heart Flashcards
right side of the heart
receives oxygen poor blood from body tissues and pumps it into the lungs
left side of the heart
receives oxygenated blood and pumps it throughout the body to supply nutrients to the body tissues
pulmonary circuit
blood vessels that carry blood to and from the lungs
systemic circuit
vessels that transport blood to and from all body tissues
2 receiving chambers of the heart
right atrium (deox) and left atrium (oxygen): receive blood from the returning chambers
2 pumping chambers of the heart
right ventricle and left ventricle: pump blood around the two circuits
describe the location of the heart within the thorax
-lies posterior to sternum and costal cartilages
-rests on the superior surface of the diaphragm
-in a oblique position, apex lies to the left of midline and anterior to the rest of the heart
orientation of the heart
-heart and roots of great vessels in posterior sac
poster and on medial ends of ribs 3-5 on left side
describe the heart shape
3 sided pyramid with and apex
-base with 4 surfaces
base of the heart
-formed:
-faces:
-extends
posterior aspect of the heart
-formed: mainly left atrium, with a small contribution from right atrium
-faces: posterior, vertebral bodies T6-T9
-extends: from pulmonary trunk bifurcation to coronary sinus
describe the 4 surfaces of the heart
- anterior: sternocostal; right ventricle
- inferior: diaphragmatic: mainly left and partly right ventricle
- left pulmonary: left ventricle, forms cardiac impression of the left lung
- right pulmonary: right atrium
Heart sac coverings
- fibrous pericardium: outer layer, strong dense CT
2.parietal layer: first layer of serous pericardium. adheres to the inner surface of fibrous pericardium - visceral layer: second layer of serous; also called epicardium, outer layer of the heart, organ layer
what are the layers of the heart wall muscle
1.epicardium: superficial, visceral layer of the serous epicardium. part of visceral and heart wall.
2. myocardium: the bulk of the heart, consists of cardiac muscle. muscle bundles arranged in circular and spiral patterns
3. endocardium: deep layer; lines the heart chamber and valves. simple squamous epithelium
great vessels of the heart
- come out from the heart or bring blood into the heart
-superior vena cava: drains all the body regions superior to the diaphragm, except the heart wall
-aorta: largest artery of the body, takes oxygenated blood to body tissues
-pulmonary trunk: carries deox blood from the heart to the lungs for oxygenation
-inferior vena cava: returns deox blood to the heart from all areas of body inferior to the diaphragm
transverse sinus
space posterior to the aorta and pulmonary trunk and anterior to the SVC. can go behind and clamp vessels to stop circulation
oblique sinus
angle behind the ventricles, a wide recess posterior to heart formed by IVC, SVC, and pulmonary veins
interatrial and interventricular septa
muscle walls the separate into right and left; run longitudinally.
external divisions
coronary sulcus:
divides the atria from the ventricles; horizontal groove
external divisions
coronary sinus
vein that drains the heart wall, separation between atria and ventricles
-residesin coronary sulcus
-posterior
anterior and posterior interventricular sulci
separate the sulci, extend vertically
-anterior: deliniated by the anterior interventricular artery
right atrium
receives oxygen-poor blood from the systemic circuit
what does the right atrium recieve blood from
-IVC
-SVC
-coronary sinus
right atrium
-right auricle
small extension of the atrium that is composed of pectinate muscle, true cardiac muscle in the atria
right atrium
-pectinate muscle
rough anterior portion of muscle wall, posterior atrial wall is smooth
right atrium
-crista terminalis:
a muscular ridge separating the anterior and posterior parts of the atrium, junction separating the smooth and cardiac muscle
right atrium
-fossa ovalis
a depression in the interatrial septum, remnant of the foramen ovale
the right atrium
-tricuspid AV valve
blood flows from the right atrium to the right ventricle
right ventricle
receives blood from the right atrium and pumps it into the pulmonary circuit via the pulmonary trunk
right ventricle
-tuberculae carnae
ventricular muscle ridges; cardiac muscle
right ventricle
-papillary muscles
project from the walls into ventricular cavity. attached to tendonous fibrous cords to the AV valve, prevent it from prolapsing into the atria, help open the AV valve, composed of cardiac muscle
right ventricle
-chordae tendineae
strong bands that project superiorly from the papillary muscles and anchor the cusps of the tricuspid valves
-composed of fibrous CT
right ventricle
-pulmonary semilunar valve
at the opening between the right ventricle and pulmonary trunk. prevent blood flow coming from the pulmonary trunk back into the right ventricle
-purely mechanical; relies on gravity
left atrium
receives oxygen rich blood returning from the lungs via the four pulmonary veins
left atrium
left auricle
where pectinate muscles are found; expands the left atrium
left atrium
-bicuspid valve
blood flows from the left atrium into the left ventricle via the bicuspid AV valve (muscular and mechanical)
left ventricle
similar to the right ventricle but its walls are three times thicker and the structures are larger
left ventricle
-aortic semilunar valve
pumps blood from the left ventricle to the aorta, prevents entry of blood during downphase. (mechanical_
describe the pathway of the pulmonary circuit *
- SVC and IVC, coronary sinus
- right atrium
- tricuspid valve AV
- right ventricle
- pulmonary semilunar valve
- pulmonary trunk
- right and left pulmonary arteries
- lungs
describe the pathway of the systemic circuit *
- lungs
- pulmonary veins
- left atrium
- bicuspid AV valve
- left ventricle
- aortic semilunar valve
- aorta
- body
anatomical differences between the left and right ventricles
-right: less pressure, thinner muscle wall, 3 papillary muscles, 3 cusps in AV valve
-left: thicker, needs more pressure, 2 papillary muscles, 2 cusps to AV valve
intrinsic abilities of the heart
-generate and conduct impulses
-signal the cardiac muscle to contract rhythmically
conducting system of the heart includes
-specialized conducting cells
-sinoatrial node: pacemaker
SA node
pacemaker; sets the inherent rate of contractions in the wall of the right atrium
-from the sa node-impulses spread to the atria-signal the atria to contract-followed by a shortly delayed contraction of ventricles to contract blood
arterial supply of the heart
6 arteries on the outside; 3 on each side
arterial supply of the heart
-right coronary artery:
runs in the coronary sulcus, mainly on the right side, runs between the auricle of the atrium and ventricle
-supplies the right atrium and ventricle
arterial supply of the heart
right coronary artery divisions
- marginal artery: inferior border of the heart
- posterior interventricular artery: posterior branch
arterial supply of the heart
-left coronary artery divisions
- anterior interventricular artery: known as LAD; descends in anterior interventricular sulcus, supplies the interventricular septum and anterior walls of both ventricles
- circumflex artery: follows coronary sulcus posteriorly and supplies the left atrium and posterior part of the ventricle
venous drainage of the heart
cardiac veins
carry deox blood from the heart wall to the right atrium
venous drainage of the heart
coronary sinus
main, located posterior and drains all the heart muscle
venous drainage of the heart
-what are the three veins that drain into coronary sinus
- great cardiac vein: runs with LAD
- middle cardiac vein: runs with posterior interventricular artery
- small cardiac vein: runs along the heart inferior margin- marginal artery
where does the heart receive innervation from
cardiac plexus: posterior to bifurcation of trachea
-autonomic nerve fibers: sympathetic and parasympathetic
innervation
sympathetic supply: thoracolumbar
from
function
from: superior 5-6 thoracic segments of the spinal cord
-increases the heart rate and force of contractions, produces dilation of arteries.
innervation
parasympathetic supply: cranio-sacral outflow
from
function
from: cranial vagus nerves (CN X), only from the brain
function: slows heart rate, constricts the coronary arteries
heart sounds
aortic semilunar valve
find at 2nd intercostal space at the right of sternal border
heart sounds
pulmonary semilunar valve
2nd intercostal space to the left of the sternum
heart sounds
tricuspid valve
left sternal border at 5th or 6th intercostal space
heart sounds
mitral valve-bicuspid
near the apex of the heart in the 5th intercostal space in line with the middle of the clavicle
blood tends to carry sound in direction of
its blood flow
