Respiratory System Flashcards
(34 cards)
gas exchange
across body surface, gills, trachea, lungs
Ventilation
bringing O2 water or air into contact with gas exchange surface
Gills
- specialized filamentous organs in aquatic animals
- used to obtain O2 and eliminate CO2
External Gills
- large surface area
- may be in one body area or scattered
limitations of external gills
- unprotected, may be damaged
- moving gills back and forth requires energy
- gills may attract predators
Internal Gills
-fish gills lie w/i opercular cavity in bony fish
gill arches: main support structure
filaments: branch off gill arches
lamellae: brand off filaments
blood vessels: run length of filaments
—O2 poor blood travel AFFERENT VESSEL (to gills)
—O2 rich blood travel EFFERENT VESSEL (away from gills)
Buccal Pumping
- one mechanism of internal ventilation
- creates hydrostatic pressure gradient
- –lower haw lowered
- —–enlarges buccal cavity–decrease H2O pressure in mouth (suction), H2O enters. increase H2O pressure
- opperculum opens
- —enlarges opp. cavity
- —decrease H2O pressure. creates suction
- —H2O flows into operculum cavity
- mouth closes
- —–buccal cavity compressed
- —-H2O forced across gills and out open opperculum
Ram Ventilation
- mechanism of internal ventilation
- swimming with open mouth
- more efficient
- many fish use buccal and ram
- —-tuna, just ram
- both ram/buccal are FLOW THROUGH SYSTEMS
- —H2O in one direction
- —gills constantly in contact with fresh/O2 rich water
trachea
(insects)
- spiracles (openings0 on body surface lead to trachea
- trachea lead/branch to tracheoles: terminate near every body cell
- small amount of fluid for gas to diffuse into
- body muscles movements draw air in/out of trachea
- O2 diffuses directly into body cells from air
- very efficient
- —supports insect flight muscles
- —highest metabolic rate known
Lungs
- with few exceptions, all air breathing terrestrial vertebrates use lungs
- filled using positive and negative (humans) pressure
- ventilated using tidal or through systems
Nasal Cavity
air is warmed, filtered, and moistened
nasal hairs
filter debris from inhaled air
mucousis cells
secret mucous trap debris
ciliated cells
generate current to move trapped debris from nasal cavity to pharynx
In nasal cavity, the purpose of a cough is to
remove material or swallow it –>digestive tract
Pharynx
conducts air “throat”
tonsils in wall
—-arregates of lymphoid tissue, protection from pathogens in inhaled air
larynx
“voice box”
- wall supported by cartilage
- contains vocal cords: sound protection
trachea
“windpipe”
-conducts, filters, moistens air
-lined with mucous cells and ciliated cells
C-shaped cartilages in wall
—-hold trachea open during ventilation
-ends of each cartilage support connected by smooth muscle
Bronchi
- conduct, filter, moisten
- no cartilage in wall
- replaced by ring of smooth muscle
- Clara cells: detoxify harmful chemicals in air
Alveoli
gas exchange region of lungs
-wall 1 cell thick: 2 types of cells
Type 1 Alveolar Cells/Pneumocyte
Type II Alveolar Cells/Pneumocyte
Type I Alveolar Cells/Pneymocyte
flat cells, site of gas exchange
Alveolar II Alveolar Cells/Pneumocyte
cuboidal, secrete surfactant that covers alveolus (decrease surface tension, prevent alveoli collapse)
Surfactant
decrease surface tension. covers alveolus. prevent collapse
Pleurae
- double serous membrane enclosing each long
- PARIETAL PLEURA: adheres to wall of thoracic cavity
- VISCERAL PLEURA: adheres to surface of lungs
- surface tension holds two membrane together
- result: lungs follow movement of thoracic cavity during ventilation
