WK7 - Cardiovascular System: Heart Flashcards
The heart is the pump of the cardiovascular system, what is its function?
to propel blodd through the estimated 120,000 km of blood vessels
describe the shape of the heart
- the heart is a hollow, cone-shaped organ that is about the size of a person’s closed fist
- it is about 12 cm long, 9 cm wide, 6 cm thick
where is the heart located?
- b/t the lungs in the mediastinum
- about 2/3 of heart’s mass lies to the LEFT of the body’s midline
describe the heart’s physical attributes
- the apex is the lower, pointed end, and the base is the broader, upper portion
- the heart has an anterior surface and an inferior surface
- the right border faces the right lung and left border faces the left lung
what does the surface projection refer to?
the heart can be projected to the anterior surface of the chest by locating which landmarks?
refers to the oulining the shpae of an organ on the surface of the body
- superior right pt
- superior left pt
- inferior left pt
- inferior right pt
what is the pericardium
the sac that surrounds and protects the heart
what are the 2 major layers of the pericardium and their fx?
- fibrous pericardium - prevents overstretching of the heart, provides protection, and anchors the heart in the mediastinum
- deeper serous pericardium, which has two sublayers: outer parietal layer (fused with the fibrous pericardium) and visceral layer or epicardium
what is between the two sublayers (the visceral and parietal layer) of the serous pericardium?
pericardial cavity that contains pericardinal fluid, a lubricating fluid that reduces friction b/t the layers as the heart moves
the wall of the heart consist of 3 layers, what are they?
- outer epicardium is composed of mesothelium and connective tissue
- thick, middle myocardium composed of cardiac muscle tissue whose cells are connected by intercalated discs (containg desmosomes and gap junctions)
- inner endocardium composed of connective tissue covered by endothelium that is continuous with the endothelium of the blood vessels
what are the 2 superior chambers of the heart?
right and left atria, each have an anterior appendage called an auricle (flap of tissue) that allows an atrium to hold a larger volumn of blood
what are the two inferior chambers of the heart?
the right and left ventricles
the pulmonary pump consists of ?
the right atrium and right ventricle, pumps deoxygenated blood towards the lungs
the systemic pump consists of ?
the left atrium and left ventricle, pumps oxygenated blood toward the rest of the body
what are the 3 major grooves of the surface of the heart?
- coronary sulcus (separates atrium from ventricle)
- anterior interventricular sulcus
- posterior interventricular sulcus
the right atrium receives what from where?
-RT atrium receives DEOXYGENATED BLOOD from 3 veins:
- superior vena cava (SVC): brings blood from most parts of the body superior to the heart
- inferior vena cava (IVC) brings blood from all parts of the body inferior to the diaphragm
- coronary sinus receives blood from most of the vessels draining the wall of the heart
what is pectinate muscles
internal muscular ridges of the anterior right atrial wall of the right atrium
what is interatrial septum
-interior of the heart has an interatrial septum that separates the atria; this septum has an oval depression called the fossa ovalis
through what does the blood from the right atrium flow into the right ventricle
tricuspid valve (right antrioventricular valve)
what is trabeculae carneae
irregular surface of ridges in the inner surface of the right ventricle (left ventricle also has this)
what ensures that the cusps of the tricuspid valve permits blood to flow int the right ventricle but prevent backflow of blood into the right atrium?
(what ensures that the cusps of the bicuspid valve permit blood to flow into the left ventricle but prevents backflow of blood into the left atrium)
chordae tendineae and their assoicated papillary muscles
the interventriuclar septum does what?
separates the two ventricles
the right ventricle pumps the blood through?
the pulmonary valve into the pulmonary trunk which divides into the right and left pulmonary arteries
oxygenated blood returns from the lungs via?
- via 4 pulmonary veins that empty into the left atrium
- there are 2 pulmonary veins (one superior and one inferior) draining blood from each lung
blood in the left atrium flows into the left ventricle through?
bicuspid (mitral) valve (or left atriventricular valve)
the left ventricle forms what of the heart?
the apex
the left ventricle pumps blood through?
aortic vale into the ascending aorta
the ascending aorta gives rise to?
right and left coronary arteries which deliver blood to the walls of the heart
the ascending aorta is continuous with the?
arch of the aorta, which is followed by the descending aorta (which consists of the thoracic aorta and the abdominal aorta)
branches of the aorta deliver blood throughout?
the systemic circulation
how is blood supply during a fetal life, and shortly after birth what happens to this system?
the temporary ductus arteriosus shunts blood from the pulmonary trunk into the aorta, shortly after birth, this blood vessel normally closes, leaving a remnant called ligamentum arteriosum
describe the myocardial thickness
- the walls of the atria are relatively thin, whereas the walls of the ventricles are relatively thick
- the wall of the left ventricle is much thicker than that of the right ventricle
the heart wall contains dense connective tissue that forms the fibrous skeleton of the heart, which consists primarily of 4 fibrous rings (that surrounds the heart valves, they are?
- right atrioventricular fibrous ring
- left atrioventricular fibrous ring
- pulmonary fibrous ring
- aortic fibrous ring
