The Respiratory System

Interesting Facts Your right lung is slightly larger than your left lung/

The highest recorded sneeze speed is 165 km/h

The capillary tubes in your lungs alone would 1,600 km laid end to end

We lose around half a litre (500 ml) of water through breathing each day.

The surface area of the air sacks in your lungs is roughly the same as a tennis court

The Respiratory System

The respiratory system can be divided into two

parts:

Respiratory tract

Nasal passages

Pharynx

Larynx

Trachea

Bronchi

Lungs

The Respiratory System

Nasal Passages

These are the passages which open to the

outside world.

They end at the opening of the pharynx.

They have two functions

To filter the air using the hairs that coat the lining.

Warm and moisten the air using the mucus in our

passages.

Nasal Passages

Pharynx

Section that serves as a common passageway

between the respiratory and digestive tracts;.

Carries air towards trachea and food towards the

esophagus.

When swallowing, the epiglottis seals the trachea.

Pharynx

Larynx

Upper section of the trachea composed of

cartilage and housing the vocal cords.

This is also common called the adam’s apple.

The larynx carries air and also produces sounds.

Larynx

Larynx

Trachea

This is a section measuring around 11 cm in

length.

It is composed of cartilaginous rings.

These rings are used to hold open.

It is located in front of the esophagus.

Trachea

Bronchi

Tubes arising from the division of the trachea.

It is composed of cartilaginous rings to hold them

open.

They branch out from bronchi into bronchioles

once inside the lungs.

The bronchi branch out further and further into

smaller and smaller branches.

Bronchi

Lungs

They are spongy, elastic organs on either side of

the heart.

They are enclosed in the rib cage.

They are composed of millions of little air sacs,

called alveoli.

What is the purpose of having these air sacs and

not just a big bag?

Lungs

Respiration

How does the air get sucked into your lungs?

Which forces are at play?

Which are the active parts of the respiratory

system?

Which parts are passive?

Respiration

Before we start, we need to understand the

relationship between volume and pressure.

A gas will fill up the volume of any given space.

The pressure comes from the collision between

the air molecules.

More collisions, more pressure!

Respiration As volume expands, if the amount of gas stays the

same, the pressure falls.

If you have a bunch of people walking in a room randomly, the number of times that people bump into each other per minute is like the pressure.

If you add more space or remove some people, less collisions.

If you add more people or reduce the space, more collisions.

Pressure and Volume

Respiration

This is the same principle with gases.

As the volume increases, the pressure drops.

As the volume decreases, the pressure

increases.

This is the principle of how our lungs work.

Respiration

Respiration has two main goals

To get oxygen out of the air for our bodies

To expel carbon dioxide from our bodies

In this section, we will discuss the parts of the

anatomy responsible for each action

Anatomy of Respiration There are 3 main parts of the anatomy which are

involved in respiration. Lungs

Diaphragm

Intercostal muscles

The lungs are simply passive players in respiration.

The diaphragm and intercostal muscles are the ones doing the work.

Inhalation

During inhalation, the diaphragm and intercostal

muscles contract.

The diaphragm descends and the rib cage

expands.

This causes the volume of the rib cage to expand

The volume of the lungs also expand.

Inhalation

When the lungs expand, the pressure inside the

lungs decrease.

This causes the air from the outside to be drawn

into the lungs.

This equalizes the pressure inside the lungs and

the outside world.

This process is used to draw in oxygen rich air.

Exhalation

During exhalation, the intercostal muscles and

the diaphragm relax.

This causes the diaphragm to ascend and ribs to

fall.

The volume of the rib cage decreases.

The volume of the lungs also decreases.

Exhalation

When the volume of the lungs decrease, the

pressure in the lungs increases.

This causes the air in the lungs to be pushed out.

This then equalizes the pressure in the lungs and

the outside world.

Exhalation is used to expel carbon dioxide rich

air.

Inhalation and Exhalation

Gas Exchange Rewind: What is cellular respiration?

Oxygen needs to get into the cells.

Carbon dioxide needs to get out of the cells.

The transportation for these gases is the blood.

How those gases get in and out of the blood is via the lungs.

Gas Exchange

Two body systems are used together to ensure

that the oxygen gets to every cell in the body and

that the carbon dioxide gets out.

Those two systems are the respiratory and the

circulatory system.

The site of the gas exchange is the alveoli, the

tiny air sacs in the lungs.

Gas Exchange

Gas Exchange

This gas exchange happens all by itself due to

diffusion.

Diffusion is the movement of dissolved

substances from a more concentrated region to a

less concentrated region.

O2 moves from the lungs to the blood.

CO2 moves from the blood to the lungs.

Gas exchange

When the blood reaches the lungs, it is rich in

CO2.

The air in the lungs is rich in O2.

The oxygen will move out of the lungs and into

the blood because of the low concentration in the

blood.

The complete opposite happens with the CO2.

Gas Exchange

Lung Diseases

There are a few common lung diseases we will

discuss.

Asthma

Bronchitis

Pneumonia

Asthma

Asthma is a common inflammatory disease of the

lungs.

It is caused by reversible inflammation of the

airways.

The causes are a combination of genetics and

environmental.

Asthma Treatments are the use of a asthma pump to

dispense the medication into the lungs.

These can be either bronchodialators or corticosteroids

Also, the avoidance of smoke or allergens is recommended as well.

There is no cure for asthma, so management is the best treatment.

Bronchitis

Can either be chronic or acute inflammation of

the bronchi.

Acute bronchitis is typically caused by the

presence of another virus, such as a cold, which

leads to irritation and then inflammation.

Chronic bronchitis is a persistent cough which

lasts for more than three months per year. Its

main cause is cigarette smoking.

Bronchitis

Acute bronchitis, since it’s caused by a virus, is

treated symptomatically. This means that you

treat the symptoms until your body has fought off

the virus.

Chronic bronchitis is also treat symptomatically.

Lung function in a patient with chronic bronchitis

can be compromised and so supplemental

oxygen can be administered in a more extreme

case to prevent low oxygen.

Pneumonia

Pneumonia is a condition mainly affecting the

alveoli.

It can be caused by viruses or bacteria.

Symptoms are a cough, chest pain, fever and

difficulty breathing.

Pneumonia affects around 450 million people per

year and kills around 4 million

Pneumonia

Antibiotics, rest, pain medications and fluids are

typically all it takes to get a patient get through

the pneumonia.

If a patients blood oxygen level gets too low,

oxygen can be administered.

Medication can be given to patients with

shortness of breath due to inflammation in the

lungs.