Module 9 - The Respiratory System

What are 2 cyclic phases of breathing

1. Inspiration/Inhalation
2. Expiration/Exhalation

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Functions of the Respiratory Systems (5)

Gas Exchange, Gas Conditioning, Sound Production, Olfaction, Defense

Gas Exchange

movement of gases across membranes, Internal and external respiration

Internal Respiration

exchange of gases btwn blood and cells of body

External Respiration

exchange of gases btwn air and blood, CO2 & O2 btwn alveolus of lung & capillaries

Gas Conditioning

warm & cleanse gases entering lungs, prevent lung damage, in nasal cavities & paranasal sinuses, mucosal lining cleanses of particulate matter

Sound Production

from forceful expiration of air thru vocal cords in larynx → vibration, diff tensions of vocal cords → diff sounds

Olfaction

receptors for smell on olfactory epithelium, stimulated by airborne molecules dissolved in mucus

Defense

coarse hairs of nostrils, ciliated cells of respiratory epithelium, mucus lining → trap particles & microorganisms

Respiratory Tract Epithelium

defense, lines surfaces (nasal cavity → terminal bronchi),

type of cells in respiratory tract epithelium (2)

1. pseudostratified ciliated columnar epithelium
2. goblet mucus cells

pseudostratified ciliated columnar epithelium

apical surface is covered in cilia

function of cilia

increase surface area for conditioning, trap inhaled particles & microorganisms → sweep back out nose and mouth

goblet mucus cells

interspersed thru pseudostratified epithelium, produce mucus → protective layer to trap particulate matter & provide moisture

Regions of Respiratory system (2)

1. Conducting Portion
2. Respiratory Portion

Conducting Portion

conduct air from outside world → lung tissue & vice versa, were humidification & trapping of debris, no absorption of O2

parts of conducting portion (7)

1. nose & nasal cavity
2. paranasal sinuses
3. pharynx
4. larynx
5. trachea
6. primary, secondary, tertiary bronchi
7. terminal bronchioles

Respiratory Portion

transfer of gases from lungs → pulmonary capillaries

pulmonary capillaries

terminal structure within lungs, have thin walls for movement of gas

Parts of Respiratory Portion (4)

1. Respiratory Bronchioles
2. Alveolar ducts
3. Alveolar sacs
4. Alveoli

Paranasal Sinuses

collection of air filled spaces within bones of skull, communicate with nasal cavity, aid in conditioning, defense against pathogens, resonance chambers for speech

Frontal Sinuses

Sphenoid Sinus

Ethmoid Sinuses

Maxillary Sinuses

Nasal Cavity

Vestibule

Nose & Nasal Cavity

1st line of defense against pathogens & debris (coarse hairs & mucus)

Bone structures/ boundaries of nose & nasal Cavity (6)

1. Roof - Ethmoid Bone
2. Floor - Hard Palate
3. Medial Wall - nasal septum
4. Lateral wall - nasal conchae
5. Anterior Wall - nares
6. Posterior border - opening to nasopharynx

nasal septum

vertical bones in skull, separate halves of nasal cavity

nasal conchae

make turbulence in air, for conditioning & catching debris

nares

opening btwn nose & nasal cavity, nostrils

1) Nasal Conchae 2) Ethmoid bone 3) Anterior nares

1) Opening to nasopharynx 2) Pharynx 3) Hard Palate

Pharynx

muscular tube, respiratory system: connect nasal cavity & larynx, digestive system: connect oral cavity & esophagus

parts of pharynx (3)

nasopharynx, oropharynx, langopharynx

1) Nasopharynx 2) Oropharynx 3) Laryngopharynx

what parts of pharynx are in BOTH digestive & respiratory systems

oropharynx and laryngopharynx

histology of nasopharynx

respiratory tract epithelium

histology of oropharynx & laryngopharynx

stratified squamous epithelium → durability

histology of nasal cavity

respiratory tract epithelium → protect from airborne debris & microorganisms, condition air

histology of roof of nasal cavity

lined with olfactory epithelium → pseudostratified ciliated columnar epithelium + bipolar olfactory receptor neurons

Larynx

produce sound, made of cartilage, ligaments, associated muscles, anterior to esophagus, connect pharynx to trachea, prevent food entering trachea

Cartilage of larynx (3) + function

1. Epiglottis
2. Thyroid Cartilage
3. Cricoid Cartilage

protect, attach, aid in function of vocal cords

epiglottis

spoon shaped, elastic, flip and cover trachea when swallow → prevent food enter

thyroid cartilage

shield shaped, hyaline cartilage, attachment for muscles + vocal cords

cricoid cartilage

complete ring, hyaline cartilage, narrow anteriorly & broad posteriorly, attachment for muscles + vocal cords

Trachea/Windpipe

from larynx to T4/5 level, slits at carina (junction), conduction of air into lungs

What is trachea made up? + function

15-20 C shaped cartilaginous rings → incomplete posteriorly, keep airway open, trachealis muscle connect posteriorly

Histology of trachea (3 layers)

1. Mucosa
2. Submucosa
3. Adventitia

Mucosa

lined with respiratory tract epithelium, clears debris/pathogens

submucosa

loose areolar connective tissue, have large vessels & nerves & mucus secreting glands

Adventitia

enclose C-shaped cartilaginous rings, make trachea flexible & durable → shift with breathing movements

Vocal Cords

small ligaments attached to laryngeal cartilage, true vocal cords = produce sound, false vocal cords = membranous flap that protect true vocal cords

What does trachea split into?

2 primary bronchi (L & R), same histology & function as trachea

Hilus

where primary bronchi enter lung on medial side

how is right primary bronchi different?

wider, shorter, more vertical

1) primary bronchi 2) secondary bronchi 3) tertiary bronchi 4) terminal bronchioles

1) True vocal cords 2) False vocal cords

1) paranasal sinuses 2) nose & nasal cavity 3) pharynx 4) larynx 5) trachea 6) primary bronchi 7) end of conducting portion

Respiratory Portion

allow gas exchange btwn air & blood, walls = 1 cell layer thick, make up majority of lung tissue

Lobes of Right lung: (3)

1) Superior 2) Middle 3) Inferior

Lobes of Left Lung (2)

1) Superior 2) Inferior

fissures of right lung (2)

1) Horizontal Fissure 2) Oblique Fissure

fissures of left lung (1)

1) oblique fissure

features of left lung

1) Cardiac Notch 2) lingula

Surfaces of lungs

1) Coastal Surface 2) Mediastinal Surface 3) Diaphragmatic Surface

1) Apex 2) Hilus

Pleural Membranes (2) + function

1. parietal pleura
2. visceral pleura

serous membranes, protect lungs, secrete pleural fluid → fill pleural space btwn membranes, lubricant for sliding during inflation & deflation, are continuous w/ each other at hilus

1) Parietal Pleural (outer) 2( Viscera pleura (inner)

1) Respiratory Bronchioles 2) Alveoli

Respiratory Bronchioles

Branch out from terminal bronchioles, 1st structure for gas exchange, thin walled ducts, simple ciliated cuboidal epithelium, branch into alvelo

Alveoli

functional unit of lung, gas exchange take place here, surrounded by capillaries

Chronic Obstructive Pulmonary Disease (COPD)

inflammation of airways → limit air flow, produce more mucus (clog airways, hard to breathe), smaller & constricted lumen, damaged air sacs → lose elasticity