CH 25 Flashcards
Respiratory system
Respiratory system functions
Exchange O2 with CO2 in the blood
4 steps of getting O2 from lungs to tissue and getting CO2 from tissues to lungs
- Pulmonary ventilation
- External respiration
- Movement of gases through blood vessels (to and from tissues)
- Internal respiration
Pulmonary ventilation
Breathing; movement of air in and out of lungs
Cyclic steps of breathing
- Expiration/ exhalation: forces gases out of the lungs
- Inspiration/ inhalation: draws gases to lungs
External respiration
Exchange of gases between the atmosphere and blood. Oxygen in the atmosphere is inhaled in the lungs and diffuses from lungs into blood at the same time carbon dioxide diffuses from blood into lungs to be exhaled
Exchange of gas between alveoli and pulmonary capillaries
Types of gas exchange
- External respiration
- Internal respiration
Alveoli
Small, saccular outpocketing in respiratory bronchioles, alveolar ducts, and alveolar sacs
Internal respiration
Exchange of gases between blood and cells of the body. Blood transports oxygen from the lungs to the body cells and transport carbon dioxide produced by body cells to the lungs
As inhaled gases pass through conducting airways, the gases are ________ prior to reaching the gas exchange surfaces of the lungs
conditioned (warmed, humidified, and cleansed)
- Warmed to body temperature by being in close contact with nasal blood vessels transporting warm blood
- Humified/ moistened and cleansed of particulate matter through contact with the respiratory epithelium and it’s sticky mucus covering
- Facilitated by twisted pathways in nasal cavity and paranasal sinuses, causing inhaled air to be turbulent
Upper respiratory tract
- Nose and nasal cavities
- Paranasal sinuses
- Pharynx
These are all parts of the conducting portion of the respiratory system
Portions of respiratory system
- Conducting
- Respiratory
Conducting portion
Includes:
Upper respiratory system
- Nose
- Nasal cavity
- Pharynx
- Larynx
Lower respiratory system
- Trachea
- Progressively smaller airways from bronchi to terminal bronchioles
Respiratory portion
- Respiratory bronchioles (small airways)
- Alveolar ducts
- Alveoli
Lower respiratory tract
Conducting portion:
- Larynx
- Trachea
- Bronchi
- Bronchioles
Respiratory portion
Nose
Main conducting airway for inhaled air
Nose components
- External nares
- Vibrissae
External nares
Nostrils (are lined with stratified squamous ET)
Vibrissae
Nose hairs
Vestibule
Anterior region of nasal cavity; space led by external nares
Nasal cavities
Located posterior to vestibule
- Nasal septum
- Lined with respiratory ET (except roof)
- Olfactory epithelium
- Nasal conchae (superior, middle, inferior)
- Nasal meatuses (superior, middle, inferior)
- Vestibule
- Chonae/ internal nares
Nasal septum
Separates nasal cavities into left and right portions
Respiratory epithelium
- Pseudostratified ciliated columnar ET
- Contains mucus-producing goblet cells
- Has extensive vascular network immediately deep to
Olfactory epithelium
Pseudostratified ciliated columnar ET and olfactory receptor cells
Nasal conchae AKA turbinates
Paired bony projections along lateral walls of nasal cavity that subdivide the nasal cavities into separate air passageways
Nasal meatuses
Inferior to nasal conchae; constricted narrow grooves (space) that create turbulent airflow so air stays in the nasal cavity longer and is moistened and humidified
Paranasal sinuses
- Air space in the bones of the skull
- Makes bones lighter in weight and provides resonance chambers for voice
- Lined with respiratory ET
- Drain into nasal cavities
What are the paranasal sinuses?
- Frontal
- Sphenoidal
- Maxillary
- Ethmoidal
Pharynx
One of the few areas of the body that is shared by 2 organ systems (digestive and respiratory)
Common pathway for inhaled and exhaled air as well as ingested food
Regions of pharynx
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
- Superior most region of pharynx
- Posterior to nasal cavities
- Lined with respiratory ET
- Opening of auditory tubes found in lateral walls
- Posterior wall houses the pharyngeal tonsil (adenoid)
- Usually only air passes through, but food can enter if someone is swallowing and laughing at the same time because soft palate can’t form a good seal
Auditory tubes
Connect the nasopharynx to the middle ear; equalizes air pressure between middle ear and the atmosphere by allowing excess air pressure to be released into the nasopharynx
Oropharynx
- Middle pharyngeal region
- Begins at the end of the soft palate and ends at the level of the hyoid bone
- Lined with stratified squamous ET (can withstand abrasion of food)
- Palatine and lingual tonsils located here - lymphatic organ providing the first line of defense
- Common respiratory and digestive pathway
Laryngopharynx
- Inferior, narrowed region of pharynx
- Starts inferior to hyoid bone, continuous with larynx and esophagus
- Common respiratory and digestive pathway
- Lined with stratified squamous ET
Larynx AKA voice box
- Produces sound for speech
- Opening to trachea
- Mostly lined with stratified squamous ET
- Contains cartilage
Produces sound for speech
Larynx contains vocal cords
Vocal cords
Ligaments (connect bone to bone) within the larynx; horizontal folds that project into the lumen of the larynx
Function of cartilages in the larynx
- Maintain an open airway
- Provides attachment sites for vocal cords and muscles in larynx
- Cover trachea when swallowing
All cartilages are made of hyaline except the epiglottis
Cartilages of the larynx
- Thyroid
- Cricoid
- Arytenoid
- Corniculate
- Cuneiform
- Epiglottic
Thyroid cartilage
- Largest cartilage in larynx
- Forms anterior and lateral walls of larynx (no posterior wall)
- Shield shaped
- Anterior attachment site for vocal cords