the heart

how many chambers of the heart are there

four - two atria and two ventricles

what are the two circuits that the heart pumps blood into

pulmonary circuit and systemic circuit

arteries

transport blood away from the heart

veins

transport blood towards the heart

capillaries

vessels that interconnect arteries and veins

pericardium

membrane that encloses heart

what are the two parts of the pericardium

fibrous and serous

what are the layers of the serous pericardium

visceral and parietal

visceral layer of serous pericardium

innermost layer, attached to the surface of the heart

parietal layer of the serous pericardium

adjacent to the fibrous pericardium

pericardial cavity

space between the two serous layers

where is pericardial fluid

pericardial cavity

how many layers is the wall of the heart

three

what are the layers of the walls of the heart

epicardium, myocardium, and endocardium

epicardium

external surface, consists of visceral pericardium

myocardium

consists of cardiac tissues, including cardiac muscle cells, connective tissue, blood vessels, and nerves

endocardium

internal, endothelial surface

are cardiac muscle cells voluntary or involuntary

involuntary (no information from CNS)

intercalated discs

specialized cell-to-cell junctions, where membranes of two adjacent cardiac cells are bound together by desmosomes

what specifically do intercalated discs bind ?

myofibrils of adjacent cells

gap junctions

connect cardiac muscle cells

how do ions move between cardiac cells

ions move directly from one cell to another creating a direct electrical connection

functional syncytium

when cardiac cells contract as one unit

what allows functional syncytium

ions moving directly from one cell to another

what is each cardiac cell wrapped in

elastic sheath

what is each cardiac muscle layer wrapped in

fibrous sheet

what does the fibrous sheets separate

superficial layer from the deep layer of muscles

what do fibrous sheets encircle

base of pulmonary trunk, ascending aorta, and valves

functions of cardiac skeleton

stabilizes position of cardiac cells and heart, provide support for blood vessels and nerves, distribute forces of contraction, provide elasticity, and present overexpansion of heart

base of heart

superior border of the heart

apex of heart

inferior portion of heart

right border of heart

formed by only the right atrium

inferior border of heart

formed by right ventricle

anterior surface of heart

right atrium, right ventricle, and left ventricle

posterior surface of heart

left atrium and a small portion of right atrium

diaphragmatic surface of heart

composed of the right and left ventricles

interatrial groove of heart

separates the left and right atria

coronary sulcus of heart

separates the atria and the ventricles

anterior interventricular sulcus of heart

separates the left and right ventricles

posterior interventricular sulcus of heart

separates the left and right ventricles

where are the left and right atria positioned

superior to the coronary sulcus

what parts of the heart has thin walls

the two atria

what parts of the heart have expandable portions called auricles

the two atria

position of the left and right ventricles

inferior to the coronary sulcus

what part of the heart has thick walls

the two ventricles

which ventricle has the thickest wall

left ventricular wall

what separates left and right atria

interatrial septum

what separates the left and right ventricles

interventricular septum

what forms the atrioventricular valves

folds of the endocardium

what blood is involved in the right atrium

oxygen poor blood

what supplies blood to right atrium

superior vena cava, inferior vena calva, and coronary sinus

pectinate muscles

anterior wall and auricle of right atrium

fossa ovalis

located on interatrial septum of right atrium, and is a remnant of the foramen ovale (allows blood to by pass the lungs as a fetus)

what type of blood is involved with the right ventricle

oxygen poor blood

what supplies blood to the right ventricle

right atrium

how does blood move from the right atrium to right ventricle

passes through the right atrioventricular (av) valve, sometimes called tricuspid valve

how does blood leave the right ventricle

via the pulmonary valve (also called pulmonary semilunar valve)

where does the pulmonary valve lead

pulmonary trunk, then to the right and left pulmonary arteries

how is the right atrioventricular valve connected to papillary muscles

chordae tendinea

how many cusps and papillary muscles are in the right ventricle

three of each

what do papillary and chordae tendineae prevent

valve inversion when the ventricles contract

what does the internal surface of the right ventricle consist of

trabeculae carneae and moderator band

trabeculae carneae

muscular ridges

where is moderator band found

only in the right ventricle

moderator band

muscular band that extends from the interventricular septum to the ventricular wall and prevents the overexpansion of the right ventricle

what type of blood is involved with the left atrium

oxygenated blood

what supplies blood to the left atrium

lungs via the left and right pulmonary veins

left atrioventricular valve

blood from lungs passes through on way to left atrium (also called bicuspid or mitral valve)

what part of the heart has the thickest walls

left ventricle

what part of the heart has prominent trabeculae carneae

left ventricle

how many cusps and papillary muscles does the left av have

two of each

how does blood leave the left ventricle

via the aortic valve (also called aortic semilunar valve)

path of blood out of heart and to the body

left ventricle → aortic valve → ascending aorta → aortic arch → descending aorta

which ventricle has thick walls

right

which ventricle has thin walls

left

which ventricle has a moderator band

right

which ventricle has weaker contractions

right

which ventricle has powerful contractions

left

how much more powerful are the contractions of the left ventricle than the right

left is 6-7 times more powerful

how many valves of the heart are there

four

what are the valves of the heart

two av (tricuspid and bicuspid) and two semilunar (aortic and pulmonary)

what are the parts of auriculoventricular (av) valve

ring of connective tissue, cusps, chordae tendinea, and papillary muscles

av valve ring of connective tissue

connects to the tissue of the heart and is part of the fibrous skeleton of the heart

when do av valves open

when papillary muscles relax and there is pressure from the atria

when do av valves close

when the ventricles contract

what does the closing of av valves do

forces blood through the semilunar valves

what supplies blood to the cardiac muscle tissue

coronary arteries

right coronary artery

atrial branch, right marginal branch, and posterior interventricular branch

left coronary artery

circumflex branch, left marginal branch, and anterior interventicular branch

main coronary veins

great cardiac vein, middle cardiac vein, and coronary sinus

great cardiac vein

delivers blood to the coronary sinus

middle cardiac vein

delivers blood to the coronary sinus

coronary sinus

drains directly into the posterior aspect of the right atrium

posterior vein of the left ventricle

parallels the posterior left ventricular branch

small cardiac vein

parallels the right coronary artery

anterior cardiac veins

branches from the right ventricle cardiac cells

contraction

systole

relaxation

diastole

atrial systole

blood flows into the ventricles

ventricular systole

blood is ejected into the pulmonary trunk and the ascending aorta