunk, into right and left pulmonary arteries, lungs. Into the pulmonary veins, left atrium, bicuspid valve (mitral), left ventricle, aortic semilunar valve, aorta
Trace the pathway of blood through the heart starting with the pulmonary veins.
Blood enters the left atrium, passes through the bicuspid valve to the left ventricle, then through the aortic semilunar valve into the aorta
What is coronary circulation?
The delivery of oxygen and nutrients to the heart muscle itself
What happens when there is a blockage in coronary blood vessels?
It can cause a heart attack
What are the branches of the right coronary artery?
- Marginal artery
- Posterior interventricular artery
What does the marginal artery supply?
Blood to the lateral aspect of the right atrium and right ventricle
What does the posterior interventricular artery supply?
Blood to the posterior side of both ventricles and interventricular septum
What are the branches of the left coronary artery?
- Anterior interventricular artery
- Circumflex artery
What does the anterior interventricular artery supply?
Blood to the anterior aspect of both ventricles and interventricular septum
What does the circumflex artery supply?
Blood to the left atrium and a portion of the posterior left ventricle
How is blood drained away from the myocardium?
Via cardiac veins
What does the great cardiac vein parallel?
The anterior interventricular artery
What does the middle cardiac vein parallel?
The posterior interventricular artery
Where does blood with low oxygen levels in the coronary sinus drain?
Directly into the right atrium
What is pulmonary circulation?
Delivers blood to the lungs and back to the heart
What happens in the capillaries during gas exchange?
Oxygen diffuses into the tissues and carbon dioxide diffuses into the blood
What is systemic circulation?
Carries oxygenated blood from the left ventricle to the rest of the body
What type of blood vessels deliver blood to body tissues?
Arteries
What type of blood vessels carry blood back to the heart?
Veins
Fill in the blank: The chamber of the heart that is the systemic circuit pump is the _______.
Left ventricle
What structures prevent the atrioventricular valves from prolapsing?
Chordae tendineae and papillary muscles
Going from deep to superficial, list the layers of the heart wall.
- Endocardium
- Myocardium
- Epicardium
What chamber of the heart is the pump for the pulmonary circuit?
Right ventricle
What type of blood vessels take blood away from the heart?
Arteries
