Overview of Respiratory System Primary Bronchi – branch to left, branch to right Left is more horizontal due to placement of heart Why important to have white blood cells in our lungs?

Tracheotomy Surgical operation where tube is inserted into trachea to provide a passageway for air when pharynx is obstructed by edema or cancer or other causes

Endotracheal Tube (Intubation) Procedure when flexible tube is inserted through mouth down into the trachea

Bronchi Tracheobrachial tree Primary Bronchus Lobar bronchi (2 left, 3 right) Segmental bronchi Bronchioles Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveolar Sacs

Composition & Structure Of Air Passages As the passageways get smaller: Structure of walls are less cartilage, more smooth muscle Cell type changes Composition of the passageways changes: Relaxation and Contraction changes diameter of the air passageways during exercise the diameter increases = increased volume of air flow during asthma attack, contraction of muscle = reduced air flow

Cell Types / Locations Trachea/Bronchi Pseudostratified Bronchioles Simple Columnar Terminal & Respiratory bronchioles Simple cuboidal Alveoli Simple squamous

Composition & Structure Of Air Passages As the passageways get smaller: Trachea/Bronchi: pseudostratified ciliated columnar Composition of the passageways changes: Relaxation and Contraction changes diameter of the air passageways during exercise the diameter increases = increased volume of air flow during asthma attack, contraction of muscle = reduced air flow

Composition & Structure Of Air Passages As the passageways get smaller: simple columnar (bronchioles) and ciliated simple cuboidal (terminal bronchioles) Composition of the passageways changes: Relaxation and Contraction changes diameter of the air passageways during exercise the diameter increases = increased volume of air flow during asthma attack, contraction of muscle = reduced air flow

Less cartilage, More smooth muscle Smooth muscle wrapped around Bronchiole Terminal Bronchiole Respiratory bronchiole Relaxation and Contraction changes diameter of the air passageways during exercise, diameter = increased volume of air flow during asthma attack, contraction of muscle = reduced air flow

Alveoli Alveolar ducts end as 2-3 alveolar sacs 300 million alveoli in the lungs

Alveoli Respiratory membrane: all of the areas in which gas exchange occurs between air and blood Alveoli are the major area of gas exchange If the thickness of the respiratory membrane increases, this will decrease the rate of diffusion across Some does occur in respiratory bronchioles and alveolar ducts

Pulmonary Edema Patients have fluid accumulate in the alveoli Gases must diffuse through a thicker layer of fluid than normal Oxygen is affected more because it diffuses 20x less easily than carbon dioxide

Asthma Chronic condition when airways of lungs inflame and narrow Treatment: quick relief meds like corticosteroids that relieve inflammation

Take five normal, quiet breaths. Now, take a normal breath. At the end of the normal inspiration, draw in as much as you can. Now, take three normal, quiet breaths. As you finish expiration – forcefully push out MORE air. Residual volume is amount STILL left in your lungs With each breath at rest, you are drawing in and exhaling about 500 mL of air. This is your tidal volume This is the reserve volume – the additional you can breath in (about 3000 mL) This is your reserve expiratory volume (about 1100mL)

Four Pulmonary Volumes Tidal volume: amount at rest that can be inspired or expired. ~500mL Inspiratory reserve volume: amount that can be forcefully inspired after resting tidal volume. ~3000mL Expiratory reserve volume: amount that can be forcefully expired after resting tidal volume ~1100 mL Residual volume: volume of air still in lungs after maximum expiration. ~1200mL Take five normal, quiet breaths. With each breath at rest, you are drawing in and exhaling about 500 mL of air. This is your tidal volume Now, take a normal breath. At the end of the normal inspiration, draw in as much as you can. This is the reserve volume – the additional you can breath in (about 3000 mL) Now, take three normal, quiet breaths. As you finish expiration – forecefully push out MORE air. This is your reserve expiratory volume (about 1100mL) Residual volume is amount STILL left in your lungs

Pleural Cavity Lung found in thoracic cavity Each lung surrounded by PLEURAL cavity Serous membrane called “pleura” surrounds each lung

Pleural Cavity Lung found in thoracic cavity Each lung surrounded by PLEURAL cavity Serous membrane called “pleura” surrounds each lung

Ventilation Ventilation = breathing Inspiration (Inhalation) Expiration (Exhalation) Respiratory muscles are responsible for changes in thoracic volume This produces changes in air pressure in the lungs This produces ventilation

Intercostals Diaphragm Dome of muscle that separates thoracic from abdominal cavity Intercostals Muscles of the ribs (costal)

Movement of Diaphragm

As volume of increases, pressure decreases As respiration muscles change thoracic volume they alter the pressure within the thoracic cavity Air flows from high to low pressure If pressure is higher outside the body than in the thoracic cavity, air will flow toward in