A&PII Ch.23 Respiratory System prt. 2 Flashcards
An air pressure gradient exists when ________ per unit area is _________ in one place than another
- force, greater
- if the two places are interconnected, air flows from high to low pressure until pressure is equal
Determinants of Gas Pressure
- Amount of Gas Particles
- Temperature
- Volume of Space
If the # of gas particles in a given volume increases pressure _________.
increases
If the volume increases while all other factors remain the same, pressure __________.
decreases
How to calculate airflow…
F=deltaP/R
F= Flow
DeltaP= difference in pressure between atmosphere and intrapulmonary pressure= pressure gradient= Patm-Palv
R= Resistance
Boyle’s law formula..
P1V1=P2V2
If temperature increases while all other factors remain the same, pressure __________.
increases
Facts about airflow
- flow is directly related to pressure gradient and inversely related to resistance
- if pressure gradient increases, airflow to lungs increases
if resistance increases, airflow lessens
F=
(Patm - Palv)/R
Compliance
ease with which the chest wall and lungs expand
Surfactant
reducessurface tension within alveoli
True or False? All pressure in the lungs are the same.
FALSE There are DIFFERENT pressures in the lungs
Atmospheric Pressure (Patm)
pressure in the atmosphere that surrounds the body
Transpulmonary Pressure
pressure differential between intrapulmonary and intrapleural pressures; represents force that tends to collapse the lungs
Intrapleural Pressure
pressure in the space between the visceral and parietal pleura
Intrapulmonary Pressure
same as intra-alveolar pressure (pressure in the alveoli)
Where is the visceral pleura located
directly touching and surrounding the outside of the lung
Resting breathing relies on _______ and ________ pressures.
Atmospheric and Intrapulmonary pressure
Prior to inspiration, atmospheric pressure..
= pulmonary pressure
Steps in the process of ventilation: resting breathing
0) Atmospheric pressure = intrapulmonary pressure
1) Lungs begin to expand, so intrapulmonary pressure DECREASES
2) Air moves from atmosphere to lungs
3) Pressures return to equilibrium
4) During expiration, thoracic volume decreases causing intrapulmonary pressure > atmospheric pressure
5) Air moves out of the lungs until pressure equilibrates again
What are the 5 non-breathing air movements?
1) Coughing and Sneezing; clear irritants from airways
2) Yawn; deepest possible breath
3) Hiccup: spasm of diaphragm causing rapid bursts of air through vocal cords
4) Laughing/ Crying: when emotional states drive the ventilatory pattern
5) Valsalva Maneuver: attempt to exhale against a closed airway
Inspiration
bringing air into the lungs
If the volume of the lungs increases _________ will decrease
pressure
When Alveolar type II cells are stimulated to produce more surfactant, this will ___________ compliance, thereby ___________ resistance and __________ overall airflow.
increase, reducing, increasing
Partial Pressure
represents the contribution of any gas in a mixture to the mixture’s total pressure
Partial Pressure =
Total Pressure x Fraction of Gas (decimal form of percentage)
Diffusion is based on the _____ ________ __________
gas’ partial pressures
In the lungs…
- Oxygen moves from air to blood
- CO2 moves from blood to air
In the tissues…
- O2 moves from blood to tissue
- CO2 moves from tissue to blood
Hemoglobin…
- Hemoglobin transports over 98% of blood’s O2
- Each RBC contains 250-300 million hemoglobin molecules
- Each RBC can carry up to 1.2 billion oxygen molecules
True or False? Some (not all) oxygen released from hemoglobin at systemic capillaries
TRUE
____% saturation as it leaves the lungs (at sea level)
98%
About ____% saturation after passing systemic cells at rest.
75%
Only ____ to ____% of transported oxygen is released.
20 to 25%
Oxygen Reserve
O2 remaining bound to hemoglobin after passing through systemic circulation
What is the oxygen reserve for?
provides a means for additional oxygen to be delivered under increased metabolic demands (ex. exercise)
Vigorous exercise produces a significant drop in saturation.. blood leaving capillaries in active muscles only about ____% saturated.
35%
Carbon dioxide enters the alveolus by..
- direct diffusion from plasma (not in erythrocytes)
- detaching from hemoglobin
- converted from bicarbonate
When CO2 diffuses into bloodstream..
7% remains dissolved in plasma (as CO2) and 93% diffuses into RBCs
93% of CO2 in RBCs is broken into two groups
- 23% binds to Hb, forming carbaminohemoglobin, Hb+ CO2
- 70% converted to H2CO3 by carbonic anhydrase
The 70% of CO2 that was converted to H2CO3 by carbonic anhydrase
dissociates into H+ and HCO3-
The dissociated HCO3-
H+ is removed by buffers, especially Hb/ HCO3-moves out of RBC in exchange for Cl- (chloride shift)
The Haldane effect:
CO2 more readily binds to unoxygenated hemoglobin
Apnea
absence of breathing, swallowing or holding your breath
How does Apnea occur
- Can occur voluntarily
- May be drug-induced
- Can result from neurological disease or trauma
Sleep Apnea
temporary cessation of breathing during sleep
Treatment for Sleep Apnea
Continuous Positive Airway Pressure (CPAP) Machine
What is Laryngitis
inflammation of the larynx
Symptoms of Laryngitis
- hoarse voice, sore throat, and sometimes fever
Cause of Laryngitis
bacterial, viral, fungal, or overuse (yelling)
Severe cases of Laryngitis
- may extend to the epiglottis
- may lead to sudden airway obstruction, especially in children
What is Bronchitis?
inflammation of the bronchi caused by bactericidal or viral infection or inhaled irritants
Acute Bronchitis
- occurs during or after an infection
- coughing, sneezing, pain with inhalation, fever
*most cases resolve on 10 to 14 days
Chronic Bronchitis
- occurs after long-term irritant exposure
- large amounts of mucus, and cough lasting 3 months
- permanent changes to bronchi occur
- increases the likelihood of future bacterial infections
What is pneumonia?
infection of the lung, resulting in alveoli filling with fluid, exudate, or puss
What is pneumonia usually caused by?
Bacterial or Viral infection
Symptoms of pneumonia
Cough, Fever, Difficulty Breathing, weakness, chills, increased HR, chest pain while inhaling
______ or ____________ individuals have a longer illness of pneumonia than younger adults.
Older or Immunocompromised
Pneumothorax
air in pleural cavity
How does pneumothorax occur?
- air is introduced externally- penetrating a wound to the chest
- air is introduced internally- rib lacerated lung/ alveolus ruptures
What problems can Pneumothorax cause for a person?
intrapleural and intrapulmonary pressures equalize ( causing atelectasis)
Small pneumothorax resolves __________
spontaneously
Large pneumothorax is _______
A MEDICAL EMERGENCY
- a tube must be inserted into the pleural space to remove the air
Atelectasis
- collapsed lung
- occurs if intrapleural and intrapulmonary pressures equalize due to air in pleural cavity
- remains collapsed until air is removed from pleural space
What causes Cystic Fibrosis?
Defective chloride channels prevent chloride ions from being pumped from epithelial cells lining the respiratory cells lining respiratory tract into the lumen of the respiratory tract
Without chloride on cell surface, ________ fails to hydrate the cells’ surface.
water
In Cystic Fibrosis when water fails to hydrate the cell’s surface…
mucus becomes thick causing cilia not to be able to mobilize it, mucus then blocks the respiratory tract
CF also presents with..
high incidence of bacterial infections
Cystic Fibrosis can also cause
- ducts of the pancreas and salivary glands to also be blocked
- backup of digestive enzyme can destroy pancreas
