Ch. 23 Respiratory System Flashcards
Body cells must obtain ____ and eliminate ____
Obtain oxygen
Eliminate CO2
What are the 5 functions of the respiratory system?
- Provide an area for gas exchange between air and circulating blood
- Move air to and from exchange surfaces
- Protect respiratory surfaces from environmental variations and defend the respiratory system and other tissues from invasion by pathogens
- Produce sounds
- Facilitate the detection of olfactory stimuli
What are the divisions of the respiratory system?
Upper and lower
What does the upper respiratory system contain?
Nose, nasal cavity, paranasal sinuses, pharynx
What does the lower respiratory system contain?
Larynx, trachea, bronchi, bronchioles, alveoli
What does the respiratory tract consist of?
The conducting airways that carry air to and from the alveoli
What do the passageways of the upper respiratory tract do?
Filter and humidify incoming air
What is the respiratory mucosa?
The respiratory epithelium and underlying connective tissues
What does the respiratory mucosa line?
The conducting portion of the respiratory tract
What is the respiratory epithelium supported by?
The lamina propria
What is the lamina propria?
A layer of areolar tissue
What is the respiratory defense system made up of?
Mucus and cilia
What prevents contamination of the respiratory system?
Mucus and cilia
Where does air enter the respiratory system normally?
Through the nostrils
What do the nostrils open into?
The nasal cavity
What is the nasal vestibule guarded by?
Hairs that screen out large particles
Where does incoming air flow through?
Superior, middle, and inferior meatuses (narrow grooves) and then bounces off the conchal surfaces
What separates the oral and nasal cavities?
The hard palate
What does the soft palate separate?
The superior nasopharynx from the rest of the pharynx
What does the choanae connect?
The nasal cavity and nasopharynx
What does the nasal mucosa do?
Trap particles, warms and humidifies incoming air, and dehumidifies and absorbs heat of outgoing air
What is the pharynx?
Also called the throat
A chamber shared by the digestive and respiratory systems
What is the nasopharynx?
The superior part of the pharynx
What is the oropharynx continuous with?
The oral cavity
What does the laryngopharynx include?
The narrow zone between the hyoid bone and the entrance to the esophagus
Inhaled air passes through the ____ on the way to the ____
Glottis
Lungs
What surrounds and protects the glottis?
The larynx
What is the glottis?
The vocal apparatus
What 3 large cartilages and 3 small cartilages composes the cylindrical larynx?
Large cartilages:
Median thyroid cartilage
Median cricoid cartilage
Epiglottis
Small cartilages:
Arytenoid
Corniculate
Cuneiform
A pair of inelastic _____ surrounds the glottis
Vestibular folds
What does the glottis include?
The elastic vocal folds and the space between them, the rima glottidis
What does air passing through the open glottis do?
Vibrates its vocal folds, producing sound
What does the pitch of sound depend on?
The diameter, length, and tension of the vocal cords
What do the muscles of the neck and pharynx do for the larynx?
Position and stabilize it
What do the intrinsic muscles do for the larynx?
Regulate tension in the vocal folds or open and close the glottis
During swallowing, what do the muscles of the neck and pharynx do that is important?
Help prevent particles from entering the glottis
What does the submucosa contain?
C-shaped tracheal cartilages, which stiffen the tracheal walls and protect the airway
Why does the posterior tracheal wall distort?
To permit large masses of food to pass through the esophagus
What does the trachea branch within the mediastinum to form?
The right and left main bronchi
Where does each bronchus enter a lung?
At the hilum (a groove)
What is the root of the lung?
A connective tissue mass that includes the bronchus, pulmonary vessels, and nerves
What do the main bronchi and their branches form?
The bronchial tree
What happens when the lobar and segmental bronchi branch within the lungs?
The amount of cartilage in their walls decrease and the amount of smooth muscle increases
Each tertiary bronchus supplies air to a single ____
Bronchopulmonary segment
What do bronchioles within the bronchopulmonary segment ultimately branch into?
Terminal bronchioles
What does each terminal bronchiole deliver air to?
A single pulmonary lobule in which the terminal bronchiole branches into respiratory bronchioles
The connective tissues of the root of the lung extend into…?
The parenchyma of the lung as a series of trabeculae
What do trabeculae branch to form?
Interlobular septa
What do interlobular septa do in the lungs?
Divide the lungs into lobules
What do the respiratory bronchioles open into?
Alveolar ducts, where many alveoli are interconnected
Where are the respiratory exchange surfaces connected to the circulatory system?
Capillaries of the pulmonary circuit
What does the blood air barrier consist of?
A simple squamous epithelium
The endothelial cell lining an adjacent capillary
Their fused basement membranes
What do pneumocytes type II scattered in the blood air barrier produce?
Surfactant that reduces surface tension and keeps the alveoli from collapsing
What do alveolar macrophages do?
Patrol the epithelium and engulf foreign particles
What are the lobes of the lungs separated by?
Fissures
How many lobes does each lung have?
Right - 3
Left - 2
What do the anterior and lateral surfaces of the lungs follow?
The inner contours of the rib cage
What is the concavity of the medial surface of the left lung called?
The cardiac notch, which conforms to the shape of the pericardium
Where does the respiratory exchange surfaces receive blood from?
Arteries of the pulmonary circuit
Where do the conducting portions of the respiratory tract receive blood from?
The bronchial arteries