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Anatomy of the Respiratory System
- a) Nose
- b) Pahrnyx
- c) Larynx
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Nose
- External Nose
- Nasal Cavity
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External Nose
- a)mostly composed of cartilage plates
- b) Bridge
- -nasal bone
- - extension of frontal and maxillary bones
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Nasal Cavity
- 1) Nares- external openings
- 2) Choanal- openings into Pharnyx
- 3) Vestibule- anterior portion directly inside of nares
- - has vibrissae- hairs which fill particles from inspired air
- 4) Hard Palate- bony plate covered by mucous membrane; forms nasal cavity and roof of oral cavity
- - posteriorly is the soft palate
- 5) Conchae- superior, inferio and midlle projections fro mthe lateral walls of nasal cavity
- -funtion to increase air turbulence allowing inhaled particles/ debris to be trapped by mucous
- 6) Paranasal sinuses
- - openings that warm and moisten air
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Pharynx
- -air/food passage
- A) 3 diff regions
- 1) Nasopharnyx
- a) uvula moves up to cover nasal cavity and Pharyngeal tonsil
- 2) Oropharnyx
- a)posteriot to oral cavity, common for food/air
- b) palatine tonsil is below soft palate and lingual posterior to tongue
- 3) Larnygopharnyx
- a)posterir to epiglottis which closes the trachea so swallowed food does not go into lungs
- b) passage of food and extension of esophagus posteriorly
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Larynx (voicebox)
- -made of thyroid and circoid cartialge
- A) outer casing of cartialge (all Hyaline cartilage except epiglottis)
- 1) Unpair cartilage
- - Thyroid( adam's apple, larger in males due to testosterone)
- -Circoids( most inferior , makes base of of the larynx)
- - Epiglottis ( elastic cartilage, all the way to the lungs)
- 2)Paired Cartialge (makes up wall of larynx)
- -Arytenoids- anchors vocal chords
- - Cuneiforms
- -Cornicular
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Conducting Zone of the Bronchi
- a)Right and Left bronchi are made up at the division of the Trachea at T7
- b)Primary branch into 2 secondary(lobar) at left lung and 3 secondary at right lung
- c)Secondary ---- Tertiary(segmental)
- d) bronchioles -----terminal bronchioles
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Mechanics of Breathing
Inspiration
Expiration
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Inspiration
- a)period of time when air is flowing into lungs
- b)contraction of the external intercostal causes the ribs to rise and move laterally
- c) contraction of the diaphragm causes it to move inferiorly
- d) pulmonary volume increases
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Expiration
- a) passive process that depends on the natural elasticity of the lungs
- b) inpsratory muscles relas causing the ribs to descend medially and diaphragm move superiorly
- c)lungs recoil and pulmonary volume decreases
- d) forced exhalation involves contraction of the abdominal mucles and the internal intercostals
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Gas Exchange
- 1) Partial Pressure Gradient
- a) gas exchange at pulmonary and systemic capillaries involves passive diffusion of O2 and CO2 down their PPG
- b)partial pressure is define as individual pressre exerted indepentently by a particular gas w/ in a mixture
- c) designate PO2 and PCO2
- d) a gradient is established when partial pressure of gas diffuses across a membrane
- e) gas will always diffuse from High to Low
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Gas Transport
- 1) Impairments of O2 transprt
- a) Anemic hypoxia- results from too few RBCs and RBCs not containing enough O2
- b) Ischemic hypoxia- decreased delivery due to blood circulation to particular tissue being blocked(Sclerotic plaque)
- c) Histoxic hypoxia- cells unable to use O2 delivered to them( cyanide poisoning)
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Chemical control of Respiration
- 2 Receptor Types:
- Peripheral chemoreceptors
Central Chemoreceptors
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Peripheral Chemoreceptors
- a) located at the arch of arota and bifurcation of carotids
- b) weakly stimualted by increase of CO2 in arterial blood volume
- c) highly sensitive to H caused by CO2 will stimulated chemoreceptors
- d) chemoreceptors send afferent signals to respiratory centers
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