Lect 5- Mam Gland, Thoracic Wall& Cavity

Front 1

Sternal Angle

Back 1

a.k.a. angle of louis (anterior to T4/T5)

change point between superior mediastinum and anterior mediastinum/inferior mediastinum

palpation at junction between manubrium and the body of the sternum at midline of body.

Front 2

Mediastinum

Back 2

space at the centermost portion of the thorax, between the lungs, after removing the sternum.

superior (sternal angle and above) is superior thoracic aperture

inferior (angle to diaphragm):

- anterior

- middle (heart and associated structures)

- posterior (some structures extending from the posterior mediastinum in this region)

Front 3

Pericardial sac

Back 3

cover that is surrounding the heart.

- fibrous pericardium: attach to great vessels superiorly, inferiorly rests upon the center tendon of the diaphragm. (protects heart from sudden overfilling)

- serous pericardium: parietal and visceral (epicardium), with tiny amount of fluid in between the pleural cavity.

Front 4

Pericarditis

Back 4

inflammation of the pericardium

- cause is usually viral in etiology (bact, fungi also possible)

- uremia (renal failure) most common systemic disorder asso'd with pericarditis

Symptoms:

- atypical chest pain

- high-pitch'd friction rub

- effusion caused by inflammation

- exudate asso'd with acute disease (fibrous with uremia or virus, fibrinopurulent with bacterial etiology)

Front 5

Pericardial Effusion

Back 5

the potential space becomes a real space with fluid build-up (pleural cavity)

Front 6

hemopericardium

Back 6

blood in pericardial cavity (acute) must be drained via pericardiocentesis

Front 7

cardiac tamponade

Back 7

pericardial effusion or hemopericardium compromises beating heart, decreases venous return and cardiac output.

- tachycardia, hypotension, muffled heart sounds, jugular vein distension (Kussmaul's sign), increased pulsus paradoxus.

- hypotension, muffled sounds and Kussmaul's sign are Beck's triad.

- bleeding can be associated with ruptured aortic aneurysm, myocardial infarct rupture, or penetrating injury.

Front 8

cardiomegaly

Back 8

enlarged heart

Front 9

Cardiac sinuses

Back 9

created by reflections of serous pericardium; visceral pericardium extends off surface of heart to become continuous with parietal pericardium.

- oblique pericardial sinus: inferior to pulmonary veins, posterior to heart

- transverse pericardial sinus: superior to pulmonary veins, posterior to pulmonary trunk and ascending aorta. separates arteries from veins

Front 10

three great vessels

Back 10

superior vena cava, ascending aorta, pulmonary trunk.

- roots are inside the pericardium

- heart is suspended in pericardial sac by the roots of these vessels

Top of pericardium ("root") blends in with tunica adventitia of superior vena cava, near its midpoint.

Front 11

Sulcus

Back 11

surface grooves produced by tissue folding during embryonic development.

1: coronary (atroventricular) sulcus between atria& ventricles, circles the heart like a crown.

2: interventricular sulcus between ventricles--both anterior and posterior

Front 12

coronary arteries

Back 12

1: left coronary artery--> left anterior descneding and circumflex branch

2: right coronary artery--> sinoatrial node branch, right marginal branch, and (85% of the time) posterior interventricular branch.

*the other 15% of the time, this branches from the left coronary artery.

Front 13

coronary veins

Back 13

1: great cardiac vein

2: middle cardiac vein

3: small cardiac vein

---> these all drain into coronary sinus

4: anterior cardiac veins

---> drains directly into right atrium like the coronary sinus

Front 14

coronary artery stenosis

Back 14

tightening of blood vessel

- angiogram (inject dye/saline)

-access via catheter from femoral artery. push retrograde into aorta and into coronary arteries

Front 15

Myocardial ischemia results in angina pectoris with referred pain often to the arms

Back 15

blockage of coronary artery circulation (not to be confused with infarct, which is necrosis) such as through chronic accumulation of plaque, results in...

paroxysmal (read: sudden) pain in the chest:

- pressure, discomfort, feeling of choking in the left chest or substernal region

this pain radiates to left shoulder and arm, neck, jaw and teeth, abs, back. can also radiate to right arm.

- pattern is referred pain (interpretation of visceral pain confused because of same location in spinal cord)

Front 16

Myocardial infarction

Back 16

Front 17

Coronary disease treatment

Back 17

stents usually coated with anticoagulants.

Hint 17

grafts and stents!

Front 18

anatomical position of heart

Back 18

In MRIs, patient observed from foot to head.

- R ventricle is "anterior chamber"

- L atrium is "posterior chamber"

When in severe car crash without seat belt, can crush the anterior-most part of the heart, i.e. right ventricle. This can cause heart to rupture, fill with blood (hemopericardium) and then result in cardiac tamponade.

Hint 18

Left atrium

Right atrium Left Ventricle

Right Ventricle

Hello cardiac cross!

Front 19

Right atrium components

Back 19

1. pectinate muscles (rough inner surface of anterior wall of atrium. allows for atrial contraction)

2. fossa ovalis (remnant of foramen ovale)

3. cristae terminalis (longitudinal ridge running superior to inferior on the lateral border of the atrium, separates anterior and posterior walls)

4. vessels that drain into atrium:

- superior vena cava

- inf vena cava

- coronary sinus

- anterior cardiac veins

Front 20

Right ventricle components

Back 20

1. tricuspid valve (3 cusps, connected to papillary muscles via cordae tendinae)

2. papillary muscles (prevent cusps from prolapsing back into right atrium)

3. septomarginal trabecula (moderator band)

4. trabeculae carneae (muscular ridges roughening inner surface of the wall, support wall of ventricle)

Front 21

Left atrium components

Back 21

- only chamber that doesn't sit on the diaphragm. large gap between diaphragm and atrium floor.

- rests directly on the esophagus posteriorly.

clinical: mitral valve stenosis causes left atrium enlargement. blood backs up into left atrium, which can grow larger than right side of heart. See on chest x-ray (PA view) as a double shadow.

Front 22

Left ventricle components

Back 22

- bicuspid valve (stronger than tricuspid)

- papillary muscles not as prominent

- muscular wall thicker than right ventricle for obvious reasons

clinical: if papillary muscles don't work well in either m or tc valves, cusps can prolapse--> regurgitation of blood back into atria can be heard as a murmur. similar effect if defect in cusps.

Front 23

Circulation sequence!

Back 23

vena cava--> right atrium--> right ventricle--> pulm artery--> lungs--> left atrium--> left ventricle--> aorta--> body--> repeat!

lung is only organ that gets 100% cardiac output.

deoxy'd blood enters right atrium from:

1. SVC and IVC

2. coronary sinus

3. anterior cardiac veins

blood travels to right ventricle, then through semilunar (pulm) valve into pulmonary trunk.

Oxy'd blood enters left atria through 4 pulm veins

passes through mitral into left ventricle, leaves through aortic semilunar valve into aorta.

Hint 23

Front 24

cardiac cycle

Back 24

Front 25

diastole

Back 25

ventricular relaxation and filling at the end of previous systole, atrial contraction at the end

Front 26

systole

Back 26

ventricular contraction and emptying at the end

Front 27

Heart sounds

Back 27

lub-- atrioventricular valves closing (S1)

dub--pulmonary and aortic valves closing (S2)

mitral valve closes slightly before tricuspid closes

aortic valve generally closes just before pulmonary valve closes

Hint 27

Front 28

E- conduction in heart

Back 28

1. SA node (pacemaker in wall of atrium)

2. Internodes fibers

3. AV node

4. AV bundle (his bundle)

5. right and left bundle branches

6. subendocardial branches of purkinje fibers)

clinical: Heart block (damage to AV node or AV bundle) interferes with ventricular reception of pacing impulses. Need to implant pacemaker.

Front 29

Left heart failure

Back 29

Ex: mitral valve too tight. Back up of blood behind the left ventricle. Blood will not effectively exit left atrium, will back up into pulm veins and fill the lungs.

Blood filling lungs is cardiopulmonary congestion (feature of left heart failure), and it can lead to pulmonary edema. trouble breathing, esp when laying down.

Front 30

Right heart failure

Back 30

Right ventricle too weak to pump blood effectively into lungs. Blood backs up behind right ventricle, into vena cava and into whole body.

Patients usually cyanotic (blue), bilateral jugular vein distention (increase in venous tension), enlarged liver, ascites (fluid filled ab), pitting edema in legs, ankles, feet.

ascites--pressure in veins builds up such that fluid is pushed out of vascular system, accumulates in serosal cavities

- pleural effusion

- percardial effusion

- peritoneal cavity (ascites)

Front 31

Mediastinum structures

Back 31

Front 32

Tricuspid valve

Back 32

anterior, posterior, and septal cusps to chordae tendinae to papillary muscles to septomarginal trabecula (moderator band, links to conduction system)

valve closes just before contraction of the ventricles

Front 33

Trabiculae carnae

Back 33

On RV, muscular ridges on wall, aid in contraction