Heart Flashcards
position of the heart
Located within the middle/central of mediastinum
Mediastinum is
an anatomical region that extends from the sternum to the vertebral column, from the first rib to diaphragm, and between the lungs
coordination of the beating heart
-pulmonary and systemic pumps work in parallel
-they are connected to each other and highly coordinated
- contract and relax together
-pump roughly the same volume of blood
the heart is located in the __________ and is protected by the _______
thoracic cavity
pericardium
features of the pericardium
fibrous pericardium: outer layer, made of dense regular connective tissue
serous pericardium: double layered pericardial fluid-filled membrane
Parietal layer: outermost layer in contact with fibrous pericardium
Visceral layer: surrounds and is continuous with surface of the heart
pericardial cavity contains
a small amount of pericardial fluid which helps lubricate the heart to facilitate contraction / relaxation
the heart is an ________ organ
multilayered
epicardium
outermost layer, made of loose areolar connective and adipose tissue (visceral pericardium)
myocardium
thickest layer, contains cardiomyocytes and cardiac skeleton (heart muscle itself)
endocardium
deepest layer, made of simple squamous endothelial tissue
superficial structure of the heart
-4 chambers
-the two superior receiving chambers are the atria (right and left), receives blood from veins
-the two inferior pumping chambers are the ventricles (right and left), eject blood from heart into arteries
right atrium
receives blood from (3 openings)
-superior vena cava
-inferior vena cava
-coronary sinus
has an auricle
pumps blood to the right ventricle
right ventricle
-receives blood from the right atrium
-pumps blood to the lungs through the pulmonary arteries (away from the heart- deoxygenated blood)
left atrium
has an auricle
receives blood from the lungs (4 openings)
- 4 pulmonary veins (oxygenated blood)
pumps blood to the left ventricle
left ventricle
receives blood from the left atrium
- pumps blood to the whole body through the aorta (oxygenated away)
-thicker wall when compared with right ventricles
major arteries of the heart -
Arch of Aorta
branches (3)
-starts after the ascending aorta
-ends as the thoracic aorta at a level between T4 and T5
branches
- brachiocephalic trunk
-left subclavian artery
-left common carotid artery
veins returning blood to the heart
superior vena cava
receives blood from veins above the diagram
veins returning blood to the heart
inferior vena cava
receives blood from veins below the diaphragm
veins returning blood to the heart
coronary sinus
receives blood from cardiac veins
blood flow through the heart and major vessels
- De-oxygenated blood enters right atrium from body through superior and inferior vena cava
- pumped through tricuspid valve to right ventricle
- blood exits heart through pulmonary arteries into pulmonary circulation
- oxygen-rich blood returns through pulmonary veins into the left atrium
- pumped through virtual valve into left ventricle
- blood exits through aorta into systemic circulation
coronary arteries
two branches
right coronary artery and left coronary artery
right coronary artery
within coronary sulcus
between right auricle and pulmonary trunk
branches:
-right marginal
-sino atrial
- posterior interventricular
left coronary artery
within coronary sulcus
between left auricle and pulmonary trunk
larger diameter then right one
anastomoses with right coronary artery via circumflex artery
branches:
1. anterior interventricular artery (LAD)
2. circumflex artery branches into left marginal artery
coronary veins
(3)
-greater cardiac veins (runs along LAD)
-middle cardiac vein (runs along posterior inter ventricular artery)
-small cardiac vein (runs along the coronary artery)
all drain in coronary sinus
right atrium: pectinate muscles
extends along the inner wall of right atrium
3 openings in right atrium
coronary sinus, superior vena cava and inferior vena cava
fossa ovalis
right ventricle
papillary muscles
chord tendinae
Chordae tendineae arise from the papillary muscles
Limit movement of the cusps when the valves close preventing backflow of blood
right ventricle
tricuspid valve
valve (separates R atrium from R ventricle)
right ventricle
conus arteriousus
cone shaped pouch – superior end of right ventricle
right ventricle
trabeculae carneae
only found in the ventricles
right ventricle
moderator band (if present)
(Septomarginal trabeculae), it carries part of the right bundle of the conduction system to the papillary muscles
left atrium features
same features like right atrium expect openings and fossa ovalis
bicuspid valve (mitral valve)
left ventricle features
-no moderator band
-2 cups (mitral valve) - bicuspid separates L atrium from the L ventricle
-thicker wall than right ones
AV valves are restrained by …
chordae tendinae (fibrous chords) which are int urn attached to papillary muscle
__________ separated pulmonary trunk from right ventricle
pulmonary seminar valve
aorta exits from left ventricle through _____________
aortic seminar valve
atrial systole begins
atrial contraction forces a small amount of additional blood into relaxed ventricles
ventricular systole-first phases
ventricular contraction pushes AV valves closed but does not create enough pressure to open seminar valves
ventricular systole- second phase
as ventricular pressure rises and exceeds pressure in the arteries, the semiulnar valves open and blood is ejected
ventricular diastole early
as ventricles relax, pressure in ventricles drops, blood flows back against cusps of semiulnar valves and forces them closed. blood flows into the relaxed aorta
ventricular diastole - late
all chambers are relaxed, ventricles fill passively
SA node - sinoatrial node
back wall of right atrium) pacemaker, spontaneously depolarizes & initiates heart beat
AV - atrioventricular node
located where the 4 chambers meet - just above tricuspid valve
* AV bundle transmits down the top of the inter-ventricular septum where it divides into two
purkinje fibers
which reflect up the external walls of the ventricles and extend into papillary muscles as well
stimulate contraction of cardiac muscle cells as a unit
