Respiratory System (Ch 25) Flashcards
What are the functions of the respiratory system?
- Pulmonary Ventilation (breathing): inhale gases/exhale gases
- External Respiration: gas exchange between atmosphere and blood
- Internal Respiration: gas exchange from blood to cells by capillaries)
What are the functional zones of the respiratory system?
- Conducting Zone: filtering, warming, and humidifying air/carrying it to lungs (most of resp system)
- Respiratory Zone: gas exchange within the lungs (alveoli, alveolar ducts
What are the respiratory system tracts?
- Upper Respiratory Tract: nasal cavity –> sinuses –> pharynx
- Lower Respiratory Tract: larynx –> trachea –> bronchi –> lungs (also include pleura + diaphragm)
What forms the nose?
- nasal bone
- frontal bones
- maxillary bone
- hyaline cartilage at tip of nose
What is the septum of the nose?
midline of nose formed by several bones
What is the floor of the nasal cavity?
formed by the hard and soft palates
-divide nasal cavity from mouth
What is the function of the nose?
“air conditioner”
-filters, warms, and humidifies incoming air
Nose and Nasal Cavity
–> composed of bone and cartilage
Includes: nares (nostrils), nasal hairs (filter particles), capillaries (warm air), mucus membranes, and nasal conchae
Nasal Conchae
- folds on the nose’s lateral walls (superior/middle/inferior) covered by a mucus membrane
- function: increase SA of mucus membrane to help moisten air
Paranasal Sinuses
- hollow sparse lined with pseudostratified ciliated columnar epithelium
- drain into nasal cavity via ducts
Pharynx
a. k.a. the throat
- 3 parts
- passageway for food/air
Nasopharynx
- posterior to nasal cavity, superior to soft palate
- lined with pseudostratified columnar epithelium (for protection, to secrete mucus)
- air passage only
- pharyngotypanic (auditory) tube opens into lateral wall of nasopharynx (drains middle ear
Oropharynx
- posterior to oral cavity
- food passage here
- becomes stratified squamous epithelium (protection)
Laryngopharynx
- posterior to larynx, connects to esophagus AND larynx
- food passage here
- becomes stratified squamous epithelium (protection)
Olfactory Nerves
Located in upper part of nasal cavity, detects smell
Larynx
a.k.a. the voice box
-anterior to esophagus, opens into laryngopharynx
-attaches to hyoid bone superiorly and trachea inferiorly
Functions:
1. produces vocalizations
2. provides open airway
3. routes air/food to proper tube
What are the parts of the larynx?
- Epiglottis
2. Glottis
Epiglottis
superior part of larynx
- cartilage covered in mucosa (epithelial tissue)
- attaches to thyroid cartilage and bone
- covers larynx during swallowing (flips over glottis to seal off)
- opens up during breathing
Glottis
- -> sound production
- vocal folds: tightness determines pitch, size determines loudness
Thyroid Cartilage
- largest laryngeal cartilage
- shaped like a shield, forms the lateral and anterior walls of the larynx
Cricoid Cartilage
- ring-shaped cartilage
- located inferior to the thyroid cartilage
Arytenoid cartilages
- posterior to larynx
- one of three paired cartilages
True vocal fold
- part of glottis
- make noise when air passes between
Trachea
-connects larynx to bronchi, anterior to esophagus
-branches into left and right main bronchi at sternal angle
Structure:
-hyaline cartilage rings –> won’t collapse
-trachealis muscles (smooth muscle), cough –> contract
-ciliated epithelium
Trachea in relation to esophagus
- trachea is anterior to esophagus
- posterior part of trachea is soft tissue –> allowing trachea to expand to breathe without constricting the esophagus during feeding
What does the brachial tree look like?
trachea –> main bronchi –> lobar bronchi –> segmental bronchioles
Bronchioles and Alveoli
-smallest part of respiratory system, end of respiratory passageway
bronchi –> terminal bronchioles –> respiratory bronchioles –> alveolar ducts –> alveolar sacs –> alveoli
Alveoli
allow for gas diffusion between respiratory system and capillaries
Pleural Cavity
between visceral (line lung) and parietal (line body wall) pleurae -fluid within decreases friction, creates surface tension that helps expand lung when thoracic cavity expands
Hemothorax
blood in pleural cavity, lungs cannot fully expand
Pneumothorax
air in pleural cavity –> collapsed lung
Which body cavity contains the lungs?
thoracic cavity
Why are lungs so light and elastic?
filled with air and composed of elastic fibers, surrounded by pleural sacs filled with fluid
What is the cardiac notch?
the indentation of the heart in the left lung
Positioning of lungs
apex of lung protrudes superior to clavicle
bases of lung rest on diaphragm
What is the hilum? What is the function of this region?
- region where blood vessels, bronchi, lymph vessels, and nerves enter/exit lung
- “root” of lung - attaches it to rest of mediastinum
What are the part of ventilation?
Inspiration and Expiration
Inspiration
- muscles contract (diaphragm, external/internal intercostals)
- lungs expand
- air pulled in (increased volume, decreased pressure)
Expiration
- muscles relax (diaphragm, external/internal intercostals)
- ->abdominal muscles contract, pushing diaphragm back up - lungs shrink
- air forced out (decreased volume, increased pressure)
* usually passive
What are the fissures of the lungs?
RIGHT:
- Horizontal Fissure
- Oblique Fissure
LEFT:
1. Oblique Fissure
Horizontal Fissure
separates the superior from the middle lobe in right lung ONLY
Oblique Fissure
separates the middle from the inferior lobe
