heart strucutre and function lab quiz

arteries

blood vessels that carry blood from the heart l

veins

blood vessels that carry blood to the heart

upper chambers of heart

atrium

lower chambers of heart

ventricles

what is the pouch like extension called on the atrium?

the auricle

what’s the purpose of the auricles?

to increase amount of blood atria can hold

where does the heart lie?

in the mediastinum

what does the inferior part of the heart lie on?

diagram by dense fibrous connective tissue

what forms the base of the heart?

right and left atria

what is the coronary sulcus?

deep groove that externally shows separation of atria and ventricles

where are coronary blood vessels and adipose tissue found?

in the coronary sulcus

what does the anterior interventricularl sulcus and posterior interventricular sulcus depict?

shallow grooves showing the boundary btwn 2 ventricles

what do the great vessels do?

return blood to atria(veins) or carry blood away from ventricles(arteries)

which 3 vessels return oxygen poor blood to the right atrium?

superior vena cava, inferior vena cava, and coronary sinus

function of superior vena cava

returns blood from head, neck, and arms

function of inferior vena cava

returns blood from body inferior to the heart

function of coronary sinus

small vein that returns blood from coronary circulation

contraction of the right ventricle pumps blood where?

to the pulmonary trunk

what does the pulmonary trunk divide into?

right and left pulmonary arteries to carry oxygen poor blood to lungs and become oxygenated

oxygen rich blood returns to left atrium through what vessels?

2 right and 2 left pulmonary veins

after blood passes into left ventricle where does it go?

to the aorta to distribute blood to systemic circulation

what is the formation of the aortas?

ascending aorta forming the arch and descends posteriorly as descending aorta

in the fetal heart what is the name of the temporary vascular chamber that connects pulmonary trunk and aorta?

ductus arteriosus

in fetal life how is oxygen obtained?

through placenta from mother not lungs

what does the ductus arteriosus turn into?

ligamentum arteriosum

what are pectinate muscles?

myocardial ridges in the anterior wall of right atrium and continues to auricles

what’s the purpose of pectinate muscles?

help atria contract and push blood into the ventricles

separation of right and left atria by thin wall is called

interatrial septum

in fetus there is a hole in the interatrial septum called what?

foramen ovale

what is the purpose of foramen ovale?

allows blood to go directly from right atrium to left atrium (bypassing the lungs)

what is the foramen ovale called post birth?

fossa ovalis (membrane forms over and closes fetal foramen)

ventricles have ridges of cardiac muscle called

trabeculae carneae

purpose of trabeculae carneae

help ventricles contract and pump blood out of heart

trabeculae carneae also forms what muscle? and for what purpose?

papillary muscles and keeps atrioventricular valves from flipping backward when ventricles contract

what is the tendon like cords attached to papillary muscles? and what is the purpose?

chordae tendineae and prevents av valves from flipping backward into atria when ventricles contract

thick wall that separates right and left ventricles

interventricular septum

the heart has 4 valves to control one way flow of blood, what are they?

2 atrioventricular valves and 2 semilunar valves

blood passing between right atrium and right ventricle goes through which valve?

tricuspid valve

blood passing between left atrium and left ventricle goes through which valve?

bicuspid valve

blood in the right ventricle goes through which valve to enter the pulmonary trunk?

pulmonary (semilunar) valve

this valve is located between the left ventricle and aorta

aortic (semilunar) valve

which valve prevents back flow of blood into the atria (when valves are closed)?

the atrioventricular valves

which valve prevents back flow of blood going into ventricles (when valves are closed)?

semilunar valves

atria receives blood returning to the heart from

veins

AV valves open causing blood in atria to flow into ventricles because

blood pressure in atria exceeds that in the ventricles (both atrial contract together to pump remaining blood to ventricles)

what happens when ventricles contract simultaneously?

papillary muscles contract and tighten the chordae tendineae

what does the chordeae tendineae prevent?

av valves from opening into the atria

what happens when blood pressure in ventricles is greater than blood pressure in aorta and pulmonary trunk?

semilunar valves open

once SL valves open, blood from right ventricle goes into the

pulmonary circulation

once SL valves open, blood from left ventricle goes into the

systemic circulation

when blood pressure in ventricles decrease what happens?

blood flows back to ventricles causing SL valves to close

what does pulmonary circulation do?

takes blood from right ventricles to lungs and back to left atrium

what does systemic circulation do?

takes blood from left ventricle to body tissues and back to the right atrium

the walls of the heart have their own blood supply and circulation called

coronary circulation

why does it require its own circulation?

lining of the heart is too thick for blood in the chambers to supply nutrients to cardiac muscle tissue

what supplies nutrients to cardiac muscle tissue?

coronary blood vessels

when are the right and left arteries supplied with blood?

when ventricles are resting (they are superior to aortic SL valve)

what happens to the coronary arteries when ventricles contract?

cusps of aortic valve open to cover the opening of the coronary arteries because it wouldn’t be able to withstand the blood pressure and burst

where does left coronary artery pass?

the base of auricles in the left atrium and into the anterior interventricular branch and the circumflex branch

what does the anterior interventricular branch do?

supplies both ventricles with oxygen rich blood in the sulcus between both ventricles

what does the circumflex branch do?

continues around left side of heart in coronary sulcus to supply oxygen rich blood left ventricle and left atrium

what does the right coronary artery do?

small branches that supplies the atrium with blood and continues inferiorly to the right and branches into marginal branch and posterior interventricular branch

what does the marginal branch do?

supplies oxygen rich blood to right ventricle

what does the posterior interventricular branch do?

lies in posterior sulcus and supplies oxygen rich blood to both ventricles

what is it called when arteries branch into smaller vessels?

arterioles

what do arterioles do?

they penetrate the heart muscle and divide into narrow vessels called capillaries

what do capillaries do?

deliver oxygen to cardiac muscle

what do capillaries drain into?

venules

what do venules do?

exit the heart muscle and connect to veins that recover oxygen poor blood and return it to right atrium

where is the great cardiac vein and what does it do?

posterior interventricular sulcus and collects deoxygenated blood from myocardium (heart muscle) to right atrium

where is the small cardiac vein and what does it do?

in the coronary sulcus and collected deoxygenated blood from heart muscle from right side of heart

where is the middle cardiac vein and what does it do?

in the posterior interventricular sulcus and collects deoxygenated blood from posterior part of heart especially ventricles

what do the coronary veins empty into?

coronary sinus (posterior)

what does the coronary sinus do?

empties the oxygen poor blood into right atrium

in the mediastinum the heart is protected and surrounded by what?

the pericardium

what is the pericardium?

tough fibrous outer layer and a delicate serous pericardium

what does the fibrous pericardium attach to?

the diagram

what is the serous pericardium and what does it contain?

double membrane composed of outer parietal layer and inner visceral layer

what is between the parietal and visceral layer?

pericardial cavity (filled with serous fluid)

what does serous fluid do?

reduces friction as the heat moves

what is the parietal layer attached to?

to the fibrous pericardium

what covers the cardiac muscle?

visceral layer of pericardium

what are the 3 layers of the heart wall?

epicardium, myocardium, and endocardium

epicardium contains

contains the visceral layer of pericardium

myocardium contains

cardiac muscle tissue

epicardium contains

deep to myocardium lining the inside chambers of heart and valves

what are cardiac muscles?

fibers in the myocardium with striations and branching cells and end of fibers are connected by intercalated discs

what are intercalated discs?

contains desmosomes that hold cardiac fibers together and have gap junctions

what are gap junctions?

enable action potentials to spread quickly from cell to cell allowing cardiac muscle contraction as a unit