heart Flashcards
the heart is a —, muscular organ about the size of a —, located between the —
hollow; fist; lungs
what is the apex of the heart and toward what direction is it pointed?
the tip and its pointed towards the left hip
fibrous pericardium
provides protection and anchors heart in place
serous pericardium
-made of parietal and visceral
-provides lubricating fluid, which collects in the paracardial cavity, to reduce friction of heart against other tissues
pulmonary circuit
carries blood from heart to lungs & back, picks up O2 & releases CO2
systemic circuit
carries blood from heart to body tissues and back, drops off O2, picks up CO2
major blood vessels attached to the heart in the pulmonary circuit
-pulmonary trunk (branches into L and R pulmonary arteries)
-pulmonary veins
major blood vessels attached to the heart in the systemic circuit
-venae cavea: superior and inferior
-aorta
four chambers of the heart
-two atria (right and left atrium) on top to receive blood
-two ventricles (right and left ventricle) on bottom to pump blood back out
which two chambers contain oxygenated blood
left side of the heart
which two chamber contain deoxygenated blood
right side of the heart
what structure separates the two sides of the heart
septum
superior venae cavea
returns blood to the heart from the upper body
right atrium
receives deoxygenated blood from the body tissues, covered by auricle
coronary blood vessels
provide O2 to heart itself, veins-blue, arteries-red
pulmonary veins
brings oxygenated blood from lungs
right ventricle
receives deoxygenated blood from right atrium
inferior venae cavea
returns blood to heart from lower body
aorta
takes oxygenated blood to body tissues
pulmonary arteries
carries deoxygenated blood to lungs to pick up more O2
left atrium
receives oxygenated blood from lungs, covered by auricle
left ventricle
receives oxygenated blood from left atrium
apex
tip of heart
what structure covers the atria?
aurcle
what is the function of the valves within the heart
flaps of tissue that prevent blood from flowing backwards
two sets of valves
atrioventricular valves and semilunar valves
atrioventricular valves
-between atria and ventricles
-R: tricuspid (3 flaps of tissue)
-L: bicuspid (2 flaps of tissue)
semilunar valves
-between ventricles and major blood vessels
-R: pulmonary valve
-L: aortic valve
oxygenated blood flow
lungs–> pulmonary veins–> left atrium–> left ventricle–> aorta (to drop off O2 to the rest of the body)
deoxygenated blood flow
body tissues–> superior and inferior venae cavea–> right atrium–> right ventricle–> pulmonary arteries–> lungs (to pick up more O2 and drop off CO2)
pathway of the intrinsic conduction system
SA node–> AV node–> AV bundle–> bundle branches–> Purkinjean fibers
how does the intrinsic conduction system regulate the heart?
-sets the pace for heart contractions
-composed of special tissues able to generate their own impulse
-sinoatrial (SA) node AKA cardiac pacemaker, begins the impulse, which causes contraction of the atria.
-next…
diastole
-relaxation of heart and filling with blood
-atrial contraction (ventricles fill with blood)
-AV valves close, making the first heart sound (“lub”)
systole
-contractions of the heart
-isovolumetric contraction: ventricles are contracting with all the valves closed
-ejection phase: pressure in the ventricles builds until the semilunar valves open and blood is released into blood vessels. blood is also refilling atria during this phase
-semilunar valves close making the second heart sound (“dub”)
-isovolumetric relaxation: ventricles…..
cardiac output
-amount of blood pumped by each ventricle in 1 min
-cardiac output= heart rate x stroke volume
heart rate
-number of times the heart beats per minute
–stress: sympathetic and parasympathetic Ns can cause rate to go up or down
–hormones: epinephrine and thyroxine raise heart rate
–ions: electrolyte imbalances affect the ability for the heart to contract
–physical factors: age, body temp, overall health
stroke volume
-volume of blood pumped out by a ventricle in a heart beat
–exercise: additional blood return from muscles brings in more volume to the ventricles
–rapid blood loss: decreases blood returning to heart
