The Respiratory System 2.

The airway conducts air into the lungsBreath of air passes in sequence:

•Nostrils, •nasal cavities, •pharynx, •larynx, •trachea, •bronchi, •bronchioles, •and alveoli

The respiratory system consists of an airway and lungs

The lower respiratory tract

• Trachea = windpipe• Main bronchi• Lobar bronchi• Lungs

- Bronchioles- Alveolar sacs- Alveoli

Tube:

•inner 20-25 mm in diameter•10-16 cm in length•15 – 20 incomplete C-shaped cartilaginous rings

The trachea = windpipe

• The cartilaginous rings are incomplete because this allows the trachea to collapse slightly to allow food to pass down the esophagus• Posterior of trachea: smooth muscle and connective tissue

trachea

Great horned owl – Amerikai uhu

Air passageway• Trachea two main bronchi (Left + Right)

• The right main bronchus is wider, shorter, and more vertical than the left main bronchus

• L main bronchus two lobar bronchi

• R main bronchus three lobar bronchi

• Lobar bronchi primary bronchioles

• primary bronchioles alveolar ducts

• alveolar ducts alveolar sacs alveoli

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6

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•1: L main bronchus•2: R main bronchus•3: two lobar bronchi •4: three lobar bronchi•5: primary bronchioles•alveolar ducts•6: alveolar sacs•alveoli

The Lung• Every time you breath in and

out your lungs are hard at work

• Lungs are surrounded by the rib cage, on sit on diaphragm

• The respiratory zone is the site of gas exchange with blood

• Color: pink, after years becomes grey

http://www.youtube.com/watch?v=nJuFmyXeHkA /

Parts

•Base: bottom•Apex: tip•Hilus: place where vessels, bronchi are step in and out the lung

The Lung• The human lungs are the organs of respiration in

humans• Humans have two lungs, with the left being divided

into two lobes and the right into three lobes• Together, the lungs contain approximately 1500

miles (2,400 km) of airways and 300 to 500 million alveoli, having a total surface area of about 70 m2 in adults (the same area as a tennis court)

The pleura• The lungs are surrounded by the pleurae, a serous

membrane which folds back upon itself to form a two-layered, membrane structure.

• The thin space between the two pleural layers is known as the pleural space; it normally contains a small amount of pleural fluid.

• The outer pleura (parietal pleura) is attached to the chest wall.

• The inner pleura (visceral pleura) covers the lungs and adjoining structures, i.e. blood vessels, bronchi and nerves.