The Reapiratory System 1 Flashcards
The respiratory system
Respiration is the exchange of ages between the atmosphere and body cells:
- external respiration
- internal respiration
Besides gas exchange, what o try er functions are performed by the respiratory system
• acid-base balance: CO, level helps to control the pH of body fluid
• communication: speech and other vocalization (laughing and crying)
• olfaction: sense of smell
Functionally the respiratory is divided into
- conductioing zone: nasal cavity to terminal bronchioles are sites for air flow(movement)
- Respiratory zone: respiratory bronchioles to alveoli are sites for external gas exchange
Structurally the respiratory system is divided
Into the upper and lower tracts
- upper tract is located in the head and neck
- lower is located in the thorax
The upper respiratory system
Functions:
- warms, humidifies and filters the air
- conducts air to the more delicate surfaces of the lower respiratory system
- transforms heat and mositure from expiring air
The Nasal Cavity
Contains nasal ridges called conchae(or turbinates) and nasal valleys called meatuses
- which increase the surface area to enhance air turbulence and help in trapping large particles in mucus
Nasal Cavity Cont
Most of the nasal mucosa is the respiratory epithelium
- contains cilitated pseudostratified columnar epithelium and goblet cells
- traps dust, pollen, bacteria and other foreign matter
The superior are of the nasal mucosa contains olfactory epithelium that binds odour molecules
Why do we have a runny nose during cold weather and a nasal infection?
cold weather:
• water in cold air condenses; nasal cilia become less active, and mucus dribbles out the nostrils
a nasal infection/inflammation:
• nasal infection or inflammation leads to irritation of mucosa
• excess production of mucus in an attempt to flush out pathogen or irritant
The pharynx:
Nasopharynx
Located posterior to the nasal cavity
- made up of pseudostratified collated columnar epithelium
- conducts air from the nasal cavity
When the digestive system is in play, e soft palate and uvula move superiority to close the nasal cavity
The oropharynx
Located posterior to the oral cavity
- resists friction and chemical trauma form food
- the passage of air and swallowed food
Laryopharynx CT
located posterior to the larynx and is continuous with the esophagus
• stratified squamous epithelium
• passage of air and swallowed food
• site where the respiratory and digestive systems diverge
The parts of the pharynx
Nasopharynx:
- for air passage only
- covered by the soft palate during swallowing
- the auditory tubes(from the middle ear) open this
- the only part lined with cilitated epithelium
Oropharynx:
- for air passage only
Laryngopharynx:
- Ab air and food passage that opens into the larynx and esophagus
Larynx(voice box)
Is a tube of 9 cartilages connected by membranes and ligaments
Functions:
- provides a patent airway
- produces out voice
- routes food into the esophagus(by contracting the epiglottis)
The larynx houses 2 vocal cords
Formed by connective tissue:
The superior pair is called the vestibular folds(false vocal cords)
- closes the larynx during swallowing
- protects the vocal folds
The inferior pair is the vocal folds(true vocal cords)
- vibrates with expired air for sound production
The trachea(windpipe)
Extends into the mediastinum
- made up of ciliated pseudostratified columnar epithelium
- supported by 16-20 C-shaped cartilage rings in the submucosa which prevents collapse or over expansion
- the point where the trachea divides is called the carina
What is the function of trachealis smooth muscle in the posterior ends of cartilage?
allows expansion of esophagus during swallowing
• allows tracheal contraction during coughing to expel mucus (parasympathetic stimulation) or dilation (sympathetic stimulation)
Bronchi and bronchioles
The bronchial tree: the tracheal progressively branches into more numerous and smaller airways
- it undergoes around 23 orders of branching
- transitions from the conducting zone to the respiratory
Conducting vs respiratory airways
CONDUCTING AIRWAYS
1. trachea
2. primary bronchus
3. secondary bronchus
4. tertiary bronchus
5. terminal bronchiole
Respiratory Airways
1. Respiratory bronchus
2. Alveolar duct
3. Alveoli
As the distance from the trachea increases
• the diameter of the airway decreases
• hyaline cartilage changes from rings to disconnected plates
• cilia and goblet cells decreases
• the relative amount of smooth muscles increases
