Respiratory system histology Flashcards
What is respiration
Breathing, gas exchange- Air-->Blood Gas transport Gas exchange- Blood--> tissues Cell respiration
Anatomic components of respiratory system
Conducting: Nasal cavity and paranasal sinuses Nasopharynx Oropharynx Laryngopharynx Larynx Trachea Bronchi, primary
Respiratory: Bronchioles Respiratory bronchioles Alveolar ducts Alveolar Sacs
Conducting portion
Nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles
Warm/Cool, humidify, filter and conduct incoming air to respiratory passageways, lined with respiratory epithelium
Conducting passages have a wall stabilized by bone, cartilage or muscle, lined by a mucosa
Produce seromucous secretion
Respiratory portion
Respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
Site of exchange of o2 and Co2 between blood and alveoli
Respiratory passage ways are line with a mucosa, aka mucous membrane
The lining membrane of cavities, lumens of tubular organs, have a connection to the exterior ot the body is mucosa
A mucosa provides an immunological and physical barrier, a source of secretory products, a selective absorptive interface
Consistent components of a mucosa include
Epithelium at the surface, consists of ciliated psuedostratified columnar with goblet cells, is an escalator for products. columnar cells, goblet cells, basal cells, small granule cells, brush cells
Lamina propria- a Connective tissue layer that supports the epithelium, seromucous glands, venous plexus
2 layers separated by basement membrane
Olfactory epithelium
Olfactory cells, supporting cells, basal cells brush cells
Olfactory cells: bipolar neurons, apical dendrite ends in olfactory vesicle have non motile cilia with receptors for smell substances.
Sustentacular cells: tall columnar cells with microvilli. Provide physical support, nourishment and electrical insulation for olfactory
Basal cells- stem cells to replace olfactory and sustentacular cells
Bowmans glands: provide serous fluid to refresh olfactory cilia
Naso pharynx
Lymphoid tissue relating to adenoids
Larynx
Has the stratified squamous epithelium, and vocal cords
Trachea
Mucsosa lined with respiratory epithelium which continuously propels mucus and debris towards the larynx
Seromucous glands in submucosa help produce mucus sheets
16-20 C shapedrings of hyaline catrilage prevent the trachea from collapsing, closed posteriorly by trachealis (smooth) muscle
Bronchi
Primary bronchi enter the lung where they subddivide into secondary and tertiary bronchi
Mucosa and submucosa similar to trachea
Smooth muscle
Plates of hylaine cartilage encircle bronchus and prevent collapse
Club (bronchiolar) cells- columnar cells with domed apices and short blunt microvilli. Aplical cytoplasm filled with secretory granules containing surfactant material that reduces surface tension and facilitates patency of bronchioles, cells also degrade inhaled toxins
bronchiole
as tubes become smaller, epithelium has fewer goblet and ciliated cells. Terminal bronchioles are lined with simple cuboidal epithelium. Propotion of smooth muscle increases allowing for constriction para and dilation (symp) of airways
Chronic irritation
Smoking, cal alter respiratory epithelium to stratified squamous epithelium for protection
the respiratory passages
respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
Subdivisions: Pulmonary lobule- a terminal bronchiole and the lung tissue it supplies. Pulmonary acinus- portion of lung supplied by a respiratory bronchioles
Alveoli
type 1 alveolar cell/pneumocyte
Type 2 alveolar cell/pneumocyte
Type 2 cells
secrete pulmonary surfactant
Phospholipid: phosphotidylcholine, phosphotidylglycerol
Proteins: surfactant proteins A, B, C, and D
antioxidants
