Respiratory System Flashcards
What are the 2 interrelated processes used to describe respiration?
-Cellular respiration -process by which cells produce energy by metabolism of organic molecules
-Mechanical respiration - process o2 absorbed from atmosphere into vascular system and co2 is excreted
What is the primary muscle for mechanical respiration?
Diaphragm
-Contracts during inspiration - increases thoracic cavity volume - draws in air
-Relaxes during expiration - elastic tissue within lungs cause lungs to collapse- expels air
What is the functionality of the respiratory system classified into?
Conducting zone - nasal cavity, nasopharynx, larynx, trachea, bronchi, bronchioles - gaseous transport - filters, humidifies and warms air
Respiratory zone - bronchioles, alveolar ducts, alveolar sacs, alveoli - sites of gaseous exchange between atmosphere and blood
What is the upper and lower respiratory tract composed of
Upper - nasal cavity to larynx (voicebox)
Lower - trachea to alveoli
Func of upper respiratory tract?
Filtration, humidification, temp regulation, olfaction, gives resonance to speech and lightens sull, equilibration of air pressure in middle ear
What is respiratory epithelium composed of?
-Pseudostratified ciliated columnar epithelium containing goblet cells
-Lamina propria - loose connective tissue layer underlying respiratory epithelium
-Respiratory Epithelium and lamina propria make up respiratory mucosa
-Mucosa separated from underlying structure by presence of submucosa
What is the 2 naval cvities divided by?
What are the nasal cavities and paranasal sinuses lined by?
-Divided by cartilaginous nasal septum- cartilage is stained blue
Lined by respiratory mucosa
What are turbinate bones?
Turbinate bones project into nasal cavities and provide large surface area
Features of the nasopharynxß
-Consists of pseudostratified ciliated columnar epithelium - patches of squamous epithelium can occur w increasing age
-Lamina propria contains serous and mucous glands and large masses of lymphoid tissue
-Space above soft palate at back of nose
-Connects nose to the mouth
-Soft palate separates the nasopharynx from the orthopharynx below soft palate
What is the purpose of the hyaline cartilage?
-Series of C shaped rings stained blue that support the tracheal mucosa
-Prevent the trachea from collapsing during inspiration
-Bands of smooth muscle - Trachealis muscle - join the free ends of the rings posteriorly
-Longitudinal muscle found behind the trachealis muscle
How does the structure of the bronchi differ from the trachea?
Respiratory epithelium
-shorter than that of trachea
-Fewer goblet cells
Lamina Propria
-more dense
-large quantity of elastin
Smooth muscle conatins fewer seromucinous glands
Cartilage framework arranged into flattened interconnected plates rather than discrete C-shaped rings
What is present in the primary bronchi respiratory epithelium?
-Pseudostratified epithelium
-Ciliated cells have large nuclei
-Goblet cells
-Underlying LP contains elastin and mast cells
What is present in the tertiary bronchi respiratory epithelium?
-Tall and columnar cells - little pseudostratified
-Goblet cells are diminished in number
LP
-Thin, elastic and completely encirculed by smooth muscle
-Permits contraction of bronchi
-Submucosa w sparse Seromucinous glands
-Cartilage framework is reduced to a few irregular plates - doesnt usually extend beyond tertiary bronchi
-MALT - small aggregations of lymphoid tissue
What is present in the bronchiole epithelium?
-Airways of less than 1mm in diameter
-No cartilage support or submucosal glands
-Respiratory epithelium consists of: ciliated columnar cells, few goblet cells, clara cells
-Smooth muscle layer in discrete bundles in various orientations
What are terminal and respiratory bronchioles?
Terminal bronchioles have the smallest diameter passages of conducting zones and divide to form short, thinner-walled branches called respiratory branches.
Respiratory bronchioles have ciliated cuboidal cells, no goblet cells, clara cells
-each divides into alveolar duct
-alveolar duct terminates in alveolar sac
What do clara cells do?
-Produce surfactant
-Act as reserve cells
-Contain enzymes
What is in the epithelium of the alveolar wall?
-Type I pneumocytes - large squamous cells, alveolar lining, part of gaseous diffusion barrier
-Type II pneumocytes - round cells, secrete surfactant, capable of division
(surfactant - reduces alveolar surface tension and prevents alveolar collapse during expiration)
