Respiratory system Flashcards
What are the features of the respiratory tract?
- Nasal Cavity= adjusts temperature and humidity of air breathed in (concha turbinate, rich blood upply)
- Pharynx
- Larynx
- Trachea
- Bronchi
- Bronchioles
- Alveoli
What are the features of the nasal cavity?
-Elongated wedge shaped space with log large inferior base and narrow apex
-Eustachian tube
-Nasal pharyngeal tonsil
-Nasal septum (divides cavity into 2= left and right)
-Septal cartilage (anterior n.c.)
-Perpendicular plate of ethmoid bone (inferiorly nasal septum)
-Choanae= (air passage into pharynx, posteriorly)
-Vomer (posteriorly n.c.)
=Conchae (x3 ridges formed of curved bone so known as shelves)= turbinate, superior, middle and inferior, divide into 4 parts, lined with mucus membrane and cilia
=Meatus=passage or opening air travels, formed by concha
(inferior, middle, superior, spheno-ethmoidal recess)
What are the Paranasal sinuses?
-All drain into nasal cavity
-Lightens weight of skull
=Frontal- triangular, drains lateral wall of cavity
=Ethmoidal (Ethmoida 1 air cells), anterior middle and posterior components
=Maxillary- largest, pyramidal
=Sphenoidal- into recess
What are the communicating structures in the nasal cavity?
Ethmoidal bulla=
- Pharyngotympanic tube (Eustachian tube) – connects nasal cavity to the middle ear cavity
- Nasolacrimal duct (tear duct) – connects lacrimal sac to nasal cavity
What is the Pharynx?
-Nasopharynx
=Choanae (posterior apertures)- soft palate
-Oropharynx
=Posterior opening of oral cavity- epiglottis
-Laryngopharynx
=Laryngeal inlet- Oesophagus (C6)
-Soft palate “flutter valve” allows to elevation and depression
-Pharyngotympanic tube opens into nasopharynx
What are the constrictor muscles of the pharynx?
- Superior, Middle attach onto hyoid bone) and Inferior constrictor
- Stylopharyngeous
- Phalangeal raphe and tubercle (posterior)
What are the longitudinal muscles of the pharynx?
-Move pharyngeal wall up and over bolus of food being moved through the pharynx
=Salpingopharyngeous
=Paltopharyngeous
=Stylopharyngeous
Describe the innervation of the pharynx
- Pharyngeal branch of Vagus nerve [X] (carrying cranial root of accessory nerve)
- Glossopharyngeal nerve [IX] to Stylopharyngeous
What is the structure of the Larynx?
-Voice Box
-Cartilaginous structure
=Thyroid cartilage (T)= largest, inferior to hyoid bone
=Cricoid cartilage (C)= inferior to thyroid cartilage
=Arytenoid cartilage x 2 (A)= on top of cricoid
=Epiglottis (E)= posterior, allows for closure of the larynx during swelling
-T, C & A are hyaline cartilage
-E is elastic fibrocartilage
-Laryngeal prominence= Adam’s apple
What are the features of the thyroid cartilage?
- Superior horn- attach to hyoid bone
- Laryngeal prominence
- Lamina (Left and Right)
- Inferior horn (articulate to cricoid)
- 90-120 degrees (angle between lamina, depends on gender, acute in males)
What are the features of the Cricoid cartilage?
- Arch of cricoid cartilage (anterior)
- Lamina of cricoid cartilage- oval shaped depressions allows for muscle attachment
- Most inferior cartilage
- Shaped like sigmoid ring
What are the features of the Arytenoid cartilage?
- Pyramidal shape
- Lamina of cricoid cartilage
- Vocal process
- Base- articulate with lamina of cricoid cartilages
- Apex
- Muscular process
What is the Epiglottis?
- Closes over the entrance to the larynx to stop food/ liquid entering during swallowing
- Leaf shape
- Elevation and depression
What are the ligaments of the larynx?
-Thyrohyoid membrane
=Tough fibro-elastic ligament
=Superior margin of thyroid cartilage- inserts into hyoid bone
-Cricotracheal ligament
=Lower border of cricoid cartilage- inserts into upper border of 1st tracheal cartilage
=Fibrous membrane between tracheal cartilage
-Cricothyroid ligament/ membrane
=Cricoid cartilage- inserts Thyroid & posteriorly inserts arytenoid cartilages
=Free upper margin = Vocal ligament
What are the vocal fold of the larynx?
-Vestibular fold= mucosa overlying vestibular ligament (false vocal folds)
-Vocal fold= mucosa overlying vocal ligament (true vocal folds)
Divide larynx into three chambers: vestibule, middle, interglossal space
What are the muscles of the larynx?
-Cricothyroid
=Straight and oblique parts
=Lengthens vocal folds
=External laryngeal nerve (branch of the superior laryngeal nerve)
-Posterior cricoarytenoid muscles
=Primary abductors of vocal folds (open the vocal folds)
=Recurrent laryngeal nerve
-Lateral cricoarytenoid muscles
=Adductors of vocal folds (close the vocal folds)
=Recurrent laryngeal nerve
Describe the sensory innervation of the larynx
- Vagus nerve
- Sensory above vocal folds – L and; R superior laryngeal nerves (internal branch)
- Sensory below vocal folds – L & R recurrent laryngeal nerves
- Recurrent laryngeal nerves man nerve supply to muscles of the larynx except cricothyroid (external branch of superior laryngeal nerves instead)
Describe the motor innervation of the larynx
- Vagus nerve
- All motor innervation – L & R recurrent laryngeal nerves
- Except cricothyroid – L & R superior laryngeal nerves (external branch)
Describe the overall innervation of the larynx
- Sensory above vocal folds- L & R superior laryngeal nerves (internal branch)
- Sensory below vocal folds-L & R recurrent laryngeal nerves
- All motor innervation L & R recurrent laryngeal nerves
- Except cricothyroid L & R superior laryngeal nerves (external branch)
Describe the trachea
-Continuous with the larynx
-Walls are held open by C-shaped rings of hyaline cartilage
=Incomplete posteriorly to allow food to travel down the oesophagus
=Immediately anterior to oesophagus
=Recurrent laryngeal nerve runs between the oesophagus and trachea in the tracheooesophageal groove
-Bifurcates into primary bronchi at T4/5
Describe the histology of the respiratory system
- Most of the upper respiratory tract is covered in pseudostratified columnar ciliated epithelium (“respiratory epithelium”)
- Goblet cells (G) – produce mucus to trap foreign particles
- Cilia (C) - beat to transport mucus out of the respiratory system
Describe the histology of the trachea
- Respiratory epithelium
- Cartilage ring (C)
- Trachealis muscle (T)- internally circular, externally longitudinal, completes the trachea posteriorly
- Mucosa (M)
- Longitudinal muscle (L)
Describe the histology of the primary bronchus
-Respiratory epithelium (RE)
-Cartilage (C), not c shaped
-Mucous/ serous glands (G)
-Elastic lamina propria (LP)
-Smooth muscle (M), increased
-Ciliated epithelial cells (CC)
=Not as tall
=Fewer goblet cells
-Right primary bronchus= lies in closer alignment with the orientation of the trachea, has largest diameter, the lung you would expect an inhaled foreign body to pass
Describe the histology of the bronchiole
- <1mm lumen
- Pseudostratified ciliated columnar epithelium -Ciliated columnar epithelium
- NO glands
- NO cartilage
- Smooth muscle (M)
