Thoracic Defects

Front 1

Pleurisy

Back 1

The parietal and visceral layers of the lung become inflamed and lose lubrication, becoming adhered to each other. Produces a sharp pain that is especially noticeable with deep breathes. If inflammation is bad enough, the two layers can actually fuse together.

Front 2

Pneumothorax

Back 2

Air in the thorax. An injury to the thoracic wall aka “sucking chest wound” because more and more air is pulled in with every breath suffers try to take. Generally a supraclavicular injury in children (as their apexes extend more superiorly). Pneumothorax is a ruptured bleb tearing the visceral pleura.

Front 3

Hydrothorax

Back 3

Fluid in the thorax, pleural effusion. Often lymphatic drainage is working well and lymph builds up.

Front 4

Hemothorax

Back 4

Blood in the thorax

Front 5

Pulmonary Thromboembolism

Back 5

A blood clot forms in a large vein (usually the leg) and passes through wider and wider veins back to the heart. The clot then goes to the lungs and lodges, causing lack of perfusion. Depending on location and size, it can block a major branch and causes the lung to lose a significant portion of function

Front 6

Asthma

Back 6

Type of COPD. It is harder to exhale than inhale and as a result, accessory respiration muscles hypertrophy. Is intermittent and is an allergic reaction that causes the smooth muscle around the bronchioles to constrict

Front 7

Emphysema

Back 7

Type of COPD. It is harder to exhale than inhale and as a result, accessory respiration muscles hypertrophy. Is uniform and is characterized by greatly oversized alveoli that have lost their elasticity, giving patients a “barrel-chested” appearance.

Front 8

thymus

Back 8

a lymphoid organ that produces T lymphocytes and involutes after puberty. It is indistinct in most adults, appearing as a fatty mass. However multiple sclerosis suffers see a reformation of lymphocyte production.

Front 9

aortic arch

Back 9

often a site for aneurysm. Sometimes syphilis weakens the vasculature. The aortic arch receives a lot of pressure from the left ventricle since it pumps blood systemically and the force of contraction is strongàresulting in aneurysm sometimes

Front 10

Coarctation of the aorta

Back 10

generally occurs near the ligamentum arteriosum (a remnant of the ductus arteriosus).

Front 11

thyroid ima artery

Back 11

concern during tracheostomy in about 10% of people.

Front 12

A tumor pressing on the left recurrent laryngeal nerve

Back 12

can cause hoarseness of voice and periods of palpitations and rapid heartbeat.

Front 13

Referred pain

Back 13

The heart has pain nerve endings deep within the myocardium which are associated with spinal cord segments T1àT4. These nerve endings are stimulated by the accumulation of metabolic products during ischemia. The patient will often feel noxious stimuli in the L upper limb, neck and jaw. The cell bodies for these structures’ afferent fibers lie in the same spinal ganglia and enter the spinal cord though the same afferent fibers of the heart

Front 14

There are 4 narrowings of the esophagus

Back 14

1. Origin in the neck 2. As it passes the aortic arch 3. As it passes the L main bronchus 4. As it passes through the diaphragm at T10 vertebral level

Front 15

Chylothorax

Back 15

The thoracic duct ruptures and lymph fluid leaks out (1.5-2L per day). Can put a shunt in to put fluid back to the abdomen. Just siphoning out the lymph causes the person’s immune system to become weak

Front 16

Cleft Sternum

Back 16

A failure of the fusion of the mesoderm that forms the ventral body wall (~weeks 4-5). Leads to multiple abnormalities at birth

Front 17

Ectopia Cordis

Back 17

Heart protrudes through the thoracic wall

Front 18

Omphalocele

Back 18

Internalization of the abdominal viscera doesn’t happen (remember, the viscera protrude through the ventral body wall during weeks 6-10 but then internalize). The viscera remain outside of the body at birth. This is associated with high neonatal mortality and other severe malformations.

Front 19

Diaphragmatic Hernias

Back 19

Most common developmental defect of the diaphragm involves failure of fusion of the pleuroperitoneal membranes which leads to the protrusion of abdominal contents into the thoracic cavity. This leaves little room for appropriate lung development (pulmonary hypoplasia). Are more common on the left side.

Front 20

Pulmonary hypoplasia

Back 20

Can result in rupture of alveoli and formation of a life threatening pneumothorax at birth.

Front 21

Tracheoesophageal fistula

Back 21

Results from improper separation of the respiratory diverticulum from the primordial foregut (around week 4). A failure of the tracheoesophageal septum to fully develop or close. Usually there is an associated stenosis (narrowing) or atresia (lack of growth) of the esophagus as well. TE fistulas are usually noticed shortly after birth because small amounts of milk causes choking or vomiting. Misdirected fluid can build up in the lungs causing pneumonia

Front 22

Tracheal/Pulmonary Agenesis

Back 22

A defect in the separation of the respiratory diverticulum from the developing esophagus can result in the complete lack of formation of a respiratory tree. Is incompatible with life and has been linked to mutations in FGF-10.

Front 23

Respiratory Distress Syndrome/Hyaline Membrane Disease

Back 23

Is due to a lack of surfactant that is produced by Type II pneumocytes. Surfactant dispels alveolar surface tension and prevents alveolar collapse. Without surfactant alveoli have a glassy appearance under the microscope (hyaline cartilage looking). In RDS, the alveoli are partially collapsed and the newborn experiences difficulties breathing which can lead to asphyxia and pulmonary fibrosis. Treated with prenatal glucocorticoids and artificial surfactant.

Front 24

Dextrocardia

Back 24

The heart is on the right because the heart tube loops to the left instead of the right (weeks 3-4).

Front 25

Atrial and ventricular septal defects

Back 25

Due to abnormal endocardial cushion formation (weeks 4-5)

Front 26

Ostium secondum defect

Back 26

Leaves a large opening between the atria. Due to excessive resorption of septum primum or inadequate development of septum secundum

Front 27

Cor triloculare biventriculare

Back 27

Complete absence of atrial septum.

Front 28

Tricuspid atresia

Back 28

Either the absence or the fusion of the tricuspid valves. Obliteration of the right atrioventricular orifice

Front 29

Ventricular septal defect involving the membranous portion of the septum

Back 29

Most common congenital cardiac malformation.

Front 30

Tetralogy of Fallot

Back 30

Unequal division of conus b/c of displacement of conotruncal septum (weeks 3-4). 4 alterations; 1. Pulmonary infundibular stenosis 2. Large interventricular septal defect 3. Over-riding aorta that arises directly above the septal defect 4. Hypertrophy of the right ventricular wall

Front 31

Persistent truncus arteriosis

Back 31

Failure of fusion of the conotruncal ridges, accompanied by a defective interventricular septum. Undivided truncus receives blood from both sides of the heart.

Front 32

Transposition of the Great Vessels

Back 32

Occurs when the conotruncal septum fails to follow spiral course and instead runs straight down. The aorta originates from the right ventricle instead of the left and the pulmonary trunk originates from the left ventricle. Usually accompanied by an open ductus arteriosus

Front 33

Valvular stenosis

Back 33

The semilunar valves are fused for a variable distance, reduces the opening of the vessel (pulmonary trunk and aorta).

Front 34

Patent ductus arteriosis

Back 34

Failure of the ductus arteriosus to close completely

Front 35

Coarctation of the aorta

Back 35

The lumen distal to the L subclavian is narrowed. Can be proximal or distal to the ductus arteriosus.

Front 36

Abnormal R subclavian artery

Back 36

Arises from the aorta distal to the L subclavian artery, then crosses behind the esophagus to reach the R limb

Front 37

Double aortic arch

Back 37

The R dorsal aorta persists and the 2 arches form a vascular ring around the trachea and esophagus

Front 38

Double inferior vena cava

Back 38

Due to failure of the L sacrocardinal vein to lose its connection with the L subcardinal vein.

Front 39

Absence of the inferior vena cava

Back 39

The blood from the lower body reaches the heart via the azygos vein (and superior vena cava). Due to failure of the R subcardinal vein to connect to the liver.

Front 40

Left superior vena cava

Back 40

Blood from the right is channeled to the L via the R brachiocephalic vein. The L superior vena cava drains into the coronary sinus. Due to the persistence of the L anterior cardinal vein and obliteration of the R common cardinal vein.

Front 41

Double superior vena cava

Back 41

-Due to persistence of the L anterior cardinal vein and failure of the formation of the L brachiocephalic vein