Presented by

Jega Subramaniam – Student

Guided by

Dr Venugopal, Dr Manah Chandra,

Dr Gargi Sonni & Dr Ravindra

Tracheobronchial Tree and Bronchopulmonary Segments

With Summary Of Histology

Upper respiratory tract

Lower respiratory tract

Anatomy of Respiratory System

Nose, nasal cavity, and paranasalsinuses

Pharynx and larynx

Trachea

Bronchi and bronchioles

Lungs and alveoli

Intro

Organization of Respiratory System

Conducting portion

Nosenasal cavity pharynx larynx trachea primary bronchi to the terminal bronchioles

Respiratory Portion

respiratory bronchiolesalveolar ducts alveoli

Anatomical Dead Space

Intro

4

Trachea

Right and Left Principal Bronchus ( Primary Bronchus )

Lobar Bronchi(Secondary Bronchus)

Segmental Bronchi(Tertiary Bronchus)

Terminal Bronchioles(25000 in no.)

Respiratory Bronchioles

Alveolar ducts

ACINUS

Alveolar sacs

Alveoli

Passage of air from trachea

Intro

• Trachea divides into Right and Left Principle Bronchus

• Each Principle Bronchus divides into Lobar Bronchus

• Each Lobar bronchus devides into Segmental Bronchus

• Segmental Bronchus devide the Lobes of the Lungs into smaller segments = Bronchopulmanory Segment

• Trachea – Principle Bronchus – Lobar Bronchus- Segmental Bronchus

Tracheobronchial Tree

C-shaped rings of cartilage Overlaping Cartigilanous Plate Degrades

It’s a Invasion of Primary Bronchus into hilum of the lungs and their branching structure of airways supplying air to the lungs.

• Divides from trachea into Right and Left Princple Bronchus

• Enter the both lungs at the hilum of the lungs

• Right = 2-3 cm long and wider then Left, more vertical

• Left = 5 cm and narrower

• Lined by Pseudostratified Ciliated columnar epithelium (Infact it , Lines all Bronchus – From Principle until Segmental Bronchus , buts it shortens in size as they move towards periphery . Thus most of the segmental bronchus will be lined by Simple Cuboidal Ep.)

• Supported by C-shaped cartilage

• Further devides into Lobar bronchus

Principle Bronchus = Primary Bronchi

• Divides from Principle Bronchus

• Enter into Each lobe of the both Lungs

• Left Lung ; Superior Lobar Bronchus; Inferior Lobar Bronchus

• Right Lung ; Superior Lobar Bronchus; Middle Lobar Bronchus; Inferior Lobar Bronchus

Lobar Bronchus = Secondary Bronchi

Right lung = 10 Segmental Bronchus

Superior Lobar Bronchus gives off ;-– Apical

– Posterior

– Anterior

Middle lobar Bronchus gives off :-– Lateral

– Medial

Inferior Lobar Bronchus gives off : Med to Lat– Superior

– Medial

– Anterior

– Posterior

– Lateral

AUNTY PINKYAND

LINKYMARRIED

SUNDAYMORNING

ATPULAU

LANGKAWI

Segemental Bronchus = Tertiary Bronchus

Segmental Bronchus

Segmental Bronchus

Basal Segmental Bronchus

Left lung = 10 Segmental Bronchus

Superior Lobar Bronchus gives off ;-

– Apical

– Posterior

– Anterior

– Superior Lingular

– Inferior Lingular

Inferior Lobar Bronchus gives off : Mid to Lat– Superior

– Medial

– Anterior

– Posterior

– Lateral

Cranial Branch

Caudal /Lingular Branch

Segmental Bronchus

AUNTY PINKYAND

LINKYMARRIED

SUNDAYMORNING

ATPULAU

LANGKAWIBasal Segmental Bronchus

Its = middle Lobar Bronchus

of Right Lung

Tracheobronchial Tree

TRACHEA

S.L.B

COLORED = SEGMENTAL BRONCHUS

APICAL

POSTERIOR

ANTERIOR

APICAL

POSTERIOR

ANTERIOR

MEDIAL

LATERAL

SUPERIOR LINGULAR

INFERIOR

LINGULARSuperior

Medial Basal

ANTERIOR BASALPost Basal Post Basal

Lateral Basal

Lateral Basal

3 3 + 2

2 -

5 5

RIGHT Lung LEFT Lung

SUPERIOR LOBEMIDDLE LOBEINFERIOR LOBE

Tracheobronchial Tree

No of Segmental Bronchus

• Well defined portions of the lungs which is aerated by Segmental / Tertiary Bronchus

• Pyramidal in shape - Apex directed towards root of the lungs , Base towards Surface

• The name of the Segmental Bronchus corresponds to the name of the Segment Ex : Apical Segment – Apical Segmental Bronchus

• It is a individual units consisting its own ;-

1 branch of Pulmanory Artery

1 or 2 branches of Pulmonary Vein

1 Segmental bronchus

Autonomic Nerves

Lymph Vessels

Broncopulmanory Segements

Refers to - Single infected segment can be surgically removed without affecting its neighbours.

Infections - never crosses the intersegmental septa and are restricted to one bronchopulmonary segment except Tuberculosis and Cancer .

Excessive accumulation of secretions in bronchi may lead to infection

Postural drainage - Such secretions can be drain out of the lungs by placing the patient in a posture that helps the fluid to be drain from the lungs by gravity .

Clinical Importance

1. Segmental Resection (Segmentectomy).

2. Postural drainage

• Right lung

• Subdivided into three lobeswith ten segments:

Right upper lobe1. Apical 2. Posterior 3. Anterior

Right middle lobe4. Lateral 5. Medial

Right lower lobe6. Superior 7. Medial Basal8. Anterior Basal 10 Posterior Basal 9 Lateral Basal

Broncopulmanory Segements

Costal aspect Medial Surface

• Left Lung

• Subdivided Into Two Lobes With Ten Segments :

• Left Upper Lobe– 1. Apical– 2. Posterior– 3. Anterior– 4. Superior Lingular– 5. Inferior Lingular

• Left Lower Lobe– 6. Superior– 7. Medial Basal– 8. Anterior Basal – 10. Posterior Basal– 9. Lateral Basal

Broncopulmanory Segements

Costal aspect Medial Surface

Relations to pulmonary artery and vein

• Pulmonary artery gives branches to accompany the bronchi

• Each segment has its own arterial supply

•Pulmonary Vein do not accompany the bronchi or pulmonary arteries

•They run in intersegmental planes forming segmental veins

•Each segment has more then 1 vein

• Segmental bronchi several million bronchioles

• Bronchioles - < 1mm in diameter

• Cartilagenous rings replaced by cartilagenous plates as the size of bronchioles decrease.

• Size reaches to 0.6mm - completely disappear

• To make it simple , just remember bronchioles have no cartilage

• Lined by Ciliated Cuboidal Epithelium and well developed layer of smooth muscle.

• Bronchioles 50 to 80 terminal bronchioles - still in the conducting zone

• Terminal Bronchiole 2 or > respiratory bronchioles which mark the beginning of the respiratory region.

Bronchiole

• Acinus = Distal to each Terminal Bronchial - consists of three to four orders of respiratory bronchioles.

• Respiratory bronchioles 2 to 10 alveolar ducts.

• Walls of alveolar ducts consist of alveolar sacs or the mouths of alveoli.

• Lined by Non-Ciliated Simple Squmous

• Smooth muscles are found in the walls of the airways upto the level of alveolar ducts.

•Respiratory zone - Resp Bronchiole , A.Duct , A.Sac and Alveoli •Respiratory bronchioles and the alveolar ducts are responsible for 10% of the gas exchange.• The alveoli are responsible for the other 90%.

Alveolus

• Singular - alveolus , plural: alveoli Latiin - "little cavity“

• Outcrop from either alveolar sacs or alveolar ducts which are both sites of gas exchange with the blood

• Typical pair of human lungs - 700 million alveoli - 70m2 of surface area

• Each alveolus is wrapped in a fine mesh of capillaries covering about 70% of its area

• Diameter of adult alveolus –200 mictometers and during inhalation

• Type I cells (simple squamous epithelium) 95 %

• Type II cells (cuboidal epithelium) 5 %

Secrete surfactant – Prevents alveoli from collapsing by reducing the surface tension of the fluid lining the alveolar surface

Repair damaged alveolar epithelium

• Macrophages (Dust Cells ) that destroy foreign materials, such as bacteria

• Surfactant is a mixture of phospholipids(dipalmitoyl-phosphatidyl-choline) 21

Alveolus

• Contain some collagen and elastic fibres

• Elastic fibers - allow the alveoli to stretch and Spring back during and inhalation and exhalation

• Each alveolus Interconnect by way of alveolar pores ( Pores of Kohn )

Alveolus

• Histology of alveoli

• Is the barrier between alveolar air and blood

• A.K.A alveolar–capillary barrier or membrane

• Permeable to molecular O2 , CO2 , CO and many other gases.

• Only simple squamous alveolar cells and squmousendothelial cells of capilary

• Their both basement membrane are fused

Respiratory Membrane

• Prevents air bubbles from forming in the blood and blood from entering the alveoli.

• Extremely thin approximately 2μm-600 nm - to allow sufficient oxygen diffusion

• Type 4 Collagen fibers will provide strength to the barrier.

Trachea

• Fibrous connective tissue • Cartilaginous Layer – Hyaline Cartilage • Mucos Membrane

Histology

Glandular Part

Lamina Propria

Secrete Mucos

Has lining Epithelia- Psedostratified Ciliated

Columnar

•Fibrous connective tissue•Muscular Layer , which have elastic fibers in between •Cartilaganeous Layer – Hyaline Cartilage •Mucos Membrane Glandular Part

Lamina Propria-Psedostratified Ciliated Columnar

Ep.

-Ciliated Simple Columnar Ep.

-Simple Cuboidal Ep.

Towards the lower parts of the Bronchus

Upper Part of Bronchus

Bronchus

Secrete Mucos

Bronchiole

• No cartilage

• Smooth Muscle is major component

• Lined by Simple Cuboidal Ep.

• No Mucos Glands

• Occasionally Goblet Cells found

• Small no . of Neuroendocrine Cells – sometimes cluster to form neuroepithelial bodies

• Clara Cells Present

Respiratory Zone

•A.Duct•Alveoli – 2 types of lining epithelia •A.Sac

Septal Alveoli -Simple Squamous Ep

Glandular Alveoli -Simple Cuboidal Ep

• Nose

• Pharynx

• Larynx

• Trachea

• Bronchus

• Bronchiole

• Alveolar Duct

• Alveoli

Upper Part

Upper Part

Lower Part

Lower

Glandular

Septal

Lower Part

Ciliated Columnar Ep.

Pseudostratified Ciliated Columnar Ep.

Terminal

Resp

Simple Cuboidal Ep.

Simple Squmous Ep

Simple Cuboidal Ep.

Ciliated Simple Columnnar Ep.

DearLecturers

and Friends

Reference

GratitudeSincere thanks to the Lectures from Dept Of Anatomy , IMS. Each of you have helped me a lot

by explaining the concept of the topic and guiding my presentation. Thank You -

Dr Venugopal . Dr Manah Chandra . Dr Gargi Sonni . Dr Ravindra Kumar