1. TRACHEA AND THORACIC DUCT
DR GARIMA SEHGAL

2. TRACHEA

3. Organization and Functions of the Respiratory System
Upper respiratory tract
(nose to larynx) and
Lower respiratory tract
( trachea onwards).

4. is a tubular passageway for air which extends as continuation of larynx
Is membrano- cartilaginous
Measurements
Length - 12 cm
External diameter 2.5 cm
Internal diameter
adults – 12mm
newborn upto 3rd year- 3mm
The Trachea windpipe

5. Course –
Begins – lower border of cricoid cartilage/ C6 verterbra
Extends through the mediastinum and lies anterior to the esophagus
At the level of the sternal angle, the trachea bifurcates into two smaller tubes, called the right and left primary bronchi.
Each primary bronchus
projects laterally toward
each lung.
Level of Bifurcation
Cadaver -T4
Living and standing -T6
Newborn – T3

6. Relations in the neck

7. Relations in thorax

8. Structure
Anterior and lateral walls supported by 15 to 20 C- shaped tracheal cartilages.
Posterior part of tube lined by trachealis muscle
What is the benefit of not having complete rings of tracheal cartilage between the trachea and the esophagus?
The most inferior tracheal cartilage separates the primary bronchi at their origin and forms an internal ridge called the carina.

9. Microscopic anatomy
Layers of the tracheal wall, from deep to superficial, are (1) the mucosa, (2) the submucosa, (3) media, or middle tunic, and (4) the adventitia.

10. Arterial supply
mainly inferior thyroid arteries, bronchial arteries
Venous drainage
mostly inferior thyroid veins
Lymphatic drainage
pretracheal and paratracheal nodes
Nerve supply
sensory, glands,trachealis
parasympathetic (vagus)
also sympathetic

11. Development the respiratory system
begins as an outgrowth of the foregut just anterior to the pharynx.
This outgrowth is called the respiratory diverticulum
As the respiratory diverticulum elongates, its distal end enlarges
to form a globular tracheal bud, which gives rise to the trachea.
Soon after, the tracheal bud divides into bronchial buds, which branch repeatedly
and develop with the bronchi.

12. APPLIED ANATOMY

13. Tracheostomy

14. TOF The trachea goes to the lungs.
The esophagus and goes to the stomach.
They run side-by-side through the neck and upper chest.
During development a single tube divides to form the esophagus and the trachea.
sometimes the wall does not form properly and a tracheal esophageal fistula and/or esophageal atresia may be the result.

15. THORACIC DUCT

16. Lymphatic System Consists of three parts
A network of lymphatic vessels (lymphatics)
Lymph
Lymph nodes

17. Lymphatic vessels begin as lymphatic capillaries.
Lymphatic capillaries are found throughout the body except in avascular tissues, the central nervous system, portions of the
spleen, and red bone marrow.
Is lymph more similar to blood plasma or to interstitial fluid? Explain your answer.

18. If lymph flow blocked = tissue swelling or edema
Lymph vessels (lymphatics) include:
Lymphatic capillaries
Lymphatic collecting vessels
Lymphatic trunks and ducts
If lymph flow blocked = tissue swelling or edema
Specialized lymphatic capillaries in vili of small intestine transport lipids - they are called lacteals, and the fluid is called chyle.

19. Lymphatic vessels join to form lymphatic trunks.
Lymphatic trunks join to form lymphatic ducts.
1)Thoracic duct
2)Right lymphatic duct
These empty into subclavian veins at junction with internal jugular vein.

20. Thoracic duct
Is an elongated common lymphatic trunk which conveys chyle and most of lymph of the body to the blood stream
Beaded in appearance
Has many valves
Length – 45 cm
Average width – 0.5 cm

21. Course
Beginning – at upper end of cisterna chyli at upper border of T12
Enters thorax through aortic opening and traverses posterior mediastinum behind oesophagous
Opposite T5 inclines left, runs upwards
Termination - at root of neck in the angle formed by junction of left subclavian and internal jugular vein

22. Relations At aortic opening At posterior mediastinum
In superior medistinum
At root of neck

23. Tributaries Descending lymph trunks Ascending lymph trunks
Left jugular lymph trunk
Left subclavian lymph trunk
Vessels draining upper six intercostal spaces

24. Drainage territory Drains lymphatics from whole of the body except
-the right side of Head and neck,
-Right upper limb,
-Right lung and thoracic wall
-right half of heart
- convex surface of liver

25. APPLIED ANATOMY

26. Thoracic duct laceration
is vulnerable to damage after thoracic surgery and particularly after oesophageal surgery
The incidence is between 0.2 and 3%
Thoracic duct laceration is a potentially life- threatening complication: mortality rates are more than 50% with conservative management and as high as 10-16% even after early surgical duct ligation.
Rupture leads to leakage of chyle, which is rich in lipid, protein and lymphocytes and hence a progressive nutritional and immune deficit occurs
Chylous effusions due to damage to some of the tributaries of the thoracic duct, rather than to the duct itself are usually self-limiting and respond to conservative treatment

27. May be obstructed by mature filarial parasites producing bursting of lymph vessels.
Causes collection of chylous fluid in pleural and peritoneal sacs , chylous hydrocele etc.