Lecture 1: Introduction Flashcards
what is contained in the thoracic cavity
ribs
sternum
T/S vertebrae
Heart
lungs
upper abdominal organs
what is contained in the mediastinum
all thoracic viscera except lungs
heart
cardiac vasculature
esophagus
trachea
thymus
thoracic duct/lymph structures
phrenic nerve
cardiac neural structures
contents can shift around
location of mediastinum
between lung pleurae
basic anatomy/location of heart
size of closed fist
apex at 5th intercostal space of midclavicular line
3 tissue layers of heart
pericardium = outer layer/ “sac”
myocardium = muscular layer
endocardium = inner layer “lining”
describe the pericardium
triple walled sac that contains heart
layers:
- fibrous pericardium = outermost; anchored to diaphragm
- parietal layer = provides lubrication
- visceral layer (epicardium) = contains coronary vessels on heart surface
pericardium has 10-20mL pericardial fluid within pericardial cavity that decreases friction throughout cardiac cycle
describe the myocardium
heart muscle
various thickness in different chambers
describe the endocardium
inner lining of heart
simple squamous endothelium
valves and chordae tendinae
contains electrical components
function of right atria
receives deoxygenated blood from venae cave
function of left atria
receives oxygenated blood from pulmonary veins
thicker walls to accommodate for higher pressure of blood coming from pulmonary circulation
describe atria in general
separated by interatrial septum
contain auricles to increase available capacity as needed
pectinate muscles contribute to strength of atrial contractions
right ventricle function
receives deoxygenated blood from R atria via tricuspid valve
sends blood to lungs via pulmonary valve and arteries
left ventricle function
receives oxygenated blood from L atrium via mitral valve
sends blood to body via aortic valve and aorta
general structure of heart valves
unidirectional flow
leaflets attached to papillary muscles via chordae tendinae
function of atrioventricular valves
prevents back flow during ventricular contraction
AV valves = tricuspid and mitral (bicuspid)
function of semilunar valves
prevent back flow during ventricular relaxation
SL valves = pulmonary and aortic
when do coronary arteries receive blood
during ventricular relaxation while aortic valve is closed
branches of L coronary artery and where those branches supply blood to
L anterior descending = anterior L ventricle, anterior 2/3 IV septum, and small part of R ventricle
Circumflex = L atrium, posterolateral L ventricle, SA node (40%), and Bundle of His
branches of L anterior descending artery (widow maker)
diagonal
septal branches
endocardial
branches of cirfumflex artery
posterior L ventricular
L obtuse marginal
branches of R coronary artery
R marginal artery
R posterior descending
where does R coronary artery supply
R atrium
SA node (60%)
AV node
where does the R marginal artery supply blood
Lateral R ventricle
where does the R posterior descending artery supply blood
inferior L ventricle
posterior 1/3 IV septum
what is coronary dominance
designates the coronary artery system that is responsible for majority of the posterior L ventricular circulation
R dominant (most common) = R coronary aa gives off posterior descending aa
L dominant = circumflex gives off posterior descending aa
superior vs inferior vena cava collect venous blood from
superior = upper body and head
inferior = lower body and trunk