GROUP 9 MEMBERS:

ANIS FAZEERA BINTI AHMAD FUAD KHOR JUU YEEI MOHD ZULFIKAR BIN AHMAD FAUZI NOR FADZLIN SAKINA BINTI JAFFERI NUR MAHIRAH BINTI ABDUL MANAF TAY SUE CHYEN TENGKU NABILAH SURAYA

FAR 131 BASIC PHYSIOLOGY

By a rich network of capillaries.

RESPIRATORY SYSTEM

Lung Tube sys lead to the lungs

Conducting portionRespiratory portion

Respiratory bronchioles

Mucosa identical to mucosa of terminal bronchioles BUT numerous alveoli extend from wall.

No goblet cell.

Ciliated cuboidal cell & clora cell

L.propria(smooth muscle,elastic fibres)

Condition inspired air

Provide passage-airlung

Cartilage Elastic fibre

Smooth muscle

Cleansed

Moisted

warmed

Dust and gaseous impuritiestrap in:

-vibrissae(specialized hair)

-layer of mucous(mucous gland)

Mucous & serous secretion(moisten air)

Protect alveolar lining from dessication

Alveolar ducts

Simple squamous epithelium.

Alveolar sacs are disintended space

Elastic fibreenable aveoli-expand(inspiration),contract(expiration).

Reticular fibre prevent-overdistension & damage to capillaries.

Alveoli

Sac-like evagination.

O2,CO2 exchangedair&blood

Interalveolar septum(alveolar wall):

-2 thin squamous epithelium layer.

-Between layer(interstitium)

-Interstitium: capillaries,CT(elastic,reticular fibre & fibroblast)

Support wall

Prevent collapselumen

At periphery Lamina propria

flexibility

Encircles tube

From tracheaalveolar duct

Flow chart

RESPIRATORY Lungs SYSTEM System of tubes Leading to the lung

FUNCTIONS:Provide an intake of O2Eliminate CO2

RESPIRATORY SYSTEM

CONDUCTING PORTION

FUNCTIONS:

1) Provide a conduct through which air can travel to & from the lungs

• Cartilage ~ support wall, preventing collapse of lumen • Elastic fibres ~ flexibility ~

•Smooth muscle ~ contraction reduce of conducting tubules

(regulate air flow during inspiration & expiration)

2) Condition the inspired air (clean, moisten, warm)

• Vibrissae ~ remove dust particles & other

substance

•Mucous & serous secretions ~ moisten incoming air, protect alveolar lining from desiccation

•Rich network of blood capillaries ~ warm in-coming air

Line the mucosa of conducting portionCiliated pseudostratified columnar + goblet cells

5 TYPE OF CELLS:

1) Ciliated columnar cell- Most abundant- Each cells have about 300 cilia on its apical

surface- Beneath cilia are numerous mitochondria, supply

ATP for cilia beating.

2) Mucous goblet cell- Next most abundant- Apical cytoplasm contains mucin granules

RESPIRATORY EPITHELIUM

3) Brush cell- Numerous microvillus on its apical surfaces- Are columnar epithelial cell- Have nerve ending on basal surface (sensory

receptor)

4) Basal cells (short cells)- Small rounded cell- Lie on basal lamina but do not extend to luminal

surface of respiratory epithelium- Generative stem cell that undergo mitosis and

differentiate to other cell types

5) Small granule cell- Resemble basal cell except it contains numerous

granules- Granules control secretory activity of goblet cells

and other glands

RESPIRATORY EPITHELIUM

MUCOSAConsist of:Pseudostratified ciliated columnar epitheliumLamina propia-elastic & reticular fibers-Provide same protection against dust as the membrane lining the nasal cavity & larynx

SUBMUCOSAConsist of:Areolar connective tissue -Seromucous glands & their ducts

HYALINE CARTILAGE•From horizontal ring that resembles C-shaped.•Fxn: Provide semirigid support so that tracheal wall does not collapsed inward.The open end s of hyaline cartilage bridged by smooth muscle,trachealis muscle, and fibroelastic ligament

ADVENTITIAConsist of:Areolar connective tissue -Joins the trachea to sorrounding tissues.

Layers of Tracheal Wall

TRACHEA ~ extended from larynx

TRACHEA

Trachea

Primary bronchi

Bronchioles

Secondary bronchi

Terminal bronchiol

es

3 in right lung

2 in left lung

BRONCHIAL TREE

BRONCHI

MUCOSA • structurally similar to trachea• Different in organization of cartilage &

smooth muscle

CARTILAGE•More irregular in shape•Large bronchi: cartilage rings completely

encircle the lumen•Bronchial diameter ↓, cartilage rings

replaced by isolated plates/ islands of hyaline cartilage

BRONCHI

LAMINA PROPRIA•Smooth muscle layer: crisscrossing bundles of spirally arranged smooth muscle•Rich in elastic fibres•Contains mucous & serous glands

BRONCHI

MUCOSA•No cartilage/glands

LAMINA PROPRIA•Consists mainly of smooth muscles & elastic fibers

BRONCHIOLES

Diameter ≤ 5mm

EPITHELIUM•Large bronchioles - have scattered goblet cells - Ciliated pseudostratified columnar epithelium

•Smaller terminal bronchioles - Ciliated simple columnar/ ciliated simple cuboidal without goblet cell - Epithelium contain Clara cells (apical cytoplasm contains secretory granules – protect the lining of bronchioles against oxidative pollutants)

BRONCHIOLES

RESPIRATORY PORTION

•Each terminal branchiole subdivide into 2 or more respiratory branchioles.

•These branchioles serve as areas of transition between conducting and respiratory portions.

•Structure of mucosa is identical to mucosa of terminal branchiole except that numerous alveoli extend from the walls of respiratory branchiole

RESPIRATORY BRONCHIOLES

•Some parts of respiratory bronchiole are lined with ciliated cuboidal cells and Clara cells

•Goblet cells are absent

•More distal parts of these bronchioles,the cuboidal cells do not have cilia

•Respiratory bronchioles terminate by branching into several alveolar ducts.

RESPIRATORY BRONCHIOLES

• Thin-walled tubes, lined with simple squamous epithelium

• Lamina propria-smooth muscle and elastic fibres and collagen fibres

• Lead into numerous single alveoli and alveolar sacs

• Alveolar sacs are distended space

• Each space gives rise to several alveoli

ALVEOLAR DUCT

•Elastic and reticular fibres form a complex network encircling the opening of alveolar sacs and alveoli.

•Elastic fibres enable the alveoli to expand with inspiration and to contract with expiration

•Reticular fibre serve as a walls that prevents over distention and damage to capillaries and thin alveolar duct.

ALVEOLAR DUCT

ALVEOLI

# Alveolar wall structure specialized to facilitate diffusion between external and internal environment

lies between 2 neighbouring alveoli

called interalveolar septum have 2 thin squamous epithelial layer

interalveolar wall between which lie the interstitium

# Interstitium capillaries elastic fibers connective tissue reticular fibers fibroblasts

ALVEOLI

# Blood air barrier cytoplasm of the epithelial cells fused basal lamina of the epithelial and

endothelial cells cytoplasm of endothelial cell

thickness 0.1-1.5μm

endothelial lining of the capillaries is CONTINUOUS

DON’T have fenestrae

ALVEOLI

ALVEOLAR EPITHELIUM

Consist of:

TYPE I CELLS TYPE II CELLS

Squamous alveolar cells Septal/ great alveolar cells

Extremely thin cells at alveolar surface

Scattered between type I cells

Make up 97% of alveolar surface Found in groups (2,3 cells) along alveolar surface

All have occluding junctions + desmosomes => to prevent leakage of tissue fluid into alveolar air space

Have more rounded shape, larger nucleus and foamy cytoplasm(due to lamellar bodies)

Organelle group around nuclei => reduce thickness of blood-air barrier

Discharged content from lamellar bodies spread and form thin layer on alveoli

Main role: provide barrier of minimum thickness that is readily permeable to gases.

This layer contain pulmonary surfactant which reduce surface tension within alveoli and prevent it to collapse during expiration

Divide by mitosis to replace their own population and type I cells.

ALVEOLAR MACROPHAGES

•also called ‘dust cell’•Found in interalveolar septum and surface

of alveolus•Wonder freely on surface of alveolus•clean epithelial surface of inspired

particles-by phagocytosis•alveoli (ameoboid movement) bronchioles

(via mucus layer) pharynx (swallowed)•due to a/m, the respiratory part of lungs are

normally kept sterile

ALVEOLAR MACROPHAGES

ALVEOLAR PORES

•Interalveolar septum has pores (10-15µm in diameter) that connect neighbouring alveoli

•These pores equalize air pressure in alveoli

•Provide alternative routes for air movement when there is obstruction

ALVEOLAR PORES

CONCLUSION

•Respiratory system consist of 2 parts: (1)conducting portion (2) respiratory portion

•The bronchial tree system are: Trachea 2 primary bronchi secondary

bronchi [2 in left lung;3 in

right lung] respiratory terminal bronchioles bronchiolesBronchioles

Alveoli duct alveoli sac /aveoli

THE END