A&p Ii, Lab 2 (Heart)

Front 1

function of heart

Back 1

acts as a double pump, moving blood to the lungs and throughout the body

Front 2

circulatory system

Back 2

composed of two systems: pulmonary and systemic

Front 3

pulmonary system

Back 3

low pressure, low resistance system, carrying blood from heart to lungs, where it picks up O2 and gets rid of CO2, and back to heart

Front 4

systemic system

Back 4

carries oxygenated blood from the heart to the body, and deoxygenated blood back to heart

Front 5

flow of blood through the heart:

Back 5

superior/inferior vena cava (deoxygenated blood) --> right atrium -->right ventricle via tricuspid valve/AV valve --> pulmonary trunk via pulmonary semilunar valves --> lungs via pulmonary arteries
*capillaries of lungs (CO2 diffuses out of blood and is exhaled, O2 diffuses into blood*
--> pulmonary veins (oxygenated blood) --> left atrium --> left ventricle via bicuspid (mitral)/AV valve --> aorta via aortic semilunar valve -->arteries, arterioles, capillaries (systemic circulation) where O2 diffuses into tissues and CO2 diffuses from tissues into blood (deoxygenated blood) -->venules --> veins --> superior/inferior vena cava --> right atrium

Front 6

superior/inferior vena cava

Back 6

empty deoxygenated blood into right atrium

Front 7

right atrium

Back 7

location of heart where deoxygenated blood is emptied and the start of the pulmonary system

Front 8

left atrium

Back 8

location of heart where oxygenated blood enters the heat; start of the systemic system

Front 9

tricuspid valve ( right AV valve)

Back 9

valve between the right atrium and right ventricle and ensures that blood pumps only one direction. Has three cusps; contains tendinous cords (chordae tendineae) and papillary muscles when attach on the floors of thee ventricle and prevent the AV valves form flipping inside out or bulging into the atria when the ventricles contract (ventricular systole)

Front 10

bicuspid (mitral) valve (left AV valve)

Back 10

Valve that regulates blood flow between the left atrium and the left ventricle. Contains 2 cusps. Contains tendinous cords (chordae tendinea) and papillary muscles.

Front 11

superior/inferior vena cava

Back 11

empty deoxygenated blood into right atrium

Front 12

right atrium

Back 12

location of heart where deoxygenated blood is emptied and the start of the pulmonary system

Front 13

left atrium

Back 13

location of heart where oxygenated blood enters the heat; start of the systemic system

Front 14

tricuspid valve ( right AV valve)

Back 14

valve between the right atrium and right ventricle and ensures that blood pumps only one direction. Has three cusps; contains tendinous cords (chordae tendineae) and papillary muscles when attach on the floors of thee ventricle and prevent the AV valves form flipping inside out or bulging into the atria when the ventricles contract (ventricular systole)

Front 15

bicuspid (mitral) valve (left AV valve)

Back 15

Valve that regulates blood flow between the left atrium and the left ventricle. Contains 2 cusps. Contains tendinous cords (chordae tendinea) and papillary muscles.

Front 16

aortic (semilunar) valve

Back 16

regulate flow of blood from the left ventricle into the aorta; contains three cusps; no tendinous cords

Front 17

pulmonary (semilunar) valve

Back 17

regulates flow of blood from right ventricle into the pulmonary trunk; contains three cusps; no tendinous cords

Front 18

semilunar valves

Back 18

do not contain tendinous cords or muscles - open and close when cusps are pushed open/closed by changes in blood pressure that occur as the heart chanbers contract and relax (systole/diastole)

Front 19

arterioles

Back 19

small arteries that emptie into a metarteriole or capillary

Front 20

capillaries

Back 20

narrowest type of vessel in the cardiovascular and lymphatic system; connects the smallest arteries to the smallest veins; engages in fluid exchange w/ surrounding tissues

Front 21

venules

Back 21

smallest type of vein, receiving drainage from capillaries

Front 22

thebesian veins

Back 22

smallest cardiac veins

Front 23

arteries

Back 23

efferent vessels of the cardiovascular system--carry blood away from heart

Front 24

veins

Back 24

afferent vessels--carry blood back to the heart

Front 25

base

Back 25

broader, superior portion of the heart where the great vessels attach

Front 26

apex

Back 26

inferior end of the heart-tapers to a blunt point immediately above the diaphragm (6 cm diameter)

Front 27

right and left ventricles

Back 27

two inferior chambers, make up largest part of heart; pumps that eject blood into the arteries and keep it flowing around the body. Right ventricle: most of the anterior aspect
Left ventricle: forms apex and inferoposterior aspect

Front 28

right and left atria

Back 28

two superior chambers, thin-walled receiving chambers fo blood returning to the heart via the great veins; most of the mass is on the posterior side

Front 29

auricle

Back 29

ear-like extension from the atrium to the ventricles that slightly increases the volume of the atria when filling with blood

Front 30

pulmonary artery

Back 30

located on the ventral surface of the heart; transports deoxygenated blood from the right ventricle to the lungs

Front 31

aorta

Back 31

thick-walled, and located just posterior to the pulmonary artery; transports oxygenated blood from the left ventricle through out the body

Front 32

brachicephalic trunk (artery)

Back 32

the first large vessel exiting the aorta

Front 33

superior vena cava

Back 33

brings dexoygenated blood from upper part of body to the heart (viewed from ventral side, left of aorta)

Front 34

inferior vena cava

Back 34

returns deoxygenated blood from below the heart to the heart (located at top of groove)

Front 35

myocardium

Back 35

(myo=muscle; cardium=heart) most of the tissue visible when viewing a cross section of the heart (thickest layer of heart wall); composed of cardiac muscle; lies between the endocardium and epicardium; performs the work of the heart

Front 36

endocardium

Back 36

(end=inner; cardium=heart) very thin epithelial lining of all chambers of the heart; contains no adipose tissue; covers valve surfaces and is continuous w/ the endothelium of the blood vessels

Front 37

epicardium (visceral pericardium)

Back 37

thin, serous membrane of the external heart surface; consists mainly of simple squamous epithelium overlying a thin layer of areolar tissue; some places include a thick layer of adipose tissue; largest branches of the coronary blood vessels travel through it

Front 38

interventricular septum

Back 38

muscular wall that separates the ventricles

Front 39

trabeculae carneae

Back 39

muscular ridges found within both ventricles

Front 40

chordae tendinea

Back 40

fibers attached to the cusps on the AV valves and papillary muscles

Front 41

papillary muscle

Back 41

attached to the chordae tendinea which holds the chordae and stops the cusps from everting into the atrium when the ventricle contracts

Front 42

coronary sulcus

Back 42

surface groove surrounding heart; marks junction between atria and ventricles

Front 43

coronary sulcus (atrioventricular sulcus)

Back 43

surface groove surrounding heart; marks junction between atria and ventricles; contains right and left coronary arteries, circumflex branch of left coronary artery, and coronary sinus

Front 44

pulmonary trunk

Back 44

originates from right ventricle; ascends within pericardium; initially anterior to ascending aorta and then to its left and slightly posterior; distributes deoxygentated blood to lungs and branches into the right and left pulmonary artery; contains pulmonary (similunar) valve at origin

Front 45

ascending aorta

Back 45

originates from left ventricle (aortic vestibule); ascends short distance (~5 cm) within pericardium; continues as arch of aorta and distributes blood to right and left coronary arteries; contains aortic valve (at origin)

Front 46

outer wall (of heart)

Back 46

a. Fibrous pericardium
b. Parietal pericardium (serous pericardium)

Pericardial Cavity (and fluid)

Front 47

inner wall (of heart)

Back 47

visceral pericardium (serous pericardium)--also the outer surface of the heart (epicardium)

Front 48

anterior interventricular sulcus (or groove)

Back 48

located on the anterior surface of the heart and marked by a shallow diagonal groove; occupied by the anterior interventricular artery, great cardiac vein, and adipose tissue

Front 49

posterior interventricular sulcus (or groove)

Back 49

on posterior surface of the heart; separated the ventricules; contains posterior interventricular artery, middle cardiac vein, and adipose tissue

Front 50

great cardiac vein

Back 50

drains blood from the anterior ventricles; originates at the apex of the heart and runs superiorly along the anterior interventricular sulcus (next to the anterior interventricular artery)

Front 51

coronary sinus

Back 51

one the posterior side of the heart, the coronary sinuses receive blood from the middle cardiac vein, posterior vein of the left ventricle, small cardiac veins, and great cardiac vein, which empties into the right atrium

Front 52

Thebesian veins

Back 52

The smallest cardiac veins. About 20% of deoxygenated blood flows directy into the heart cavities from them, especially in the left atrium.

Front 53

cardiocytes (cardiac myocytes)

Back 53

cardiac muscle cells that make up the myocardium portion of the heart wall--relatively short, branched fibers that measure ~10-20 mm in diameter and 50-100 mm in length; contain a single, centrally positioned nucleus; thick and thin myofilaments are present and organized into myofibrils

Front 54

striations (of cardiac myocytes)

Back 54

overlapping arrangement of myocytes creates alternating dark (A) and light (I) bands, similar to skeletal muscle

Front 55

myofibrils (of cardiac myocytes)

Back 55

surrounded by sarcoplasmic reticulum tubules; not well organized and do not have terminal cisternae; T-tubules present, but run along Z-discs (instead of the myofilament overlap zones)

Front 56

mitochondria (of cardiac myocytes)

Back 56

large and numerous; supply the ATP needed for repeated contractions of the heart

Front 57

intercalated discs (of cardiac myocytes)

Back 57

unlike other types of muscle tissues, cardiac myocytes are joined end to end by intercalated discs--these complex, highly convoluted couplings contain both anchoring junctions and electrical junctions

Front 58

anchoring junctions (of cardiac myocytes)

Back 58

formed by fascia adherens and desmosomes, which attach the adjacent myocytes

Front 59

electrical junctions (of cardiac myocytes)

Back 59

composed of connexon protein channels, which usually occur in clusters referred to as gap junctions

Front 60

connexon proteins (of cardiac myocytes)

Back 60

span the distance between adjacent plasma membranes and ions can travel through the channel pores; ion movement allows action potentials to pass directly from cell to cell, which makes the entire myocardium act like a single cell (functional synctium)

Front 61

P wave

Back 61

atria depolarize--first small bump on ECG

Front 62

AV node

Back 62

pause before blood releases into ventricles--line after P wave on ECG

Front 63

QRS wave

Back 63

ventricles depolarize and atria repolarize--sharp (most noticeable) peak on ECG

Front 64

T wave

Back 64

ventricles repolarize--final slow, rounded bump on ECG

Front 65

atrial systole

Back 65

atria contract to forcibly fill the ventricles with blood

Front 66

ventricular systole

Back 66

ventricles begin to contract after they are filled, which increases the intraventricular pressure; in response, the AV valves move upward and block blood from flowing back into the relaxing atria-->semilunar valves open

Front 67

ventricular diastole

Back 67

after ventricles contract, they enter a period of relaxation; the intraventricular pressure drops and blood in the large arteries reverses flow, which forces the semilunar valves to close, preventing blood from entering the ventricles. The drop in ventricular pressure allows the AV valves to re-open and a new cycle begins

Front 68

atrial diastole

Back 68

beginning of the cardiac cycle--relaxation of the atria allowing blood to flow in