Anatomy of the Heart

Question 1

heart

Answer 1

cone-shaped muscular pump

Question 2

where is the heart located

Answer 2

in the thorax between the lungs

Question 3

what is the heart protected by

Answer 3

the ribs and sternum

Question 4

between which ribs does the heart lie

Answer 4

ribs 2-5 to the left of the midline

Question 5

where is the apex of the heart found

Answer 5

in the 5th intercostal space in the midclavicular line

Question 6

pericardium

Answer 6

the coverings of the heart- composed of an outer fibrous layer and an inner serous pericardium

Question 7

fibrous pericardium

Answer 7

-inelastic, made of dense connective tissue
-fuses inferiorly with the diaphragm and superiorly with the great vessels.

Question 8

function of fibrous pericardium

Answer 8

prevents overfilling of the heart and anchors it in position

Question 9

serous pericardium

Answer 9

Fuses inferiorly with the diaphragm and superiorly with the great vessels

Question 10

serous pericardium: parietal layer

Answer 10

-outer layer
-lines the inner surface of the fibrous pericardium

Question 11

serous pericardium: visceral layer

Answer 11

-epicardium
-inner layer
-adheres to the surface of the heart

Question 12

coronary vessels runs through which pericardium of the heart

Answer 12

visceral layer

Question 13

serous pericardium: pericardial cavity

Answer 13

potential space between the parietal and visceral layers containing pericardial fluid
-allows smooth movement

Question 14

function of the serous pericardium

Answer 14

prevents friction

Question 15

what are the 3 layers of the heart wall

Answer 15

Endocardium: inner layer – endothelium
Myocardium: middle layer - cardiac muscle (thick layer of muscle)
Epicardium: outer layer - visceral pericardium

Question 16

trabeculae carnae

Answer 16

meaty ridges found inside the heart

Question 17

look at internal diameter of the heart diagram

Question 18

fibrous skeleton of the heart

Answer 18

bands of fibrous connective tissue between the atria and ventricles

Question 19

what does the fibrous skeleton of the heart electrically separate

Answer 19

the atria from the ventricles preventing the chambers from contracting at the same time

Question 20

what does the fibrous skeleton of the heart surround

Answer 20

the pulmonary trunk and aorta

Question 21

does the fibrous skeleton of the heart contain heart valves

Answer 21

yes

Question 22

what are heart valves

Answer 22

one way valves that prevent the backflow of blood

Question 23

what are the two different heart valves

Answer 23

atrioventricular valves (AV)
semilunar valves

Question 24

tricuspid valve

Answer 24

right AV valve (3 cusps)

Question 25

bicuspid/ mitral valve

Answer 25

left AV valve (2 cusps)

Question 26

what are the different semilunar valves

Answer 26

pulmonary aortic

Question 27

view diagram on heart valves

Question 28

where are the atrioventricular valves located

Answer 28

between the atria and ventricles

Question 29

how are the AV valves opened

Answer 29

by the blood flowing from atria to the ventricles

Question 30

what are the AV valves anchored by

Answer 30

chordae tendinae to papillary muscles (form part of the heart wall)

Question 31

what does contraction of the papillary muscles prevent

Answer 31

eversion of the valves and therefore backflow of blood into the atria

Question 32

when do AV valves open

Answer 32

when ventricular pressure is less than atrial pressure

Question 33

when do AV valves close

Answer 33

when ventricular pressure is greater than atrial pressure

Question 34

functions of the semilunar valves

Answer 34

guard the entrance of the aorta and pulmonary trunk prevents backflow of blood into the ventricles

Question 35

how do the semilunar valves open

Answer 35

by the force of blood as the ventricles contract

Question 36

what causes the semilunar valves to close

Answer 36

blood flows backwards in the aorta and pulmonary trunk during ventricular relaxation, this pools in the cusps and pushes them shut

Question 37

how much blood does the heart receive

Answer 37

250 ml/min

Question 38

during ventricular relaxation, where is the blood delivered to

Answer 38

myocardium

Question 39

what does the left coronary artery split into

Answer 39

-anterior interventricular (runs anteriorly down between the ventricles and descends at the front of the vessel) -circumflex

Question 40

what does the right coronary artery split into

Answer 40

marginal artery posterior interventricular

Question 41

which veins drain into the coronary sinus

Answer 41

the great, middle and small cardiac veins

Question 42

the coronary sinus empties into which atrium

Answer 42

right atrium

Question 43

the patency of coronary vessels are examined by?

Answer 43

angiography (x-ray used to check blood vessels and how blood flows through them)

Question 44

what is heart contraction coordinated by

Answer 44

the cardiac conducting system

Question 45

what type of cells initiate electrical impulses in heart contraction

Answer 45

non-contractile cells

Question 45

what cells are involved in the cardiac conducting system

Answer 45

-Sinoatrial (SA) node - Atrioventricular (AV) node - AV bundle (bundle of His) - Right & left bundle branches - Purkinje fibres

Question 46

what measures the activity of the heart

Answer 46

electrocardiogram

Question 47

why is foetal circulation different from usual circulation

Answer 47

* oxygen and nutrients are received from the placenta via the umbilical vein * Need to bypass non functional lungs

Question 48

foetal circulation: foramen ovale

Answer 48

connects the right to the left atria-bypassing right ventricle and pulmonary system

Question 49

foetal circulation: ductus arteriosus

Answer 49

connects the pulmonary trunk to the arch of the aorta bypassing pulmonary system and the left side of the heart -rather than going to the lungs, it goes directly to the aorta

Question 50

foetal circulation: ductus venosus

Answer 50

connects the umbilical vein to inferior vena cava bypassing the liver

Question 51

why is here limited need for the liver in fetal circulation

Answer 51

nutrients are being produced by the mother so limited need

Question 52

what valve does the foramen ovale contain

Answer 52

shutter valve

Question 53

foetal circulation: shutter valve

Answer 53

pressure in the heart forces the valve to be open -pressure in the right side of the heart is greater than the left so the blood goes directly from the right to the left atrium

Question 54

when the newborn takes the first breath, what happens after the lungs expand

Answer 54

blood rushes into the pulmonary circulation increasing oxygen levels and constricting the ductus arteriosus

Question 55

when a newborn takes their first breath and the left atrium pressure increases, what happens

Answer 55

the foramen ovale closes to become fossa ovalis -pressure in the left atrium will now be higher than pressure in the right atrium and pressure in the lungs have dropped

Question 56

when the umbilical cord is tied, what happens

Answer 56

the umbilical vessels close leading to the ductus venosus fibroses

Question 57

once a foetus changes to an adult, the ductus venosus changes to

Answer 57

the ligamentum venosum

Question 58

when the foetus becomes an adult, the foramen ovale becomes the

Answer 58

fossa ovalisw

Question 59

when the foetus becomes an adult, the ductus arteriosus becomes what

Answer 59

the ligamentum arteriosum