The Respiratory System Part 1 – Structures Grade 12 Biology Ms. Marcos

Why do we need a respiratory system? Need O2 in for cellular respiration make ATP Need CO2 out waste product food ATP O2 CO2

The basic terms: Breathe In! Move air in  Breathing Take O2 from the air and put it in the blood  External respiration Take O2 from the blood and give it to the tissues  Internal respiration Use O2 (and food) to make ATP Cellular respiration Now get rid of CO2 by doing the opposite and breathe out!

What structures can you name?

Major parts of the Respiratory System Nasal passages or mouth receive the air Warm / moisten Hair and cilia trap dust and debris  Sensory nerves create a sense of smell

 Tonsils help to fight infection Pharynx Openings to the nose, mouth and lungs What problems can happen here?  Tonsils help to fight infection

Larynx Produces sound Vocal chords Enlarged in males Opening (the glottis) covered by the epiglottis during swallowing See the difference?

Movement of the glottis with different pitches

Trachea Lined with cilia C-shaped rings of cartilage

Trachea  bronchi  bronchioles  alveoli From large  small Trachea Bronchi Many bronchioles End in small sacs called alveoli Spongy Large surface area Gas exchange Trachea  bronchi  bronchioles  alveoli

Alveoli Huge amount of surface area Surrounded by blood capillaries Right: 3 lobes Left: 2 lobes Why would there be only 2 lobes on the left side?

Gas exchange occurs in alveoli

Diaphragm Band of muscle below the lungs Contracts and relaxes to bring air into / out of the lungs

What structures can you name now?