Human Respiratory System Figure 10.1. Components of the Upper Respiratory Tract Figure 10.2.
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Transcript of Human Respiratory System Figure 10.1. Components of the Upper Respiratory Tract Figure 10.2.
Human Respiratory System
Figure 10.1
Components of the Upper Respiratory Tract
Figure 10.2
Passageway for respiration Receptors for smell Filters incoming air to filter larger foreign
material Moistens and warms incoming air Resonating chambers for voice
Upper Respiratory Tract Functions
The nasal passages and lungsAir is drawn into the body via the nose or mouth. There are advantages to breathing through your nose:
the air is warmed so that it is closer to body temperature
tiny hairs and mucus in the nose filter the air, preventing larger dust and pollen particles reaching the alveoli
mucus moistens the air, making it easier for the alveoli to absorb.
Components of the Lower Respiratory Tract
Figure 10.3
Functions: Larynx: maintains an open airway, routes food and air
appropriately, assists in sound production Trachea: transports air to and from lungs Bronchi: branch into lungs Lungs: transport air to alveoli for gas exchange
Lower Respiratory Tract
When you breathe in:
intercostal muscles between the ribs contract, pulling the chest walls up and out
the diaphragm muscle below the lungs contracts and flattens, increasing the size of the chest
the lungs increase in size, so the pressure inside them falls. This causes air to rush in through the nose or mouth.
Mechanisms of breathing – inspiration
Diaphragm contracts and moves down
Intercostal muscles pull ribs up and out
Mechanisms of breathing – inspiration
Mechanisms of breathing – expirationWhen you breathe out:
Intercostal muscles between the ribs relax so that the chest walls move in and down.
The diaphragm muscle below the lungs relaxes and bulges up, reducing the size of the chest.
The lungs decrease in size, so the pressure inside increases and air is pushed up the trachea and out through the nose or mouth.Diaphragm
relaxes and bulges up
Ribs move in and down
Mechanisms of breathing – expiration
Respiratory Cycle
Figure 10.9
Gas exchange at the alveoliThe alveoli are bunches of tiny air sacks inside the lungs.
Each individual sack is called an alveolus.
When you breathe in, they fill with air.
The alveoli are covered in tiny capillaries (blood vessels).
Gases can pass through the thin walls of each alveolus and capillary, and into the blood stream.
Gases can also pass from the blood stream, into the alveolus.
Gas exchange at the alveoli