As you breathe
-influence our speech, acid base balance and olfaction
- Anatomically: Upper and lower respiratory tract (lower is housed in the ribcage).
- Functionally: Conducting zone and respiratory zone.
anatomical division:
-the upper res tract -nasal cavity, nostril, pharynx, epiglottis, and larynx
-the lower respiratory tracts - trachea, primary. 2ndary, 3ary bronchus. bronchiole, terminal bronchiole, resp bronchiole, alveolar ducts, alveolar sacs, alveoli and left lung
functional division: iconduction system from nose to the bronchiole
-nasal cavity, pharynx, larynx, trachea, primary. 2ndary, 3ary bronchus. bronchiole, terminal bronchiole, resp bronchiole (resp mark end of conducting system)
Gaseous interchange system: gas moving from alveoli in the lungs into the bloodstream
-alveolar ducts, alveolar sacs, alveoli - left lung
pharynx connects nasal cavity and mouth - naso, ora, phar. epiglottis will stay open to go through the larynx
MUCOCILIARY ESCALATOR
Respiratory epithelium
* Pseudostratified columnar with goblet cells and cilia. Pseudo because the nuclei are at different levels creating stratification. True epi will rest on BM and cilia is not present on true strat epi
* Goblet cells- Mucous, antibacterial, traps dust, moistens air.
* Transported by cilia.
Seromucous glands- Compound tubuloacinar.
Function: Cilia propels a surface layer of
mucous containing entrapped particles towards the pharynx to keep it away from the lungs
lungs with CF will have bronchial tubes blocked by mucus. Inherited disorder build up of thick mucus
NASAL CAVITY
NASAL MUCOSA & Cell types
PARANASAL SINUSES
NASAL MUCOSA
* Olfactory epithelium-smell
* Pseudostratified columnar with goblet cells and cilia.
*concha-bony plates in the nasal cavity increase surface area of these cavities, thus providing for rapid warming and humidification of air as it passes to the lungs.
Cell types
* Sustancular cells .Olfactory cells -receptor , Basal cells -stem cells
PARANASAL SINUSES
* Air-containing spaces that open or drain into the nasal cavity. can get sinosinide if not working well
* Pseudostratified columnar with goblet cells and cilia.
- Four pairs of sinuses:
1. Frontal
2. Ethmoid
3. Sphenoid
4. Maxillary
PHARYNX
Composition
Functions
THREE ANATOMICAL PARTS
- base of the skull to the esophagus.
Composition: - Skeletal muscles.
- Lined with mucous membranes.
- Seven openings.
Functions:
* Common pathway for respiratory and digestive tracts.
* Plays a role in phonation (speech production) syllables
Nasopharynx:
* Auditory (eustachian) tubes
* Posterior nares
* Pharyngeal tonsils
Oropharynx -tonsils first line of defense
* Palatine tonsils
* Lingual tonsils
Laryngopharynx
* Opening into larynx
* Opening into esophagus
LARYNX
functions
- Voice box lined with respiratory epi
-below the tongue, leads to the trachea.
*only the air pass through the larynx
*surrounded by the vocalis muscles
Functions:
* Air passage way
* Filtration, warming and humidification of air
* Swallowing
* Phonation- sound production
- Respiratory epithelium – except in true vocal cords - SSNK resistant to wear and tear 2nd
- Vestibular (false vocal) folds -1st
- True vocal cords – glottis
- Ventricle
- Cartilage framework
LARYNGEAL CARTILAGES
MUSCLES OF THE LARYNX
Formed by nine cartilages:
*Thyroid cartilage - Largest, gives shape
* Epiglottis cartilage -Flap like cartilage that covers glottis
*Cricoid cartilage-Ring of cartilage between thyroid surrounding trachea
* Pair of arytenoid cartilage- Moves vocal cords
* Pair of corniculate cartilage
* Pair of cuneiform cartilage
Extrinsic
* Move larynx as a whole.
* Origin on other structures, insertion on larynx.
-elevate or depress the larynx
- Intrinsic
- Control vocal fold length.
- Origin and insertion on larynx.
VOCAL CORDS
False vocal cords - With mucociliary escalator (respiratory epithelium + seromucous glands).
True vocal cords (glottis)- short ssnk
* With SSNK epithelium (resistant to trauma).
* Vocalis muscle (striated voluntary muscle (skeletal)- SVM).
* Vocalis ligament – (elastic CT) control the pitch of sound.
Ventricle – AKA. Laryngeal saccule where the change in epithelium will occur
* Cleft between false and true vocal cords which terminates in the saccule.
* Squamocolumnar junction present.
TRACHEA - STRUCTURE
- Windpipe start of lower resp tract
Structures:
* 15-20 C-shaped cartilage rings keeping the lumen open
* Fibroelastic tissue
* Smooth muscles
* MUCOCILIARY ESCALATOR = Respiratory epithelium + seromucous glands. Filters
- Presence of elastic fibers in the wall
- Debris in the lumen
*esophagus is neighboring tissue (behind) which can be seen depending on plane of cut
HISTOLOGY OF THE TRACHEA
Mucociliary escalator
* Respiratory epithelium + seromucous glands
Lamina propria – fibroelastic tissue + cartilage
* expansion of the diameter + extension in
length during inspiration
* Passive recoil during expiration
Tracheal ligaments
* Attach muscle to each other and to the ends of the C shaped cartilage
- Submucosa merges with perichondrium of the C- ring cartilages
Trachealis muscle –
* Smooth muscle – joins the ends of C rings.
Epithelial cells :
* Columnar cells
* Goblet cells
* Serous cells
* Basal cells (neuroendocrine cells)
* Basal stem cells
LUNGS
- Air distribution
- Gas exchange
- Provide air-tight bag for thorax to pull and
push on. movement of air in and out of lungs
*lobules separated by septae
Inspiration
* Taking in air (high pressure to low pressure
* Flattens or contracts the diaphragm.
Expiration
* Releasing air out of the lungs
* Lowering of the chest therefore relaxing the diaphragm.
THE BRONCHIAL TREE in the lungs
- Primary bronchi
- Secondary bronchi
- Tertiary bronchi
- Bronchioles
- Terminal bronchioles
- Respiratory bronchioles → Alveolar ducts →
alveolar sacs → alveoli
HISTOLOGY OF THE PRIMARY
BRONCHIAL WALL
- Columnar cells are less tall and less goblet cells.
- upper Lamina propria contains more elastin fibers.
- Smooth muscles with elastin fibers separate lamina propria from submucosa.
- Less seromucous glands in the submucosa.
- C-rings are gradually replaced by hyaline cartilage plates.
- BALTs
SECONDARY TO TERTIARY
BRONCHUS
- Resemble large bronchus just smaller.
- Columnar cells are tall but little pseudostratification; decrease in goblet cell from secondary to tertiary
- Lamina propria - thin, elastic, surrounded by more smooth muscles.
- Seromucous glands are sparse.
- Cartilage plates are very few (cease to exist beyond the tertiary level)
TERMINAL AND RESPIRATORY
BRONCHIOLE
- Smallest diameter air passages (<0.5 mm diameter).
- Terminal portion of the conducting system.goblet cells - replaced by Clara cells
- Produce components of surfactant - reduce surface tension
- Stem cells – divide and replace damaged cells
- Contain enzymes that can detoxify noxious substances
Terminal and respiratory bronchioles.
* Simple cuboidal with cilia.
- Smooth muscles in respiratory bronchioles and alveolar ducts regulate air movement
- alveolar ducts and sacs are the gaseous interchange system
BRONCHIOLE
- No cartilage or seromucous glands.
- Simple columnar with cilia and few goblet cells.
In the terminal and respiratory bronchioles:
* Clara cells take the place of goblet cells.
* Tall columnar cells with apical secretory granules.
*Part of the diffuse neuroendocrine system
* Secrete peptide hormones (serotonin and
bombesin) that regulate muscle tone in bronchial and blood vessel walls
TERMINAL PORTIONS OF
BRONCHIAL TREE consist of
- Respiratory bronchiole (end)
- Alveolar duct
- Alveolar sac
- Alveoli
ALVEOLI = AIR SACS
Function: Gas exchange
Structure:
* Functional unit of respiratory system.
* Simple squamous epithelium – called Pneumocytes.
There are two types of pneumocytes.
* Type 1 – gas exchange
alveolar lining cells - large squamous cells that are parts of the gas diffusion barrier
* Type 2 - secretion of pulmonary surfactant
reduce surface tension within the alveoli.
- Alveolar ducts → sacs → alveoli
- Intimate with capillary endothelium (diffusion through 2 cells thick)
- Allow for easier diffusion of gases
Alveolar wall: surface epithelium + supporting
tissue + blood vessels.
