Respiratory System

Chapter 37

• Respiration in humans is the exchange of oxygen and carbon dioxide between blood, tissue and air

• Respiratory system includes the nose, pharynx. Larynx, trachea, bronchi, and lungs

• Function of cilia and mucus:• Lung tissue is very delicate.• Air must be warmed and cleaned before it

enters the lungs• Cilia and mucus help to do those things

Pharynx

• Also called throat• Passageway for both food and air

trachea

• Also called wind pipe• The epiglottis is a flap that covers the trachea

when you swallow food• Has c- ring cords of cartilage

larynx

• Also called the voice box• Two very stretchy folds of tissue that vibrate

when air moves over it

bronchi

• Air passes into two large passageways. (one to each lung)

• Within each lung the bronchi will branch into smaller and smaller branches called bronchioles

alveoli

• Bronchioles reach a sac called the alveoli, which are found in clusters like grapes

• The alveoli are surrounded by a network of capillaries

Gas exchange

• There are around 150 million alveoli in each healthy lung.

• The alveoli are moist, oxygen will dissolve into the moisture and diffuse across the membrane into the capillaries to the red blood cells

• Oxygen bonds to hemoglobin found in the RBC

• At the same time Carbon dioxide will cross from the red blood cells to the alveoli and then out the lungs and out the body

diaphragm

• There are no muscles attached to the lungs, in stead the lungs are found in sacs

• The diaphragm is what causes the lungs to expand and contract

• When the diaphragm pulls down the lungs expand

• When the diaphragm push up air pushes out of the lungs

What controls breathing?

• Your brain controls your breathing• You have some control- up to a point, and

then your body will force you to breathe

Fun facts?

• Most vertebrate animals (animals with spines) have two lungs.

• Your left and right lungs aren’t exactly the same. The lung on the left side of your body is divided into two lobes while the lung on your right side is divided into three. The left lung is also slightly smaller, allowing room for your heart.

• Can you live without one lung? Yes you can, it limits your physical ability but doesn’t stop you from living a relatively normal life. Many people around the world live with just one lung.

• People who have a large lung capacity can send oxygen around their body faster. You can increase you lung capacity with regular exercise.

• When resting, the average adult breathes around 12 to 20 times a minute.

• An average person breathes in around 11,000 liters of air every day.

• The study of lung diseases is known as pulmonology.

• When at rest, humans exhale up to 17.5 milliliters (0.59 fluid ounces) of water per hour

• The average time an adult can hold his or her breath is between 30 and 60 seconds.

• But free divers — people who practice the sport of diving underwater without using equipment like scuba gear — have different techniques, such as hyperventilation, to decrease the concentration of carbon dioxide in the blood, allowing them to hold their breath for remarkably long times. Denmark's Stig Severinsen currently holds the Guinness World Record for the longest free dive — in 2010, he held his breath underwater for 22 minutes.

• The lungs are the only organs that can float on water.

• Horses only breathe through their noses