Chapter 18

Respiratory System

What is the Respiratory System?

• Your respiratory system is made up of the organs in your body that help you to breathe. Remember, that Respiration = Breathing. The goal of breathing is to deliver oxygen to the body and to take away carbon dioxide.

The Respiratory System

Functions: 1. The respiratory system moves oxygen

from the outside environment into the body.

2. The respiratory system also removes carbon dioxide and water from the body.

3. Lastly, the respiratory system produces carbon dioxide and water.

Respiratory Diagram

The flow of air:

1. Air enters through the nostrils – the two openings in of your nose:

The flow of air:

2. The air then travels through the pharynx – a muscular tube to the larynx:

The flow of air:

• The larynx is a short tube that is located in the throat. The larynx provides a passage way between the pharynx and lower tract organs. The larynx protects the lower tract organs from food and drink entering and also houses the vocal folds that produce voice sounds.

The flow of air:

• The trachea or windpipe is a 4-5 inch tube which conducts air between the larynx and bronchi. In the trachea are 16-20 hyaline cartilage rings that stiffen the wall to keep the 1 inch tracheal lumen open and prevent air flow from collapsing.

The flow of air:

• The trachea splits into the right and left bronchi. Air is conducted through each bronchi into or out of the lung.

The flow of air:

Inside the lungs, each bronchus divides into smaller tubes (bronchioles). At the end of the tubes are the alveoli: sacs of tissue specialized for the movement of gases between air and blood.

The Diaphragm

• A dome-shaped muscular fibrous partition that separates the abdominal and thoracic cavities. The diaphragm contracts and relaxes with respiration and is a significant part of helping a person breathe normally.

Animation

http://www.getbodysmart.com/ap/respiratorysystem/lungs/menu/animation.html

Inferring?

• Come up with a possible explanation for these questions before discussing:

1. Why do we yawn?

2. Why do we sneeze?

3. What causes hiccups?

FQA – Why do I yawn?

When you are sleepy or drowsy the lungs do not take enough oxygen from the air. This causes a shortage of oxygen in our bodies. The brain senses this shortage of oxygen and sends a message that causes you to take a deep long breath---a YAWN.

FAQ – Why do I sneeze?

• Sneezing is like a cough in the upper breathing passages. It is the body's way of removing an irritant from the sensitive mucous membranes of the nose. Many things can irritate the mucous membranes. Dust, pollen, pepper or even a cold blast of air are just some of the many things that may cause you to sneeze.

FAQ – What causes hiccups?

Hiccups are the sudden movements of the diaphragm. It is involuntary --- you have no control over hiccups, as you well know. There are many causes of hiccups. The diaphragm may get irritated, you may have eaten to fast, or maybe some substance in the blood could even have brought on the hiccups.

What happens to the Carbon Dioxide?

It goes through the lungs, back up your windpipe and out with every exhale. It's a remarkable feat, this chemical exchange and breathing in and out. You don't have to tell your lungs to keep working. Your brain does it automatically for you.

Breathing In, Breathing Out

Smoking

• Tobacco contains tar, carbon monoxide, and nicotine. – Tar is the dark, sticky substance produces when

tobacco burns. When you inhale smoke, tar settles on the cilia. Tar also contains chemicals that are known to cause cancer.

– Carbon Monoxide also produces when tobacco burns.

Comparison of Lungs

Black is tar deposits and white spot

is cancer growths.

Tar collected from 2,000 Cigarettes

Smoking

Molecules of carbon monoxide bind to hemoglobin in the red blood cells. Smokers’ blood contains little oxygen causing a faster heartbeat and breathing rate.

Nicotine speeds up the nervous system, the heart rate, and other organ systems. Smoking starts out as a habit, but quickly turns into an addiction, dependent on the nicotine.

Long Term Problems

1. Chronic bronchitis – bronchitis is an irritation of the breathing passages.

2. Emphysema – a disease that destroys lung tissue – you do not get enough oxygen and cannot adequately eliminate carbon dioxide.

3. Lung cancer – irregular growth of lung cells from smoking.

Passive Smoking

Passive smoking is the involuntary inhaling of other people’s smoke.

Here are the Facts:

• In as little as 2 weeks nicotine changes the brain chemistry and addiction can begin.

• Cigarette smoke contains 69 chemical compounds that are known to cause cancer.

• Pee contains urea. Some tobacco companies add urea to cigarettes.

• Smoking kills 1,200 Americans a day.• Tobacco companies make 1.8 billion from under

age sales – under 18 years old.

Here are the Facts:

• 70 percent of smokers want to quit. Only about 5% actually succeed every year.

• The impact of nicotine is jacked up because tobacco companies add ammonia.

• Cigarette smoke contains benzene, carbon monoxide, arsenic, hydrogen cyanide and polonium 210.

Excretory System

The Kidney’s

• The kidneys are the major organs of the excretory system.

The Skin

• The skin gets rids of excess oils and salt through excretion through the skin. The skin also serves as a protection layer

for the body to block out harmful viruses and bacteria.

The Lungs

• The lungs excrete carbon dioxide through inhaling and exhaling.

The Liver

• Keeping pollutants from hurting the body.

• Filtering toxic chemicals from the body.

• Remove waste products of nutrient breakdown.

Functions

• Collect water and filter body fluids

• Remove and concentrate waste products from body fluids.

• Return other substances to body fluids as necessary for homeostasis.

• Eliminate excretory products from the body.