Respiratory System Flashcards
Respiratory system
■ Cells produce energy:
■ for maintenance, growth, defense, and reproduction
■ through mechanisms that use oxygen and produce carbon dioxide
Oxygen
■ Is obtained from the air by diffusion across delicate exchange surfaces of lungs
■ Is carried to cells by the cardiovascular system which also returns carbon dioxide to the lungs
5 functions of the respiratory system
- Provides extensive gas exchange surface area between air and circulating blood
- Moves air to and from exchange surfaces of the alveoli
- Protects respiratory surfaces from outside environment
- Produces sounds
- Participates in olfactory sense
Organization of respiratory system
■ The respiratory system is divided into the upper respiratory system, above the larynx, and the lower respiratory system, from the larynx down
Respiratory tract
■ Consists of a conducting portion (zone):
■ from nasal cavity to terminal bronchioles
■ Consists of a respiratory portion (zone):
■ the respiratory bronchioles and alveoli
Alveoli
■ Are air-filled pockets within the lungs
■ where most gas exchange takes place
Respiratory Epithelium
■ For gases to exchange efficiently:
■ alveoli walls must be very thin (< 1 µm)
■ surface area must be very great (about 35 times the surface area of the body)
Respiratory mucosa
■ Consists of:
■ an epithelial layer
■ an areolar layer
■ Lines conducting portion of respiratory system
Lamina propria
■ Underlies areolar tissue
■ In the upper respiratory system, trachea, and bronchi:
■ contains mucous glands that secrete onto epithelial surface
■ In the conducting portion of respiratory system:
■ contains smooth muscle cells that encircle lumen of bronchioles
Alveolar epithelium
■ Is a very delicate, simple squamous epithelium
■ Contains scattered and specialized cells
■ Lines exchange surfaces of lungs
Respiratory defense system
■ Consists of a series of filtration mechanisms
■ Removes particles and pathogens
Components of respiratory defense system
■ Goblet cells and mucous glands:
■ produce mucus that bathes exposed surfaces
■ Cilia:
■ sweep debris trapped in mucus toward the pharynx
■ This results in a moving carpet of mucus called the mucus escalator
■ Filtration in nasal cavity removes large particles
■ Alveolar macrophages engulf inhaled particles that reach lungs
Upper respiratory system: nose
■ Air enters the respiratory system:
■ through nostrils or external nares
■ into nasal vestibule
■ Nasal hairs (Vibrissae):
■ are in nasal vestibule
■ are the first particle filtration system
Nasal cavity
■ The nasal septum:
■ divides nasal cavity into left and right
■ Mucous secretions from paranasal sinus and tears:
■ clean and moisten the nasal cavity
■ Pseudostratified ciliated columnar epithelium
■ Mucous and serous secretions contain lysozyme and defensins
■ Cilia move contaminated mucus posteriorly to throat
■ Superior portion of nasal cavity is the olfactory region:
■ provides sense of smell
Air flow
■ From vestibule to internal nasopharynx:
■ through superior, middle, and inferior meatuses
■ Nasal cavity opens into nasopharynx through internal nares
Meatuses
■ Constricted passageways that produce air turbulence:
■ warm and humidify incoming air
■ trap particles
Paranasal sinuses
■ In frontal, sphenoid, ethmoid, and maxillary bones
■ Lighten skull; secrete mucus; help to warm and moisten air
Palates
■ Hard palate:
■ forms floor of nasal cavity
■ separates nasal and oral cavities
■ Soft palate:
■ extends posterior to hard palate
■ divides superior nasopharynx from oropharynx
Nasal mucosa
■ Warm and humidify inhaled air for arrival at lower respiratory organs
■ Breathing through mouth bypasses this important step
Pharynx
■ A chamber shared by digestive and respiratory systems
■ Extends from internal nares to entrances to larynx and esophagus
Divisions of pharynx
■ Nasopharynx
■ Oropharynx
■ Laryngopharynx
Cartilages of larynx
■ 3 large, unpaired cartilages form the
■ larynx:
■ the thyroid cartilage
■ the cricoid cartilage
■ the epiglottis
Thyroid cartilage
■ with laryngeal prominence (Adam’s apple)
■ Is a hyaline cartilage
■ Forms anterior and lateral walls of larynx
■ Ligaments attach to hyoid bone, epiglottis, and laryngeal cartilages
Cricoid cartilage
■ Is a hyaline cartilage
■ Form posterior portion of larynx
■ Ligaments attach to first tracheal cartilage
■ Articulates with arytenoid cartilages
Epiglottis
■ Composed of elastic cartilage
■ Ligaments attach to thyroid cartilage and hyoid bone
■ covered in taste bud-containing mucosa
Cartilage functions
■ Thyroid and cricoid cartilages support and protect:
■ the glottis
■ the entrance to trachea
■ During swallowing:
■ the larynx is elevated
■ the epiglottis folds back over glottis
■ Prevents entry of food and liquids into respiratory tract
Small cartilages of larynx
■ 3 pairs of small hyaline cartilages:
■ arytenoid cartilages – anchors vocal cords
■ corniculate cartilages
■ cuneiform cartilages
The glottis: cartilage functions
■ Corniculate and arytenoid cartilages function in:
■ opening and closing of glottis
■ production of voice
■ Anchoring the vocal cords
Vocal ligaments
■ Attach arytenoid cartilages to thyroid cartilage
■ Contain elastic fibers
■ Form core of vocal folds (true vocal cords)
■ Glottis-opening between vocal folds
■ Folds vibrate to produce sound as air passes through
■ Vestibular folds (false vocal cords)
Trachea
■ Also called the windpipe
■ Extends from the cricoid cartilage into mediastinum
■ where it branches into right and left pulmonary bronchi
Submucosa
■ Beneath mucosa of trachea
■ Contains mucous glands
Adenoids normally destroy pathogens because they contain…
Lymphocytes
What could be involved in causing bronchioles constriction during asthma attack?
Release of histamine and inflammatory chemicals in airways walls
During pneumonia, the lungs become water logged; this means that within the alveoli there is an abnormal accumulation of…
Interstitial fluid
which region contains the opening of a canal that equalize pressure in middle ear?
Nasopharynx
what part of the larynx covers the laryngeal inlet during swallowing to keep food out of lower respiratory passages?
Epiglottis
What structure forms a complete ring around airway?
Cricoid cartilage
what type of epithelial tissue forms the walls of the alveoli?
Simple squamous epithelium
In children with infant respiratory distress syndrome (IRDS), the walls of the alveoli cling to each other and make them difficult to inflate. It is common in babies born prematurely. what cells in these infants are not fully developed and are not doing their job?
Type 2 alveolar cells
which cavity surrounds the lungs alone?
Pleural cavity
indentation of the medial surface of each lung through which pulmonary and systemic blood vessels, bronchi, lymphatic vessels ahd nerves ebter and leave is called the _
Hilum
during pleurisy, the inflamed parietal pleura of one lung rubs against the inflamed _
Visceral pleura of the same lung
what pressure rises and falls wit the phases of breathing but eventually equalizes with the pressure of the air in the environment?
Intrapulmonary pressure
what pressure must remain negative to prevent lung collapse?
Intrapleural pressure
quiet inspiration is _, and quiet expiration is _
Active process; passive process
true or false: to produce the pressure gradient responsible for inspiration, thoracic volume must first increase in order to decrease intrapulmonary pressure relative to atmospheric pressure
True
which volumes are combined to provide the inspiratory capacity?
Tidal volume (TV), and inspiratory reserve volume (ERV)
amount of air that is normally ventilated in one breath?
Tidal volume
T or F: residual volume can be measured with a spirometer
False
true or false: henry’s partial pressures states that when a gas is in contact with a liquid, that gas will dissolve in the liquid in proportion to its partial pressure
True
most common method of carbon dioxide transport
As bicarbonate ions in the plasma
which form of co2 transport accounts for the least amount of co2 transported in blood?
Dissolved in plasma
true or false if your core temperature becomes colder, it is more difficult for oxygen to dissociate from hemoglobin at any P02
True
Tidal volume
Volume of air coming in and out of lungs during normal quiet breathing (500ml)
Inspiroratory reserve volume
Total volume of air inspired forcefully beyond the tidal volume (3100ml)
Expiroratoy reserve volume
Amount of air forcefully exhaling beyond tidal volume expiration (1200ml)
Residual volume
Volume of air remaining in long after fire up expiration (1200ml)
Inspiratory capacity (IC)
Total volume of air that can be inspired
o Tidal volume of inspiration + inspiratory reserve volume
o TVi + IRV
o 500 ml + 3100 ml
o Average = Approximately 3600 ml
Expiratory capacity (EC)
Total volume of air that can be expired
o Tidal volume of expiration + expiratory reserve volume
o TVe + ERV
o 500 ml + 1200 ml
o average = approximately 1700 ml
Functional residual capacity (FRC)
• Normal amount of air in the lungs without forceful expiration
o Expiratory reserve volume + residual volume
o ERV + RV
o 1200 ml + 1200 ml
o Average = approximately 2400 ml
Vital capacity (VC)
Total volume of air that can be inhaled and exhaled
normally and forcefully
o Total volume of air that can be inhaled and exhaled
normally and forcefully
o Tidal volume + inspiratory reserve volume + expiratory reserve volume
o TV + IRV + ERV
o 500 ml + 3100 ml + 1200 ml
o Average = Approximately 4800 ml
Total Lung Capacity (TLC)
Total volume of air that can be occupied in the lungs
o Vital capacity + residual volume
o (Tidal volume + inspiratory reserve volume + expiratory reserve volume) + residual volume
o TV + IRV + ERV + RV
o 500 ml + 3100 ml + 1200 ml +1200 ml
o Average = approximately 6000 ml
