Respiratory System - Anatomy & Physiology PDF

RESPIRATORY SYSTEM A. FUNCTION: Exchange of gases B. PHASE OF RESPIRATORY: 1. Exchange of gases between blood and air (external respiratory) 2. Exchange of gases between blood and cells (internal respiratory) C. PARTS: 1. Nose - Internal part in the skull above the roof of the oral cavity; exter...

RESPIRATORY SYSTEM A. FUNCTION: Exchange of gases B. PHASE OF RESPIRATORY: 1. Exchange of gases between blood and air (external respiratory) 2. Exchange of gases between blood and cells (internal respiratory) C. PARTS: 1. Nose - Internal part in the skull above the roof of the oral cavity; external part protruding from the face - Opens to the exterior through the anterior nares and to the nasopharyngeal the posterior nares - Floor formed by the palatine bones and maxillae - Lined with ciliated mucosa - Serves as passageway for incoming and outgoing air filtering, warming, and moistening it - Sense organ of smell 2. Pharynx Divided into: a. Nasopharynx – behind the nose with four opening, two auditory or Eustachian and two posterior nares b. Oropharynx – behind the mouth with one opening, filtering from the oral cavity c. Laryngopharynx – behind the pharynx with two openings, into the larynx and into the esophagus - Serves as passageway into respiratory and digestive tracts - Tonsils found in the nasopharynx destroys incoming bacteria and detoxify foreign protein 3. Larynx - Box-like cartilaginous structure located just below the pharynx - Consists of: a. Thyroid cartilage or “Adam’s apple b. Epiglottis or “lid cartilage” c. Cricoid or “signet ring” cartilage d. Arythenoid or “pyramid shaped: cartilage - Vocal cords of two types: 1. False vocal cord – folds of mucus lining 2. True vocal cord - fibro – elastic bands stretched across the interior of the larynx - Slit between vocal cords if the glottis through which air enters and leaves the lower respiratory passages. 4. Trachea - Cartilaginous tube 10 – 11 cm. in length extending from larynx to bronchi - Lined with ciliated mucosa - For passageway of air, to and from the lungs 5. Lungs - Cone-shape organs which completely fill the pleural spaces extending from slightly above the clavicle to the diaphragm where the base of the lungs rest - Covered by visceral pleura  Structures associated with lungs: a. Bronchi–right and left formed by branching of trachea b. Bronchioles – smaller branches of bronchi c. Alveolar ducts–microscopic branches of bronchioles d. Alveoli – microscopic sacs at the ends of the alveolar ducts provided with a network of lung capillaries - Serves for the exchange of gases between blood and air. D. Amount of Air Exchanged in Breathing - Measured by apparatus called spirometer a. Tidal Air - average amount expired after a normal respiration 500ml. b. Expiratory reserved volume (ERV) – largest additional volume of air that can be forcefully expired after a normal inspiration and expiration; 1,000- 1,200ml. c. Inspiratory reserved volume (IRV) – largest addition of volume of air that can be forcibly inspired after a normal respiration; 3,000 – 3,300ml. d. Residual Air – that which cannot be forcibly expired from lungs; about 1,200 ml. e. Minimal Air – that which can never be removed from alveoli if they have been inflated even once, even though lungs are subjected to atmospheric pressure that squeezes part of the residual air out. f. Vital Capacity – approximate capacity of lungs as measured by amount of air that can be forcibly expired after forcible inspiration; varies with size of thoracic cavity, which is determined by various factors (size of rib cage, size of the heart). E. Types of Breathing: 1. Eupnoea – normal quite breathing 2. Apnea – temporary cessation of breathing 3. Dyspnea – difficult breathing 4. Orthopnea–inability to breath easily in horizontal position 5. Tachypnea–excessively rapid and shallow breathing