Respiratory System

Respiratory System
Anatomy
Upper Tract lined with ciliated mucosa
warms, humidifies, filters, moves dust and
secrets lysozyme.
Nose chamber for speech, nasal cavity and
houses the scent.
Pharynx passageway for for and air, houses
the tonsils.
Lower Tract
Larynx
Cartilaginors tube lined with mucus
membrane.
Voice box
formed with 3 pieces of large cartilage
Internal and External laryngeal muscles.
Production of sounds
The mucus membrane of the larynx forms as
upper pair of vestibular folds and the Lower
vocal folds. The vocal cords are elastic
ligaments stretched between rigid cartilage.
Trachea
Divids into 2 main bronchi and very
flexible.
Supported by 20 C shaped cartilage bands
Bronchi and Bronchioles
Left and right bronchi are supported by in
complete rings of cartilage.
Lungs
covered by the pleura
right lung has 3 lobes and left lung has 2
lubes ands Is 10% smaller.
Each lung contains bronchi, then
bronchioles, smaller which end in alveoli.
Alveoli
25 million at birth and 300 million in adult
hood.
Have tiny passage which allows them to
pass air to each other
2 major types of epithelial cells fro, there
waves secretes and gas exchange
surfactant.
Respiratory physiology
Pulmonary
exchange of oxygen and C02
Transport of gases in the blood
regulation of ventilation
factors influencing respirated
Factors influencing respiration
the rate and depth of breathing is mainly
influence by changes in PC02, P02 and pH
The branch stem has central
chemoreceptors
the aortic arch and carotid arteries have
peripheral chemoreceptors.
voluntary control by the cereal cortex.
anxiety, anticipation and commencing
exercise raises respiratory rate and depth.
pain may raise or lower the respiratory rate.
irritation of the pharynx or larynx stops
breathing then causes coughing or
sneezing,
Exchange of Oxygen and Carbon Dioxide
Independently C02
diffuses in the opposite direction because
PC02 is higher in the blood than in the
alveoli.
Cells
constantly make C02 (which raises in PC02)
whilst consuming oxygen to make ATP
(lowers the Pc02)
Transport of Oxygen
Oxygen doesn't dissolve well in water.
98.5% is carried by erythrocytes as
oxyhemoglobin.
When P02 is high oxyhemoglobin bind
tightly together and becomes saturated.
When PC02 of temp rises haemoglobin
releases oxygen more readily.
Transport of Carbon Dioxide
About 7% dissolves in the plasma.
Proteins in the blood pick up and carry
another 23% as carbonminohaemoglobin.
The majority (70%) combines with water to
form carbonic acid
Bicarbonate Ions are transported in the
plasma.
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