Pulmonary Physiology 5 Flashcards
The second mechanism results from increased rate of
Vetilation
In response to increased ventilation, the pressure difference between the chest and gut is
Widened
Therefore, we establish a very favorable pressure gradient for
Venous return
In order to allow more blood to be delivered during periods of increased metabolic demand, exercise stimulates skeletal muscle to undergo
Angiogenesis
In exercise that is intense enough to exceed the anaerobic threshold (i.e. the point at which the generation of lactic acid exceeds the removal capacity), the accumulation of lactic acid can result in a very mild metabolic acidosis, which further drives
Ventilation
The increase in ventilatory rate then tends to lower
PaCO2
A wet epithelium, kept moist by the secretions of glands
Mucosa or mucous membrane
Secretions from glands in the mucosa and/or deeper connective tissue provide
Protection from drying, lubrication, and control of bacteria
The epithelium of the respiratory tract is
Pseudostratified columnar epithelium
The epithelium of the GI system is
Columnar epithelium
There are many components of the immune system in the lamina propria such as lymphocytes, neutrophils, and plasma cells. This is called
MALT (mucosa associated lymphoid tissue)
Olfactory receptor cells have ciliated dendritic processes that are bathed in a serous secretion from
Bowman’s glands
The bronchi have a very important defense system called
BALT (Bronchus associated Lymphatic Tissue)
What is the respiratory system made up of?
30% goblet cells, 30% ciliated cells, and 30% basal cells
Ciliary action that moves foreign particles up the respiratory tree
Mucous Elevator
The mucociliary escelator is a very important defense mechanism and extends as far distally as the
Terminal Bronchioles
Tobacco smoke is known to increase mucous secretion and to poison the
Cilia
An inherited disorder in which cilia lack dynene
-Males are sterile and both sexes suffer from sinusitis and bronchitis due to immotile cilia
Kartagener’s (immotile Cilia) syndrome
The respiratory epithelium contains 3-5% of cells that secrete neuropeptides and vasoactive substances into the lamina propria. These are called
DNES cells (Hulchitsky or K cells)
A bronchiole lacks
Cartilage
As the bronchioles get smaller and smaller, we no longer find goblet cells. but we do find
Ciliated cells
Course with the bronchiole
Pulmonary arteries
Secrete a lipoprotein material that reduces the surface tension in the airways to keep them open during the pressure changes of the respiratory cycle
-Appear in smallest bronchioles
Clara cells
Can also metabolize foreign materials and proliferate to replace other bronchiolar epithelial cells
Clara cells
Loss of elastic tissue in the bronchiole tree contributes to diseases such as
Emphysema
All tissue served by a terminal bronchiole
Lobule
The tissue served by one respiratory bronchiole
Acinus
Immediately distal to the terminal bronchioles are the respiratory bronchioles, which are the first elements to participate in
Gas exchange
The predominant cells of the respiratory bronchioles are the
Clara cells
The walls of the alveoli are composed of
Type I and II pneumocytes
Squamous cells through which gas exchange occurs. They form about 95% of the surface of the alveoli
Type I pneumocyte
Dome shaped cells in the alveolar wall that contain lamellar or multilamellar bodies
Type II Pneumocytes
Contain surfactant that is discharged into the lumen of the alveolus where it functions to reduce surface tension and prevent alveolar collapse during expiration
Lamellar bodies
Because Type II pneumocytes mature late in gestation premature infants may not produce sufficient surfactant for adequate respiratory function. Such infants suffer from
Respiratory Distress Syndrome (Hyaline MEmbrane Disease)
Phagocytose microscopic foreign matter that escaped the mucous blanket in the conductive respiratory system
Alveolar macrophages (Dust Cells)
Characterized by the distruction of tissue distal to the terminal bronchioles
-a type of COPD
Emphysema
With emphysema, support for the air passages is lost and gas movement into and out of the alveoli is
Compromised
In emphysema, elastic fibers in the interstitial tissues are destroyed and air passages can not remain
Open
Macrophages secrete a protease inhibitor that limits the action of elastases called
a1-antitrypsin
Environmental toxins such as tobacco smoke disrupt the normal function of macrophages by suppressing the production and/or function of
a1-antitrypsin
The respiratory epithelium is pseudostratified and made up of
30% goblet cells
30% ciliated cells
30% basal cells
3-5% DNES cells
Secretes a watery, proteinaceous secretion which serves as a solvent for odoriferous substances
-found in lamina propria of respiratory and olfactory epithelium
Bowman’s Glands
The olfactory epithelium is made up of
-NO goblet cells
- ) Olfactory receptor cells
- ) Sustentacular cells
- ) Basal cells
- ) DNES cells
Has cartilage plates and is the introduction of smooth muscle to the wall of the resporatory tract
-Surrounded by lung tissue
Intrapulmonary bronchi
Has no cartilage, but has smooth muscle walls, and where goblet cells start to disappear and clara cells start to appear
Muscular bronchioles
The blood-air barrier is made up of
Type I pneumocytes, endothelium of capillary, shared basement membrane
