Respiratory System Flashcards
Functions of the Respiratory System
- Bring in oxygen to fuel cells & remove
carbon dioxide
- At rest we take in 5-6 liters of air/minute
- Brain damage & death after 5 to 10 min. w/o air - Sound production →air through vocal
folds - Smell →air past receptor cells in nasal
cavity - Protection via coughing & sneezing to keep
airways clear
What is Respiration?
- Ventilation
- Breathing = inhalation & exhalation - Gas Exchange
- External respiration
- Internal respiration - Oxygen utilization by cells
External and Internal Respiration
External respiration
- Gas exchange between air & red
blood cells in the lungs
Internal respiration
- Gas exchange between red blood
cells & body tissues outside of the
lungs
Organs of the Respiratory System
Divided into
* Conducting zone
- Respiratory passageways that transport air
- Filter out dust, humidify and warm
incoming air
* Respiratory zone
- Site of gas exchange in the lungs
What are the structures of the conducting zone?
Structures of the conducting zone (in order of passage with inhalation):
* Nasal cavity
* Pharynx
* Larynx
* Trachea
* Main bronchi
* Lobar bronchi
* Segmental bronchi
* Bronchioles
* Terminal bronchioles
What are the structures of the respiratory zone?
Respiratory zone: site of gas exchange; includes:
* Respiratory bronchioles
* Alveolar ducts
* Alveoli
- Cluster of alveoli = alveolar sac
What is pleura
Lungs are lined with pleural membranes
* Visceral pleura →serous membrane surrounding lungs
* Parietal pleura →serous membrane lining cavity
- Thoracic wall
- Mediastinum
* Pleural fluid between the visceral and parietal pleura causes the lungs to inflate with breathing
- Vacuum is created
What is Pneumothorax and Pleural Effusion?
- If the negative pressure is broken between the two pleurae, lung can collapse
- Results in a pneumothorax
- Pleural effusion
- Accumulation of fluid in
pleural cavity
What is external nose?
Support structures of external nose
* Nasal bones
* Hyaline cartilage
* Dense CT
Functions of the nose & nasal cavity:
* Filter, warm, humidify air
* Smell →epithelium in roof of cavity has special receptor cells
* Speech →resonating chamber
What kinds of mucos membranes line the nasal cavity?
- Olfactory mucosa
- Respiratory mucosa
What is Olfactory mucosa?
Olfactory mucosa
* Near roof of nasal cavity
* Houses the receptors for smell
(more in Special Senses lecture)
What is Respiratory mucosa?
Respiratory mucosa
* Lines most of the respiratory
passageway (nasal cavities to lungs)
What is Respiratory mucosa made of?
- Pseudostratified ciliated columnar epithelium
- With scattered goblet cells (mucus)
- Underlying lamina propria (CT)
- Has mucous cells
– Secrete mucus - And serous cells
– Secrete watery fluid containing digestive enzyme (lysozyme—destroys bacteria) - Very vascular
– Warms air
– Why nosebleeds so easily occur - Pseudostratified ciliated columnar epithelium + lamina propria = mucous membrane
- Sticky mucus helps trap pathogens and debris
What is the make up of mucus?
- Goblet cells and glands produce ~ 1 quart per day
- Covers epithelium and traps debris
- Mucociliary escalator:
- Cilia constantly moving sheets of mucus to posterior region of nasal cavity
- Cold air slows cilia down →runny nose in winter
What are the components of the nasal cavity?
External nares and vestibule
* Opening to nasal cavity
* Lined with protective hairs = vibrissae (not seen in image)
Nasal conchae
* Bony ridges that create air turbulence
* Flings pathogens onto mucus-lined epithelium
* Warms air
What are Olfactory receptor cells?
- Olfactory receptor cells pass through the cribriform plate into olfactory mucosa
- Odorants bind to receptors (smell)
- found in nasal cavity
Where does nasal cavity end?
- Nasal cavity ends at posterior nasal
aperture
What are Paranasal Sinuses?
- Air-filled cavities in bone
- Functions
- Lighten the skull
- Warm and moisten the air
- Have single opening into nasal cavity
- Lined with pseudostratified ciliated columnar epithelium
- Named for the bone found in
- Frontal
- Ethmoid
- Sphenoid
- Maxillary
What is the nasal meatus?
Nasal meatus: opening for sinus into nasal cavity
* Superior, middle, inferior
Sinus infection
* Inflammation of epithelium caused by virus or bacterial →over-secretion of mucus
* Meatus becomes blocked
* Pressure within sinus very painful
What is a deviated septum?
Nasal septum
* Bone and cartilage that separates nasal cavity in half
Deviated septum
* Typically the cartilage becomes misaligned
* Disrupts air flow into cavity
What are the components of the Pharynx?
Nasopharynx
* Posterior nares to soft palate
Oropharynx
* Soft palate to epiglottis
Laryngopharynx
* Epiglottis to superior esophagus
What are the epithelium of the pharynx?
Nasopharynx
* Pseudostratified ciliated columnar epithelium
* Primarily air passes through
Oropharynx
* Stratified squamous epithelium; protection
* Food and air
Laryngopharynx
* Stratified squamous epithelium; protection
* Food and air