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Fibrous Pericardium

Tough outer CT layer, anchors the heart

Parietal Serous Pericardium

Lines fibrous pericardium, contracts fibers (outer)

Pericardial Cavity

Space between visceral and parietal. Contains serous fluid

Visceral Serous Pericardium

Outer layer of the heart wall, contracts epicardium (inner)

Heart Layers (Outer -> Inner)

Epicardium

Outer layer of the heart wall. Comprised of meseothelial cells + CT.

Function: protection

Myocardium

Thick cardiac muscle layer

Function: contraction

Endocardium

Inner endothelial lining. Comprised of Endothelium + CT

Function: Smooth blood flow

Subendocardium

Purkinje fibers; most ischemia-prone

Function: Electrical conduction

Diaphragm - openings, levels, structures

Caval Opening

Level : T8

Structures passing through: IVC, right phrenic nerve branches

Esophageal hiatus

Level : T10

Structures passing through: Esophagus, vagal trunks

Aortic hiatus

Level : T12

Structures passing through: Aorta, thoracic duct, azygos vein

Heart Chambers and Their Structures

Right Atrium

SVC

IVC

Coronary sinus

Fossa ovalis

SA node

AV node

Pectinate muscles

Crista terminalis

Right Ventricle

Tricuspid valve

Chordae tendineae

Papillary muscles

Moderator band

Trabeculae carneae

Pulmonary valve

Left Atrium

4 pulmonary veins

Left atrial appendage (AFib thrombus site)

Mitral valve orifice

Left Ventricle

Thick myocardium

Papillary muscles

Chordae tendineae

Aortic valve

Aortic sinuses (coronary origins)

Blood Flow Through the Heart (In->Through-> Out)

1. SVC / IVC / Coronary sinus

2. Right atrium

3. Tricuspid valve

4. Right ventricle

5. Pulmonary valve

6. Pulmonary trunk

7. Pulmonary arteries

8. Lungs

9. Pulmonary veins

10. Left atrium

11. Mitral valve

12. Left ventricle

13. Aortic valve

14. Aorta → Body

Air Flow - Inhale

1. Nose/mouth

2. Pharynx

3. Larynx

4. Trachea

5. Main bronchi

6. Lobar bronchi

8. Segemntal bronchi

9. Terminal bronchioles

10. Respiratory bronchioles

11. Alveolar ducts

12. Alveoli

Exhale (Air Out - Reverse Order)

1. Alveoli

2. Ducts

3. Respiratory bronchioles

4. Terminal bronchioles

5. Bronchioles

6. Segmental bronchi

7. Lobar bronchi

8. Main bronchi

9. Trachea

10. Larynx

11. Pharynx

12. Nose/mouth

Major Lymphatic Ducts

Thoracic Duct

Drains entire body except right upper quadrant

Empties at left venous angle (left ij + left subclavian)

Passes through aortic hiatus (T12)

Most clinically important duct

Right Lymphatic Duct

Drains right upper quadrant only

Right head / neck

Right thorax

Right upper limb

Empties at right venous angle

Rib Types

True ribs

Numbers: 1-7

Attachment: Directly to sternum

Clinical notes: Most mobile

False ribs

Numbers: 8-10

Attachment: Indirect via costal cartilage

Clinical notes: Form costal margin

Floating ribs

Numbers: 11-12

Attachment: No anterior attachment

Clinical notes: Rib 12 -> kidney injury

Lung Structures, Fissures, Hilum, RALS

Right Lung

3 lobes: superior, middle, inferior

2 fissures: horizontal, oblique

Hilum: pulmonary artery anterior to bronchus (RALS)

Left Lung

2 lobes: superior, inferior

1 fissure: oblique

Cardiac notch

Hilum: pulmonary artery superior to bronchus (RALS)

RALS Mnemonic

Right lung -> Artery is Anterior "RA"

Left lung -> Artery is Superior

"LS"