Lecture 18: The Respiratory System Flashcards
What is the function of the respiratory system?
- Gas Exchange (CO2 AND O2)
- Regulate blood pH
- Receptors for sense of smell
- Filters, warms and moistens inspired air
- Produces sounds
Structurally classify the components of the respiratory system?
- Upper respiratory system
→ Nose
→ Nasal Cavity
→ Pharynx
→ Larynx (above vocal chords)
- Lower respiratory system:
→ Larynx (below vocal)
→ Trachea
→ Brochi
→ Lungs
Functionally classify the respiratory system:
Conductive portion: Collection and conditioning of air via tubes carrying into the lungs.
Respiratory portion: Site of gas exchange; bronchioles, alveolar ducts and sacs
What is the role of the mucous membrane?
- Lines body cavity that opens to the exterior
- Lubrication of body cavity/tissues and protection from foreign particles
PRODUCED MORE ON COLD DAYS
Where is the respiratory epithelium located and what are its specializations?
- Located in most of the conductive portion of respiratory system (Nasal cavity → Bronchi)
- Specializations: Goblet cells (mucous), brush (microvilli endings), Basal cells, cilli
Describe the anatomy of the nose:
External: Nasal bones which form bridge, Opening nostrils (external nares), nasal vestibule divided by septum contains vibrissae (hairs).
Internal: Nasal Cavity (divided by septum), Conchae (superior, middle and inferior), internal nares (choanae)
Where is the olfactory epithelium located and what is its function:
Located in the superior nasal conchae
Contains chemoreceptors for the sense of smell
- Sustentacular Cells (support)
- Basal Cells
- Olfactory cells
- Olfactory Bowman’s gland (mucous secretion)
Where is the pharynx?
Tube connecting the nasal and oral cavities and the larynx (oesophagus)
Skeletal muscle lined with mucous membrane acts as a passageway for food and air.
What are the 3 components of the pharynx
- Nasopharynx- Choane to soft palate, openings for eustachian tubes and lined with respiratory epithelium
- Oropharynx- Soft palate to hyoid bone, tonsils, lined with non keratinised stratified squamous epithelium
- Laryngopharynx- Hyoid Bone to Trachea, Respiration and Digestion, non keratinised stratified squamous epithelium
What is the function of the Larynx and identify any key features
Connects the laryngopharynx to the trachea; midline of the neck anterior to oesophagus
Made up of 9 pieces of cartilage:
Thyroid - Anterior wall connected to the hyoid
Epiglottis- Leaf life structure posterior to thyroid: closes glottis when food is swallowed
Cricoid- Circular cartilage inferior to thyroid
Cuneiform- Bumps on cartilage where vocal chords attach (2)
Corniculate- Apex of arytenoid cartilage (2)
Arytenoid- Prong like structures attached to cricoid cartilage (2)
What is your vocal chords made out of?
- Ventricular folds (false) → Will close of to form pressure when lifting heavy object
- Vocal Folds (true) → contains elastic ligament which can be altered to form sounds through tension
What are the main function of the vocal chords?
Control airflow and allow the production of sound
Describe the anatomy of the trachea
Anterior to the oesophagus from larynx
Wall:
- Mucosa: Respiratory Epithelium
- Submucosa: Areolar Tissue
- Media: 16-20 C-shaped rings of hyaline cartilage unified by fibrocartilage (trachealis muscle)
- Adventitia: Areolar tissue joins trachea with surrounding tissues.
Outline the Structural classification of the bronchi as it enters the lung:
Primary (main) Bronchi
- L + R main bronchus
- Right is more vertical than left (means food can be more easily transported to R)
Secondary (lobar) bronchi
- L + R lobar bronchus 3 RIGHT AND 2 LEFT (match number of lobes of lung)
Tertiary (Segmental) Bronchi
- 10 in each lung and they will divide into bronchioles
How does epithelium change throughout the bronchiole tree?
pseudostratified ciliated columnar epithelium (bronchi) → Simple non ciliated cuboidal (terminal bronchioles)
How does cartilage change throughout the bronchiole tree?
Incomplete rings of cartilage gradually gets replaced with smooth muscle.
How do cell specialisations change throughout the bronchiole tree
Goblet cells gradually decrease until zero at terminal bronchioles where it is replaced with Clara cells- produce surfactant
Anatomically describe the lungs
- Paired organs within thoracic cavity - Surrounded by visceral pleura
- APEX- projects superiorly to the clavicle
- Anterior base, mediastinal base, diaphragmatic base
- Left lung slightly smaller and has a cardiac notch for the heart
Describe the anatomy of the right lung
- 3 lobes
- Horizontal fissure and Oblique fissure
- Superior lobe = Most superior lobar bronchus
- Middle lobe = middle superior lobar bronchus
- Inferior lobe = Most inferior lobar bronchus
Describe the anatomy of the left lung:
Only oblique fissure
Superior lobe = superior lobar bronchus
Inferior lobe = inferior lobar bronchus
What is after the terminal bronchioles
Respiratory Bronchi → Alveolar Ducts → Alveolar sacs → Alveolus
What is the function of the alveolus and identify its histological cells features:
Sites of gas exchange where it is surrounded by networks of capillaries
Made of 2 types of cells:
- Simple squamous epithelium where gas exchange occurs.
- conciliated simple cuboidal, synthesize and secrete surfactant
Identify the full bronchiole tree
Main Bronchi → Lobar Bronchi → Segmental bronchi → Terminal bronchi → respiratory bronchioles → Alveolar ducts → Alveolar Sacs → alveoli
