Lec 21 - Heart 1 Flashcards
Both the heart and roots of the great vessels are enclosed in a double walled sac referred to as the?
pericardium
Which 2 serous membranes is the pericardium composed of?
visceral pericardium
parietal pericardium
what is the difference between visceral pericardium and parietal pericardium?
visceral pericardium is the inner layer of sac attached to the heart (like skin of apple)
parietal pericardium is the other sac, it is fibrous
what is the pericardial cavity?
it holds the serous fluid
what is serous fluid?
a lubricant; thin layer of watery fluid.
the purpose is to lessen friction caused by pumping of heart.
Where is the position of the heart?
the heart is situated between the lungs, it is protected by the rib cage. Its position is NOT STATIC, it does not remain in the same position at all times.
Since the position of the heart is not static, how is its approximate position defined? describe location of each
right border - curved line between 3rd rib to junction of xyphoid process & body of sternum
left border - curved line from 2nd rib to left 5th intercostal space
lower border - line passing through junction of body and xiphoid process of sternum.
what is the atrioventricular sulcus?
it separates the atria from the ventricles
contains origins of right and left coronary arteries & circumflex artery
what are the anterior and posterior interventricular sulci?
it separates right and left ventricles
contains interventricular arteries (anterior & posterior)
the heart is composed of which 3 distinct layers?
epicardium, myocardium, endocardium
describe the epicardium aka visceral pericardium.
the epicardium is the outermost layer of heart
composed of fibrous CT
has special conduction capabilites
describe the myocardium
middle layer of heart
composed of cardiac muscle (myo = muscle)
describe the endocardium
innermost layer of heart
composed of simple squamous epithelium
valves are also covered with endocardium
what is the path of a red blood cell from the heart to the systemic circulation to supply tissues of the body with oxygen?
blood enters through either superior vena cava, or inferior vena cava, or coronary sinus –> right atrium –>
pass through tricuspid valve –> right ventricle –>
pulmonary semilunar valve to enter one of the 2 pulmonary arteries –> lungs to pick up oxygen –> return to heart through one of FOUR pulmonary veins –> left atrium to pass through bicuspid valve –> left ventricle –> aortic semilunar valves –> leave heart and enter the arch of the aorta.
where are the papillary muscles, chordae tendinae, and pulmonary trunk found? describe each
found in right ventricle (left ventricle: same, except no pulmonary trunk.)
papillary muscle - fingerlike projections from wall of the heart. prevents valve inversion
chordae tendineae - looks likes strings on a guitar
pulmonary trunk - divides into 2 pulmonary arteries [deoxygenated blood to lungs, arteries return from lungs via pulmonary veins carrying oxygenated blood]
