Transcript Respiratory

Functions of Respiratory System
Ventilation - moves air to and from alveoli
Gas exchange between air and circulating blood
Defend respiratory system from pathogens
Help homestasis of:
blood volume, pH, and pressure
Permit vocal communication
Respiration
• Ventilation- environment and lungs
• External Respiration – alveoli and
blood
• Internal respiration – Blood and cells
• Cellular Respiration – Biochemical
inside cell
Respiratory organs
Respiratory organs
Nose, nasal cavity, and paranasal sinuses
Pharynx, larynx, and trachea
Bronchi and smaller branches
Lungs and alveoli
• Divided into:
– upper
– lower
External nares
• Upper respiratory system
– Nose
– Nasal cavity
– Pharynx
• Functions
• Warm, Filter and Humidify
incoming air
• Lower Respiratory
System
• Larynx
• Trachea
• Bronchi
• Bronchioles
• Alveoli
The Nose
• Provides an
airway for
respiration
• Moistens and
warms air
• Filters inhaled air
• Houses olfactory
receptors
PARANASAL SINUSES
Respiratory Epithelium.
• Lines conducting portions
• Pseudostratified ciliated
columnar epithelium with
goblet cells PSCC
– Produces mucus to trap
foreign particles
Respiratory Epithelium.
cilia rhythmically ‘sweeps’ debris up to
be swallowed or expelled at pharynx
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Mucus escalator
Alveolar macrophage
Hairs in nose
Cilia - lining respiratory tract
• External nares
– Open into nasal cavity
– Vestibule guarded by hairs
• Nasal cavity
– Superior, middle and inferior meatuses
• Narrow grooves and conchal surfaces
• Hard palate
– Nasal and oral cavities
• Soft palate
– Superior nasopharynx and pharynx
• Internal nares
– Between nasal cavity and nasopharynx
The Pharynx
Shared by digestive and respiratory systems
Nasopharynx
Superior portion: from internal nares
to uvula.
Oropharynx
Continuous with oral cavity
Laryngopharynx
Between hyoid and entrance to esophagus
Nasopharynx
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Superior to the point where food enters
Only an air passageway
Closed off during swallowing
Pharyngeal tonsil (adenoids)
– Located on posterior wall
– Destroys entering pathogens
• Contains the opening to the auditory tube
Oropharynx
• Extends from soft palate to the epiglottis
• Epithelium is stratified squamous
epithelium
• Two tonsils in the oropharynx
– Palatine tonsils – in the lateral walls
– Lingual tonsils – covers the posterior surface
of the tongue
Laryngopharynx
• Passageway for both food and air
• Lined with stratified squamous epithelium
• Continuous with the esophagus and larynx
The Lower Respiratory System
• Surrounds glottis - air passes through glottis to reach lungs
• Epiglottis - prevents solids from entering respiratory system
Larynx
During swallowing, elevation of the larynx folds epiglottis over the
glottis, steering materials into the esophagus.
Trachea
• Submucosa includes “C” rings of cartilage
– Tracheal cartilages
– Stiffen tracheal walls and protect airway
– Posterior wall distorts allowing food passage through
esophagus
Left and Right 1o Bronchi
• Right and left primary bronchi
– Trachea branches within mediastinum
• Bronchial tree
– Enters lungs at hilus
• Root of lung
– Bronchus, primary vessels, nerves
• Bronchial tree – extensively branching respiratory
passageways
• Primary bronchi (main bronchi) – largest bronchi
• Right main bronchi – wider and shorter than the left
Lungs
• Right lung has three lobes
• Superior lobar, middle lobar and inferior lobar bronchi
• Left lung has two lobes
• Superior lobar and inferior lobar bronchi
• Cardiac notch
• Secondary (lobar) bronchi
– Three on the right
– Two on the left
• Tertiary (segmental) bronchi
– Branch into each lung segment
• Bronchioles – little bronchi, less than 1 mm
in diameter
• Terminal bronchioles – less than 0.5 mm in
diameter
Bronchi and Bronchioles
• For clarity, the degree
of branching has been
reduced: an airway
branches approximately
23 times before
reaching the level of a
lobule.
Fig
24.11
Alveolus – cells and composition
1. Simple squamous
epithelium (type I)
2. Septal cells (type II)
Produce surfactant
3. Alveolar macrophages
(dust cells)
Patrol epithelium
Engulf foreign particles
Basic structure of a lobule,
cut to reveal the arrangement
between the alveolar ducts
and alveoli.
Respiratory Membrane
•Respiratory Membrane (blood-air Barrier)
•“point of gas exchange”
• Aveolar Epithelium simple squamous
epithelia
•Fused basement membrane
Capillary endothelium simple squamous
epithelia
Respiratory Epithelium
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Air
epithelia tissue
Nasal cavity
stratified squamous
Nasopharynx
PSCC
Oropharynx
stratified squamous
Laryngopharynx
stratified squamous
Larynx
PSCC
Trachea
PSCC
Rt./Lt. primary bronchi
PSCC
Secondary (lobar) bronchi
PSCC
Tertiary (segmental) bronchi
PSCC
Terminal bronchioles
simple cuboidal
Respiratory bronchioles simple cuboidal
Alveolar duct
simple squamous
Alveolar sac
simple squamous
Alveolus
simple squamous
Ep=pscc
Sumb=tunica
submucosa
Cart=tracheal
ring
Adv=tunica
Respiratory Muscles
Ventilation - movement of air into and out of lungs.
Eupnea - normal quite
breathing at rest.
Inspiration:
 volume of
thoracic cavity.
Muscle activity required:
Diaphragm
External Intercostals
Sternocleidomastoid
When Forcefully
exhaling (hypereupnea):
Muscles used:
Internal Intercostals
Rectus abdominis
Transverse abdominis,
Internal and External
obliques.
• Bronchial asthma – a type of
allergic inflammation
– A hypersensitivity to irritants in
the air or to stress
– Asthma attacks characterized by:
• Contraction of bronchiole smooth
muscle
• Secretion of mucus in airways
• Chronic obstructive
pulmonary disease (COPD)
– Airflow into and out of the
lungs is difficult
• Obstructive emphysema
• Chronic bronchitis
– History of smoking
• Cystic fibrosis (CF) –
inherited disease
– Exocrine gland function is
disrupted
– Respiratory system affected
by:
• Oversecretion of viscous mucus
• Epistaxis – nosebleed
• Epiglottitis – inflammation and swelling of the
epiglottis
• Dyspnea – difficulty in breathing
• Apnea – cessation of breathing