Hubs 192 L14

What’s the role of the respiratory system

It’s a series of connected organs ands structures that function to conduct clean, warm and moist air in close proximity to the cardiovascular system’s blood for gas exchange

To be effective, what does the respiratory system need?

• A surface of gas exchange(Blood and air are brought close together but separated)

• A path for air to flow to reach the gas exchange surface in optimal conditions

• Ability to draw breath in and out

• Sound production & olfaction(smell )

What’s the main components of the respiratory system?

Upper and lower respiratory tract and the thoraic cavity, joints and the respiratory muscles

What makes up the upper respiratory tract?

Nose, nasal Cavity, Paranasal Sinuses and the Pharynx

What makes up the lower Respiratory Tract?

Larynx, Trachea, Bronchus, Bronchioles, Alveoli and the respiratory Bronchioles

Whats the main component of the Nasal Cavity?

Olfaction

Whats the main components of the conducting Zone?

Nose to bronchioles- ensuring air is clean, warm and moist

Whats the main components of the Respiratory Zone?

Bronchioles to alveoli- sites of gas exchange

Whats the main components of the Oral Cavity?

Passage for air and food

What is the respiratory tract lined with?

Mucosa

What is mucosa made of?

Epithelium, attatched via basement membrane to lamina propria(CT).

Why does Epithelium change along the length of the tract?

To reflect function

What epithelium is most of the conducting region?

Respiratory epithelium

What epithelium does air and food travel?

Stratified Squamous

What epithelium is the site of gas exchange?

Simple squamous

What epithelium involves olfaction(smell)?

Olfactory mucosa

Most organs are lined with …………., which has how mnay parts?

Mucosa, and has 3 parts

What are the 3 parts of mucosa?

Epithelia

Basement Membrane

Lamina Propria

What makes up the lamina propria?

Connective tissue and may contain glands

Order of mucosa

Epithelia

Attacched via a basement membrane to the

Lamina Propria, below this is usually a

Submucosal Layer(Which is made up of more connective tissue and may contain glands)

What repsiratory epithelium is found in the nasal cavity, part of the pharynx, larynx, trachea and bronchi?

Pseudostratified dilated columnar epithelium(with goblet cells)

What do goblet cells produce?

Mucus

What does mucus do?

Traps debris and moistens the air

What does ciliated cells allow for? and why

Patterned movements and push mucus towards the pharynx(which is swallowed and digested by stomach acid)

Why does your nose run on a cold day?

In the cold it will stop cilia from beating, with nothing to help move the mucus towards the pharynx

Why do we cough up mucus when we are unwell?

We normally produce 1-2L of mucus a day, when were sick the body produces more, so we cough to help the cilia move the mucus

Why do smokers cough frequently?

Cigarettes smoke paralyses and destroys cilia, this leads to mucus accumulation and coughing to try and dislodge it

Order of the Upper Respiratory Tract?

Nose

Nasal Cavity —> Conchae

Paranasal Sinuses

Pharynx(throat)

What are the three pharynx’s ?

• Nasopharynx

• Oropharynx

• Laryngopharynx

What are the functions of the upper respiratory tract?

• Acts as a conducting passage(not just air)

• Prepares air in its optimal condition for the reespiratory zone(gas exchange) i.e clean, warm and moist

• Olfaction- sensory receptors for smell

• Paranal Sinuses- resonating chambers for speech

What is the primary passageway for air?

Nose

What is ther anterior aspect of the nose made of? Whats the function

Cartilage, Which is soft and flexible and maintains patent(unobstructed) airway.

What are the nostrils seperated by?

Nasal Septum

What is the Nasal Vestibule lined with? and what does it have?

Skin and it has sebecaous and sweat glands, hair follicles

What does vibrissae(hairs) do?

Filter inhaled air

What is the nasal septum in the midline made of?

Anterior end- Cartilage

Posterior end- bone

What does the internal nares open into?

Nasopharynx

What is the roof of the cavity formed by?

ethmoid and sphenoid bones

What is the floor of the cavity formed by?

The hard and soft palates

Where are the conchae found?

The Lateral walls inside the nasal cavity

Three projections of the conchae?

Superior, middle and inferior

Fucntion of the conchae?

To swirl the incomeing air around hence also known as turbinates

What lines the conchae?

Respiratory epithelium(mucosa)

Whats the fucntion of the Respiratory epithelium(mucosa) in the conchae?

Allows dust particles to stick to it- which allows more contact time for warming and humidyfing the air, plus olfactory detection

How many types of epithelia lines the nasal cavity?

2= predominantly respiratory epithelium and olfactory epithelium

What makes up respiratory epithelium in the nasal cavity?

Pseudostratified ciliated columnar + goblet cells

What makes up Olfactory epithelium in the nasal cavity?

Smell(olfactory) receptors

Plexus refers to …

A network of Vessels

The nasal epithelium sits on the ? to form what? of the nasal mucosa

Lamina propria to form the mucosa

The thinned wall vascular plexus lies underneath what? in the nasal mucosa

The respiratory mucosa

In the nasal mucosa when the air temperature drops what dilates?

The plexus(vaso) dilates, causing great heat transfer- which warms the incoming air

Where do nose bleeds originate from damage to the ?

Plexus

Sinus means?

Cavity within a bone(normally air filled)

Paranasal means?

Surrounding the nose and is

• found within the frontal, sphenoid, ethmoid and maxillary bones

• Lined with respiratory mucosa

• Drain into pharynx(throat)

Functions of the paranasal Sinuses?

• Lightens the skull

• Increased surface area to clean, warm and moisten air

• Sound resonance

• Infected mucus can block drainage= blocked sinus

What is the pharynx commonly called?

Throat

What is the sturcture of the pharynx?

A muscular funnel shaped tube shared in parts by both the respiratory and digestive systems

How many regions is the pharynx divided into?

3

What are the three regions of the pharynx?

• Nasopharynx(air passage ONLY)

• Oropharynx(air and food)

• Laryngopharynx(Air and food)

What is the Nasopharynx lined with only?

Respiratory mucosa

Where is the nasopharynx located?

Posterior to the nasal cavity from the internal nares to the soft palate.

What blocks the nasopharynx during swallowing to prevent food from entering the nasal cavity?

The soft palate and uvula

Where do auditory tubes drain from?

The middle ear

Pharyngeal tonsils(adenoids) on the posterior wall is what?

Lymphatic tissue for trapping pathogens

What is the oropharynx lined by?

Stratified squamous epithelium(protects from abrasions)

Where does the oropharynx sit posteriorly to?

Oral Cavity

Where does the oropharynx extend from?

From the soft palate to the hyoid bone

What does the oropharynx contain?

Palatine(commonly removed) and lingual tonsils for immune functions

What is the laryngopharynx lined with?

Squamous epithelium(protects from abrasions)

Whats does the laryngopharynx extend from?

The hyphoid bone to the opening of the larynx/ beginning of the oesophagus

Where does the laryngopharynx end?

At the level where the respiratory and digestive tracts diverge

What has the right of way in the laryngopharynx?

Food