Anatomy of respiratory system

1. ANATOMY OF
RESPIRATORY SYSTEM
SELINA SRAVANTHI
SAROJINI NAIDU VANITA PHARMACY MAHA VIDYALAYA,
TARNAKA, HYDERABAD, TELANAGANA

2. Respiration provides homeostasis
Cells require energy.
 Most of the energy from chemical reactions in presence of O2
 Waste product of these reactions is CO2 .
 Respiratory system provides route for the supply of O2 and
excretion of CO2.
 As the air moves through the passages, to reach lungs, the
air is warmed or cooled to body temperature, saturated with
vapour, cleaned as the dust particles stick to the mucus lining
the membrane.
 Blood provides the transport system for O2 and CO2
between lungs and cells of the body.
Types of Respiration
External respiration – b/w blood and lungs
 Internal respiration - b/w blood and cells
 Branch of Science – Ears, Nose, Throat (ENT)-
OTORHINOLARYGOLOGY
Pulmonologist

3. ANATOMY OF RESPIRATION
 Organs of the Respiratory system
Nose
Pharynx (Throat)
Larynx (Voice Box)
Trachea
Two bronchi
Bronchioles and smaller air passages
Two Lungs and their pleura
 Muscles of breathing – intercostal muscles and
diaphragm

4. Human Respiratory System
Figure 10.1

5. Respiratory
System
Conductin
g Zone
Nose, Nasal
cavity,
Pharynx,
Layrnx,
Trachea,
Bronchi
Resiratory
Zone
Respiratory
Bronchioles, alveolar
ducts, alveolar sacs,
Alveoli

6. Divisions of the Respiratory System
 Upper respiratory
tract (outside thorax)
 Nose
 Nasal Cavity
 Sinuses
 Pharynx
 Larynx

7.  Lower respiratory
tract (within thorax)
 Trachea
 Bronchial Tree
 Lungs
Divisions of the Respiratory System

9. NOSE
• Divided into external and
internal portion.
• External nose- supporting
framework of bone (frontal
bone, nasal bones and maxillae)
and hyaline cartilage (septal
nasal cartilage, lateral nasal
cartilage and alar cartilages),
covered by muscle and skin.
• Two openings called the
external nares or nostrils.

10. NOSE
• Posterior part of the septum
– ETHMOID BONE AND
VOMER
•Roof is formed by cibriform
plate of ETHMOID BONE and
SPHENOID BONE, FRONTAL
BONE and NASAL BONES.
• Floor of the nose is formed
by the roof of the Mouth.
•Consists of hard palate
(maxilla and palantine bones)
and soft palate (involuntary
muscle).

11. NOSE• Nasal Cavity large space in the
anterior nose.
• Lined by muscle and mucous
membrane (Ciliated epithelium
with mucous secreting goblet
cells).
• Anteriorly merges with external
nose, Posteriorly connects to
pharynx through two openings –
Internal nares/ Choanae.
•Paranasal sinuses – cavities in the
bones of the face, lined with
mucous membrane and continuous
with nasal cavity. (responsible for
speech)
•Naso lacrimal ducts

12. •Para nasal sinuses – 3 types
•Maxillary sinuses (lateral walls)
•Frontal and sphenoidal sinus (roof)
•Ethemoidal sinus (upper part of the lateral walls)
•Nasal Cavity is divided into
•Larger inferior respiratory region- Lined with
pseudostratified ciliated columnar epithelium with
goblet cells/ Respiratory epithelium.
•Smaller superior olfactory region - Olfactory
Epithelium – Specialised receptors located in the roof
of the nose. Stimulated by airborne odours.
NOSE

13. FUNCTIONS OF THE NOSE
•FILTERING AND CLEANING:
•WARMING
•HUMIDIFICATION
•SMELL
Air enters nostrils
Three nasal chonchae divide nasal
cavity into superior, middle and
inferior meatuses – lined by mucous
membrane-increase surface area and
prevents dehydration by trapping
water droplets during exhalation
Inhaled air whirls around
chonchae and meatuses-
warmed by blood in
capillaries.
Mucous secreted by goblet cells
traps dust particles, drainage from
nasolacrimal ducts help moisten air
assisted by secretions from paranasal
Cilia move mucus and dust
particle towards pharynx-
swallowed or spit out
pass through vestibule lined by skin with coarse
hairs- FILTERING
FUNCTIONS OF THE NOSE
•SPEECH
•WARMING
•HUMIDIFICATION
•SMELL

14. •Funnel shaped,
13 cm long.
•Starts at nares
end at cricoid
cartilage of
larynx.
•Walls composed
of skeletal
muscle, lined with
mucous
membrane.
PHARYNX
Superior- base of skull
Anterior wall incomplete-
openings of nose, mouth
and larynx
Posterior- aerolar tissue,
involuntary muscle, 6
cervical vertebrae

16. NASOPHARYNX OROPHARYNX LARYNGOPHARYNX
• Behind nose, above
soft palate.
•5 Openings- 2
internal nares, 2
openings lead to
eustachian tubes, 1-
oropharynx
•Posterior wall
contains adenoid/
pharyngeal tonsil
(Lymphoid tissue)
• Connected to the
auditory tubes.
•Pseudostratified
ciliated columnar
epithelium
• Behind mouth,
below soft palate-
upper part of 3rd
cervical vertebra.
•Fauces – opening
into mouth
•Lateral walls blend
with soft tissue to
form folds- between
the fold- palantine
tonsil and Lingual.
•Respiratory and
digestive pathway
•Nonkeratinised
stratified squamous
epithelium
•Connects to larynx
anteriorly.
•Continues as
oesophagus.
•Respiratory and
digestive pathway
•Nonkeratinised
stratified squamous
epithelium

17. Wall of the pharynx ix composed of inner mucous membrane
and outer skeletal muscle (outer circular and inner
longitudinal)
FUNCTIONS
•Passage for airway and food
•Skeletal muscle contraction- deglutition (swallowing)
•Warming and Humidifying.
•Hearing- allows air into middle ear- maintain pressure,
protecting tympanic membranes
•Protection –Pharyngeal and Laryngeal tonsils produce
antibodies (immunological reactions)
•Speech – resonanting chamber

18. LARYNX
• Voice box.
•Connects laryngopharynx with trachea
•Middle of neck anterior to oesophagus, from 4th through 6th
cervical vertebrae.
•Wall of Larynx – nine pieces of cartilage
•Thyroid cartilage
•Epiglottis
•Cricoid
•Arytenoid
•Cuneiform
•Corniculate
Occur singly
Occur in pairs

20. • Thyroid cartilage (Adam’s Apple) – consists of two fused hyaline
cartilage, triangular shape.
•Epiglottis :
•Large leaf shape elastic cartilage, stem is tapered, attached
to thyroid cartilage and hyoid bone.
•Broad leaf portion is unattached and free to move up and
down like a trap door.
•During swallowing the pharynx and larynx rise.
•Elevation of pharynx- widens to receive food or drink.
•Elevation of Larynx – causes epiglottis to move down and
form a lid over the glottis.
•Glottis is a pair of folds of the mucous membrane, vocal
cords, and space between them called rima glottidis.
•Closing of larynx during swallowing of foods and liquids
prevents them from entering the larynx and airways.
•If food passes into larynx, cough reflex occurs expelling the
material.

21. • Cricoid cartilage - ring of hyaline carilage. Attached to trachea
and thyroid cartilage
•Arytenoid Cartilage (influence changes in position and tension
of true vocal cords for speech)–triangular pieces of cartilage.
Have wide range of mobility.
•Corniculate Cartilage – horn shaped pieces of elastic cartilage at
the apex of the each arytenoid cartilage.
•Cuneiform cartilage – club shaped elastic cartilage. Support the
vocal folds and the lateral aspects of epiglottis.
•Linings of larynx superior to vocal cords – nonkeratinised
stratified squamous epithelium.
•Linings of larynx inferior to vocal cords – pseudo stratified
ciliated columnar epithelium.
•Goblet cells secrete mucous that trap dust not removed by
upper passages.
•Cilia move mucous upwards towards the pharynx

22. FUNCTIONS OF LARYNX
•Production of sound
•Speech
•Protection of lower respiratory tract
•Passage for airway
•Humidifying, filtering and warming

23. VOICE PRODUCTION
•Mucous membrane of larynx- 2 pairs of folds-
•Superior Pair – Ventricular folds- false vocal cords
•Inferior pair – vocal folds – true vocal folds
•Space between them – rima vestibuli
• when the ventricular folds are brought together – they hold
breath against pressure in thoracic cavity.
•Deep to the vocal folds- elastic ligaments are stretched between
rigid cartilage like strings on a guitar.
•Intrinsic laryngeal muscles attach to cartilage and vocal folds
•When muscles contract – ligaments and vocal cords are stretched,
so that rima glottidis is narrowed.
•If air is directed towards vocal folds- vibrate and produce sound.
•Pitch is controlled by tension on vocal cords.
•In males- vocal folds are thicker – lower pitch than females.
•Pharynx, mouth and nasal cavity- act as resonating chambers.
•Whispering – all closed except posterior rima glottidis

27. TRACHEA
• Wind pipe
•Anterior to oesophagus, extends
from larynx upto 5th thoracic
vertebrae.
•Divides into right and left
primary bronchi.
•It consists of 16-20 incomplete
horizontal C shaped rings
connected by dense connective
tissue.
•Open part of the C is posterior
to oesophagus.
•The solid C shaped cartilage
provides semirigid support so
that the tracheal wall does not
collapse.

28. •Layers from innermost to
outermost are
•Mucosa – protects against
dust
•Epithelial layer-
pseudostratified ciliated
columnar epithelium
•Underlying layer – lamina
propia- elastic and reticular
fibres.
•Submucosa- Aerolar
connective tissue – seromucous
glands and their ducts.
•Hyaline cartilage
•Adventia –Aerolar connective
tissue
TRACHEA

29. FUNCTIONS OF TRACHEA
• Support and Patency
•Hold trachea permanently open.
•Soft tissue between cartilage provide flexibility for head and
neck
•Absence of cartilage posterior to oesophagus allows it to
expand.
•Mucociliary escalator
•Cilia move mucous upwards towards the larynx where it is
either swallowed or coughed up.
•Cough reflux
•Nerve endings are sensitive to irritation-nerve impulse by vagus
nerves to respiratory center. Reflex motor respose- closure of
glottis-abdominal and respiratory muscles contract – sudden
pressure in lungs – glottis opens expelling air along with
mucous.

30. BRONCHI
•Trachea divides into right and left
bronchi which goes into respective
lungs.
•Point where trachea divides into
right and left primary bronchi –
CARINA
•Mucous membrane of the carina is
sensitive for triggering cough reflex.
TRACHEA
10 BRONCHI
20 BRONCHI
30 BRONCHI
TERMINAL
BRONCHI
BRONCHIAL
TREE
Clara cells in bronchioles protect from
harmful effects of inhaled toxins and

31. • The incomplete C shaped rings gradually disappear in primary
bronchi and are replaced by plates of cartilage.
•Cartilage is disappeared in distal bronchioles.
•As the amount of cartilage decreases, smooth muscle increases.
• Smooth muscle encircles lumen and maintain patency.
•Muscle spasms close off airways – asthma attack
FUNCTIONS OF BRONCHI
• Control of air entry
•Warming and humidifying
•Support and Patency
•Removal of particulate matter
•Cough reflex

32. LUNGS
•Paired , cone shaped organs.
•Located in the thoracic cavity
•Separated by heart and other structures in the mediastinum.
•Each lung is enclosed and protected by a double layer serous
membrane- Pleural membrane.
•Superficial membrane- parietal pleura
•Deep layer - Visceral Pleura
•Between the visceral and parietal pleura- pleural cavity filled with
fluid
•Extend from diaphragm to slightly superior to clavicles and lie against
ribs anteriorly and posteriorly.
•Lung is divided into
• Broad inferior portion- Base
•It is concave and fits over the convex area of the diaphragm.
• Narrow Superior portion- Apex
•Surface lying against the ribs – Costal surface
•Medial / Mediastinal surface – contains Hilum – triangular shape-

35. •Lungs are divided into lobes- by fissures
•Right lung – three lobes – divided by Oblique fissure and Horizontal
fissure –into Superior, Middle, Inferior Lobes
•Left Lung – two lobes – divided by Oblique fissure – into Superior
and Inferior Lobes
•Each lobe receives its own secondary (lobar) bronchus.
•Right – 3 Bronchioles
•Left – 2 bronchioles
• Each lung contains 10 tertiary bronchi.
•Lungs has many small compartments- Lobules – contain Lymphatic
vessel, arteriole, venule and branch from terminal bronchiole.
•Terminal Bronchioles- divide into microscopic branches –
respiratory bronchioles.
•Respiratory bronchioles- divide into Alveolar Ducts

36. ALVEOLI•Around alveolar ducts – Alveoli and alveolar sacs
•Alveolus is cup shaped- lined by simple squamous epithelium
supported by basement membrane.
•Alveolar sac- consist of 2 or more alveoli
•Walls of alveoli- 2 types of epithelium
•Type I alveolar cells- simple squamous epithelium- continuous
lining
•Type II alveolar cells/ septal cells - rounded or cuboidal epithelium
with free surfaces containing microvilli – secrete alveolar fluid
•Alveolar fluid- contains surfactants (phospholipids+ phospho proteins)-
prevent collapse of alveoli.
•Alveolar walls have alveolar macrophages (dust cells)- phagocytes-
remove fine dust and debris from alveolar spaces.
•Exchange of O2 and CO2 between air spaces and blood – Diffusion.
•Respiratory membrane- 4 layers
•Alveolar wall – Type I and II alveolar cells
•Epethelial basement Membrane
•Capillary Basement Membrane

38. FUNCTIONS OF ALVEOLI
•External Respiration- between alveoli and blood vessels.
•Defence against infection – lymphocytes and plasma cells (produce
antibodies and phagocytes), alveolar macrohages.
•Warming and Humidifying
•Breathing- Movement of air in and out of lungs
•Exchange of gases – internal and external respiration