HUMB1000 Lecture 3: 4 - Respiratory System
12 Jun 2018
School
Department
Course
Professor
Respiratory System
Functions of the respiratory system:
1. Respiration
❖ External – gas exchange between lungs and blood
❖ Internal – gas exchange between blood and tissues
2. Regulation of blood pH
3. Voice production
4. Smell
5. Protection
Divisions of the respiratory system:
• Structural classification
❖ Upper respiratory tract
❖ Lower respiratory tract
• Functional classification
❖ Conducting zone
❖ Respiratory zone (in lungs)
Nose
• Nasal cavity
❖ From nostrils (nares) to choana
❖ Vestibules – entry to nasal cavity
▪ stratified squamous epithelium, sweat and sebaceous glands and
hair follicles
❖ Hard palate – floor of nasal cavity
▪ bone
❖ Septum – separates nasal cavity into left and right parts
▪ cartilage and bone
❖ Concha – ony ridges in nasal aity
▪ superior, middle and inferior concha
▪ superior, middle and inferior meatus
❖ Concha vs Choana
❖ Epithelium of concha (and most of nasal cavity)
▪ pseudostratified ciliated columnar epithelium
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Functions of the nasal cavity:
1. Passageway for air
2. Cleans the air
3. Humidifies and warms the air
❖ via warm blood flowing through nasal cavity
❖ via moisture from mucous epithelium and excess tears with drain into nasal
cavity
4. Olfactory
5. Sound of your voice
Pharynx
• 3 regions:
❖ NASOPHARYNX
▪ posterior to nasal cavity
▪ pseudostratified ciliated columnar epithelium
▪ houses openings of the Eustachian tubes
▪ posterior surface of nasopharynx has the pharyngeal tonsils
❖ OROPHARYNX
▪ posterior to oral cavity
▪ stratified squamous epithelium
▪ palatine tonsils
▪ lingual tonsils
❖ LARYNGOPHARYNX
▪ lies posterior to epiglottis
▪ stratified squamous epithelium
Larynx
• also known as voice box
• passageway for air
• made up of 9 cartilage
❖ 6 paired
▪ arytenoid
▪ corniculate
▪ cuneiform
❖ 3 unpaired
▪ thyroid
▪ cricoid
▪ epiglottis
Functions of the larynx
• maintains an open passageway for air movement
• directs food into the oesophagus away from respiratory tract
• sound production via vocal folds
• trap debris from entering lungs
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find more resources at oneclass.com
Trachea
• descends from the larynx and sits anterior to oesophagus
• has 15-20 C-shaped hyaline artilage rings
• dense connective tissue and smooth muscle in between cartilage rings
• tracheal lumen lined with pseudostratified ciliated columnar epithelium with goblet
cells (mucous producing)
Tracheobronchial tree
Moving from trachea to terminal bronchioles:
• increase in smooth muscle
• decrease in cartilage
• change in epithelium in lumen from pseudostratified ciliated columnar → simple
ciliated columnar → simple ciliated cuboidal
Alveoli Respiratory membrane
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
External gas exchange between lungs and blood. Internal gas exchange between blood and tissues: regulation of blood ph, voice production, smell, protection. Divisions of the respiratory system: structural classification. Vestibules entry to nasal cavity stratified squamous epithelium, sweat and sebaceous glands and hair follicles. Hard palate floor of nasal cavity: bone. Septum separates nasal cavity into left and right parts cartilage and bone. Concha (cid:271)ony (cid:862)ridges(cid:863) in nasal (cid:272)a(cid:448)ity superior, middle and inferior concha superior, middle and inferior meatus. Epithelium of concha (and most of nasal cavity: pseudostratified ciliated columnar epithelium. Functions of the nasal cavity: passageway for air, cleans the air, humidifies and warms the air. Via warm blood flowing through nasal cavity. Via moisture from mucous epithelium and excess tears with drain into nasal cavity: olfactory, sound of your voice. Nasopharynx: posterior to nasal cavity, pseudostratified ciliated columnar epithelium, houses openings of the eustachian tubes, posterior surface of nasopharynx has the pharyngeal tonsils.
