Respiratory System Flashcards
Ventilation versus respiration
Ventilation: physical process of the air going in and out of the lungs
Respiration: chemical process of how gas exchange occurs
Inspiration
Volume of thoracic cavity increases
Decreases internal gas pressure
Diaphragm flattens
Intercostal muscles contract and raise the ribs
What muscles do deep inspiration require?
Scalenes
Sternocleidomastoid
Pectoralis minor
Erector spinae - extends back
Expiration (quiet and forced)
Quiet expiration is chiefly a passive process (no energy)
Inspiratory muscles relax, diaphragm moves superiorly, volume of thoracic cavity decreases
Forced expiration is an active process
Produced by contraction of internal and external obliques, transversus abdominis
Pleura
A double layered sac surrounding each lung (visceral and parietal)
Help divide the thoracic cavity (central mediastinum and 2 lateral pleural compartments)
Pleural cavity
Potential space between the visceral and parietal pleurae
So little you dont really know it exists
Sternal angle
Line between manubrium and sternu
Where the aorta beings
Corresponds to second rib
Where the trachea bifurcates into right and left bronchus
2 important factors to prevent lung collapse
Surfactant
Pleura
Pneumothorax
Air in the pleural cavity, resulting in lung collapse
Can be severe enough that the heart and lung get pushed to the other side
Can be bad enough that no gas exchange can occur in the lung
Can be caused by COPD, thoracentesis, trauma, or secondary infection
Treat with chest tube and oxygen
Diagnose by chest x-ray or ABG’s
Symptoms are dyspnea, anxiety, tachycardia, pleural pain, asymmertrical chest wall expansion, decreased breath sounds
Conducting zone
Respiratory passageways that convey air
Filter, humidify, and warm incoming air
Only transmits gases, no exchange occurs
Respiratory zone
Site of gas exchange in the lungs
Includes structures that have alveoli
Where gaseous exchange begins
Starts at the respiratory bronchioles
Nose and nasal cavity
Moistens, warms and filters air Resonating chamber for speech Skin of nose is thin and contains many sebaceous glands External nares are nostrils Divided by nasal septum Continuous with nasopharynx Posterior nasal apertures are choanae Houses olfactory receptorsL near roof of nasal cavity
3 parts of respiratory mucosa
Pseudostratified ciliated columnar epithelium mostly
Goblet cells within epithelium
Underlying layer of lamina propria
Where does cilia move the mucus?
Move the contaminated mucus posteriorly to the pharynx
Filtered particles and mucus are swallowed
Eventually digested by digestive juices in the stomach
3 sections of the pharynx
Nasopharynx
Oropharynx
Laryngopharynx
Nasopharynx
Superior to the point where food enters
Only an air passageway
Closed off during swallowing
Uvula reflects superiorly
Oropharynx
Air and food pathway
Archlike entraceway - fauces
Extends from soft palate to the epiglottis
Stratified squamous epithelium
Laryngopharynx
Passageway for both food and air
Stratified squamous
Continuous with esophagus and larynx
Nasal chonchae or turbinates
Filter the air
Superior, middle and inferior nasal conchae
Project medially from the lateral wall of the nasal cavity
Deflect particulate matter to mucus coated surfaces
During inhalation they filter, heat and moisten incoming air
During exhalation moisture and heat are reclaimed
Paranasal sinuses
Air filled spaces located within 4 facial bones
Sinuses open into nasal cavity
Infection: sinusitis (maxillary cavity is the most common one to get inflammed)
Why does the maxillary sinus get infected the most
Because the opening is high up
So only what is on top can get drained
4 bones that have paranasal sinuses
Frontal bone
Maxillary bones
Sphenoid bone
Ethmoid bone
Tonsils
Collections of lymphoid tissue - provides immunity
Pharyngeal tonsil
Also called adenoids
When inflammed they cause snoring
Located on posterior wall
Destroys entering pathogens
Tubal tonsil
At entrance to pharyngotympanic tube (auditory tube)
Provides some protection from infection
2 types of tonsils in the oropharynx
- Palatine tonsils (in the lateral walls of the fauces)
- Lingual tonsils (cover the posterior surface)
All together form the Waldeyer’s ring
Larynx
Extends from 4th to 6th cervical vertebrae
Attaches to hyoid bone superiorly
Opens into laryngopharynx
Inferiorly is continuous with the trachea
3 functions of the larynx
Voice production
Acts as a sphincter (stops things from entering the trachea)
Provides an open airway
Rima glottidis
Medial opening between vocal folds
Space between the two vocal chords
Thyroid cartulage
Shield shaped, forms laryngeal prominence
Trachea
C-shaped cartilage rings keep airway open
Trachealis
Smooth muscle
Located between open ends of C-shaped cartilage rings along length of posterior trachea
Carina
Marks where the trachea divides into 2 primary bronchi
Sternal angle on the surface
Major landmarks of the lungs
Apex
Base (concave inferior surface)
Hilum (indentation on mediastinal surface - region where blood vessels, bronchi, and nerves enter and exit the lung)
Left versus right lung
Left: superior and inferior lobes, oblique fissure, cardiac notich (depression that accomodates the heart)
Right lung: superior, middle, and inferior lobes, oblique and horizontal fissues
Root
The structures that enter and leave the lung at the hilum
Blood vessels, bronchi and nerves
Right versus left bronchi
Right is shorter, wider, and more in line with the trachea
Changes in tissue composition as you go down the bronchial tree
Supportive connective tissue change (C-shaped rings replaced by cartilage plates) Epithelium changes (from pseudostratified to simple columnar, to simple cuboidal) Smooth muscle becomes important (widens with sympathetic, constricts with parasymp)
Bronchial asthma
A type of allergic inflammation
Hypersensitivity to irritants in the air or to stress
Characterized by contraction of bronchiole smooth muscle and secretion of mucus in airways
Type 2 alveolar cells
Secrete surfactant which reduces surface tension within alveoli
