THORAX (thoracic cavity/ribs, heart, lungs)

pericardium

protective layer around the heart, decreases friction

pericardioacophrenic ligament

connects pericardium to respiratory diaphragm

internal thoracic artery branches from

anterior chest wall from subclavian artery

internal thoracic artery then branches into

pericardioacophrenic artery to supply the pericardial sac

at the beginning of diastole, both valves are

closed

in early moment of diastole blood fills both atria and the

atrioventricular valve opens

during final moments of disatole

both atria contract and push blood into ventricles

very soon after systole begins

atrioventricular valves close

during systole

both ventricles contract and both aortic and pulmonary valves open

foramen ovale

connects the two atria in the fetal heart

in the fetal heart, oxygenated blood passes

from right to left atrium, then left ventricle and into systemic circulation

formaen ovale turns into

fossa ovales in adults

in the fetal heart blood can pass from the pulmonary trunk to the aorta via the

ductus arteriosus

ductus arteriosus turns into

ligamentum arteriosus in adults

atrial septal defect (like lack of foramen ovale closure - patent arteriosis) would cause

right ventricular hypertrophy and pulmonary hypertension

ventricular septal defect would cause

right ventricular hypertrophy and pulmonary hypertension

systemic hypertension would be from

left sided hypertrophy, thickening of myocardial wall causing decreased blood volume, forcing harder contraction to get blood to the body

first heart sound - lub

AV valves closing

second heart sound - dub

SL valves closing

where to hear aortic semilunar valve

right 2nd intercostal space (parasternal)

where to hear pulmonary semilunar valve

left 2nd intercostal space (parasternal)

where to hear tricuspid valve

left 5th intercostal space (parasternal)

where to hear bicuspid valve

left 5th intercostal space (midclavicular)

conduction of the heart

SA node, AV node, bundle of HIS, bundle branches, purkinje fibers

moderator band

brings conductive fibers to anterior papillary muscle to allow contraction at the same time as the rest of the heart

parasympathetic innervation of the heart

vagus nerve

vagus nerve acts on the heart to

slow HR, decrease force of contraction, and constrict coronary arteries

sympathetic innervation of the heart

levels T1-T5

sympathetic innervation of the heart by T1-T5 causes

increased HR, conduction, force of contraction, and blood flow through coronary arteries

contents of the right atrium

auricle, pectinate muscle, SA node, AV node, opening for coronary sinus, fossa ovalis in intratrial septum, superior and inferior vena cava

contents of left atrium

auricle, fossa ovalis (less distinct than r. side), pulmonary veins

contents of right ventricle

interventricular septum, tricuspid valve, trabeculae carnae, papillary muscle, moderator band, chrodae tendinae, pulmonary SL valves, pulmonary trunk and arteries

contents of the left ventricle

interventricular septum, bicuspid valve, trabeculae carnae, papillary muscle, chordae tendinae, aortic SL valve, aorta

visceral pleura

inner layer of pleura lying closer to the lung tissue

parietal pleura

lines the pulmonary cavity lying closer to body wall

pleural space

The potential space between the parietal pleura and the visceral pleura

when inhaling and exhaling, the lungs can slightly

change their position

best place for auscultation and percussion on the lungs

between scapula and vertebral column and above the diaphragm

pneumothorax

collapsed lung

pneumothorax is caused by

air in the chest cavity between the visceral and parietal pleuras

pneumothorax is often subsequent to

injury - but can be sponatneous

hemothorax

blood in the space between visceral and parietal pleuras

hemothorax is usually subsequent to

injury of a thoracic blood vessel

the lymphatic drainage pathway of the lungs makes it particularly easier for

cancer to spread between two lungs and systemically to the rest of the body

order of vessels at right lung root, superior to inferior

bronchus, artery, vein

order of vessels at left lung root, superior to inferior

artery, bronchus, vein

external intercostal function

elevate ribs during forced inspiration

internal intercostal interosseous part (main) (between bones) function

depress ribs

internal intercostal interchondral part (between cartilage - anterior) function

elevate ribs

innermost intercostal function

depress ribs - likely proprioceptive

transversus thoracis function

proprioception

the thoracic cavity is divided into

2 pulmonary cavities and the mediastinum

the heart is in the

mediastinum

the parts of the mediastinum are divided by the

transverse thoracic plane at T4

superior mediastinum contains

arch of aorta and branches, great vessels, trachea, esophagus, thoracic duct, vagus nerve, phrenic nerve (thymus in peds)

anterior mediastinum contains

connective tissue

middle mediastinum contains

heart in pericardium, phrenic nerve, lives on surface of pericardium

posterior mediastinum contains

thoracic aorta, esophagus, thoracic duct, vagus nerve, azygous veins, sympathetic trubks

thoracic duct

receives lymph from the body and empties into venous system

intercostal veins drains into

azygous veins which goes to the superior vena cava to drain back into the heart

branches from the arch of the aorta

brachiocephalic trunk, left common carotid, and left subclavian

brachiocephalic trunk branches into the

right common carotid and right subclavian

vagus nerve form the

esophageal plexus

important nerves in the superior mediastinum

phrenic nerve, vagus nerve, recurrent larygneal nerve, anterior vagal trunk

roots of the phrenic nerve

C3-C5 (3, 4, and 5 keep the diaphragm alive)

the phrenic nerve provides motor innervation to the

respiratory diaphragm

the intercostal nerve provides motor innervation to

transversus thoracis and innermost intercostal muscles

function of the vagus nerve

PSNS innervation to thoracic organs