22 1-8 Flashcards
Some functions of the respiratory system aside from the four processes of respiration?
Speech, laugh, cry, smell, pH, BP reg via angiotensin II (RAAS)
*Four processes of respiration
- Pulmonary ventilation (breathing - air moves in/out of lungs, gases continuously refreshed.)
- External respiration (O2 diffuses from the lungs to the blood, co2 diffuses from the blood to lungs)
- Transport of respiratory gases (O2 is transported from the lungs to the tissue cells of the body, co2 is transported from the tissue cells to the lungs)
- Internal respiration (O2 diffuses from blood to tissue cells and co2 diffuses from tissue cells to blood)
***respiratory sys is only responsible for first two processes
*Identify the organs forming the respiratory passageway(s) in descending order until the alveoli are reached.
Nose, Nasal cavity, Paranasal sinuses, pharynx, larynx, trachea, bronchi + smaller branches, lungs, alveoli.
Nose function
Airway for respiration, moisten and warm air, filter/clean air, resonating chamber for speech, houses olfactory receptors
Paranasal sinus function
(Frontal, ethmoidal, maxillary, sphenoidal) Lighten skull, warm and moisten air
Pharynx function
Passageway for air and food. Also houses tonsils so exposes immune sys to inhaled air. (“throat”)
Larynx function
Provide air passageway, route air/food into proper channels. Also houses vocal folds so voice production. (“voicebox”)
Trachea function
Air passageway, cleans/warms/moistens incoming air
Bronchial tree function
Air passageway connecting trachea with alveoli, cleans/warms/moistens air.
Alveoli function
Main site of gas exchange. Also, surfectant which reduces surface tension/prevents lung collapse.
Lung function
Houses respiratory passages smaller than the main bronchi.
Pleurae function
Produce lubricating fluids and compartmentalize lungs.
*Respiratory (functional) zone
Actual site of gas exchange; composed of: respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli, all microscopic structures
*Conducting (structural) zone
Includes all other respiratory passageways - fairly rigid conduits for air to reach gas exchange sites. Also cleanse/humidify/warm air.
nose/nasal cavity/paranasal sinuses/pharynx/larynx/trachea
R/L primary bronchi, secondary bronchi, tertiary bronchi, bronchioles, terminal bronchioles
Nasopharynx
Posterior to nasal cavity. Only an air passageway (above where food enters, uvula moves up when swallowing). Contains pharangeal tonsil
Oropharynx
Posterior to oral cavity, both food and air pass through. Palatine tonsils embedded in lateral walls. Lingual tonsils on posterior surface of tongue.
Laryngopharynx
Posterior to epiglottis, extend to larynx where it is continuous with the larynx. Food and air pass.
Epiglottis function
Projects upward when air is flowing, during swallowing the larynx pulls upward and epiglottis tips to cover the laryngeal inlet.
Valsalva’s maneuver
During abdominal straining, the glottis closes to prevent exhalation and ab muscles contract causing intraabdominal pressure to rise.
*Structure of the trachea
16-20 C-shaped rings or hyaline cartilage.
Layers from innermost to outermost:
mucosa (pseudostrat ciliated columnar epithelium),
submucosa (areolar CT with blood vessels/nerves/glands),
hyaline cartilage,
adventitia (elastic CT)
What travels on the mucociliary escalator?
mechanism involving ciliary action and flow of mucus from bronchioles, through the bronchi and trachea to the larynx, by which particulate matter (especially alveolar macrophages) is removed from the respiratory tract.
Bronchial tree consists of?
Air passageways in the lungs that branch and branch again. From primary bronchi to terminal bronchi.
*Structural changes as the conducting tubes become smaller? (structure of bronchial tree)
Cartilage rings give way to plates of cartilage then no more cartilage in the bronchioles.
Epithelium type changes - psuedostrat columnar –> columnar –> cuboidal in terminal bronchioles.
Smooth muscle amount increases as the conducting tubes get smaller, bronchioles have a complete layer.
- Stucture of respiratory membrane? 6
Consists of: Capillary, alveolar walls and their fused membranes.
Primarily Type I alveolar cells (single layer squamous) surrounded by thin basement membrane.
Scattered amid the type I are type II alveolar cells which secrete surfactant and antimicrobial proteins.
External surfaces are covered with pulmonary capillaries.
bound by elastic fibers,
have open alveolar pores between alveoli,
have alveolar macrophages.
*How does the respiratory membrane structure contribute to function?
Thin membranes for exchange
And caps to exchange to.
Alveolar pores allow for equal air pressure.
Surfactant decreases surface tension.
Elastic fibers allow for recoil
Shape gives surface area for diffusion
Describe the innervation of lung structures by the ANS.
Through pulmonary plexus… Para/sym constrict/dilate, plus visceral sensory fibers.
Describe the gross structure of the pleurae
Thin, double layered serosa. Parietal lines the thoracic wall, superior surface of diagphram and continues around the heart between the lungs. Visceral covers the external lung surface.
Describe the gross structure of the lungs
Occupy the thoracic cavity except mediastinum.
- Each lung is suspended within its own pleural cavity and connected to themediastinum by vascular and bronchial attachments called the lung root.
- Each lobe (L has 2, R has 3 lobes) contains a number of broncho-pulmonary segments each served by is own artery/vein/tertiary bronchus.
- Lung tissue consists largely of air spaces with the balance comprised of mostly stroma/elastic tissue.
- Two circulations: pulmonary network carries systemic blood to the lungs for oxygenation, bronchial arteries provide blood to the lung tissue.
Aside from gas exchange, Type I cells are involved in?
Blood pressure regulation via angiotensin conerting enzyme (ACE)
Type II cells secrete?
Surfactant, a mixture of phospholipids and proteins which coats alveolar surfaces and decreases surface tension created by water’s hydrogen bonding.
Alveolar macrophages (dust cells)
Dead ones are continously swept up by the ciliary current of superior regions and carried away to the pharynx then swallowed.
*Anatomic properties that keep the lungs inflated?
Transpulmonary pressure - the difference in Ppul - Pip
Elasticity of chest wall
*List and describe several protective mechanisms of the respiratory system.
Nasal cavity: Hair catches debris, shape of nasal conchae creates air turbulence, mucus traps debris and kills with defensing and lysozyme, ciliated cells move mucus with debris to be swallowed, sneeze reflex
Uvula: Closes off nasopharynx inlet, prevents food from entering nose
Epiglottis: Covers laryngeal inlet. If food does get in then cough reflex
Cilia: moves mucus containing particulates out of the lungs to be swallowed.
Atelectasis
Partial or complete collapse of a lung. Occurs when a bronchiole becomes plugged - alveoli absorb all their air and collapse. Also happens from a chest wound
Pneumothorax
The presence of air or gas in the pleural cavity, causing collapse of the lung
Lung landmarks
Root (vascular and bronchial attachments to mediastinum), lobes, costal surfaces, apex, base.
Hilum - indentation on mediastinal surface, pulmonary and systemic vessels/bronchi/lymphatic vessels/nerves enter/leave lungs.
Cardiac notch - concavity in L lung that accommodates the heart
Bronchopulmonary segments - pyramid shaped, R-10, L8-10, each is separated by CT and served by its own artery and vein.
Stroma - Mostly elastic CT
*Factors that keep alveoli open/closed
OPEN
Surfactant
Transpulmonary pressure
Alveolar interdependence (Kohn pores/pressure eq)
COLLAPSE
Surface tension
Elastic recoil of lungs
