respiratory system Flashcards
what is the purpose of breathing?
to get oxygen down to the mitochondria of the cells for ATP production
What are the functions of the respiratory system?
- gas exchange
- communication
- olfaction
- acid-base balance
- blood pressure regulation
- blood and lymph flow
- blood filtration
- expulsion of abdominal contents
What makes up the upper respiratory tract?
- In head and neck
- nose through larynx
What makes up the lower respiratory tract?
- organs of the thorax
- trachea through lungs
What is the conducting zone?
A system of tubes that delivers air to the alveoli
What is the respiratory zone?
It consists of alveoli and other gas exchange regions
What are the major organs of the respiratory system?
- nose, nasal cavity
- pharynx
- larynx
- trachea
- bronchi and their branches
- lungs and alveoli
What does the epiglottis do?
It closes the entrance to the larynx and trachea (prevent food from going down wind pipe)
What is the esophagus?
food pipe
What do alveoli’s do and where are they located?
- tiny air sacs
- in the lungs
which is anterior, which is posterior (trachea/esophagus)?
- trachea: anterior
- esophagus: posterior
Where is the visceral pleura located?
serous membrane that covers the lungs
where is the parietal pleura located?
mediastinum, inner surface of the rib cage, and superior surface of the diaphram
Where is the pleural cavity located?
potential space between pleurae
What are the function of pleurae and pleural fluid?
- reduce friction
- create pressure gradient
- lower pressure then atmospheric pressure
- compartmentalization: prevents spread from one organ to another
What is the Pharynx?
the muscular funnel extending about 5 inches from the choanae to the larynx
- (voice box), which, in turn, moves air to your trachea and lungs
Where is the point where vessels enter and exit?
Root of lung at hilum
what are the three regions of the pharynx?
- nasopharynx
- oropharynx
- larynngopharynx
What is the oropharynx?
- space between soft palate and epiglottis
- contains palatine tonsils
what is the nasopharynx?
- posterior to nasal apertures and above soft palate
- receives auditory tubes and contains pharyngeal tonsil
What is the laryngopharynx?
- epiglottis to cricoid cartilage
- esophagus begins at that point
What is the primary function of the Larynx?
keep food and drink out of the airway
What is the Epiglottis and what is its function?
- flap of cartilage that prevents unwanted things from going down the trachea
- closes airway and directs food to esophagus
what is a tracheostomy?
insertion of a temporary breathing tube
At what diameter is the structure a bronchiole?
less then 1mm
What are the factors that facilitate efficient gas exchange?
- huge surface area
- copious blood supply
- thin respiratory membrane
What is pulomonary ventilation?
A repetitive cycle of inspiration and expiration
What is the respiratory cycle?
one complete inspiration and expiration
what is forced respiration?
deep, rapid breathing
what is quiet respiration?
while at rest, effortless and automatic
What 2 phases does Pulmonary Ventilation consist of?
- inspiration
- expiration
What volume changes do the ventilation processes depend on?
thoracic cavity
(vol up/p d)
what is atmospheric pressure?
pressure exerted by the air surrounding the body
how do the pleurae layers stick together?
cohesion of water
What is intrapulmonary (intra-alveolar) pressure.
- pressure in the alveoli
- fluctuates with breathing
- 760mm Hg
What is intrapleural pressure?
- pressure in the pleural cavity
- always a negative pressure
- (-4mm Hg)
What type of process is inspiration?
- active
What is Pneumothorax?
the presence of air in pleural cavity
What are the sequence of events for inspiration?
- inspiratory muscles contract (diaphragm descends; rib cage rises)
- thoracic cavity vol incr
- lungs are stretched; intrapul vol incr
- intrapul pressure drops (to -1mm Hg)
- air flows into lungs down pressure gradient until intrapul press =0
What type of process is Expiration?
- passive
What are the sequence of events for expiration?
- Inspiratory muscles relax (diaphragm rises; rib cage descends due to recoil of costal cartilages)
- thoracic cavity vol decr
- elastic lungs recoil passively; intrap vol decr
- intrapul pressure rises (to +1mm Hg)
- air flows out of lungs down press gradient until intrapul = 0
what is the relationship between resistance and airflow?
increased resistance = decreased airflow
what are the factors that influence resistance to airflow?
- diameter of the bronchioles
- pulmonary compliance
what is bronchodilation?
increase in diameter of a bronchus or bronchiole
what stimulants stimulate dilation?
epinephrine and sympathetic stimulation
- increased airflow
What is bronchoconstriction?
decrease in diameter of a bronchus or bronchiole
what is pulmonary compliance?
ease with which the lungs can expand
- the change in lung vol relative to a given pressure change
what stimulants stimulate constriction?
histamine, parasympathetic nerves, cold air, and chemical irritant
- decrease airflow
how is compliance reduced?
degenerative lung diseases in which the lungs are stiffened by scar tissue
how is compliance limited?
by the surface tension of the water film inside alveoli
is all air that is inhaled available for gas exchange?
no, only air that enter the alveoli
what is atomic dead space?
conducting zone of airway where there is no gas exchange (150ml)
what does sympathetic dilation do to dead space?
increases dead space allowing for greater flow
what is physiologic dead space?
sum of anatomic dead space and any pathological alveolar dead space
what is a spirometer?
a device that recaptures expired breath and records such variables as rate and death of breathing, speed of expiration, and rate of oxygen consumption
what is tidal volume and its avg value?
amount of air inhaled or exhaled with each breath under resting conditions
- 500 ml (150ml stay in dead space)
what is inspiratory reserve volume?
amount of air that can be forcefully inhaled after a normal tidal volume inhalation
what is expiratory reserve volume?
amount of air that can be forcefully exhaled after a normal tidal volume exhalation
what is residual volume?
amount of air remaining in the lungs after a forced exhalation
what is the avg total lung capacity for male and female?
male: 6000ml
female: 4200ml
TLC=TV+IRV+ERV+RV
what is the vital capacity for male and females?
inspiratory effort
male: 4800ml
female: 3100ml
what is the alveolar ventilation rate?
air that ventilates alveoli
what is spirometry?
aids in diagnosis and assessment of restrictive and obstructive lung disorders
what is apnea?
temporary cessation of breathing
what are restrictive disorders?
those that reduce pulmonary compliance
what are obstructive disorders?
those that interfere with airflow by narrowing or blocking the airway
What is Eupnea?
relaxed quiet breathing
what is dyspnea?
labored, gasping breathing
what is hyperpnea?
increased rate and depth of breathing in response to increased metabolic demand
what is hyperventilation?
increased pulmonary ventilation in excess of metabolic demand
- (co2 down = ph^ (basic))
what is hypoventilation?
reduced pulmonary ventilation leading to an increase in blood
what are the gases involved in Atm air with their percentages?
N2 - 79%
O2 - 21%
CO2 - 0.04%
h20 - 0.46%
what is partial pressure?
the separate contribution of each gas in a mixture
how does the composition of inspired and alveolar air differ?
- air is humidified by contact with mucous membranes
- air in alveoli mixes with residual air left from previous respiratory cycle
- alveolar air exchanges 02+CO2 in blood
what is alveolar gas exchange?
the swapping of O2 and CO2 across the respiratory membrane
what is the PO2 of inspired air?
159mm Hg
what is the PCo2 of inspired air?
0.3mm Hg
what is PO2 of oxygenated blood?
95mm Hg
what is the PCO2 of oxygenated blood?
40mm Hg
what is the path of air through the body?
inspired air - alveolar air - oxygenated blood - tissue fluid - deoxygenated blood - expired air
what are the factors that influence alveolar gas exchange?
- solubility of the gases
- membrane surface area. (70m^2)
- membrane thickness (thicker/gas exchange less efficient)
what is ventilation-perfusion coupling?
the ability to match air flow and blood flow to each other
what does increased perfusion lead to?
- increased blood flow
- elevated PCO2 in alveoli
- dilation of bronchioles
- increased airflow
what does reduced perfusion lead to?
- decreased blood flow
- reduced PCO2 in alveoli
- constriction of bronchioles
- decreased airflow
what does increased ventilation lead to?
- increased airflow
- elevated PO2 in blood vessels
- vasodilation of pulmonary vessels
- increased blood flow
what does reduced ventilation lead to?
- decreased airflow
- reduced PO2 in blood vessels
- vasoconstriction of pulmonary vessels
- decreased airflow
what is gas transport?
process of carrying gases from the alveoli to the systemic tissues and vice versa
what is the percentage of carbon dioxide transport?
- 70% carbonic acid
- 23% proteins
- 7% plasma
what is the percentages of oxygen transport?
- 98.5% hemoglobin
- 1.5% in plasma
oxygen transport?
- carries 4 protein globin portions
- 4 iron per 1 oxygen
what are the 3 ways that carbon monoxide is transported?
- carbonic acid (90%)
- carbamino compounds (5%)
- dissolved in plasma
what is systemic gas exchange?
- the unloading of O2 and loading of CO2
- carbonic anhydrase in RBC catalyzes
- chloride shift
what is oxygen unloading?
- H+ binding to HbO2 reduces its affinity for O2
what is venous reserve?
oxygen remining in the blood after it passes through the capillary bedsq
what is CO2 unloading?
Hb loads O2 its affinity for H+ decreases, H+ dissociates from Hb and binds with HCO3-
what is a reverse chloride shift?
HCO3- diffuses back into RBC in exchange for Cl-, free CO2 that is generated into alveolus to be exhaled
what are the adjustments made to the metabolic needs of individual needs?
- ambient PO2
- ambient ph
- bisphosphoglycerate
- temperature
what is the haldane?
low levels of oxyhemoglobin enables the blood to transport more
what are the effects of CO2 and O2 on breathing?
- maintain arterial blood at pH of 7.35 to 7.45
- stimulate peripheral chemoreceptors and trigger ventilation (direct)
what nerve is involved in keeping the respiratory under control?
phrenic nerves
