The Respiratory System

Functions of the Respiratory System

• Breathing– The movement of the chest that brings air into

the lungs and removes waste gas

• Respiration– The exchange of oxygen (02) and carbon

dioxide (CO2) that takes place in the tissues of the body

Cellular Respiration

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

glucose + oxygen → carbon + water + energy dioxide

Oxygen is needed to release energy from glucose to be used by the body!

Respiratory System Organs• Air enters the body through the nostrils and the

mouth.– Hairs in the nostrils trap dust from the air.

• Air then goes into the nasal cavity (and oral cavity) where it is moistened and warmed.– Sticky mucus is produced in the nasal cavity that

traps pollen, dust and other irritants

• Cilia are tiny, hair-like structures that sweep mucus and trapped materials to the back of the throat to be swallowed.

• Materials trapped in the mouth are also swallowed and sent to the digestive system

Boogers!!!!!

More Respiratory Organs

• Air then travels to the Pharynx, which is a tube-like passageway used by food, liquids and air.

• The epiglottis is a flap at the lower end of the pharynx that prevents food and liquids from entering the airway.

• Air next moves through the larynx, which is the airway that leads to the vocal cords, and is also often called the voice-box

• Air then moves through the trachea, which is a tube lined with mucus membranes that trap dust, bacteria and pollen.

And Into the Lungs!

• From lower end of the trachea, air moves through the bronchi which are two short tubes branching out into the lungs.

• Inside the lungs, the bronchi branch into smaller and smaller tubes called bronchioles.

• Bronchi and bronchioles are known collectively as bronchial tubes!

Inside the lungs!

• Attached to the bronchioles are alveoli, which are tiny, thin-walled sacs that are surrounded by capillaries.

• The lungs are masses of alveoli arranged in grapelike clusters

Exchange of gases• The walls of the capillaries

and alveoli are only one cell thick

• Oxygen moves through the alveoli walls, then through the capillary walls and into the blood

• Then the oxygen is picked up by hemoglobin in the RBC and carried to the body.

• Carbon Dioxide and other waste gases first move through the capillary walls and then through the alveoli walls and are exhaled out of the body.

Breathing

• Inhaling and exhaling• Partly due to changes

in air pressure.• Diaphragm – a

muscle beneath you lungs that contracts and relaxes to help move gases into and out of the lungs.

Pathway of Oxygen and CO2 through the Body

→ Nostrils and mouth → nasal and oral cavities → pharynx → larynx → trachea → bronchi → bronchioles → alveoli → capillaries → pulmonary vein → heart → arteries → capillaries → body tissues (cellular respiration) → capillaries → veins → heart → pulmonary artery → capillaries → alveoli → bronchioles → bronchi → trachea → larynx → pharynx → nasal and oral cavities → nostrils and mouth →