Lecture 3 Flashcards
Aspects of the thoracic skeleton (Ribs)
12 pair of ribs (c shape)
1. Ribs 1-7 -join at sternum with cartilage endpoints
2. Ribs 8-10 - Join sternum with combined cartilage at 7th rib.
3. Ribs 11-12 no anterior attachment
Other aspects of the thoracic skeleton
Sternum
1. Manubrium
a) joins to clavicle and 1st rib
b) jugular notch
- Body
Superior- angle of Louis (sternal angle)
attachment of 2nd rib. - Xiphoid process
distal portion of sternum
Aspects of the Superior Medistinum
- Trachea
- Thymus
- Brachiocephalic vein
- Aortic arch
- Esophagus thoracic duct
Aspects of Middle Mediastinum
- Heart
- Ascending Aorta
- Pulmonary Trunk and veins
- Phrenic nerves (nerves of the diaphragm
Aspects of the posterior Mediastinum
- Esophagus
- Vagus nerves
- Descending aorta
- Thoracic duct
- Sympathetic trunks
Anterior Mediastinum
- Fat
- Connective tissue
- Thymus in children
Anterior thoracic landmarks
- Suprasternal notch
- Entire three parts of sternum
Posterior Thoracic Landmarks
- Vertebra Prominens - (C7)
- Spinous processes
- Scapula
Point of maximal impulse (PMI)
Left margin of heart between r and l ventricle. (Fifth intercostal space at the midclavicular line)
Compensatory mechanisms for decrease in cardiac output
- Increased heart rate
- Stroke volume
CO=SV+HR
Cor pulmonale
Right sided heart failure unrelated to the left side.
*pulmonary hypertension could be the cause.
Some Right heart failure effects
Fluid in lungs, liver swelling, JVD
How do we increase heart contraction?
Dlgoxin
Origin of the great vessels
Bifurcation of the trachea
Red - aortic valve
Green- tricuspid valve
Purple - bicuspid valve
Blue- pulmonary valve
Dextrocardium
Rare condition where the heart is flipped positions on the right side of the chest.
Usually happens in the embryonic state where the heart doesn’t rotate.
Pericardium function
- Protects and anchors the heart
- Protects overfilling
- Minimizes most friction
Pericardial effusion
Fluid filling and buildup in the pericardial space and causes the heart not to pump properly.
Causes: difficulty breathing, can’t hear heart sounds, the heart can’t expand normally so that creates conduction issues.
** common in lupus
Cardiac Tamponade
Caused by pericarditis, which compresses the heart and inhibits usual pumping and can cause a drop in BP.
TB is often a cause.
Branches of the aorta
- Brachiocephalic
- Left common carotid
- Subclavian arteries
** branches off the aorta; an aneurysm can effect all.
Arteries of the heart muscle
Anterior view-
1. R&L Coronary (atrioventricular groove)
2. Marginal
3. Circumflex
4. Anterior interventricular arteries
Posterior view-
1. Right coronary (I’m AV groove)
2. Posterior interventricular artery
Veins of the heart muscle
Anterior view-
1. Small cardiac
2. Anterior cardiac
3. Great cardiac
Posterior view-
1. Great cardiac vein
2. Posterior vein to left ventricle
3. Coronary Sinus
4. Middle cardiac vein
AV Valve function
Prevent back flow into atria when ventricles contract.
Chordae Tendinae anchor AV valves to papillary muscles and prevent valves from being inverted.
Semilunar valve function
Prevent backflow of blood into the ventricles.
(Aortic and pulmonary)
Ventricles contract, interventricular pressure rises and blood is pushed against semi lunar valves forcing them open.
As ventricles relax, interventricular pressure drops, blood flows back from arteries filling the cusps of the semilunars forcing them closed.