Respiratory System

• What are the functions of the respiratory system?

  • Influences speech
  • Allows sense of smell
  • Air distributor
  • Gas exchanger
  • Filters, warms and humidifies air
• Respiration

  is the overall process by which the body gets oxygen and gets rid of carbon dioxide.
• External respiration


  is the exchange of gas between the air in the alveoli and the blood within the pulmonary capillaries.
• Internal respiration


  is the exchanging of gases at the cellular level.
• There are two divisions in the respiratory system, the upper and lower. Give me the parts of the upper respiratory system.

  • Nose
  • Pharynx
• What about the lower respiratory system?

  • Larynx
  • Trachea
  • Bronchial tree
  • Alveoli
  • Lungs
• Nose


  It is the primary passageway for air entering and exiting the respiratory system. It also warms and moistens air
• Air enters through nostrils, communicates to nasal cavity.
• Respiratory epithelium


  ciliated cell layer (goblet cells and mucous glands).
• Cilia sweep debris and pathogens into pharynx (throat).
• Nasal cavity


  it is also flushed by mucus produced by nasal sinuses and by tears through the nasolacrimal duct.
• Nasolacrimal duct


  drain tears from the eyes
• Nasal septum


  divides nose into left and right sides.
• Palantine bone


  separates nasal cavity from mouth
• Cleft palate


  Palantine bone does not form correctly, difficulty in swallowing and speaking.
• rich blood supply = nose bleeds
• Pharynx


  (throat) is a tubelike structure about 12.5 cm long that connects the posterior nasal and oral cavities to the larynx and oesophagus.
• Throat is shared by digestive and respiratory tracts.
• What are the three divisions of the pharynx?

  • Nasopharynx
  • Oropharynx: fauces
  • Laryngopharynx: hypopharynx
• Larynx is also known as the voice box
• What are the three functions of the larynx?

  • Provides an open airway
  • Routes food and air into proper tubes
  • Voice production
• The laryngeal skeleton consists of nine cartilages, three single and three paired and is connected by membranes and ligaments.
• Single (Unpaired cartilages)

  • (thyroid, cricoid, and epiglottis)
• Paired cartilages

  • (arytenoid, corniculate, and cuneiform)
• Epiglottis ( single or unpaired )


  a leaf-shaped piece of elastic cartilage located at the top of the larynx. The free superior end bends up and down like a flap to open and close the opening into the larynx.
• Thyroid cartilage or Adam's apple


  formed by the fusion of two cartilage plates and is the largest cartilage of the larynx
• Cricoid cartillage 


  a ring-shaped cartilage so-called because the signet end forms part of the posterior wall of the larynx. It is attached to the top of the trachea and is the most inferiorly placed of the nine cartilages.
• The lower pair of folds , which form a slit-like opening called the glottis
• True vocal cords


  vibrate to produce sound
• False vocal cords


  it support the true vocal cords and play a minimal role in phonation or sound production
• Trachea or windpipe


  connection between Larynx to bronchi. tubelike structure which acts as the main passageway to the lungs
• Goblet cells secrete mucus that traps dust particles and bacteria that manage to get past the nose
• Hyaline cartilage


  C - shaped rings of cartilage supporting the wall of the trachea.
• Bronchial tree


  Tubes that branch off trachea and enter into lungs
• Name the five branches of the bronchial tree.

  • Primary bronchi
  • Secondary bronchi
  • Tertiary bronchi
  • bronchioles
• Carina


  end junction where the trachea splits to form the left and right bronchi
• Alveoli


  It is the gateway for the oxygen into the body.
• Air leaving the bronchioles enters alveolar ducts.
• Brochioles end with grapelike clusters of air sacs called Alveolar sacs.
• The lungs has two types: the right and the left lung