[4] Trachea

the trachea is a … tube forming the beginning of the …

• cartilaginous and membranous tube

• lower respiratory tract

it is kept patent by the …, and the posterior membranous part permits …

• anterior C-shaped cartilaginous rings

• expansion of the oesophagus during the passage of bolus of food

length of the trachea

4-6 inches in length

situation of the trachea

upper half lies in the neck and the lower half in the superior mediastinum

the … is smaller in the living than in the cadaver

lumen

it begins at the …

lower border of cricoid cartilage (C6), as the continuation of larynx

it ends at the …

• lower border of the T4 (sternal angle) by dividing into two principal bronchi

in the living subjects, in erect posture, the trachea bifurcates at the …

• lower border of T6

in its course it mostly lies in the … except at the … end where it …

• median plane

• lower

• deviates slightly to the right

development of the trachea

laryngo-tracheal diverticulum

structure of trachea:

1. made up of what type of wall

2. supported by what type of cartilaginous skeleton

3. number of rings

4. name of the last tracheal ring

5. the gap of the C shaped ring is closed by … membrane and … muscle

6. mucous membrane is lined by …

7. the submucosa is rich in …

1. fibro elastic wall

2. c-shaped cartilaginous skeleton

3. 16-20

4. carina

5. fibroelastic membrane and trachealis muscle

6. ciliated columnar epithelium

7. mucous and serous glands

blood supply of the trachea

cervical part of the trachea is supplied by branches coming from inferior thyroid artery

venous supply of the trachea

drain into left brachiocephalic vein

lymphatics of the trachea

drain left into pretracheal and paratracheal lymph nodes

parasympathetic nerve supply of the trachea

recurrent laryngeal through vagus, which is motor to trachealis and secretomotor to mucous membrane

sympathetic nerve supply of the trachea

middle cervical sympathetic ganglion, which reach through inferior thyroid arteries, and are vasomotor

clinical correlation: clinically trachea is palpated in the …, normally it is … in position

• suprasternal notch

• median

clinical correlation:

• trachea may be compressed by pathological enlargements of the …, …, … and …

• this causes …, … and often …

• thyroid, thymus, lymph nodes and aortic arch

• dyspnea, irritative cough and often husky voice

clinical correlation:

• an reversible emergency operation done in cases of laryngeal obstruction

• commonly done in … after cutting the isthmus of the thyroid gland

• tracheostomy

• retrothyroid region