cardiovascular system

Question 1

What is the transthoracic plane?

Answer 1

horizontal plane at junction of manubrium to the sternum

Question 2

what is the level of the heart?

Answer 2

T2-5 thoracic level and ribs

Question 3

what is the mediastinum?

Answer 3

area between pleura/ both lungs and above the diaphragm

Question 4

what are the subdivisions of the mediastinum?

Answer 4

superior
anterior
middle
posterior

Question 5

superior mediastinum

Answer 5

above transthoracic plane - angle of louis

Question 6

anterior mediastinum

Answer 6

anterior to pericardium

Question 7

middle mediastinum

Answer 7

pericardium and its contents

Question 8

posterior mediastinum

Answer 8

posterior to pericardium

Question 9

what are the contents of the superior mediastinum?

Answer 9

arch of aorta and its 3 divisions
superior vena cava
vagus nerve - right branch runs posterior to superior vena cava
left vagus splits to create left recurrent laryngeal nerve which loops under the aortic arch
thymus

Question 10

what are the major branches of the aortic arch?

Answer 10

1. brachiocephalic artery
2. Left subclavian artery
3. Left common carotid artery

Question 11

what are the borders of the superior mediastinum?

Answer 11

thoracic inlet
manubrium
vertebral bodies of T1-4
pleura of the lungs

Question 12

What are the contents of the anterior mediastinum?

Answer 12

thymus - usually in children as shrinks with age

Question 13

What are the borders of the anterior mediastinum?

Answer 13

body of sternum
pericardium
pleura of lungs
diaphragm

Question 14

what are the contents of the middle mediastinum?

Answer 14

pericardium
heart
tracheal bifurcation - left and right main bronchi
ascending aorta
pulmonary trunks
superior vena cava
cardiac plexus
phrenic nerves - L&R

Question 15

what is the cardiac plexus?

Answer 15

collection of sympathetic (T1-4) and parasympathetic nerves (vagus) that innervate the heart

Question 16

what are the contents of the posterior mediastinum?

Answer 16

thoracic aorta - crosses diaphragm at T12
oesophagus
thoracic duct
sympathetic trunks

Question 17

what are borders of the posterior mediastinum?

Answer 17

transthoracic plane
pericardium
vertebral bodies of T5[12
pleura of lungs
diaphragm

Question 18

what are the borders of the middle mediastinum?

Answer 18

transthoracic plane
pericardium
pleura of the lungs
diaphragm

Question 19

what are the layers of arterial wall?

Answer 19

tunica intima
tunica media
tunica adventitia

Question 20

tunica intima

Answer 20

endothelial cells with a thin subendothelium of connective tissue and discontinuous elastic laminae

Question 21

tunica media

Answer 21

elastic membranes and smooth muscle cells

Question 22

tunica adventitia

Answer 22

thin layer containing lymphatics, nerves and blood supply for the artery itself

Question 23

what are the layers of the heart?

Answer 23

pericardium
epicardium - connective areolar tissue
myocardium - cardiomyocytes and connective tissue
endocardium - thin layer of connective tissue and endothelium

Question 24

what are the layers of the pericardium?

Answer 24

2 layers:
1. outer, fibrous, tough sac = fibrous pericardium
2. inner serous sac which splits into 2 more layers:
- parietal pericardium
- visceral pericardium/ epicardium
cavity contains pericardial fluid for lubrication

Question 25

what does the pericardium allow?

Answer 25

heart has room to move in the pericardium but effusion or bleeding into this space will constrict the heart as the fluid is trapped resulting in a cardiac tamponade.

Question 26

Epicardium

Answer 26

outermost layer of heart wall forms visceral layer of pericardium composed of connective tissue and fat, the connective tissue secretes the lubricating fluid into the pericardial cavity external surface is lined by simple squamous epithelial cells subpericardial layer separates the epicardium from myocardium

Question 27

myocardium

Answer 27

made of cardiac muscle

Question 28

endocardium

Answer 28

innermost layer of heart wall lines the cavities and valves similar to endothelial lining of blood vessels loose connective tissue and simple squamous epithelium subendocardial layer

Question 29

subendocardial layer

Answer 29

joins the endocardium and myocardium contains loose fibrous tissue, vessels and nerves of heart purkinje fibres are located here

Question 30

what does infective endocarditis do and what causes it?

Answer 30

affects valves causes heart murmurs caused by alpha haemolytic strep from dental work

Question 31

fibrous cartilage of the heart

Answer 31

dense collagen framework | forms 4 rings around openings of heart valves

Question 32

what does the fibrous cartilage of the heart do?

Answer 32

structural foundation of heart valves - keeps them open and prevents overstretching anchors the myocardium electrical insulator between atria and ventricles

Question 33

right atrium

Answer 33

receives blood from superior and inferior vena cava and opening of coronary sinus 75% of cardiac venous return 25% empties into atria and ventricles via transmural and endomural systems tricuspid valve into ventricle fossa ovalis in interatrial septum

Question 34

right ventricle

Answer 34

ejects blood to lungs through pulmonary valve and pulmonary trunks

Question 35

left atrium

Answer 35

receives blood from 4 pulmonary veins | mitral valve into left ventricle - bicuspid

Question 36

left ventricle

Answer 36

pumps blood to systemic circulation through aortic valve

Question 37

how is the left side of the heart different from the right?

Answer 37

3 x more muscular than right | can generate 4-6 x the pressure of right side

Question 38

right side of the heart

Answer 38

weaker/ less muscular and generates less pressure than the left side.

Question 39

valve structure

Answer 39

made of mainly collagen layers with elastin and proteoglycan allow for one way flow of blood

Question 40

how do the mitral and tricuspid valves work?

Answer 40

supported by chordae tendineae which are supported by papillary muscles which contract to put tension on chordae tendineae resisting pressure from blood trying to get back into atria

Question 41

how do the aortic and pulmonary/ semilunar valves work?

Answer 41

3 cusps open by blood from ventricles pushing them out and collapsing them close when blood in aorta/ pulmonary trunks tries to return to ventricles as it will fill the cusps first, opening them up and clasping them shut.

Question 42

what are all the coronary arteries?

Answer 42

``` right coronary left coronary right marginal left anterior descending left marginal posterior interventricular circumflex ```

Question 43

what part of the heart does the right coronary supply?

Answer 43

right atrium SAN AVN posterior part of interventricular septum

Question 44

what part of the heart does the right marginal supply?

Answer 44

right ventricle | apex

Question 45

what part of the heart does the posterior interventricular supply?

Answer 45

right and left ventricles | posterior 1/3 of interventricular septum

Question 46

what part of the heart does the left coronary supply?

Answer 46

left atrium and ventricle interventricular septum AV bundles

Question 47

what part of the heart does the left anterior descending supply?

Answer 47

right and left ventricle | anterior 2/3 of interventricular septum

Question 48

what part of the heart does the left marginal supply?

Answer 48

left ventricle

Question 49

what part of the heart does the circumflex artery supply?

Answer 49

left atrium and left ventricle

Question 50

morphology of skeletal muscle

Answer 50

long and cylindrical

Question 51

morphology of cardiac muscle

Answer 51

branched

Question 52

morphology of smooth muscle

Answer 52

spindle

Question 53

nuclei of skeletal muscle

Answer 53

many located peripherally

Question 54

nuclei of cardiac muscle

Answer 54

1 or 2 located centrally

Question 55

nuclei of smooth muscle

Answer 55

1 located centrally

Question 56

T tubules of skeletal muscle

Answer 56

yes, form triad with sarcoplasmic reticulum

Question 57

T tubules of cardiac muscle

Answer 57

yes, form dyad with sarcoplasmic reticulum

Question 58

T tubules of smooth muscle

Answer 58

no, have caveolae - lipid invaginations

Question 59

regulation of cross-bridge formation in skeletal muscle

Answer 59

troponin

Question 60

regulation of cross-bridge formation in cardiac muscle

Answer 60

troponin

Question 61

regulation of cross-bridge formation in smooth muscle

Answer 61

calmodulin activated by Ca2+ which activates myosin light chain kinase

Question 62

control of contraction of skeletal muscle

Answer 62

motor neurones

Question 63

control of contraction of cardiac muscle

Answer 63

autonomic nerves

Question 64

control of contraction of smooth muscle

Answer 64

autonomic nerves | hormones

Question 65

what pressure does the left side of the heart generate?

Answer 65

arterial pressure systemically = 120mmHg | systemic mean capillary pressure = 17mmHg

Question 66

what pressure does the right side of the heart generate?

Answer 66

systemic arterial pressure = 25mmHg | systemic mean capillary pressure = 7mmHg