Respiratory System Flashcards
(106 cards)
1
Q
The term respiration has 3 meanings:
A
1) Ventilation
2) exchange of gases between air and blood and btwn blood and tissue fluid
3) The use of oxygen in cellular metabolism
2
Q
The respiratory system:
A
is an organ system that rhythmically takes in air and expels it from the body, supplying body with oxygen and expelling carbon dioxide.
3
Q
7 other functions of respiratory system:
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1) provides O2 and CO2 exchange between blood and air
2) Speech & other vocalizations
3) Olfaction
4) Control pH by eliminating CO2
5) BP regulation by Angiotensin II
6) Venous return/lymph flow
7) Valsalva maneuver-Breath holding helps expel abdominal contents
4
Q
Principal Organs of Respiratory system:
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Nose, pharynx, larynx, trachea, bronchi and lungs.
5
Q
Within lungs air flows how?
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Bronchi->bronchioles->alveoli
6
Q
Conducting division
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consists of those passages that serve only for airflow, from nostrils to major bronchioles.
7
Q
Respiratory division
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consists of alveoli and other distal gas exchange regions
8
Q
Upper respiratory tract
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airway from nose through larynx
9
Q
Lower respiratory tract
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regions from trachea through lungs
10
Q
Nose has several functions
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warms, cleanses, and humidifies inhaled air
11
Q
Odors are detected by
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sensory cells in OLFACTORY epithelium
12
Q
Nasal cavity is lined with
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respiratory epithelium
13
Q
Inferior concha
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has extensive venous plexus called erectile tisse (swell body)
14
Q
Pharynx
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muscular funnel extending 13cm from chonae to larynx. 1) nasopharynx 2)oropharynx 3) laryngopharynx
15
Q
Nasopharynx
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posterior to chonae. recieves auditory tubes from middle ears and houses pharyngeal tonsil.
16
Q
Oropharynx
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space bwtn inferior margin of soft palate and epliglottis. Contains palatine tonsils
17
Q
Laryngopharynx
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posterior to pharynx. lined by pseudostratified columnar epithlium
18
Q
Larynx
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voice box
19
Q
epiglottis
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flap of tissue opening of larynx. stands vertically
epi-upon glottis-back of tongue
20
Q
cricoid cartilage
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connects larynx to trachea
21
Q
Trachea
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windpipe, tube about 12cm, 2.5 cm wide
22
Q
adventitia
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outermost layer of trachea, fibrous connective tissue tht blends adventitia to other organs of mediastinum
23
Q
Lung mediastinal surface exhibits:
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slit named hilum, lung recieves main bronchus, blood vessels, lymphatics, and nerves. ROOT of lung
24
Q
Left lung indentation
A
cardiac impression
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Each lung has a branching system of tubes:
bronchial tree, extending to 65,000 terminal bronchials
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Bronchioles have what type of cells?
cilliated cuboidal epithelium, well developed layer of smooth muscle in their walls
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Each bronchial divides into :
50-80 terminal bronchioles
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Terminal bronchioles divides into :
2 or more smaller respiratory bronchioles, have alveoli budding from their walls
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Each respiratory bronchiole divides into:
2 -10 elongated thin walled passages called alveolar ducts.
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Alveolar ducts have what type of cells?
have non-ciliated simple squamous epithelia.
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Alveolar ducts end in:
alveolar sacs, grape-like clusters of alveoli around atrium.
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Distinction between alveolar duct and atrium:
Their SHAPE. ELONGATED DUCT. Atrium: EQUAL LENGTH AND WIDTH
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Path of airflow
Nasal cavity -> pharynx -> trachea -> main bronchus -> lobar bronchus -> segmental bronchus -> bronchiole ->terminal bronchiole.
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Respiatory division gas exchange:
respiratory bronchiole -> alveolar ducts -> atrium -> alveolus
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Alveolus
pouch about .2-.5mm in diameter
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Squamous (type I) alveolar cells
cover 95% of alveolar suface. THey are thin broad cells. other 5% covered by round to cuboidal great (type II) alveolar cells.
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Alveolar cells (type II) have two functions:
1) repair alveolar epithelium when squamous alveolar cells are damaged
2) they secrete pulmonary sufacant, a mixture of phospholipids and protein that coats the alveoli and smallest bronchioles and prevents them from collapsing when one exhales.
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Most numerous cells are:
Alveolar macrophages (dust cells). Phagocytize dust particles that escape entrapment.
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Respiratory membrane has what type of cells:
squamous alveolar cells, squamous endothelial cell of capillary, and shared basement membrane
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Visceral Pleura
serous membrane that covers surface of lung
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Parietal Pleura
Visceral pleura turns back on itself and forms this. It attaches to the mediastinum, inner surface of rib cage, and superior surface of diaphragm.
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Pleural cavity
This is the space between the parietal and visceral pleura. It wraps around the lung, like a pillowcase. Contains pleural fluid.
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Pleurae and pleural fluid have 3 functions:
1) reduction of friction
2) creation of pressure gradient
3) compartmentalization
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One complete inspiration and exhalation is called
respiratory cycle
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Quiet respiration
the way one breathes at rest, without effort. unconcious automatic breathing
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Forced respiration
unusually deep or rapid breathing, such as exercise or singing, coughing, etc.
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Cycle of breathing is controlled by 3 respiratory centers in reticular formation of medulla oblongotta and pons
1) Ventral respiratory group - VRG primary generator
2) Dorsal respiratory group -DRG
3) Pontine respiratory group - PRG
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Central chemoreceptors
brainstem neurons respond to changes in pH of cerebrospinal fluid (CSF)
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Peripheral chemoreceptors
Located in carotid and aortic bodies of large arteries. respond to O2 and CO2 content and pH of blood.
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Stretch receptors
Found in smooth muscle of bronchii and and bronchioles and in visceral pleura, respond to inflation of lungs
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Irritant receptors
Nerve endings amid epithelial cells of airway. Respond to smoke, dust, pollen, etc.
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Gas Laws of Respiratory Physiology
1) Boyle's Law
2) Charle's Law
3) Dalton's Law
4) Henry's Law
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Boyle's Law
Pressure of given quantity of gas is inversely proportional to its volume (assuming a constant temp)
If lungs contain a quantity of gas and lung volume increases, internal pressure falls.
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Charle's Law
Volume of a given quantity of gas is directly proportional to is absolute temperature (assuming constant pressure)
Warming of inhaled air
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Dalton's Law
Total pressure of gas mixture is equal to the sum of the partial pressure of its individual gases
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Henry's Law
At the air-water interface, the amount of gas that dissolves in water is determined by its solubility in water and its partial pressure in air (assuming a constant temp)
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Atomospheric (barometer) pressure
This is the weight of the air above us, the pressure that drives respiration. average pressure 760mm Hg
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Intrapleural pressure
This is the pressure between the two layers of pleura, there is a slight vaccum measuring -4mm Hg and drops to -6mm Hg during inspiration
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Pneumothorax
Presence of air in pleural cavity
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Atelectasis
collapse of part of lung. can result from airway obstruction, lung tumor, aneurysm, swollen lymph node or aspirated object.
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3 factors of resistance to airflow
1) Diameter of bronchioles
2) Pulmonary compliance
3) Surface tension of the alveoli and distal bronchioles
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Surfactant
agent that disrupts the hydrogen bonds of water and reduces surface tension.
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Anatomical dead space
The conducting division that cannon exchange gas and blood from the air that inhaled. Not all air that inhaled can be used to gas exchange.
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Physiological dead
Sum of anitomical dead space and any pathological alveolar dead space that may exist.
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Alveolar ventilation rate (AVR)
Person inhales 500ml of air 150mL of it stays in dead space, then 350mL of air ventilates the alveoli. Multiply this by respiratory rate gives you AVR. 350mL breath X 12 breaths/min=4200 mL/min
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Residual Volume
leftover air from the alveoli that never completely empty during expiration. cycle out.
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Spirometer
A device that measures pulmonary ventilation, recaptures the expired breath and records such variables as rate and depth of breathing, speed of expiration and rate of oxygen consumption.
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Tidal volume (TV)
Amount of air inhaled and exhaled in one cycle of quiet breathing, normlaly 500 mL
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Inspiratory reserve volume (IRV)
Amount of air in excess of tidal volume that can be inhaled with maximum effort. 3000 mL typical
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Expiratory reserve volume (ERV)
Amount of air in excess of tidal volume that can be exhaled with maximum effort. 1200mL typical
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Residual Volume (RV)
Amount of air remaining in the lungs after maximum expiration: the amount that can be voluntarily be exhaled. 1300mL typical
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Respiratory capacities
obtained by adding two or more of the respiratory volumes
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Vital Capacity (VC)
ERV+TV+IRV. The amount of air that can be inhaled and then exhaled with maximum effort. Very important measure of pulmonary health
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Inspiratory Capacity (IC)
TV+IRV. MAximum amount of air that can be inhaled after a normal tidal expression.
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Funcitonal residual capacity (FRC)
RV+ERV. amount of air remaining in lungs after normal tidal expression
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Total lung compacity (TLC)
RV+VC. MAximum amount of air the lungs can contain.
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Spirometry
measurment of pulmonary function, an aid to the diagnosis and assessment of restrictive and obstructive lung disorders.
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Restrictive disorders
reduce pulmonary compliance, limiting the amount of which lungs can be inflated. ex. black lung diease and tuberculosis
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Obstructive disorders
interfere with airflow by narrowing or blocking the airway. make it harder to inhale or exhale a given amount of air. ex. asthma, chronic bronchitis, emphysema
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Forced expiratory volume (FEV)
percentage of VC that can be exhaled in a given time interval. average: expel 75%-85% VC in 1.0 sec
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Minute Respiratory Volume (MRV)
amount of air inhaled per min. multiply TV by respiratory rate
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Maximum voluntary ventilation (MVV)
maximum breathing compacity. 125 to 170 L/min
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Eupnea
relaxed, quiet breathing. Typical tidal volume 500mL and respiratory rate 12-15 breaths per min.
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Partial Pressure
Separate contribution for each gas, through Daltons Law.
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Alveolar gas exchange
Back and forth traffic of O2 and CO2 across respiratory membrane. Each gas diffuses down its own pressure gradient.
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Henry's Law in practice:
The greater the PO2 in the alveolar air, the more O2 the blood picks up. since blood arriving at an alveolus has higher PCO2 than air, it releases CO2 into the air. At alveolus, blood unloads CO2 and LOADS O2.
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Gas transport is
THe process of carrying gases from the alveoli to the systemic tissues and vice versa.
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If one ore more molecules of O2 are bound to hemoglobin, it is called:
OXYHEMOGLOBIN (HbO2)
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Hemoglobin with NO oxygen bound is
DEOXYHEMOGLOBIN (HHb)
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Carbonic Acid is formed by
the CO2 (90%) is hydrated (reacts with water), which then dissociates into bicarbonate and hydrogen ions.
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Carbon Dioxide is transported in 3 forms:
1) Carbonic acid
2) carbamino compound
3) Dissolved gas
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Carbamino compounds
5% of the amino groups of plasma proteins and hemoglobin form to make them
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Dissolved gas
5% of CO2 is carried in the blood as dissolved gas, like the CO2 in carbonated beverages
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Acidosis
Blood pH lower than 7.35
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Alkalosis
Blood pH higher than 7.45
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Hypocapnia
Pco2 less than 37mm Hg, most common cause of alkalosis
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Hypercapnia
Pco2 greater than 43mm Hg, most common cause of acidosis
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hypoxic drive
Long-term hypoxia, low Po2 that by co2 or pH. situation such as emphysema and pneumonia, interfere with gas exchange, mountain climbing of at elast 2 or 3 days duration
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Hypoxia
deficiency of oxygen in a tissue or inability to use oxygen.
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Hypoxemia hypoxia
state of low arterial Po2, due to inadequate pulmonary gas exchange
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Ischemic hypoxia
inadequate circulation of the blood, congestive heart failure
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Anemic hypoxia
Due to anemia and resulting inability of blood to carry adequate oxygen
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Histotoxic hypoxia
metalic poison such as cyanide prevents the tissues from using the oxygen delivered to them.
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Cyanosis
blueness of the skin
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Emphysema
alveolar walls breakdown and the lungs exhibits larger but fewer alveoli. Less respiratory membrane available for gas exchange. Lungs, less elastic and fibrotic.
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Cor Pulmonale
hypertrophy and potential failure of right heart due to obstruction of pulmonary circulation
