Respiratory SystemBy Ben K, Sam W, and Aaron W

Getting to the lungs The diaphragm is a sheet of muscle that runs below the rib cage and is the main muscle in the respiration

process. ● When it contracts it increases the volume of the

chest cavity, decreasing the pressure, and due to the pressure gradient air is drawn into the lungs(1).

The sinuses are hollow spaces in the bones of the head and they help regulate the temperature and humidity of air breathed in. Small openings connect them to the nose.

● There are two entrances for the air to enter your body. The nose and the mouth. The

nose is preferred as the hairs with in it help clean the air.

Getting to the lungs cont. ● After the air enters through the mouth and or nose

it is travels down the Larynx, and into the Trachea, otherwise known as the windpipe.

● The Trachea is the passage leading from the larynx to the lungs, like the Larynx it too is made of cartilage.

● The trachea then divides into the right and left BRONCHIAL TUBE (or Bronchus), one for each lung,

● These bronchial tubes are lined with cilia that carry mucus upward into the throat.

● Mucus helps clean the dust germs and other unwanted things in the air from entering the lungs(1).

Asthma actually causes the airways of the throat and trachea to swell up and become more narrow; this is why asthmatics often suffer from wheezing, shortness of breath, chest tightness, and coughing. (3)

The Lungs:The Bronchial Tubes divide into the lobes of the lung.

The right lung is divided into three lobes, or sections. The (barely) smaller left lung is divided into only two lobes.

Inside the lungs, the Bronchial Tubes divide further and further, branching out in the lungs

The smallest component of bronchial tubes are called Bronchioles,

At the end of each bronchiole are a group of Alveoli, microscopic air sacs.

Alveoli are where the actual gas exchange takes place. (2)

The left lung is slightly smaller as it has the “Cardiac notch” which allows room in your chest for the heart.

Gas Exchange:Gas Exchange in the respiratory system is the diffusion of oxygen and Carbon Dioxide in opposite directions across a membrane.

Gas Exchange is simple (non-facilitated) diffusion across a membrane, and thus a pressure (concentration) gradient drives it.

Most of the Gas Exchange in the body occurs in the in the lungs, and takes place between the Alveoli and the Capillaries which surround them.

The (O2) hypertonic air inside the alveoli diffuses

Oxygen molecules into the hypotonic blood cells

While the (CO2) hypertonic blood cells diffuse

Carbon Dioxide molecules into the alveoli. (2)

That is why things like smoking,

which can gradually damage the

alveolar, lead to shortness of

breath because less space for

oxygen diffusion into the blood

means oxygen is needed more

rapidly to fuel the body.

Alveoli:The alveoli have a structure specialised for efficient

gas exchange:

● Alveoli have thin walls which allow gas to easily diffuse across them.

● They are spherically in order to maximize surface area and thus maximize the available space for gas exchange.

● The alveoli share a membrane with the capillaries surrounding it, allowing the Oxygen in the Alveoli to and the Carbon DIoxide in the Blood cells to easily diffuse into one another.

● These membranes are also fluid lined, allowing gas to dissolve making it easier for it to diffuse across the membrane. (1)

There are about

600 million

alveoli

in your lungs and

if you stretched

them out, they

would cover an

entire tennis

court.

Main Components of Red Blood Cells● Haemoglobin is the thing in red blood

cells that the Oxygen molecules and carbon Dioxide molecules bind to.

● The reaction that binds Oxygen and Carbon Dioxide to the Haemoglobin is catalysed by the carbonic anhydrase enzyme in red blood cells. (4)

Main Components of Blood● Platelets- Fragments of cytoplasm who stop bleeding by causing clots.● White Blood Cells- Cells of the immune system● Red Blood Cells- The component specifically related to gas exchange,

they carry oxygen and carbon dioxide across the body.

A red blood cell can make a complete circuit of your body in 30 seconds! (Dailymail.co.uk)

Relation to Circulatory System

● Capillaries, part of the circulatory system are so narrow that they force blood cells to line up single file, making it easier for the Oxygen in the Alveoli to diffuse into each red blood cell, and the Carbon Dioxide to diffuse out of each red blood cell.

● Once the red blood cells gain oxygen and lose carbon dioxide while in the lungs they become oxygen rich. They then travels through the circulatory system throughout the entire body (4) Gas Exchange Diagram

There are 10 billion capillaries in your body!The largest capillary is just 0.2 mm wide — thinner than a hair!

References

1. "The Respiratory System." Body by Design. Gale, 2007. Science in Context. Web. 17 Nov. 2014.

2. "Lungs." World of Anatomy and Physiology. Gale, 2007. Science in Context. Web. 17 Nov. 2014.

3. "Respiratory diseases." The Gale Encyclopedia of Science. Ed. K. Lee Lerner and Brenda Wilmoth Lerner. 5th ed. Farmington Hills, MI: Gale, 2014. Science in Context. Web. 17 Nov. 2014.

4. “Circulatory system." World of Anatomy and Physiology. Gale, 2002. Science in Context. Web. 17 Nov. 2014.