Anatomy- Thorax

Front 1

Back 1

Anterior Median (midsternal) Line- vertical line through sternum in mid-saggital plane

Midclavicular Lines (MCLs)- vertical through midpoints of the clavicles, parallel to median line

Front 2

Back 2

Anterior axillary line- vertical line along anterior axillary fold (formed by pec major)

Mid Axillary Line- vertical line through apex of axilla

Posterior axillary line- vertical line though posterior axillary fold (formed by latissimus dorsi and teres major)

Front 3

Back 3

Posterior median (mispinal or midvertebral) line- vertical line through spinous process of vertebrae in mid-saggital plane

Scapular lines- vertical lines that pass through inferior angles of the scapula, line is parallel to the posterior median line

Front 4

Thoracic Wall

Back 4

Bones of the thoracic wall- ribs, thoracic vertebrae and sternum

Function- protect thoracic content (heart, lung, blood vessels, esophagus)

Front 5

True Ribs

Back 5

1-7, attach "directly" to sternum

Front 6

False Ribs

Back 6

8-10, attach "indirectly" to sternum

Front 7

Floating Ribs

Back 7

11-12, do not attach to the sternum

Front 8

Back 8

Front 9

Back 9

Head- has two facets, Neck, Tubercle (articulates with transverse proces), shaft (thin flat, curves)

Costal angle- MC site of rib fracture, weakest point of rib

Front 10

Back 10

Cervical Rib

Front 11

Back 11

1. costal facets along vertebral bodies (2 on each side except lower 3 thoracic vertebrae)
2. costal facets along transverse processes (except lower 2-3 thoracic vertebrae

Front 12

Back 12

3 segments: manubrium, body and zyphoid process

manubrium- jugular (supersternal) notch, articulations iwth clavicle and 1st rib

Body- articulates with the manubrium, forms the sternal angle (bifurcation of trachea/carina, beginning and ending of aortic arch, palpation of sternal angle is location for 2nd rib)

Xiphoid Process- might be cartiliginous or ossified, site of subcostal (infrasternal) angle

Front 13

Back 13

Major-
costochondral joints,
sternocostal (articulation between costal cartilage and sternum),
sternoclavicular joint (contains disc- critical for shoulder girdle function)

Minor:
Interchondral joints (articulation between costal cartilage of lower ribs)
Manubriosternal joint ("sternal angle")
Xiphosternal (junction of xiphoid and sternum)
Intervertebral joints of thoracic spine

Front 14

Back 14

Major joint-

includes articulation with vertebral (and TP where appropriate)

Front 15

Movements of Thoracic Wall

Back 15

inspiration- increase in AP and transverse diameter of rib cage d/t bucket handle motion of ribs

Front 16

Back 16

Male- clinical landmark, nipple lies at 4th intercostal space (betw 4 &5)

Female-

Circular base extends from sternum to MAL (mid-axillary line), ribes 2-6

Glandular (approx 15-20 lobes drain into ducts) and adipose tissue

Axillary tail of brests- extends along inferior border of pec towards the axilla

Understanding of the anatomy is critical for optimal clinical exam of potential cancer (upper inner, lower inner, lower outer, upper outer

Lymph drainage- approx 75% drains into axillary lymph nodes then back to the axillary drainage system, lymphadema of upper extremity is potential secondary complication following surgery for breast CA

Front 17

Back 17

Superior aperture- contains esophagus, trachea, nerves & blood vessels that supply the head, neck and UE

Inferior aperture- allows the esophagus, IVC and aorta to pass inferior

Front 18

Back 18

External- inspiration, internal- expiration, innermost- ?elevate, not completely understood

Front 19

Back 19

Transversus thoracis- expiration (depresses ribs), located along internal ribs, located on internal anterior thoracic cage

Subcostal Muscles- inspiration (elevate ribs), located on internal portion of the ribs, located on internal posterior thoracic cage

Front 20

Back 20

Levator costarum- inspiration (elevate the ribs), attach to ribs and transverse processes of C7-T11, located on external posterior thoracic carriage

Serratus posteiror superior-inspiration (elevates ribs)
Serratus posterior inferior- expiration (depresses ribs)

Front 21

Back 21

Diaphragm- innervated by phrenic nerve (C3-5) provides motor and sensory components of diaphragm
major muscle of inspiration, contraction will flatten diaphragm- increasing thoracic volume (pressure changes cause increase of air into the lungs)
central tendon
regions- sternal, costal, lumbar

Right is higher than left /c of liver

Front 22

Back 22

contains 3 layers of muscles (external, internal, innermost)
Neuro bundle (intercostal vein, artery, nerve)

Nerve gives off lateral and anterior cutaneous branches

Herpes zoster/shingles is common in thoracic region (dominant virus in single segmental nerve will become active, painful, red, vesicular lesion in dermatone pattern, shingles is not limited to thoraic region - will see head/face and LE)

Front 23

Mechanics of breathing

Back 23

Inspiration- rest=diaphragm, exercise= diaphragm + external intercostals, extreme exercise= above + accessory muscles (SCM and scalens) pecs also- pts with COPD can have this type of breathing pattern

Expiration- rest= elastic recoil of lungs, exercise=recruit the internal intercostals + abdominal mm (rectus abdominis, int/ext oblique)

Front 24

Arterial Blood Supply of Thorax

Back 24

Descending Aorta- provides blood to segmental branches known as posterior intercostal arteries

Subclavain Arteries- provide blood to R/L internal thoracic arteries (descend along anterior wall of internal rib cage), anterior intercostal arteries

Front 25

Back 25

Posterior Intercostal Arteries
travel anteriorly between ribs- along with intercostals vein and intercostals nerve

Front 26

Back 26

Anterior Intercostal arteries
(originate from internal, travel between ribs and anastomose with posterior intercostal arteries)

Front 27

Back 27

Azygous vein- right posterior internal rib cage, drains into SVC

Hemiazygous and accessory hemizygous veins- located on left posterior internal rib cage, hemiazygous drains, drain segmental portions of thorax

Front 28

Thoracic Cavity and Viscera

Back 28

3 compartments- 2 pulmonary cavities (contain lungs and pleura), mediastinum (contains heart, great vessels, trachea, esophagus, thymus and lymph nodes)

Front 29

Pleurae

Back 29

each lung is invested by pleural sac

2 layers of continuous, thin, serous membranes- layers are "enfolded" on each other during embryonic development

Clinical-
pneumothorax- air enters pleural cavity, partial or complete collapse of lung
pleural effusion- abnormal accumulation of fluid from pathology within pleural cavity, potential compression of lung
Hemothorax- blood accumulates in pleural cavity, potential compression of lung
Pleuritis- inflammation of pulmonary pleura, lung sounds "friction rub"

Front 30

Back 30

Parietal Cavity- potential space between the two pleural layers, libricated by serous pleural fluid, allows layers to glide smoothly
Parietal Pleura- lines the thoracic wall and diaphragm
Visceral pleura- invests the lungs
Costodiaphragmatic recess- pleural recesses that can accumulate fluid with various conditions, lateral and posterior removed via thorencentesis (hypodermic needle inserted through intercostal space)

Front 31

Back 31

Costomediastinal recess- smaller pleural recesses located posterior to sternum

Front 32

Ventilation

Back 32

mechanical movement of air in/out of lungs, inspiration- increase in volume of thorax creates negative pressure in lungs/pleural cavity causes air to be sucked in

measure by spirometry- static lung volumes (TLC, TV, IRC), dynamic (FEV1, Ve)

Front 33

Respiration

Back 33

gas exchange that occurs in lungs (at alveolar/capillaries) and throughout the body (at target tissue/capillaries)

Pulse Ox- measures arterial oxygen saturation, ideal 96-100%

Front 34

Hilum of Lungs

Back 34

root of each lung (site where the lung becomes covered by visceral pleura), opaque on film

primary bronchus,
2 pulmonary veins (superior and inferior),
1 pulmonary artery (eventually supply pulmonary capillaries for gas exchange),
bronchial vessels (supply the lung tissue and pleura),
pulmonary nerve plexus (autonomic nerves and sensory nerves),
lymph vessels

Front 35

Back 35

3 lobes separated by oblique fissure and horizontal fissure
superior, middle and inferior lobe
right lung eventually divides into 10 bronchopulmonary segments (2- superior, 3- middle, 5- inferior)

Front 36

Back 36

Left lung- 2 lobes separated by oblique fissure, superior and inferior lobes
Lingula- similar to middle lobe of right lung, placement due to heart

Left lung eventually divides into 10 bronchopulmonary sgements (5 superior, 5 inferior)

Front 37

Bronchial Tree

Back 37

trachea- bifurcates at carina
R/L primary bronchi (enter the hilum)
divide into lobar bronchi (secondary)
further divide into segmental bronchi- supply 10 bronchopulmonary segments
continue to divide into 20-25 generations of smaller divisions of bronchioles,
eventually end as terminal bronchiole (no gas exchange)
terminal bronchioles become respiratory bronchioles which supply alveoli (gas exchange)

Front 38

Pulmonary Embolism (PE)

Back 38

obstruction of pulmonary arterial blood flow

embolus may travel from periphery (classically the veins of the legs) back to right side of the heart

right side of heart pumps it through the pulmonary trunk to pulmonary artery and gradually into smaller diameter vessels where it will eventually obstruct blood flow

obviously a large embolus could be disastrous- acute respiratory distres/failure, potential for death

Front 39

Mediastinum

Back 39

Region between pleural cavities
borders- superior (superior thoracic aperture), inferior (diaphragm), anterior (sternum and costal cartilages), posterior (thoracic vertebrae)

Front 40

Back 40

Superior Division of Mediastinum- thymus in children (remnants in adults), arch of aorta, great vessels, trachea, esophagus

Front 41

Back 41

Anterior inferior mediastinum- internal thoracic vessels, fat, few lymph nodes

Front 42

Back 42

Middle Inferior Division of mediastinum- pericardium, heart, roots of great vessels

Front 43

Back 43

Posterior inferior division- esophagus, descending (thoracic) aorta, thoracic duct, lymph nodes

Front 44

Back 44

Pericardium- double walled, fibroserous sac

Outside sac- fibrous pericardium attaches to diaphragm via pericardiacophrenic ligament, attaches to sternum via sternopericardial ligament

Inside sac- serous pericardium, similar to pleura of lungs, heart invests in on the serous pericardium forming two layers (parietal and visceral- becomes the outer layer of the heart/epicardium), pericardial cavity- potential space between parietal and visceral layers, smooth fluid allows heart to move freely within pericardial sac

Heart- epicardium (visceral serous pericardium), myocardium (smooth muscle), endocardium (thin, smooth endothelial layer that lines the heart and valves)

Front 45

Back 45

Fibrous Skeleton- four fibrous rings surounding orfices of valves

provides attachments for myocardium of atria and ventricles, provide attachment for cardiac valves, provide electrical insulation between atria and ventricles

Front 46

Back 46

Apex- formed by tipof left ventricle, located between left ribs 5 and 6, just medial to midclavicular line
clincally- might be visible in some patients (apical impulse), sometimes helpful to have pt on left side to visualize/plapate, obesity, pregnancy, excessive muscular development, abnormalities, etc, if location is lateral to midclavicular line, may suggest displacement or cardiac enlargement

Base- posterior side of heart as it sits in vivo, formed by the left atrium (technically some right atrium included)

Front 47

Right Border of Heart

Back 47

right atrium, extending between SVC and IVC

Front 48

Left border of heart

Back 48

primarily left ventricle and some left atrium

Front 49

Inferior Border

Back 49

primarily right ventricle and some left ventricle

Front 50

Superior border

Back 50

junction where great vessels enter and leave the heart

Front 51

Back 51

Sternocostal (anterior) surface- mostly right ventrical

clinical- the right ventricle can be examined along the left sternal border (3-5 intercostal spaces)

Front 52

Back 52

Diaphragmatic/Inferior Surface
mostly left ventricle and partially right ventricle

Front 53

Back 53

Pulmonary (left) surface- mostly left ventricle

Front 54

Back 54

Right Atrium
SVC/IVC openings, opening coronary sinus, fossa ovalis (closed off at birth), tricuspid valve

Front 55

Back 55

Right Ventricle- tricuspid valve, papillary muscle/chordae tendinae, pulmonary valve

Front 56

Back 56

Left Atrium- foramen ovale, 4 opening sof pulmonary veins

Front 57

Back 57

Left ventricle- bicuspid valve, papillary muscle/chordae tendonae, aortic valve

Front 58

Back 58

Great Vessels-

SVC- returns blood back to right atrium from areas superior to diaphragm (except from heart and lungs)

IVC- returns blood back to the right atrium from areas inferior the diaphragm

Pulmonary Trunk- sends oxygenated blood from right ventricle to lungs
Right/left pulmonary veins- returns oxygenated blood back to the left atrium from the lungs

Aorta- sends blood to body from left ventricle, branches of the aortic arch include - left CCA, L subclavian artery, brachiocephalic trunk (RCCA, R subclavian)

Front 59

Back 59

Tricuspid Valve (right AV)- located between right atrium and right ventricle, chordae tendinae and papillary muscles anchor cusps of valve, clinical- auscultate along left sternal border at 5th or 4th intercostal spaces

Pulmonary valve (right semilunar valve)- located between the right ventricle and pulmonary trunk, auscultate along the laft 2nd intercostal spaces

Bicuspid valve (left AV valve)- located between left atrium and left ventricle, chordae tendinae and papillary muscles anchor cusps of valve, auscultate along apex (5th intercostal space medial to midclavicular line)

Aortic valve (left semilunar)- located between left ventricle and aorta, coronary arteries plug into it, auscultate along right 2nd intercostal space

Front 60

Coronary Arteries

Back 60

arise from base of aorta- backflow from aortic pressure creates blood flow through coronary arteries

RCA- supplies right atrium and ventricle, nodal branches supply SA and AV nodes, marginal branch of RCA is portion that supplies right ventricle, posterior interventricular artery (right posterior descending)

LCA- divides into anterior interventricular artery (LAD) (supplies R/L ventricles and marjority of interventricular septum), circumflex artery (behaves like RCA, supplies atrium and ventricle) marginal branch (supplies left ventricle)

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Back 61

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Back 62

Front 63

Back 63

Front 64

Back 64

Cardiac Veins- most of the cardiac veins drain into the coronary sinus, coronary drains directly into the right atrium, great, middle, small cardiac veins and oblique vein of the left atrium all empty into coronary sinus, anterior cardiac vein and smallest cardiac veins empty directly into right atrium