TRACHEA AND THORACIC DUCT
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Transcript of TRACHEA AND THORACIC DUCT
TRACHEA AND THORACIC
DUCTDR GARIMA SEHGAL
TRACHEA
Organization and Functions of the Respiratory System
Upper respiratory tract (nose to larynx) and
Lower respiratory tract ( trachea onwards).
The Trachea windpipe
is a tubular passageway for air which extends as continuation of larynx
Is membrano-cartilaginous
MeasurementsLength - 12 cm External diameter 2.5 cm
Internal diameter adults – 12mm
newborn upto 3rd year- 3mm
Course –Begins – lower border of cricoid
cartilage/ C6 verterbraExtends through the mediastinum
and lies anterior to the esophagusAt 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 -T4Living and
standing -T6Newborn – T3
Relations in the neck
Relations in thorax
Anterior and lateral walls supported by 15 to 20 C-shaped tracheal cartilages.
Posterior part of tube lined by trachealis muscle
The most inferior tracheal cartilage separates the primary bronchi at their origin and forms an internal ridge called the carina.
What is the benefit of not having complete rings of tracheal cartilage between the trachea and the esophagus?
Structure
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.
Arterial supplymainly inferior thyroid arteries, bronchial arteries
Venous drainagemostly inferior thyroid veins
Lymphatic drainagepretracheal and paratracheal nodes
Nerve supplysensory, glands,trachealisparasympathetic (vagus)also sympathetic
Developmentthe respiratory systembegins as an outgrowth of the foregut just anterior to the pharynx.This outgrowth is called the respiratory diverticulum Soon after, the
tracheal bud divides into bronchial buds, which branch repeatedlyand develop with the bronchi.
As the respiratory diverticulum elongates, its distal end enlargesto form a globular tracheal bud, which gives rise to the trachea.
APPLIED ANATOMY
Tracheostomy
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.
THORACIC DUCT
Lymphatic System Consists of three parts
1. A network of lymphatic vessels (lymphatics)
2. Lymph
3. Lymph nodes
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.
Lymph vessels (lymphatics) include:◦ Lymphatic capillaries◦ Lymphatic collecting
vessels◦ Lymphatic trunks and
ductsIf 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.
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.
Thoracic ductIs 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 cmAverage width – 0.5
cm
CourseBeginning – 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 upwardsTermination - at root of neck in the angle formed by junction of left subclavian and internal jugular vein
Relations
At aortic openingAt posterior
mediastinumIn superior
medistinumAt root of neck
Tributaries
Descending lymph trunks
Ascending lymph trunks
Left jugular lymph trunk
Left subclavian lymph trunk
Vessels draining upper six intercostal spaces
Drainage territoryDrains 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
APPLIED ANATOMY
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
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.