The document describes the anatomy and features of the trachea. It notes that the trachea is a non-collapsible cartilaginous tube that extends from the lower border of the cricoid cartilage to the lower border of T4. It divides at its lower end into the two principal bronchi. The trachea is supported by rings of hyaline cartilage and has a D-shaped cross-section. Tracheostomy is also briefly discussed as a surgical procedure to open the trachea in cases of laryngeal obstruction.

1. V.S.Rashmi Priyem
Ultra’s BEST Dental Science College

2.  Non-Collapsible
Membrano-Cartilaginous
Tube forming the Beginning
of Lower Respiratory
Passage
Rashmi Priyem Saravanan

3.  Extends
 From the Lower Border
of Cricoid Cartilage at the
Lower Border of the C6
Vertebra
 To the Lower Border of
T4Vertebra in Supine
Position
 Terminates by Dividing
into Right And Left
Principal Bronchi
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4.  4–6 inch (10–11 cm) LongTube
 The External Diameter ofTrachea is 2 cm in
Males and 1.5 cm in Females
 It is about 3 mm in Newborns and Remains so
up to the IIIYear of life
 ThereafterThe Lumen Increases by 1 mm
EachYear UpTo 12Years, AfterWhich It
Remains Fairly Constant
Rashmi Priyem Saravanan

5.  The Upper Half of
Trachea is located in the
Neck (Cervical Part)
 The Lower Half lies in
the Superior
Mediastinum of the
Thoracic Cavity
(Thoracic Part)
 The Lumen Is Smaller In
Living HumanThanThat
In Cadavers
Rashmi Priyem Saravanan

6.  TheTrachea Is
ComposedOf About 16–
20 C-shaped Rings Of
Hyaline Cartilage Lying
One AboveThe Other
 The Cartilages Are
Deficient Posteriorly
WhereThe Gap Is Filled
By ConnectiveTissue
And Involuntary Muscle
Called Trachealis
Rashmi Priyem Saravanan

7.  The Absence Of
Cartilages OnThe
Posterior Aspect
Allows Expansion Of
Esophagus During
Deglutition
 In Cross SectionThe
Trachea Appears D-
shaped Or Horseshoe-
shaped
Rashmi Priyem Saravanan

8.  About 7 cm In Length
 Extends FromThe
Lower Border Of
Cricoid CartilageTo
The Upper Border Of
Manubrium Sterni
 Extends Downwards
And Slightly
Backwards In Front Of
The Esophagus
Following Curvature Of
The Cervical Spine
 EntersTheThoracic
Cavity InThe Median
Plane With Slight
Deviation OnThe Right
Side
Rashmi Priyem Saravanan

9. (A) Skin
(B) Superficial Fascia
Containing Anterior
JugularVeinsAnd
JugularVenousArch
(C) Investing Layer Of Deep
Cervical Fascia
(D) SternothyroidAnd
Sternohyoid Muscles
(E) Isthmus OfThyroid
Gland In Front OfThe
2nd, 3rd, And 4th
Tracheal Rings,
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10. (F) InferiorThyroidVeins
And ArteriaThyroidea
Ima (Occasional)
(G) Left Brachiocephalic
Vein In Children May
Rise InThe Neck
(H)Thymus Gland (In
Children)
(I) Brachiocephalic Artery
(Sometimes) In
Children
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11. (A) Esophagus
(B) Recurrent Laryngeal
Nerve InThe
Tracheoesophageal
Groove (On Each Side)
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12. (A) Lobe OfThyroid
Gland Extending UpTo
The 5th Or 6th Tracheal
Ring
(B) Common Carotid
Artery InThe Carotid
Sheath
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13.  The Arterial Supply Of
The Cervical Part Of
Trachea Is Derived
Mainly From Branches
OfThe Inferior
Thyroid Arteries
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14.  TheVeins From
Trachea Drain IntoThe
Left Brachiocephalic
Vein
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15.  The Lymph FromTrachea Drains Into Pre-
And Paratracheal Nodes
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16.  The Parasympathetic
Fibres Are Derived
FromVagus Through
The Recurrent
Laryngeal Nerve
 They Are
Secretomotor
 SensoryToThe Mucus
Membrane
 MotorToTheTrachealis
Muscle.
Rashmi Priyem Saravanan

17.  The Sympathetic Fibres Are Derived From
Middle Cervical Sympathetic Ganglion
 TheyAreVasomotor
Rashmi Priyem Saravanan

18.  It Is A Life-saving Surgical Procedure Done In
Cases Of Laryngeal Obstruction
 Commonly Done InThe Retrothyroid Region
After DisplacingThe Isthmus OfTheThyroid
Gland Upwards Or Downwards
 After DisplacingThe IsthmusTheTrachea Is
Opened By A Vertical Incision InThe Region Of
The 3rd And 4th Or 2nd And 3rdTracheal Rings.
 This IsThen Converted Into Circular Opening
AndTracheostomyTube Is Inserted.
Rashmi Priyem Saravanan

19. Rashmi Priyem Saravanan

20. Rashmi Priyem Saravanan