This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: February 24, 2009 The Respiratory System- The process of gaseous exchange within the body- Respiration has two phases: o External respiration The exchange of gases between the blood within the pulmonary capillaries and the air spaces that exist within the lung o Internal respiration The exchange of gases between the blood and the metabolic tissue (nervous, hepatic, muscle etc.)- Respiratory system is located above the respiratory diaphragm- Embryologically, the respiratory system begins as out growths from the primitive gut system o Makes appearance early into gestation (at about 4 weeks) o From the outgrowths, the entire bronchial tree will develop o Derived from the primitive germ layer known as the endoderm Same tissue as the anterior lobe of the pituitary and primitive gut- Respiratory system is different to a variety of other bodily systems (brain, heart, etc.) o Respiratory system does not become functional until the moment of birth (not until the fetus takes its first breath of air) o The respiratory system will begin to function as the fetal circulatory changes at birth (foramena and ducts close to allow pulmonary circulation to take place) Structures of the Respiratory System- Nose and nasal cavities- Nasal cavities lead to the pharynx- From the pharynx , at the lower back portion of the oral cavity is the larynx- Larynx leads directly to the trachea- Trachea divides into two bronchi- At the end of the branchial tree, the bronchioles are present- Bronchioles will then lead to the secular structures known as alveoli The Nose- The natural pathway for air entering and leaving the respiratory system o Not the only route, the mouth may be used if more air is needed- It is in the nose and nasal cavity that the air is filtered o The air is filtered by short stiff hairs known as vibrissae o Vibrissae project from the inner surface of the nose and the roof of the nasal cavity o Vibrissae functions Important in filtering out dust particles, bacteria, or any other debris located in the atmosphere which is inhaled- Lining of nasal cavity is made up of pseudostratified cilliated columnar epithelium...
View Full Document