Respiratory System Flashcards
What are the main functions of respiratory system?
- Ventilation
- Air movement into and out the lungs
- Exchange of gases (O2 and CO2) between lungs and blood
What are the 2 subdivisions of respiratory system?
- Upper Respiratory System
- Nose, Nasal cavity, pharynx
- Lower Respiratory System
- Larynx, trachea, bronchial tree, lungs
Mucosa/Mucous
- most of the respiratory tract is ciliated pseudostratified epithelium with goblet cells sitting on the lamina propria
- Goblet cells secrete mucous
- Cilia sweep mucous to esophagus where swallowed
Respiratory System Organs
- Nose
- Nasal Cavity
- Paranasal Sinuses
- Pharynx (Throat)
- Larynx (Voice-Box)
- Trachea
- Lungs
- Bronchial Tree
- Respiratory Membrane
Nose
- Supported by bone and hyaline cartilage
- Nostrils are called nares
Nasal Cavity Function
- Airway passage (warms, moistens, and filters air)
- Olfaction (sense of smell)
- Speech (resonance chamber)
Nasal Septum (Nasal Cavity)
- Anterior Part
- Hyaline cartilage
- Posterior Part
- Vomer, Ethmoid, Maxillae, Palatine bones
What are the 3 areas of Nasal Cavity?
- Vestibule
- Respiratory Area
- Olfactory Area
Vestibule (Nasal Cavity)
- Anterior region
- No mucosa; lined by thin skin with hair that filters particles (e.g. dust, pollen)
Respiratory Area (Nasal Cavity - PART 1)
- Posterior region
- Chonchae protrude medially from the lateral walls of nasal cavity
- Superior (projection of the ethmoid)
- Middle (projection of the ethmoid)
- Inferior (separate bones referred to as the inferior nasal chonchae)
Respiratory Area (Nasal Cavity - PART 2)
- Air passes through nasal meatuses (channels) that are between the nasal chonchae
- Chonchae and meatuses cause air turbulence that helps to humidify air and trap dust/pollen on the ciliated epithelium
- Nasolacrimal duct connects the medial region of eye to the inferior nasal meatus, allowing lacrimal fluid (which includes tears) to drain into nasal cavity
Olfactory Area (Nasal Cavity)
- Found in roof of nasal cavity
- Mucosa contains olfactory neurons that are sensory receptors for the sense of smell
Paranasal Sinuses
- 8 Air filled spaces in skull
- Paired left & right spaces in:
- Frontal
- Sphenoid
- Ethmoid
- Maxillae
- Paired left & right spaces in:
- Open directly into nasal cavity
- Function: Warm, moisten air (Skull lighter)
- Sinusitis: When the mucous membrane becomes inflamed due to infection
Pharynx (Throat)
- Walls are formed of skeletal muscle lined by mucous membrane
- 3 interconnected regions
- Nasopharynx
- Oropharynx
- Laryngopharynx
Nasopharynx
- Located posterior to nasal cavity
- Passageway for air only
- Contains:
- Pharyngeal tonsil located on posterior wall
- Openings:
- 2 Posterior nasal apertures - connect nasal cavity to nasopharynx
- 2 Pharyngotympanic (auditory) tubes - connect middle ear to nasopharynx
Oropharynx
- Posterior to oral cavity
- Epithelium of mucosa is a stratified squamous epithelium
- Passageway for both air and food from soft palate to top of epiglottis
- Contains:
- Palatine Tonsils
- Lingual Tonsil
Laryngopharynx
- Posterior to the larynx - from the epiglottis to the opening of the larynx
- Epithelium of mucosa is a stratified squamous epithelium
- Passageway for both air and food
Larynx (Voice-Box)
- Anterior to laryngopharynx
- Air passageway that connects the pharynx to the trachea
- Composed of 8 hyaline cartilages and 1 elastic cartilage (epiglottis):
- The epiglottis is flexible and covers the glottis during swallowing to prevent food from entering the larynx
Vocal Cords (Larynx)
- Ligaments are 2 sets of paired folds under the laryngeal mucosa in the mid-larynx
- Vestibular Folds
- Vocal Folds
Vestibular Folds
- Are the superior folds
- Are called the False Vocal Cords
- Helps close the glottis
Vocal Folds
- Are the Inferior folds
- Are called the True Vocal Cords
- Produce sounds by vibration
Glottis (Larynx)
- Includes the vocal folds (true vocal cords) and the opening between them
- Closes to prevent food and liquid from entering trachea
- Laryngitis:
- Inflammation of larynx due to infection or irritation
Trachea
- Anterior to esophagus
- Connects larynx to main bronchi (the two main bronchi are branches off trachea leading to each lung)
- Passageway for air only
- Consists of 20 C-shaped pieces of hyaline cartilage
- Open part of C faces esophagus - permits expansion of esophagus
Lungs
- Right and left lungs are separated by mediastinum
- Right Lung
- Left Lung
- Pleura
- Pleural Cavity
Right Lung
- 3 Lobes
- Superior, middle, inferior
Left Lung
- 2 Lobes
- Superior, Inferior
- Has cardiac notch (where heart lies)
Pleura
- Serous membrane
- Visceral - on surface of lung
- Parietal - on inner thoracic wall, superior diaphragm and mediastinum
Pleural Cavity
- Filled with serous fluid
- Prevents friction when lungs move
- Holds lungs to thoracic cavity wall
Bronchial Tree
- Connects trachea to alveoli of lungs
- Extends from left and right main brachi to alveolar ducts
- Air passageway that repeatedly branches into smaller and smaller passageways
what does Bronchial Tree consists of?
- Conducting Zone Structures
- Respiratory Zone Structures
Conducting Zone Structures
- 2 Main (primary/ 1st level) bronchi (left and right)
- 5 Lobar (secondary/ 2nd level) bronchi
- 3 on right side, 2 on left side
- Segmental bronchi (multiple levels of branching)
- Terminal bronchioles (multiple levels of branching)
- Epithelium of mucosa transitions from ciliated pseudostratified epithelium in larger bronchi to ciliated simple cuboidal epithelium in the terminal bronchioles
Respiratory Zone Structures
- Site of gas exchange (oxygen enters blood and carbon dioxide exits blood in these structures)
- Epithelium of mucosa transitions from ciliated simple cuboidal epithelium in respiratory bronchioles to simple squamous in the alveolar ducts
What does Respiratory Zone Structures consists of?
- Respiratory bronchioles (multiple levels of branching)
- Alveolar ducts (tips of bronchial tree)
- Alveoli (millions)
- Honeycomb-like chambers
- Main site of gas exchange
- Form part of respiratory membrane
Respiratory Membrane
- 3 layers = 2 epithelia and their fused basement membrane
Wall of Alveolus
- Simple epithelium
- Made of 2 cell types:
1. Type I alveolar cells
2. Type II alveolar cells - Alveolar pores (openings) allow air movement between adjacent alveoli
- Macrophages
- Freely move between blood and alveoli
- Remove dust, cellular debris and pathogens
Type I alveolar cells
- Simple squamous
- Allow gas diffusion
Type II alveolar cells
- Simple cuboidal
- Secrete surfactant - molecule that covers inner surface of alveoli
- Reduces atractive forces between water molecules making it easier for alveoli to expand during inhalation
Wall of capillary
Simple Squamous Epithelium (Endothelium)
What the 2 routes for Blood Supply to the Lungs?
- Pulmonary Circulation
- Bronchial Circulation
Pulmonary Circulation
- Blood to be oxygenated
right ventricle
↓ (Deoxygenated)
pulmonary trunk
↓ (Deoxygenated)
pulmonary arteries
↓ (Deoxygenated)
capillaries in respiratory portion of lungs
↓ (Oxygenated)
pulmonary veins
↓ (Oxygenated)
left atrium
Bronchial Circulation
- Subdivision of systemic
- Blood of nourish lung tissue
- Bronchial arteries
- Arise from aorta (systemic)
- Carry oxy blood to lung tissues (eg bronchi) except respiratory portion
- Returning to heart blood drains into:
- Bronchial vein (little blood) (to right atrium - systemic)
- OR pulmonary veins (most blood) ( to left atrium - pulmonary)
Blood Flow 1 (Bronchial Circulation)
Left ventricle
↓ (Oxygenated)
Aorta
↓ (Oxygenated)
Bronchial arteries
↓ (Oxygenated)
All lung/bronchial tissue (EXCEPT respiratory portion)
↓ (Deoxygenated)
pulmonary veins
↓ (Oxygenated)
left atrium
Blood Flow 2 (Bronchial Circulation)
Left ventricle
↓ (Oxygenated)
Aorta
↓ (Oxygenated)
Bronchial arteries
↓ (Oxygenated)
All lung/bronchial tissue (EXCEPT respiratory portion)
↓ (Deoxygenated)
Bronchial veins
↓ (Deoxygenated)
Vena cava
↓ (Deoxygenated)
left atrium
Related Medical Conditions
- Pulmonary Edema
- Pulmonary Embolism
Pulmonary Edema
Accumulation of fluid in the lungs - between cells and within alveoli
Pulmonary Embolism
- Blockage of pulmonary vasculature
- Results from blood clots, arteriosclerosis, air buubbles in vessels, etc
