10/14/24, 9:45 Pathophysiology Exam 3
AM Nursing
Pathophysiology Exam 3 Nursing
Disorders of Respiratory Function:
Ch. 21:
Conducting Airways
- Air moves through here as it passes between the atmosphere and the lungs
- Consists of:
o Nasal passages
o Mouth and pharynx
o Larynx
o Trachea
o Bronchi
o Bronchioles
- Lined by pseudostratified columnar epithelium – mucus secreting glands, ciliated
cells, serous glands secreting antibacterial enzymes
- Cigarette smoking slows down or paralyzes motility of the cilia, allowing smoke,
dust, etc to build up in the lungs.
- Air is kept moist by water contained in the mucous layer of upper airways
and tracheobronchial tree
- Air in alveoli maintained at body temp has more water vapor than the atmospheric-
temp air we breathe
- ~ 1 pint of water is used each day to humidify the air we breathe
- With fever, water vapor in lungs increases, causing more water to be lost through the
respiratory tract causes respiratory secretions to thicken, preventing free movement of
the cilia and impairing the protective function of the mucociliary defense system
Respiratory Lobules
- Where gas exchange function takes place in the lungs!
- Smallest functional unit of the lung
- Supplied by a terminal bronchiole, alveoli, and pulmonary blood vessels
- Surrounded by lymphatic structures and aid in the removal of plasma proteins and
other particles from the interstitial spaces
- Alveoli
o Actual sites of gas exchange b/w air and blood
o Ducts – elongated airways that have almost no walls at their peripheral boundary
o Sacs – cup-shaped, thin-walled structures that are separated from each other by
thin alveolar septa
o ~300 million alveoli in the adult lung, 50-100 m2 surface area
o Do NOT have separate walls! continual mixing of air via pores of Kohn which
are small holes in the walls of adjacent alveoli.
o Contain brush cells and macrophages
▪ Brush cells – few in #, act as receptors that monitor the air quality of
the lungs
- Alveolar cells
o Type I – extremely thin, squamous cells occupying about 95% of the surface
area. NOT capable of regeneration.
about:blan 1/
k 14
, 10/14/24, 9:45 Pathophysiology Exam 3
AM Nursing
Pathophysiology Exam 3 Nursing
o Type II – interspersed between type I cells – secretory cells producing
surfactant. They are also the progenitor cells for type I they will proliferate and
restore both type I and type II cells following lung injury
- Surfactant molecules
o Reduce surface tension at the air-epithelium interface
o Multiple types: A, B, C, and D that all do different things
- Alveolar macrophages
o Remove offending substances from the
alveoli Pulmonary and Bronchial Circulation
- Pulmonary
o Arises from pulmonary artery – provides gas exchange function of the lungs
o Removes thromboemboli (blood clots) from circulation – traps them via small
pulmonary vessels – endothelial cells lining vessels release fibrolytic
substances that help dissolve them
o Functions as a metabolic organ
o Serves as a blood reservoir for the left side of the heart
- Bronchial
o Provides blood supply for the conducting airways and the supporting structures
of the lung.
o Warms and humidifies incoming air as it moves through the conducting airways
o Arteries arise from the thoracic aorta blood is deoxygenated
o Dilutes oxygenated blood returning to the left side of the heart by way
of pulmonary veins
o ONLY ones that can undergo angiogenesis and develop collateral
circulation when vessels in the pulmonary circulation are obstructed.
Regulation of Breathing
- Automatic (via chemoreceptors and lung/chest wall receptors) and voluntary
- Chemoreceptors –
o Monitor blood levels of O2, CO2, and pH
o Adjust ventilation to meet the changing metabolic needs of te body
o Input transmitted to respiratory center
o Two types:
▪ Central –
• Located in the brain stem – medulla!
• Bathed in CSF! Allowing CO2 to cross blood-brain barrier
▪ Peripheral
• Located in carotid arteries and aorta
• Monitor arterial PO2 levels most importantly
• Have little control over ventilation until the PO2 has
dropped below 60 mmHg
• Hypoxia main stimulus for ventilation in persons with
chronically elevated levels of CO2.
• WARNING: if patients with chronically elevated levels of CO2
are given oxygen therapy at a level sufficient to increase the PO2
about:blan 2/
k 14
AM Nursing
Pathophysiology Exam 3 Nursing
Disorders of Respiratory Function:
Ch. 21:
Conducting Airways
- Air moves through here as it passes between the atmosphere and the lungs
- Consists of:
o Nasal passages
o Mouth and pharynx
o Larynx
o Trachea
o Bronchi
o Bronchioles
- Lined by pseudostratified columnar epithelium – mucus secreting glands, ciliated
cells, serous glands secreting antibacterial enzymes
- Cigarette smoking slows down or paralyzes motility of the cilia, allowing smoke,
dust, etc to build up in the lungs.
- Air is kept moist by water contained in the mucous layer of upper airways
and tracheobronchial tree
- Air in alveoli maintained at body temp has more water vapor than the atmospheric-
temp air we breathe
- ~ 1 pint of water is used each day to humidify the air we breathe
- With fever, water vapor in lungs increases, causing more water to be lost through the
respiratory tract causes respiratory secretions to thicken, preventing free movement of
the cilia and impairing the protective function of the mucociliary defense system
Respiratory Lobules
- Where gas exchange function takes place in the lungs!
- Smallest functional unit of the lung
- Supplied by a terminal bronchiole, alveoli, and pulmonary blood vessels
- Surrounded by lymphatic structures and aid in the removal of plasma proteins and
other particles from the interstitial spaces
- Alveoli
o Actual sites of gas exchange b/w air and blood
o Ducts – elongated airways that have almost no walls at their peripheral boundary
o Sacs – cup-shaped, thin-walled structures that are separated from each other by
thin alveolar septa
o ~300 million alveoli in the adult lung, 50-100 m2 surface area
o Do NOT have separate walls! continual mixing of air via pores of Kohn which
are small holes in the walls of adjacent alveoli.
o Contain brush cells and macrophages
▪ Brush cells – few in #, act as receptors that monitor the air quality of
the lungs
- Alveolar cells
o Type I – extremely thin, squamous cells occupying about 95% of the surface
area. NOT capable of regeneration.
about:blan 1/
k 14
, 10/14/24, 9:45 Pathophysiology Exam 3
AM Nursing
Pathophysiology Exam 3 Nursing
o Type II – interspersed between type I cells – secretory cells producing
surfactant. They are also the progenitor cells for type I they will proliferate and
restore both type I and type II cells following lung injury
- Surfactant molecules
o Reduce surface tension at the air-epithelium interface
o Multiple types: A, B, C, and D that all do different things
- Alveolar macrophages
o Remove offending substances from the
alveoli Pulmonary and Bronchial Circulation
- Pulmonary
o Arises from pulmonary artery – provides gas exchange function of the lungs
o Removes thromboemboli (blood clots) from circulation – traps them via small
pulmonary vessels – endothelial cells lining vessels release fibrolytic
substances that help dissolve them
o Functions as a metabolic organ
o Serves as a blood reservoir for the left side of the heart
- Bronchial
o Provides blood supply for the conducting airways and the supporting structures
of the lung.
o Warms and humidifies incoming air as it moves through the conducting airways
o Arteries arise from the thoracic aorta blood is deoxygenated
o Dilutes oxygenated blood returning to the left side of the heart by way
of pulmonary veins
o ONLY ones that can undergo angiogenesis and develop collateral
circulation when vessels in the pulmonary circulation are obstructed.
Regulation of Breathing
- Automatic (via chemoreceptors and lung/chest wall receptors) and voluntary
- Chemoreceptors –
o Monitor blood levels of O2, CO2, and pH
o Adjust ventilation to meet the changing metabolic needs of te body
o Input transmitted to respiratory center
o Two types:
▪ Central –
• Located in the brain stem – medulla!
• Bathed in CSF! Allowing CO2 to cross blood-brain barrier
▪ Peripheral
• Located in carotid arteries and aorta
• Monitor arterial PO2 levels most importantly
• Have little control over ventilation until the PO2 has
dropped below 60 mmHg
• Hypoxia main stimulus for ventilation in persons with
chronically elevated levels of CO2.
• WARNING: if patients with chronically elevated levels of CO2
are given oxygen therapy at a level sufficient to increase the PO2
about:blan 2/
k 14
