The respiratory system (Chapter 22) Flashcards
- body tissues must be supplied with oxygen, CO2 waste must be disposed of
- CO2 can interfere with reactions
Gas exchange
what are the four processes involved with gas exchange?
1. Pulmonary ventilation: breathing
2. External respiration: Gas exchange occurring in the lungs, O2 brought into lungs, CO2 brought out of the lungs
3. Transport of respiratory gases to/from tissues: not a function of lungs, function of cardiovascular system
4. Internal respiration: Gas exchange occurring in the tissues, deeper in body, remove oxygen from blood, pushes CO2 in blood to be transported for disposal
what are the two zones of the respiratory system
Conducting zone and respiratory zone
- respiratory passages leading from nose to the respiratory bronchiole
- transports air to/from the lungs
Conducting zone
- actual site of gas exchange
- found in respiratory bronchioles, alveolar ducts and alveoli
respiratory zone
- air is warmed and humidified as it passes thought this cavity (keeps a normal respiratory rate)
- cavity is so large it allows air to be warmed and humidifed before it reaches the lungs. Cold dry air causes a decrease in respiratory rate and slows down breathing
Nasal cavity
What are the two cell types of nasal cavity (mucous membranes)?
- goblet cells- muscous producing cells
- seromucous nasal glands- “mucous” portion traps particles and debris, the “serous” portion secretes watery fluid containing lysozyme which destroy pathogens
- There are nerve endings in membrane- invading debris triggers a sneezing reflex (sneezing removes debris, removes air)
- Vascularization- capillaries and veins located superficially to help warm air as it passes through
what 3 regions do the pharynx contain?
- nasopharynx
- oropharynx
- laryngopharynx
- contains pharyngeal tonsils and tubal tonsils
- tonsils provide some immune defense
- closes during swallowing by soft palate and uvula (prevents u from getting food to nasopharynx)
Nasopharynx
- meets oral cavity at isthmus of the facues
- contains palatine tonsils and lingual tonsils
oropharynx
- where respiratory and digestive passage splits
- respiratory sits in front of digestive system
- split enters the lower conducting zone
laryngopharynx
divides the laryngopharynx from the respiratory passages
lower conducting zone
cartilage flap that closes off lower conducting zone
epiglottis
- composed of thryoid cartilage and cricoid cartilage
- contains vocal cords for sound protection
- Glottis: open passageway surrounded by vocal cords
- vocal cords are ligaments composed of elastic fibers (fibers vibrate as we exhale to produce sound)
Larynx (voice box)
- if chords are tense=
- air passes across chords with greater force=
- if chords are tense= higher pitch
- air passes across chords with greater force= increase loudness
composed of elastic fibers and cartilage rings
trachea (windpipe)
smooth muscle tissue of trachea
trachealis
allow air to reach the respiratory zone
bronchi
bronchi bran 20-25 times, eventually form
bronchioles
smallest of the bronchioles in conducting zone are
terminal bronchioles
- organ where extenal gas exchange occurs
- composed of air space and elastic connective tissue
lungs
point at which the bronchi and any blood/nerve supply enter/leave the lung
hilum
pulmonary artery brings oxygen poor blood to lungs
Pulmonary circulation
immediately surrounds alveoli
pulmonary capillary network
bronchial arteries supply lung tissue with oxygenated systemic blood
bronchial circulation
nerve fibers enter lungs at
pulmonary plexus
parasympathetic causes the air tubes to become
narrow and constrict
sympathetic causes the air tubes to
dilate or become wider
thin, double layered serous membrane
Pleurae
covers thoracic wall and upper portion of diaphragm
parietal pleura
covers external lung feature
visceral pleura
fills cavity between visceral and parietal layers
pleural fluid
branch from the terminal bronchioles of the conducting zone
respiratory bronchioles
individual alveoli connected to “neighbors” via
alveolar pores
- squamous epithelial cells
- create walls of alveoli-where gas exchange occurs
Type 1 alveolar cells