Upper Respiratory Tract Flashcards
What are the components of upper and lower respiratory tracts?
- Upper: nasal cavity and sinuses, pharynx
- Lower: larynx, trachea, bronchi, bronchioles and lungs
What are the functions of the respiratory system?
- Primary: transport of gases, surface for gas exchange
- Secondary: phonation and smell
What are some common upper respiratory tract infections?
- Common cold
- Sinusitis
- Tonsilitis
Classify the epithelium of the upper respiratory tract
- Pseudostratified, ciliated columnar epithelium with goblet cells
- Lamina propria- thin layer of CT part of the mucous membrane
What are the 3 cell types found in the respiratory epithelium?
- Progenitor cells in the basal lamina that produce goblet cells
- Goblet cells
- Psuedostratified ciliated columnar cells
Describe goblet cells
- Apocrine or merocrine
- Secretion of mucus (Gel-like complex of proteins)
Classify the epithelium in the back of the throat
- Stratified squamous epithelium (non-keratinised)
- Food makes contact here
Classify epithelium of small bronchioles and alveoli
- Small bronchioles= cuboidal epithelium
- Alveoli: simple squamous, type 1 pneumocytes
What is the muco-ciliary escalator?
- Co-ordinated movement of cilia
What are the external nares?
- Nostrils with hairs
What are the nasal conchae and what is their purpose?
- Superior, middle (formed by ethmoid bone)
- Inferior (individual bone
- Also meatus beneath each one to increase SA
- Moisten air
What are choanae?
- Internal nares that joint the throat
What are paranasal air sinuses?
- Air spaces in skull surround nasal cavities
Describe the frontal sinus
- Lined with respiratory epithelium, inside frontal bone
- Infunribrulum drains into frontonasal duct which drains frontal sinus
- Ethmoidal cells also drain here
Describe ethmoidal cells
- Openings of middle ethmoid cells drain into bulla ethmoidalis
- Openings of posterior ethmoid–> lateral wall of superior meatus
- Above this is the sphenoid-ethmoidal recess
Where does the sphenoid-ethmoidal recess drain?
- Drains sphenoid sinus§
Where does the sphenoid-palatine foramen drain?
- Lateral and posterior end of superior meatus
Where is the hiatus semi-lunaris found?
- Under ethmoid bulla
- Maxillary sinus drains into this
What is the Eustachian tube?
- For balance
- Drains into middle ear
Where is the opening of the nasolacrimal duct found and what does it drain?
- Under inferior concha
- Drains eyes and nose
How many openings are there on each side of the nose?
- 11 on each side
- 22 in total
Summarise where each sinus and duct opens into
- Sphenoidal air sinus–> spenoethmoidal recess
- Posterior ethmoidal sinuses–> superior meatus
- Middle ethmoidal sinuses–> bulla ethmoidalis
- Maxillary sinus–> hiatus semilunaris
- Anterior ethmoidal sinuses–> hiatus semilunaris
- Frontal sinus–> infundibulum
- Nasolacrimal duct–> inferior meatus
Describe nerve supply to the nasal cavity
- Pterygopalatine ganglion (parasympathetic) supplies all nasal cavity
- Found in pteryomaxillary fissure
What two nerves in the pterygopalatine ganglion made up of?
- Greater petrosal nerve- branch of cranial nerve VII (facial)
- Maxillary nerve- middle branch of cranial nerve V2 (trigeminal nerve)
What supplies the roof of nasal cavity?
- Olfactory nerves
- Cranial nerve I
- Sense of smell
Describe the arterial supply to the nasal cavity
- Ophthalmic artery (anterior and posterior ethmoid arteries branches)
- Sphenopalatine artery from maxillary (lateral and septal branch)
- Both maxillary and ophthalmic come from external carotid artery
Describe what happens with a nose bleed
- Kiesselbach’s plexus formed from branches of anterior ethmoid
- superior labial artery (and a bit of greater palatine artery)
- Rupture of plexus is bad for those with comprised haemostasis
Describe the venous drainage of the nasal cavity
- Sphenopalatine vein–> pterygoid venous plexus–> maxillary vein–> internal jugular vein
What are the four paranasal sinuses?
- Frontal
- Maxillary (in cheeks)
- Sphenoidal
- Ethmoidal air spaces (surround orbit of the eye)
What are the functions of the paranasal sinuses?
- Warm and moisten air
- Lightens weight of cranium
- Crumple zone to protect vital structure
- Mechanical and thermal insulation of orbit
- Regulates intranasal pressure
- Acts as a reservoir (aids in olfaction)
What is sinusitis?
- Inflammation and swelling of mucosa
- Local pain
- Swelling of mucosa
- Difficulty of drainage blocks openings
What would happen in sinusitis of the maxillary sinus?
- Opening difficult to move
- Requires incision in root of mouth and draniage
- Treat with antibiotics
What would happen in sinusitis of the frontal sinus?
- Gravity will drain the mucus
What are the three parts of the pharynx?
- Nasopharynx- pos tip of inf + mid conchae to tip of uvula (soft palate)
- Oropharynx- tip of uvula to tip of epiglottis, squamous stratified epithelium
- Laryngopharynx- tip of epiglottis to false vocal folds, respiratory epithleium
What is tonsillitis?
- Inflammation of tonsils
What is pharyngitis?
- Swelling of palatine tonsils
- Soar throat
What infections could occur in the pharynx?
- Rhinitis
- Tonsilitis
- Pharyngitis
- Persistent cough
Describe Waldeyer’s Rung
- Top= Adenoid
- Tubal tonsils
- Visible palatine tonsils
- Lingual tonsil in mouth
- Tonsils are full of lymphocytes and immune cells
