5: Cardiology

Question 1

Divisions of the mediastinum

Answer 1

1. Superior mediastinum

2. Inferior mediastinum -> anterior, middle, and posterior mediastina

Question 2

What forms the superior and inferior mediastinum

Answer 2

Sternal angle

Question 3

What is in the middle mediastinum

Answer 3

Heart

Question 4

What is the start of the systemic circulation? Start of the pulmonary?

Answer 4

Systemic: LA
Pulmonary: SVC and IVC

Question 5

What typically causes MI’s

Answer 5

Lack of blood flow to a specific area of myocardium, usually due to coronary A blockage

Question 6

Coronary atherosclerosis

Answer 6

Buildup of lipids on internal walls of coronary A’s -> decreases sizes of lumens, increasing likelihood of an embolus

Question 7

Angina pectoris

Answer 7

Pain that originates in heart -> strangling pain in chest in a distinct pattern

Question 8

What usually causes angina pectoris

Answer 8

Narrow/obstructed coronary A’s -> ischemia of myocardium

Question 9

What is the ligamentum arteriosum

Answer 9

Adult remnant of the ductus arteriosus (shunts blood from pulmonary trunk to aorta)

Question 10

Where does ligamentum arteriosum span?

Answer 10

Superior pulmonary trunk -> inferior border of aortic arch

Question 11

What nerve loops around the aortic arch and ligamentum arteriosus?

Answer 11

Left recurrent laryngeal N (of the vagus)

Question 12

Common atrial septal defect

Answer 12

PFO: patent foramen ovale

Question 13

Cardiac catheterization

Answer 13

Inserting a catheter into the femoral vein -> IVC to allow radiographic visualization of the RA, RV, pulmonary trunk, and pulmonary arteries

Question 14

Ventricular septal defects

Answer 14

Particularly susceptible to defects bc of embryo logically divergent tissues; all defects are clinically relevant bc they allow mixture of O2 rich and depleted blood

Question 15

Artificial cardiac pacemaker

Answer 15

Produces regular electrical impulses to the ventricles via electrodes

Question 16

Where are electrodes inserted with artificial pacemakers?

Answer 16

Through a large vein to the SVC, into the RA -> into endocardium of trabeculae carnae of RV

Question 17

How does cardiac referred pain work?

Answer 17

Ischemia stimulates visceral pain sensory fibers that share a spinal ganglion with somatic sensory fibers in areas of the upper limb/superolateral chest wall

Question 18

Where does anginal pain typically refer?

Answer 18

Area innervated by left medial brachial cutaneous N, left sub sternal area, left pectoral area, medial left UE

Question 19

Transverse pericardial sinus in surgery

Answer 19

Space that allows surgeons to access the area posterior to the aorta and pulmonary trunk to clamp/insert tubes of a bypass into these large vessels

Question 20

Pericarditis

Answer 20

Inflammation of pericardium - > can roughen pericardium and cause friction -> pericardial friction rub that can be heard on auscultation

Question 21

What happens if pericarditis is left untreated?

Answer 21

Pericardium can calcify

Question 22

Pericardial effusion

Answer 22

Pericarditis can result in accumulation of fluid/pus in pericardial sac -> compresses heart -> cardiac tamponade

Question 23

Pericardiocentesis

Answer 23

Drainage of fluid/blood/pus from pericardial sac to relieve cardiac tamponade

Question 24

Three layers of the heart

Answer 24

1. Epicardium: outermost of visceral serous pericardium
2. Myocardium: thick muscular layer of spiraling, overlapping layers of muscle
3. Endocardium: thin internal endothelium lining chambers

Question 25

Three functions of the fibrous skeleton of the heart

Answer 25

1. Produces attachment points for: myocardium, valves
2. Supports/strengthens AV and semilunar orifices
3. Electrically insulated barrier between atria and ventricles

Question 26

What do right and left atrioventricular groove house?

Answer 26

Right: R coronary A
Left: coronary sinus

Question 27

What do anterior and posterior interventricular grooves house?

Answer 27

Anterior: anterior interventricular A, great cardiac V
Posterior: posterior interventricular A, middle cardiac V

Question 28

What does the external sulcus terminalis correspond to internally?

Answer 28

Crista terminalis

Question 29

Apex of the heart

Answer 29

Inferolateral part of LV that projects to the left

Question 30

Interatrial septum

Answer 30

Between two atria, houses fossa ovalis

Question 31

Right atrioventricular orifice

Answer 31

Passage from RA to RV with tricuspid valve

Question 32

Which atria/ventricle are thicker walled?

Answer 32

Left A/V are thicker

Question 33

Interventricular septum + what it houses

Answer 33

Separates two ventricles; AV bundle, R and L bundle branches, subendocardial branches

Question 34

Where is the sinoatrial node?

Answer 34

In myocardium, where SVC meets RA

Question 35

Where is the AV node?

Answer 35

Interarterial septum, near opening of coronary sinus

Question 36

AV bundle function

Answer 36

Crosses electrically insulated barrier provided by fibrous skeleton -> distributes impulse from AV not into L and R AV bundles

Question 37

Subendocardial branches (Purkinje fibers)

Answer 37

Distribute impulses from R and L AV bundles -> interventricular septum

Question 38

Two parts of the pericardium

Answer 38

1. Serous: parietal + visceral

2. Fibrous: tough

Question 39

Parietal vs visceral serous membrane of pericardium

Answer 39

Parietal: adheres to fibrous pericardium
Visceral: adheres to heart, making up epicardium

Question 40

Oblique and transverse pericardial sinuses

Answer 40

Oblique: posterior to base of heart
Transverse: traverses origins of great vessels