A dangerous lung condition that can develop after severe illness or injury to the
body. Neutrophils leave the body’s capillaries in large numbers
and then secrete chemicals that increase capillary permeability.
The capillary-rich lungs are heavily affected. As the lungs
fill with the fluids of edema, the patient suffocates. Even with
mechanical ventilation, ARDS is hard to control and often
lethal.
Adult respiratory distress syndrome (ARDS)
Trachea - Bronchial tree
Trachea
-windpipe
-larynx at division forming
two primary bronchi at midthorax
-mucosa –
pseudostratified
epithelium (goblet cells)
-submucosa –
connective tissue
seromucous glands –
mucous -advantitia –
CT hyaline cartilage
Bronchial tree
-left and right primary bronchi
-formed by divisions of the trachea
-secondary bronchi (lobar)
-inside the lungs
-3 on the right
-2 on the left
-tertiary bronchi (segmental)
-fourth-order
-fifth-order
-23 orders of branching air ways
-bronchioles (under 1 mm in diameter
Cartilage:
-rings
-irregular plates
-no cartilage in bronchioles
-replaced by elastic fibers
Epithelium:
-pseudostratified (ciliated)
-columnar (ciliated)
-cuboidal in terminal bronchioles (no cilia)
Smooth Muscle:
-increases as tubes get smaller
Human Anatomy and Physiology
The respiratory zone
Respiratory Zone:
Respiratory bronchioiles
Alveoli (300 million)
Alveolar ducts
Alveolar sacs
Transport of Gases
- The gas exchange through the alveoli membrane and capillaries occur by simple diffusion
- Fick's law describes transalveolar gas exchange VO2=DO2 A(PalO2-ParO2)t
- t is the transalveolar thickness
- The path lenght for diffusion includs the thickness of the alveolar epithelium and underlying basement membrane and the capillary endotheliumç
- Respiratory pigments in blood often transport O2 from the respiratory surface to the tissues but can also transfer 02 from blood into cells or act as intracellular oxygen stores such as myoglobi and neuroglobins.
- increase temperature increase dissociation of oxygen from hemoglobin.
- 2-3 Diphosphoglycerate in erhythrocyte; it increase dissociation of oxygen from hemoglobin.
- The rate of 02 transport by the circulatory system depends on the rate of blood flow and the O2 contents of arterial blood and venous blood.
Cellular respiration
Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products.
The reactions involved in respiration are catabolic reactions that involve the redox reaction so oxidation of one molecule and the reduction of another.
Respiration is one of the key ways a cell gains useful energy to fuel cellular changes.
nose and pharynx
Nose:
external nose nasal cavity
Functions:passageway for air, cleans the air, humidities, warms air, smell
along with paranasal sinuses are resonating chambers for speech
Pharynx: common opening for digestive and respiratory systems
Three regions: nasopharynx, oropharynx, laryngopharynx
composition of Air
The composition of normal, dry, atmospheric air is 20.95% oxygen, 0.03% carbon dioxide and 78.08% nitrogen. The normal atmospheric pressure at sea level is about 76 mmHG. the total pressure exterted by a gas mixture is equal to the sum of pressures exerted by each constituents gas ( Dalton's law)
pO2= 159.2 mmHg
pCO2= 0.003 mmHg
pN2=600.6 mmHg
Atmospheric pressure increases markedly underwater.
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