What is the most common site for TB disease?
TB disease can occur in pulmonary and extrapulmonary sites. TB disease most commonly affects the lungs; this is referred to as pulmonary TB. In 2011, 67% of TB cases in the United States were exclusively pulmonary. Patients with pulmonary TB usually have a cough and an abnormal chest radiograph, and may be infectious.
Is there congenital TB?
Congenital tuberculosis is an infection that develops as a result of an encounter between an infant and its mother with tuberculosis during the intrauterine period or during the normal birth process [1].
Which is the most common site affected in lung in case of tuberculosis of lung?
TB in adults can present in a variety of ways. The lung is the predominant site of TB as infection with Mycobacterium tuberculosis (Mtb) or other members of the TB complex arises almost exclusively from inhaling droplets containing the bacilli….Table 2.
| Cause | Examples |
|---|---|
| Congenital | Sequestered lung; bronchogenic cyst |
Why TB occurs in the apex of the lung?
Moreover, ex vivo experiments conducted with macrophages demonstrated that a high oxygen pressure induced a higher bacillary growth than a low oxygen pressure 39, thus explaining why most cases of lung TB develop at the apex of the lungs, where oxygen concentrations are higher 6.
Which part of the lung is affected by tuberculosis?
When TB bacilli are inhaled, they rapidly pass through the mouth and nose and pass into the lowest and smallest parts of the airways. They move into the terminal bronchioli and alveoli of the lung.
Does TB cross the placenta?
Infants born to women with untreated TB may be of lower birth weight than those born to women without TB and, in rare circumstances, the infant may be born with TB. Although the drugs used in the initial treatment regimen for TB cross the placenta, they do not appear to have harmful effects on the fetus.
Can tuberculosis be transmitted through placenta?
tuberculosis from mother to infant through the placenta or amniotic fluid has been reported in approximately 300 patients. Infection of the placenta has been demonstrated, and tubercle bacilli have been grown from the tissues of stillborn infants and from living infants within a few days of birth.
Why does TB affect upper lobes?
Recurrent tuberculosis (reinfection and postprimary tuberculosis due to reactivation) predominantly involves the apical and posterior segments of the upper lobes and the superior segments of the lower lobes because of the relatively higher oxygen tension and delayed lymphatic drainage in these areas.
Why is TB more common in the upper lobe?
What is left lung apex?
Anatomically, the lung has an apex, three borders, and three surfaces. The apex lies above the first rib. The three borders include the anterior, posterior, and inferior borders. The anterior border of the lung corresponds to the pleural reflection, and it creates a cardiac notch in the left lung.
How tubercle is formed?
Once inhaled, the body’s immune system typically reacts by engulfing the bacteria, forming a tubercle that contains the bacteria to help keep it from spreading.