Lecture 14: OVERVIEW AND UPPER RESPIRATORY TRACT Flashcards
What is the respiratory system?
Connected organs and structures that function to conduct warm, clean, moist air into close proximity with blood fo the circulatory system for gas exchange
What are the key characteristics of air?
Warm, clean and moist
What does the respiratory system need to be effective?
A surface for gas exchange, a path for air to flow to reach the gas exchange surface in optimal condition, ability to draw breath in and out, plus produce sound (voice) and olfaction (smell)
What happens at the surface for gas exchange?
Blood and air come close together but are separated (don’t mix)
What are the main components of the respiratory system?
Upper respiratory tract, lower respiratory tract plus thoracic cavity, joints and respiratory muscles
What are the regions of the respiratory system?
Conducting region, respiratory region, oral cavity and nasal cavity
Where is the conducting region?
From the nose to the bronchioles
What does the conducting region do?
Ensures air is warm, clean and moist
Where is the respiratory region?
Alveoli deep in the lungs
What is the respiratory region the site of?
Gas exchange
What is the oral cavity?
Passage for air and food= different cellular structure
What is the nasal cavity for?
Olfaction
Where is mucosa found?
Lining most hollow body organs
What is mucosa?
Epithelia attached via a basement membrane to the lamina propria (connective tissue and glands)
What is below the mucosa?
Usually the submucosal layer
What does the submucosal layer contain?
Depending on the region may contain many glands, also connective tissue and blood vessels
What is the respiratory tract lined with?
Mucosa
What changes along the respiratory tract?
The epithelia to reflect function
What is the epithelia of most of the conducting region?
Respiratory epithelium
What is the epithelia where air and food travel?
Stratified squamous for protection against abrasion like in skin
What is the epithelia at sites of gas exchange?
Simple squamous so it is thin
What is the epithelia at the olfaction?
Olfactory mucosa
What is respiratory epithelium?
Pseudostratified, ciliated, columnar epithelium (with goblet cells)
What is pseudo stratified?
Fake layering where all cells touch the basement membrane
Where are cilia found?
On the apical surface of cells
WHere is respiratory epithelium found?
In the nasal cavity, parts of the pharynx, larynx, trachea and bronchi
What do goblet cells do?
produce mucus
What does mucus do?
Traps debris, cleans and moistens air
What do ciliated cells do?
Patterned movement pushes mucus to the pharynx. It is then swallowed and digested by stomach acid
What are the components of the URT?
Nose and nasal cavity, paranasal sinuses and pharynx
What is the components of the pharynx?
Nasopharynx, oropharynx and laryngopharynx
What is the function of the URT?
A conducting passage (not only for air) which prepares air for the respiratory membrane (gas exchange)
What are paranasal sinuses?
Resonating chambers for speech
What is olfaction?
Sensory receptors for smell
What is the nose?
The primary passageway for air
What is the secondary passageway for air?
The mouth
What is the nose made of?
Cartilage and bone
What is the cartilage of the nose?
Soft and flexible, maintains a patent (open and unobstructed) airway
What are the bones of the nose?
2 nasal bones on the bridge of the nose
What are nostrils?
External anterior nares
What is part of the nose?
Vestibule
What is the vestibule lined with?
Skin
Wha does the vestibule have?
Sebaceous glands, sweat glands and hair follicles
What are the hairs in the vestibule?
Vibrissiae
What do vibrissiae do?
Filter inhaled air (remove big particles)
What divides the nasal complex in half?
The nasal septum in the midline
What is the anterior of the nasal complex?
Cartilage
What is the posterior of the nasal complex?
Bone
Where do the internal posterior nares open into?
The nasal pathway
What is the roof of the nasal complex cavity formed by?
Ethmoid and sphenoid bones
What is the floor of the nasal complex cavity formed by?
Hard and soft palates
What is on the lateral walls of the nasal complex?
Conchae
How many conchae are there?
3
What are the names of the conchae?
Superior, middle and inferior conchae (turbinates)
What are conchae covered by?
Respiratory epithelium
What do conchae do?
Swirl inspired air
What do particles do at the conchae?
Stick to the mucosa
What does the conchae give more time for?
Warming and humidifying fo air, plus olfactory detection
What is the nasal epithelium?
Mostly respiratory epithelium plus area of olfactory mucosa
What does the area on the roof of the nasal cavity contain?
Smell (olfactory) receptors which is sent along olfactory nerve fibres
What does the epithelium of the nasal mucosa sit on?
Lamina propria (connective tissue layer)
What does the nasal mucosa contain?
A plexus (network) of thin walled veins
What does the nasal mucosa help?
Warm incoming air (radiation)
What happens when air temperature drops?
Vascular plexus dilates meaning there is greater heat transfer
Where do nose bleeds normally originate?
from damage of the nasal mucosa
what is sinus?
A cavity within a bone (normally air filled)
What is paranasal?
Surrounding the nose
Where are paranasal sinuses found?
Within frontal, sphenoid, ethmoid and maxillary bones
What is the paranasal sinuses lined with?
Respiratory mucose
Where do the paranasal sinuses drain into?
The pharynx
what is the functions of the paranasal sinus?
Lighten skull, increase surface area to clean, warm and moisten air, sound resonance (amplifies voice)
What can infected mucus in the paranasal sinus do?
Block drainage causing blocked sinuses
What is the pharynx?
Muscular funnel shaped tube shared by the respiratory and digestive system
What is the pharynx commonly called?
The throat
What is the nasopharynx a passage for?
Air only so has respiratory mucosa
Where is the nasopharynx found?
Posterior to the nasal cavity
Where does the nasopharynx go from?
Posterior nares to the soft palate
What do the soft palate and uvula do?
Block the nasopharynx during swallowing to prevent food entering the nasal cavity
What do auditory do?
Drain mucus to the nasopharynx from the middle air and also have a role in equalising pressure
What tonsils are in the nasopharynx?
Pharyngeal tonsils (adenoids) on the posterior wall
What is the oropharynx a passage for?
Air and food
What is the epithelium of the oropharynx?
Stratified squamous which protects against abrasion
Where is the oropharynx?
Posterior to the oral cavity
Where does the oropharynx go from?
The soft palate to the hyoid bone
What tonsils are in the oropharynx?
The palatine (lateral) and lingual (beneath the tongue)
What is the laryngopharynx a passage for?
Air and food
What is the epithelium of the laryngopharynx?
Stratified squamous which protects against abrasion
Where does the laryngopharynx go from?
Hyoid bone to opening of the larynx/beginning of the oesophagus
Where does the laryngopharynx end?
At a level where the respiratory and digestive tracts diverge
What has right of way during swallowing?
Food
