The Human Respiratory System

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The Human Respiratory System

• Biology 314
• Mr. Doron

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Game Plan

• Introduction to the respiratory system
• Pathway the air takes
• Role of the nasal cavity
• Role of the pharynx
• Role of the epiglottis
• Role of the trachea
• Role of the bronchi lungs
• Fun FAQs (yawning, sneezing, hiccups)

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Respiratory System
Nasal Cavity
Mouth
Trachea
Bronchioles
Lung
Diaphragm
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Human Respiratory System

• The respiratory system has two parts
• The respiratory airways (nasal, cavity, pharynx,
  trachea, bronchi)
• The lungs
• What pathway does air take in the respiratory
  system?
• Nasal cavity --gt pharynx --gt trachea --gt bronchi
  --gt lungs

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What is the role of the nasal cavity?

• Hairs filters out the largest foreign particles
  in the air that enters the nostrils
• Capillaries warm up the air that is inhaled
• Mucous glands moisten the air

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The Role of the Pharynx

• Pharynx crossover point (for the digestive and
  respiratory tracts).
• collects incoming air from the nose and passes it
  downward to the trachea (windpipe).

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The Role of the Epiglottis

• Known as the switching mechanism
• It is a flap of tissue that guards the entrance
  to the trachea, closing when anything is
  swallowed that should go into the esophagus and
  stomach

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What is the role of the trachea?

• The larynx is situated at the upper end of the
  trachea.
• Contains vocal chords
• In males its the adams apple.

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Role of the Trachea Cont

• The walls of the trachea are lined with numerous
  cilia (hair) and mucous glands
• The mucus secreted by the mucous glands capture
  the foreign particles that have escaped nasal
  filtration.
• The beating of the cilia move the particles now
  coated with mucus back to the pharynx.
• At the pharynx, they are either swallowed down
  the esophagus or expelled from the respiratory
  tract.

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Role of the Pharynx

• Serve as the crossover point
• Serves as the pathway that either
• Air enters the respiratory tract or
• Food enters the esophagus

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Role of the Bronchi

• Extensions of the trachea
• Branch into the bronchioles
• Carry air to the lungs
• Have cilia and mucous glands

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Role of the Lungs

• Each bronchus enters a lung and branches into
  smaller bronchi known as bronchioles. These in
  turn subdivide into millions of alveoli.
• Alveolus is the functional unit of the lungs
• It is here that venous blood (carbon dioxide
  carrying blood) is oxygenated to become arterial
  blood (oxygen carrying blood)
• Thus, oxygen enters the alveolus
• Carbon dioxide leaves the alveolus

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A Picture is Worth 1000 words
Chest Anatomy
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More Pictures
X ray of human chest
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Work in Class / Homework

• Do Page 83, 84 85. Copy in your notes 1-

• Enters the body
• Move out and up
• Contract, moving the rigs up and out, the
  diaphragm contacts and moves down

• Air
• The ribs
• Intercostal muscles

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Why Do You Yawn?

•      When you are sleepy or drowsy the lungs do
  not take enough oxygen from the air. This causes
  a shortage of oxygen in our bodies. The brain
  senses this shortage of oxygen and sends a
  message that causes you to take a deep long
  breath---a YAWN.

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Why Do You Sneeze?

• Sneezing is like a cough in the upper breathing
  passages. It is the body's way of removing an
  irritant from the sensitive mucous membranes of
  the nose. Many things can irritate the mucous
  membranes. Dust, pollen, pepper or even a cold
  blast of air are just some of the many things
  that may cause you to sneeze.

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What Causes Hiccups?

• Hiccups are the sudden movements of the
  diaphragm. It is involuntary --- you have no
  control over hiccups, as you well know.
• There are many causes of hiccups. The diaphragm
  may get irritated, you may have eaten to fast, or
  maybe some substance in the blood could even have
  brought on the hiccups.