Ch 13.1 -- Respiratory Anatomy -- VTPP 435

Ch 13.1 -- Respiratory Anatomy -- VTPP 435

Cellular Respiration

entire series of chemical reactions involving intracellular breakdown of nutrient-rich molecules to yield energy using O2 and making CO2 in the process

Respiratory Quotient (RQ)

-ratio of CO2 produced to O2 consumed
-avg = 0.8

External Respiration

entire sequence of events in exchange of O2 and CO2 between external environment and tissue cells

Non Respiratory Functions of Respiratory System

-route for water loss and heat elimination
-enhances venous return
-helps maintain normal acid-base balance
-enables vocalization
-defends against inhaled foreign matter
-removes, modifies, activates, or inactivates various materials passing thru pulmonary circulation
-nose for smell

Respiratory Airways

-system of tubes that conduct air between atmosphere and alveoli of lungs
-begin with the nose

Trachea (wind pipe)

conducting airway that extends from pharynx and branches into 2 bronchi, each entering a lung

Vocal Folds

-two bands of elastic tissue that lie across opening of larynx
-can be stretched and positioned in different shapes by laryngeal muscles
-tightened when swallowing to close off trachea
-air passes between them

Bronchi

-2 main branches right and left that enter the right and left lungs respectively
-split off from trachea

Bronchioles

-small branching airways within lungs
-made of smooth muscle
-innervated by autonomic smooth muscle
-contraction can vary to vary caliber

Alveoli

-air sacs across which O2 and CO2 are exchanged between blood and air in lungs
-clustered at ends of terminal bronchioles
-thin walls

Type I Alveolar Cells

single layer of flattened epithelial cells that forms the wall of alveoli within lungs

Alveolar-Capillary Membrane

-a 0.5 micrometer barrier that separates air in alveoli from blood in pulmonary capillaries
-facilitates gas exchange

Type II Alveolar Cells

-cells within alveolar walls that secrete pulmonary surfactant
-facilitates lung expansion

Pores of Kohn

-in the wall between adjacent alveoli
-needed to allow fresh air to enter an alveolus whose terminal conducting airway is blocked because of disease

Lungs

-each lung supplied by one bronchi each
-has a series of alveoli, pulmonary vessels, and elastic
-has only smooth muscle

Thorax

-outer chest wall
-formed by 12 pairs of curved ribs

Thoracic Vertebrae

-backbone
-behind the ribs and join them

Diaphragm

-forms floor of thoracic cavity
-separates thoracic cavity from abdominal cavity

Pleural Sac

-double-walled closed sac that separates each lung from thoracic wall and surrounding structures

Pleural Cavity

-interior of pleural sac

Intrapleural Fluid

-thin fluid that lubricates pleural surfaces as they slide past each other during respiratory movements

Pleurisy

-inflammation of pleural sac
-accompanied by painful breathing because inflation and deflation causes a friction rub