Respiratory system Flashcards
Respiration
Exchange of oxygen and carbon dioxide with the environment
Which respiration processes are functions of the respiratory system?
Ventilation and external respiration
Which respiration processes are functions of the cardiovascular system?
Gas transport and internal respiration
Ventilation
Move air in/out of lungs
External respiration
Gas diffuses between lungs and blood
How does gas transport happen?
Via blood
Internal respiration
Gas diffuses between blood and cells
Conducting zone
Passageway for air (NO DIFFUSION)
What process does the conducting zone use?
Ventilation
Where does the conducting zone range from?
External nose through most tubes in lungs
Respiratory zone
Oxygen diffuses into blood
What process does the respiratory system use?
External respiration
Where is the respiratory system?
Pulmonary alveoli and respiratory bronchioles
What are the layers of the conducting zone?
Mucosa and submucosa
What is mucosa’s connective tissue layer?
Lamina propria
What is the epithelium in the conducting zone that is exposed to food?
Nonkeratinized stratified squamous
What is the epithelium in the conducting zone that is NOT exposed to food?
Pseudostratified ciliated columnar
What is a function of pseudostratified ciliated columnar epithelium?
Removing debris
What are two glands that secrete mucus to trap debris in the conducting zone?
Goblet cells and seromucous glands
Goblet cells
1-celled glands in mucosal epithelium
Seromucous glands
In lamina propria and submucosa
External nares
Entrance and exit
What does the nasal septum separate?
Left and right nasal cavitites
What type of epithelium is in the external nose?
Pseudostratified ciliated columnar
Which way is debris swept to be swallowed?
Posteriorly
What does the highly vascularized lamina propria do?
Warms and moistens inspired air
Paranasal sinuses
Paired air spaces in the bones of skull
What do paranasal sinuses do?
Connect to nasal cavity by drainage ducts
Pharynx
Where respiratory and digestive tracts intersect
What are the divisions of the pharynx?
Nasopharynx, oropharynx, laryngopharynx
Nasopharynx
Connects to nasal cavity and has pseudostratified ciliated columnar
Oropharynx
Connects to oral cavity and has nonkeratinized stratified squamous
Laryngopharynx
Connects to larynx and esophagus and has nonkeratinized stratified squamous
Larynx functions
“Gateway to lungs”, control speech (voice box)
What type of cartilage are most larynx structures made of?
Hyaline cartilage
Thyroid cartilage
Laryngeal prominence (adam’s apple)
Cricoid cartilage
Most inferior cartilage of larynx (circular)
Arytenoid cartilage
Attached on back of cricoid cartilage (not visible in anterior view)
What happens in the epiglottis?
Swallowing elevates the larynx, epiglottis passively tilts down, laryngeal inlet (opening) closes
What other type of cartilage does the epiglottis have?
Elastic cartilage
Vocal folds
Vibrated by air to produce sound
Rima glottidis
Opening between vocal folds
Glottis
Rima glottidis + vocal folds
Where are the vocal folds attached?
Attached to thyroid cartilage at anterior end and arytenoid cartilage at posterior end
How do the vocal folds open/close?
By moving arytenoid cartilages in transverse plane
How is the pitch controlled?
Cricoid cartilage moves in sagittal plane and carries arytenoid cartilages along (high tension = high pitch)
Vestibular folds
False vocal cords that are superior to vocal folds
Do vestibular folds have a direct role in sound production?
No
What are the vestibular folds important for?
Holding the breath against pressure in the thoracic cavity
Superior larynx epithelium
Stratified squamous
Inferior larynx epithelium
Pseudostratified ciliated columnar
Where is the trachea located?
Mediastinum
Which tissue in the trachea helps to get rid of dust?
Pseudostratified ciliated columnar epithelium
Which tissue in the trachea prevents the collapse of airways?
Rings of hyaline cartilage
Which structure in the trachea contracts when coughing?
Smooth muscle structure
Why does the trachea need elastic connective tissue?
For elastic recoil (more efficient ventilation)
Do the same tissues continue throughout most of the conducting zone?
Yes
Which bronchi is outside of the lungs?
Primary bronchi
Where is the primary bronchi located?
Mediastinum
Which zones does the lung contain?
Part of conducting and all of respiratory
Pleuare
Serous membranes surrounding the lungs
What are the pleuare membranes in order superficial to deep?
Outer pleura, pleural cavity, and inner pleura
Outer pleura
Parietal pleura (attached to chest wall)
Pleural cavity
Space that contains pleural fluid
What does the pleural cavity provide?
Subatmospheric pressure for breathing
Inner pleura
Visceral pleura (outer layer of lung)
How many lobes are in the left lung?
2 to make space for the heart
How many lobes are in the right lung?
3
How many bronchopulmonary segments are in each lung?
About 10
What does the bronchial tree connect?
Trachea to alveoli
How many secondary (lobar) bronchi are there and where are they?
1 per lobe
How many tertiary (segmental) bronchi are there and where are they?
1 per bronchopulmonary segment
What is the size of bronchioles?
<1mm wide
Asthma
Allergic inflammation where the smooth muscle of bronchioles contracts and increases mucus secretion
Where are the terminal bronchioles?
End of conducting zone
Where are the respiratory bronchioles and what are they attached to?
Start of respiratory zone, attached to the alveoli
Pulmonary alveoli
Where gas exchange occurs by diffusion
Pulmonary alveoli characteristic (1)
Covered with pulmonary capillaries
Pulmonary alveoli characteristic (2)
Very short diffusion distance (thin wall = fast diffusion)
Pulmonary alveoli characteristic (3)
Very large surface area
Pulmonary alveoli characteristic (4)
No mucus (slows down diffusion)
Emphysema
Walls between alveoli break down which decreases surface area for oxygen to reach blood vessels
Alveolar macrophages function
Trap dust
Type 1 cells (main component of alveolar lining)
Thinnest for diffusion, have simple squamous epithelium
Type 2 cells
Secrete surfactant, simple cuboidal epithelial cells
Surfactant
Molecules that decrease surface tension of water allowing alveoli to expand
Respiratory distress syndrome
Not enough surfactant produced which makes it difficult for alveoli to expand
What age is respiratory distress syndrome common and why?
In premature infants because their type 2 cells take longer to mature
Inspiration (active)
External intercostal and diaphragm contract (skeletal muscles)
What happens during inspiration?
Increased thoracic volume then decreased pressure in lungs and air enters
Expiration (passive)
Muscles relax and tissues recoil because it has elastic connective tissue
Pneumothorax
Presence of air in the pleural cavity
What can a pneumothorax cause?
A collapsed lung
Where can air enter the body?
From the lung or outside thorax
