Respiratory system Flashcards
Specialized to bring oxygen into body, and expel carbon dioxide
Respiratory system
Process of exchanging gases between the atmosphere and body cells
Respiration
Ventilation or breathing; allows gas exchange in lungs
External respiration
Gas transport in blood and exchange with body cell
Internal respiration
Process of ATP production in mitochondria, which uses oxygen to harness energy and gives off carbon dioxide
Cellular respiration
-Nose
*Nasal cavity
*Sinuses
*Pharynx
*Larynx
Upper respiratory tract
-Trachea
*Bronchial tree
*Lungs
Lower respiratory tract
provide openings for air to enter and leave nasal cavity (opening are protected by internal hairs)
Nostrils (external nares)
*Hollow space behind the nose
*Separated into left and right portions by the nasal septum
Nasal cavity
curl in from lateral walls of cavity
Nasal conchae (turbinate bones)
Conchae separate nasal cavity into passageways
meatuses
sense of smell
olfactory receptors
Air-filled spaces in the maxillary, frontal, ethmoid, and sphenoid bones of the skull
*Open into the nasal cavity
*Reduce weight of skull
Sinuses (paranasal sinuses)
due to infection or allergic reaction, may result in blockage of sinus drainage, causing sinus pressure and headache
Sinusitis
-Upper (vestibular) folds
*No sound production
*Help close airway during swallowing
False vocal cords
*Lower folds
*Vocal sounds
*Sound created as air is forced between them, vibrating them
True vocal cords
True vocal cords + opening between them is called the
Glottis
-Extends downward anterior to the esophagus
*As it enters thoracic cavity, splits into left and right primary bronchi
Trachea
20 C-shaped rings of hyaline cartilage Prevent collapse of?
Trachea
A procedure that cuts an opening in the trachea, to insert a tube for air exchange; done, for example, if an object is lodged in the larynx or trachea
Tracheostomy
are air passages, transporting air, but not performing gas exchange
Branches of bronchial tree
provide surface area for gas exchange
Alveoli
Soft, spongy, cone-shaped organs in the thoracic cavity
Separated from each other by heart and mediastinum
Lungs
Right lung has 3 lobe
Left lung has 2 lobe
(Part of lung) Region on medial surface of each lung through which bronchus and large blood vessels enter
Hilum
Double-layered serous membrane surrounding lungs
Pleura
Inner layer of serous membrane; attached to surface of lung
Visceral pleura
Outer layer of serous membrane; lines thoracic cavity
Parietal pleura
Potential space between visceral and parietal pleura
Pleural cavity
Movement of air from outside of the body into the bronchial tree and the alveoli
Breathing (or ventilation)
inspiration (inhalation), and expiration (exhalation)
Air movement
One inspiration + the following expiration
respiratory cycle
Force that moves air into the lungs
When respiratory muscles are at rest, atmospheric pressure and alveolar pressure are equal
Atmospheric pressure
Pressure and volume of gases are inversely proportional
Boyles law
*Diaphragm and external intercostal muscles enlarge the size of the thoracic cavity
*Lung expansion is aided by surface tension in the pleural cavity
*Surfactant reduces surface tension in the alveoli, to help lung expansion
Normal, resting inspiration
-Requires contraction of several other muscles, to enlarge thoracic cavity even more
*Pectoralis minors, sternocleidomastoids, scalenes are used
Maximal (forced, deep) inspiration
*Elastic recoil of lung tissues and abdominal organs occurs, as tissues return to their original shape at the end of inspiration
*Surface tension develops on the moist surfaces of the alveolar linings shrinks alveoli
Normal resting expiration
that does not involve muscle contraction
Passive process
-Due to contraction of internal intercostal and abdominal muscles
*Increased abdominal pressure forces diaphragm into a higher position, which pushes more air out of lungs
Maximal (forced, deep) expiration
Volume of air moved in or out of the lungs during a respiratory cycle
Tidal volume (TV)
500 mL
Maximum volume of air that can be inhaled at the end of a resting inspiration
Inspiratory reserve volume (lRV)
3,000 mL
Maximum volume of air that can be exhaled at the end of a resting expiration
Expiratory reserve volume (ERV)
1,100 mL
Volume of air that remains in the lungs even after a maximal expiratory effort
Residual volume (RV)
1,200 mL
Maximum volume of air that can be exhaled after taking the deepest breath possible: VC = T V + I R V + E R V
Vital capacity (VC)
4,600 mL
Maximum volume of air that can be inhaled following exhalation of resting tidal volume: I C = T V + l R V
Inspiratory capacity (IC)
3,500 mL
Volume of air that remains in the lungs following exhalation of resting tidal volume: F R C = E R V
Functional residual capacity (FRC)
2,300 mL
Total volume of the air that the lungs can hold: TLC= VC+RV
Total lung capacity (TCL)
5,800 mL
Some air entering respiratory tract during breathing does not reach functional alveoli; these are called
Dead Spaces
Air in respiratory tract that remains in conduction structures, and does not reach alveoli
Anatomic dead space
Air in respiratory tract that reaches nonfunctional alveoli, such as alveoli associated with capillaries with poor blood flow; this occurs occasionally
Alveolar dead space
Total of anatomical and alveolar dead space
Physiologic dead space
-Air movements other than breathing are called nonrespiratory movements
*Some clear the air passages, as in coughing and sneezing
*Some express emotions, as in laughing and crying
*Usually result from reflexes, but sometimes they can be started voluntarily
Nonrespiratory movements
Deep breath is taken, glottis is closed, and air is forced against the closure; suddenly the glottis is opened, and a blast of air passes upward
Clears lower respiratory passages
Coughing
Same as coughing, except air moving upward is directed into the nasal cavity by depressing the uvula
Clears upper respiratory passages
Sneezing
Deep breath is released in a series of short expirations
Expresses happiness
Laughing
Deep breath is released in a series of short expirations
Expresses sadness
Crying
Diaphragm contracts spasmodically while glottis is closed
Useful function unknown
Hiccuping
Deep breath is taken
Some hypotheses, but no established function
Yawning
Air is forced through the larynx, causing vocal cords to vibrate; actions of lips, tongue, and soft palate form words
Supports vocal communication
Speech
*Groups of neurons in the brainstem that control breathing
*Initiate impulses that travel on cranial and spinal nerves, causing inspiration and expiration
*Adjust rate and depth of breathing
Respiratory Areas
Medullary respiratory center contains 2 groups of neurons
Ventral respiratory group: Sets basic rhythm of breathing
*Dorsal respiratory group: Modifies activity of ventral group
groups help set rhythm of breathing by limiting duration of each inspiration
Pontine respiratory
-Amount of pressure each gas contributes to the total pressure
*Proportional to its concentration
Partial pressure
Main controlling factors (Of breathing)
are usually the Pco2 and H+ ion concentration
In ventral part of medulla oblongata
*Mainly monitor pH in the brain
*Low blood Po2 does not have much effect on them
*H+ ions do not cross blood-brain barrier well
*CO2 crosses blood-brain barrier, and binds to H2O to produce H2CO3
*H2CO3 dissociates to release
these ions are detected by the
central chemoreceptors
*Mainly sense changes in blood Po2
*In carotid and aortic bodies
*Decreased Po2 causes an increase in breathing rate and tidal volume, leading to an increase in alveolar ventilation
*Usually does not cause a major response, until Po2 decreases to about 50% of normal value
Peripheral Chemoreceptors
*Helps regulate depth of breathing
*As lung tissues stretch during inspiration, stretch receptors are stimulated
*Sensory impulses travel over vagus nerve to respiratory areas
*Duration of inspiratory bursts is then shortened
*Prevents overinflation of the lungs during forced breathing
Inflation (Hering-Breuer) Reflex
Tubular organs of the respiratory system transport air into and out of lungs
Alveoli
Blood transports O2 and CO2 between the lungs and the body cells
As the gases enter the blood, they dissolve in the plasma or chemically combine with other substances
Gas transports
