Respiratory System L14-16 Flashcards
Role of Respiratory System
Connected organs & structures that function to conduct CLEAN, WARM & MOIST air in close proximity w/ circulatory system’s blood for GAS EXCHANGE.
Effective Respiratory System Needs: (4)
- surface for gas exchange (blood & air brought close but separated)
- path for air flow to reach gas exchange surface in optimal conditions
- ability to draw breath in & out
- Sound production & olfaction (smell)
Main Components
URT (upper respiratory tract)
LRT
- Thoracic cavity
- joints
- respiratory muscles
Nasal Cavity
Olfaction (smelling)
Conduction Zone
nose to bronchioles (ensures air is warm, clean & moist))
Oral Cavity
Passage for air & food
Respiratory Zone
Bronchioles to alveoli
- sites of gas exchange
Tract lined with…
mucosa; Epithelium attached via basement membrane to lamina propria (connective tissue)
Epithelium…
Changes along lengths of tract to reflect function
Submucosa
Layer beneath mucosa
- more connective tissue
- may contain many glands
Pseudostratified Ciliated Columnar Epithelium (with goblet cells) Found in:
Nasal cavity, part of pharynx, larynx, trachea & bronchi
Goblet cells produce…
Mucus which traps debris & moistens air
Ciliated cells…
Patterned movement pushes mucus towards pharynx
- swallowed & digested by stomach acid
Components of URT
- Nose & Naval Cavity
- Paranasal sinuses
- Pharynx (nasopharynx, oropharynx, laryngopharynx)
Function URT
Conducting passage (not just air)
- prepares air for respiratory membrane (gas exchange) ~ warm, clean, moist
- paranasal sinuses ~ resonating chambers for speech
- olfaction ~ sensory receptors for smell
Nose (primary passageway for air)
Cartilages: soft, flexible; maintain patent (unobstructed) airway
Nostrils: external nares
Vestibule (lined w/ skin): has sebaceous & sweat glands, hair follicles; vibrissae (hairs) filter inhaled air
Conchae
Three projections: superior, middle, inferior (turbinates)
- covered by respiratory epithelium
- swirl inspired air
- particles stick to mucosa
- more time for warming & humidifying of air, plus olfactory detection
Nasal Epithelium
- specialised area of olfactory epithelium (area on roof of nasal cavity containing smell (olfactory) receptors
Nasal Mucosa
- thin walled vascular plexus
- helps warm incoming air
- when air temp drops, plexus dilates = greater heat transfer
- nose bleeds normally originate from damage here
Paranasal Sinuses
sinuses: cavity in bone
paranasal: surrounds nose
- found lined w/ respiratory mucosa
- drain into pharynx
Functions:
- lighten skull
- increased surface area to clean, warm, moisten air
- sound resonance
- infected mucus can block drainage = blocked sinuses
Pharynx (throat)
Muscular tube shared by respiratory & digestive systems
- splits into 3 sections of throat
Nasopharynx (first section)
Air passage only
- posterior to nasal cavity
- From internal nares to soft palate
- soft palate & uvula block naso- during swallowing to prevent food from entering nasal cavity
- auditory tubes drain here from middle ear
- pharyngeal tonsils on posterior wall
Oropharynx (second section)
Air & Food can pass (stratified squamous epithelium = protection against abrasion)
- posterior to oral cavity
- from soft palate to hyoid bone
- palatine tonsils
- lingual tonsils
Laryngopharynx
Air & food can pass (stratified squamous epithelium)
- from hyoid to opening of larynx/beginning of oesophagus
- ends at lvl where respiratory & digestive tract
- Food has “right of way” during swallowing
Components of LRT
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Alveoli
Larynx
Trachea
Lungs
Bronchial Tree
Respiratory Zone
Alveolus
