The respiratory system Flashcards
(103 cards)
1
Q
What is the major function of the respiratory system?
A
-supply the body with O2 and remove CO2 this is called respiration and involves 4 processes
2
Q
ventilation
A
-breathing
-air moves in and out of the lungs so that gases are exchanged
-air flows in and ribs move up and out while the diaphragm flattens
-air flows out and ribs move down and in while the diaphragm domes up
-air flows from high pressure to a low pressure
3
Q
External respiration
A
-exchange of gases between the lungs and blood
-O2 diffuses from the lungs to the blood and CO2 diffuses from the blood to the lungs
-deoxygenated blood –> oxygenated blood
4
Q
Transport of Respiratory gases
A
-O2 is transported from the lungs to the tissue cells of the body and CO2 is transported from tissue cells to the lungs
5
Q
Internal respiration
A
-exchange of gases between the blood and the body cells
-O2 diffuses from the blood to tissue cells
-CO2 diffuses from the tissue cells to blood
6
Q
Respiration requires what two systems to function properly?
A
-cardiovascular system and respiration system
7
Q
Conducting zone
A
-The volume of air contained in this conducting zone is known as anatomic dead space
-conduits (aka conducting airways)
8
Q
What are the two zones of the respiratory system?
A
- conducting zone
- respiratory zone
9
Q
respiratory system
A
-gas exchange occurs here (respiratory bronchioles, alveolar ducts, and alveoli
10
Q
nose
A
-conducting zone
-the external parts are composed of bone and cartilage covered by this skin
-encloses the entrance to nasal cavity
11
Q
External nares
A
nostrils
12
Q
internal nares
A
openings to nasopharynx
13
Q
nasal septum
A
-separates the nasal cavity into two chambers
14
Q
vestibule
A
portion of the nasal cavity just superior to the nostrils
15
Q
nasal hairs
A
hairs visible within the vestibule
16
Q
Nasal cavity: tissue type
A
respiratory mucosa (pseudostratified ciliated columnar epithelium
-mucosa and serous glands produce a sticky fluid lysozyme (antibiotic enzyme)
17
Q
nasal conchae
A
-bony shelves covered with mucous membranes
-superior, middle, and inferior
18
Q
nasal meatus
A
groove inferior to each conchae
19
Q
The function of nasal cavity
A
-moisten air
-warms air (mucosa has a rich vascular bed underneath it)
-filters air, traps particulate matter in the air
20
Q
Paranasal sinuses
A
-the nasal cavity is surrounded by a ring of this
-cavities within the skull bones continuous with the nasal cavity
21
Q
Pharynx
A
throat
22
Q
nasopharynx
A
posterior to the nasal cavity that contains:
-pharyngeal tonsils (aka adenoid tonsils)
- openings to eustachian tubes (aka auditory tubes)
-tissue type: pseudostratified ciliated columnar epithelium
23
Q
oropharynx
A
posterior to the oral cavity (extends from the soft palate to the epiglottis that contains:
-Isthmus of the Fauces: archway connecting oral cavity with oropharynx
-palatine tonsils: located on lateral walls
-lingua tonsils: located at the base of the tongue
-Tissue type: stratified squamous epithelium
24
Q
Laryngopharynx
A
-superior to the larynx and inferior to the oropharynx (posterior to the upright epiglottis)
-Tissue type: stratified squamous epithelium
-as the inferior portion of the laryngopharynx, the respiratory and digestive pathways diverge into the larynx or esophagus
25
Larynx- the voice box
-consists of 9 pieces of cartilage connected by membranes and ligaments
26
thyroid cartilage
-laryngeal prominence (adam's apple)
-this is the largest piece of cartilage in the larynx. it is larger in a typical man because of testosterone
-contains cricoid cartilage and arytenoid cartilage. cuneiform cartilage (2), corniculate cartilage (2), epiglottis (elastic cartilage)
-the epiglottis tips as the larynx moves superiorly to close over the passageway forcing food into the esophagus
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cricoid cartilage
-ring-shaped cartilage
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arytenoid cartilage (2)
pyramid-shaped cartilage that anchors the vocal folds (true vocal cords)
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vestibular folds (upper pairs)
-false vocal cords
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vocal folds (lower pair)
true vocal cords, they vibrate to initiate sound
-the vocal cords surround the glottis
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glottis
-a medial opening through which air passes
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trachea (windpipe)
-flexible and mobile tube
-has layers: mucosa, submucosa, adventitia
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mucosa layer of the trachea
-inner layer lined with pseudostratified ciliated columnar epithelium
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submucosa layer of the trachea
-middle layer consist of CT
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Adventitia layer of the trachea
-outer layer, consist of connective tissue with rings
36
C-Rings
wall contains 16-20 C shaped rings of cartilage
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carina
-most inferior C ring of trachea
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Bronchi (primary bronchi) and the bronchial tree pathway
1. primary bronchi (CZ)
2. secondary (lobar) bronchi (CZ)
3. Tertiary (segmental) bronchi (CZ)
4. Bronchioles (CZ)
5. Terminal bronchioles (CZ)
6. respiratory bronchioles (RZ)
7. alveolar ducts (RZ)
8. alveoli (RZ)
CZ: conduting zone
RZ: respiratory zone
39
What are the bronchi called when entering the lung?
-primary bronchi
- right bronchus (more vertical, wider, and shorter
-left bronchus
40
What bronchi are within the lungs
- primary bronchi
-secondary (lobar) bronchi
-tertiary (segmental) bronchi
- bronchioles
-terminal bronchioles
-respiratory bronchioles
-alveolar duct
-alveolus
41
Alveolar compartment
1. squamous pulmonary epithelial cells (type 1 cell)
2. alveolar macrophages (dust cells)
3. septal cells (type 2 cells) (produces surfactant which reduces the surface tension of alveolar fluid)
4. capillary component
42
Lungs
-extends from the clavicles to the diaphragm and is separated by the mediastinum
-consist of bronchi, bronchioles, and alveoli
43
hilum
an indentation on the medial surface
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base
the broad interior surface resting on diaphragm
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apex
the pointed upper margin just below the clavicle
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left lung
-has two lobes
-separated by oblique fissures
-cardiac notch concavity on the lung's medial aspect molded to accommodate the heart
47
right lung
-has three lobes (superior, middle, inferior lobes)
-separated by oblique and horizontal fissures
48
bronchopulmonary segments
-segments of lung tissue
-pyramid-shaped sections separated by connective tissue septa
-each segment is served by its own artery and vein
-each segment is served by its own segmental bronchus
- each lung contains 10 segments
49
lobule
the smallest division seen with a naked eye
50
the pleural membrane of the lungs?
-parietal pleura
-visceral pleura
-pleural cavity
51
parietal pleura
lines the pleural cavity
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visceral pleura
covers surface of lung
53
pleural cavity
-space between the two membranes
-filled with pleural fluid (serous fluid secreted by pleural membranes)
-the fluid decreases friction with the movement of lungs and thoracic cavity walls
54
respiration
-principal purpose is to supply the cells of the body with oxygen and remove carbon dioxide
55
boyle's law
Increase pressure = decrease volume
56
breathing
-the movement of air between the atmosphere and the lungs
57
What are the three pressures important in pulmonary ventilation
1. Atmospheric pressure
2. Intra-pulmonary pressure
3.Intra-pleural pressure
58
Atmospheric pressure
-pressure exerted by the air (gases) surrounding the body
760 mmhg
-constant so always 0 mmHg
59
Intra-pulmonary pressure (intra-alveolar pressure)
-pressure inside the alveoli
-also 0 mmHg
60
Intra-pleural pressure
-pressure inside the pleural cavity
-prevents collapse (atelectasis)
- will be -4 mmHg (756 mmHg)
61
Inhalation steps
1. diaphragm and external intercostal muscles contract
2. results in an increase in the volume of the thoracic cavity
3. the volume of the lungs increases
4. air pressure in the lungs decreases
5. air rushes in
6. during exercise, other muscles (pectoralis minor and sternocleidomastoid) contract to further increase thoracic volume -deeper breath
62
Exhalation steps
1. Diaphragm and external intercostal muscles relax
2. results in an decrease thoracic cavity volume
3. the volume of the lung decreases (lungs snap back to original volume)
4. air pressure in the lung increases
5. air rushes out
6. During exercise, contraction of other muscles (internal intercostals, etc.)- decrease thoracic cavity volume-force a greater exhalation
63
What are three physical factors influencing pulmonary ventilation?
1. airway resistance
2. alveolar surface tension
3. lung compliance
64
Airway resistance
-created by friction in the respiratory pathways
ex: asthma (acute resistance), chronic bronchitis (chronic resistance)
65
alveolar surface tension
-type 2 cells produce surfactant
-prevents respiratory distress syndrome of newborns
66
Lung compliance
-the ease at which the lungs and thoracic wall expand during breathing
ex: emphysema: decrease compliance of lungs due to deterioration of elastic fibers surrounding alveoli
67
Chronic Obstructive Pulmonary Disease (COPD)
-a condition defined by the inability to exhale air (this it is causes obstruction of exhalation)
-this obstruction can be caused by chronic bronchitis or emphysema
68
Partial Pressure of the gas
-due to Dalton's law each gas in a mixture of gases exerts its own pressure (as if all other gases were not present)
-the partial pressure of a gas is directly related to the concentration of the gas in a mixture of gases
- increase O2 = increase partial pressure of O2 same as decreasing
69
Factors that influence external respiration
1. Thin membranes for easy diffusion of gases
2. large surface area for exchange between alveoli and capillaries
3. capillaries have a narrow lumen (TBC pass one at a time, touch capillary wall surface)
4. partial pressure gradients and gas solubilities
-Oxygen diffuses rapidly from alveoli into blood b/c of large partial pressure of O2 (PO2) 104mm Hg--> 40 mmHg)
-CO2 diffuses rapidly from pulmonary blood to alveoli b/c its highly soluble in plasma and alveolar fluid
5. Precise match between ventilation and perfusion
70
External respiration: Partial Pressure in the lungs and blood
In the alveoli: PO2 = 104 mmHg
In the pulmonary arterial blood: PO2 = 40 mmHg
In the alveoli: PCO2 = 40 mmHg
In the pulmonary arterial blood: PCO2 = 45 mmHg
71
Internal Respiration: Partial Pressure in the lungs and blood
In the systemic arterial blood: PO2 = 100 mmHg
In the body tissues: PO2 = 40 mmHg
In the systemic arterial blood: PCO2 = 40 mmHg
In the body tissues: PCO2 = 45 mmHg
72
Transportation of O2 in the blood
1. For every 100 ml of oxygenated blood, 20 ml is oxygen
2. 3% of the oxygen is dissolved in the plasma
3. 97% of oxygen is carried on the hemoglobin of RBCs
Hemoglobin + O2 <--> oxyhemoglobin
-hemoglobin can be described as fully saturated or partially saturated
73
fully saturated
-when hemoglobin is completely converted to oxyhemoglobin
74
partially saturated
-when some of the hemoglobulin is converted to oxyhemoglobin
75
Factors affecting hemoglobin's ability to carry O2
1. Partial pressure of O2:
-the greater the pressure of O2, the more O2 binds to the hemoglobin to form oxyhemoglobin
- the lesser the partial pressure of O2, the more O2 id released from the oxyhemoglobin
76
CO2 Transport
1. For every 100 ml of deoxygenated blood there is 4 ml of CO2
2. CO2 is transported in the blood in several forms
a. 7% is transported and dissolved in the plasma
b, 23% binds to the globin portion of hemoglobin
c. 70% is transported as bicarbonate ions in the plasma
Hemoglobin + CO2 <--> carbaminohemoglobin
-in the tissue capillaries carbaminohemoglobin forms
-in the pulmonary capillaries, carbaminohemoglobin splits --> releasing CO2
77
Bohr effect
-both declining blood pH (acidosis) and PC02 weaken the Hb-O2 bond- enhancing oxygen unloading where it is most needed (capillaries)
78
Haldane effect
-the lower the PO2 and the lower the Hb saturation with oxygen the more CO2 that the blood can carry
79
carbon monoxide poisoning
-CO binds to hemoglobin similarly to oxygen but does not split apart
80
ventral respiratory group (VRG)
-pacesetting respiratory center = inspiratory center
-medullary rhythmicity center
Diaphtagm Contracts <-- VRG (Fire) -->External Intercostal Muscles Contract
<-- VRG (Stop) -->
81
Eupnea
normal breathing
82
Dorsal respiratory group (DRG)
-integrates input from peripheral stretch receptors and chemoreceptors
-modifies the rhythms generated by the VRG
-medullary rhythmicity center
83
Poutine respiratory center
-formerly called pneumotactic and apneustic centers
-interact with medullary centers to smooth respiratory pattern
-also used to fine-tune breathing rhythms generated during: vocalization, sleep, and exercise
84
cerebral cortex controls
-can exert conscious control to alter breathing patterns (bypass medulla oblongata)
-this voluntary control is limited because if CO2 gets to high, breathing is automatically initiated
85
Hypothalamus
1. increased breathing if one gets excited
2. paused breathing if one gets angry (breath holding)
86
Chemical regulation of respiration
1. Chemoreceptors detect: CO2, O2, and H+
2. Central chemoreceptors located in the brain stem
3. Peripheral chemoreceptors located in the aortic arch and carotid arteries
87
Influence of partial pressure on CO2
1. Increase in PCO2
2. Leads to an increase in H+ (decrease in pH)
3. This alerts the central chemoreceptors in the brain stem
4. Ventilation increases
5. Exhalation of CO2 increases
6. Decrease in partial pressure of CO2
88
Influence of partial pressure on O2
1. Decrease in partial pressure of O2
2. This alerts the peripheral chemoreceptors in the aortic arch and carotid arteries
3. Ventilation is increased
4. Inhalation of O2 is increased
5. Increase of partial pressure of O2
89
Respiratory volumes
- The amount of air that can be inhaled, exhaled, or remain in the lungs
-respiratory volumes are measured with a spirometer
90
Pulmonary function test (PFTs)
-the clinical measurement and analysis of respiratory volumes (often performed within hospitals)
91
tidal volume (TV)
-amount of air inhaled or exhaled within each breath under resting conditions (500 ml)
92
Inspiratory Reserve Volume (IRV)
Amount of air that can be forcefully inhaled after a normal tidal volume inspiration
93
expiratory reserve volume (ERV)
Amount of air that can be forcefully exhaled after a normal tidal volume expiration
94
Residual volume (RV)
-Amount of air remaining in the lungs after a forced expiration
95
respiratory capacities
-consist of two or more lung volumes added together
96
inspiratory capacities (IC)
-maximum amount of air that can be inspired after a NORMAL expiration
IC = TV + IRV
97
Functional Residual Capacity (FRC)
-volume of air remaining in the lungs after a normal tidal volume expiration
FRC = ERV + RV
98
Vital Capacity (VC)
-maximum amount of air that can be expired after a maximum inspiratory effort
VC = IRV + TV + ERV
99
Total Lung Capacity (TLC)
-maximum amount of air contained in lungs after a maximum inspiratory effort
- TLC = IRV + TV + ERV + RV
100
Rate of gas movement
-rate of gas movement in and out of lungs
101
Minute respiratory Volume (MRV)
-The amount of air that flows into or out of the respiratory tract in 1 minute
MRV (mL/minute) = TV (tidal volume) * frequency (breaths/minute)
102
Dead Space (DS)
-the amount of air trapped in the conduction zones (does not reach the alveoli to function in gas exchange)
-for every 500 mL of tidal volume (TV), 150 mL is dead space
-for this value we estimate by using the person's weight
103
Alveolar Ventilation Rate (AVR)
-measures the flow of fresh gases in and out of the alveoli during a particular time interval
AVR (mL/minute) = frequency (breaths/minute) * (TV-DS)
