The Respiratory System

The Respiratory System

The main function of the respiratory system is to take in oxygen and get rid of carbon dioxide.

It works closely with the circulatory system (the lungs supply oxygen to the blood which is then pumped through our blood vessels).

3 Stages of Respiration

1. Ventilation/Breathing: You breathe in oxygen and you breathe out carbon dioxide

2. Pulmonary respiration: Oxygen travels from your lungs to your body every time your heart beats

3. Tissue Respiration: Oxygen enters your cells and carbon dioxide exits and is transported back to your heart and lungs

Tracing the Path of Air...1. Your nose

1. In humans and all other mammals, you breathe in and out through your nasal cavity (nose).

Your nose has hair inside, which filters bacteria, viruses, dust, mold, fungi and other particles so they don’t get into your lungs

It also warms your breath, helps you speak, and helps you smell

2. Pharynx

2. Next, the air travels through the pharynx, the tube that is used for both food and air

It is 5 inches long, and this is where your tonsils are located

3. Larynx

3. Next, the air goes through your larynx, or voice box.

It is made up of 10 tiny muscles and ligaments

4. Trachea4. Air passes next into the trachea (the epiglottis closes off the esophagus) which is the tube to the lungs

It is made of rings of cartilage and lined with little hairs (called cilia) that push air along

The trachea is also called the windpipe

5. Bronchi

5. The trachea splits into two tubes called the left and right bronchi.

Each one leads to one of the lungs

6. Bronchioles

6. As the bronchi enter the lungs, they branch off into lots of tiny tubes called bronchioles

7. The lungs/Alveoli

7. You have 2 lungs, the right and the left. Their movement is controlled by a large muscle under your rib cage called your diaphragm

Inside your lungs, the bronchioles end at structures called alveoli.

They look like grapes filled with fluid

This is where oxygen diffuses into your blood and carbon dioxide leaves and goes back up and out your nose

Blood supply to the lungs

Deoxygenated blood enters the lungs through the pulmonary artery (from the heart)

Oxygenated blood is returned to the heart through the pulmonary veins

Fun Facts

A normal, healthy adult averages 12 breaths per minute

The brain (the medulla oblongata and the pons) control your breathing

Oxygen is transported in your red blood cells, while Carbon dioxide dissolves in your blood plasma

Respiratory Diseases and Disorders: Asthma

Asthma is caused by your airways becoming swollen and/or blocked, which causes difficult breathing

It can be caused by allergies, stress, aspirin usage, exercise, breathing cold air, or smoking

It is treatable with inhalers and steroid medications that reduce swelling

Emphysema

Emphysema is destruction of the alveoli

It can be caused by smoking, pollution, and exercise

Hiccups

When your diaphragm muscle starts contracting involuntarily, that forces air back out of your esophagus, which causes hiccups

Pneumonia

Pneumonia is an infection of the alveoli.

The most common cause is bacteria, and it can be treated with antibiotics.

It is the most common cause of infectious death in the US

Tuberculosis

Tuberculosis (TB) is an inflammation of the lungs produced by an organism called a mycobacterium.

It is contagious and it destroys lung tissue

Most strains can be treated with antibiotics

You are not allowed on airplanes if you have TB

Cystic Fibrosis

Cystic fibrosis is a genetic disease.

Your body puts too much fluid into your lungs and respiratory passageways.

It is manageable, but you cannot cure it

5% of all Caucasian people are carriers (Aa). If 2 carriers have a baby, they have a 25% chance of a baby with the disease.