Respiratory System Part II Flashcards
Expiration
process that moves air out of lungs
true or false: during expiration intra-alveolar pressure > atmospheric pressure?
true
true or false: resting expiration is a passive process
true
process of resting expiration
- diaphragm and external intercostals relax
- Thoracic cavity and lungs return to original size
Who aids the lungs in the process of inspiration and expiration?
elastic tissue in lungs and thoracic wall
What happens during resting expiration?
lung volume decreases
intra-alveolar pressure increases to +1 cm of H2O (pushes air out)
True or false: air outflow continues until both pressures are equal
true
Forceful expiration requires muscle contraction:
- intercostal muscles (depress and retract the ribs)
- abdominal muscles (force abdominal viscera and diaphragm upward)
True or False: muscle contraction further decreases volume of the thoracic cavity and lungs
true; causing a greater increase in intra-alveolar pressure, causing more air to flow out.
In a healthy adult number of breathing cycles per min?
12- 15
breathing cycle
one inspiration followed by one expiration
True or false: volume of air inhaled and exhaled during resting and forceful breathing cycle varies?
true
factors that affect breathing cycle
- size
- age
- sex
- physical condtion
true or false: volumes 80% or less than healthy range indicate pulmonary disease
true
spirometers
used to determine respiratory volume
spirogram
graphic record of air volume being exchanged
Tidal Volume (VT)
volume of air exchanged (inhaled or exhaled) during a resting breathing cycle.
Normal tidal volume
500 mL
Inspiratory reserve volume (IRV)
max. volume of air that can be forcefully inhaled after tidal inspiration
normal inspiration reserve volume
3,000 mL
Expiratory Reserve Volume (ERV)
Max. volume of air forcefully exhaled after tidal expiration
normal expiration reserve volume
1,100 mL
Residual Volume (RV)
volume of air in lungs after expelling ERV
normal residual volume
1,200 mL
True or False: residual volume exists because of intrapleural pressure and surfactant
true
True or false: respiration capacities can be calculated by the summation of 2 or more respiratory volumes.
true
Vital capacity (VT + IRV + ERV)
max. amount of air that can be exchanged
normal vital capacity (VC)
4,600 mL
total lung capacity (TLC)
VC+ RV
normal value for total lung capacity
5,800 mL
Centers for involuntary control of breathing are located
medulla oblongata and pons
Who controls voluntary override of breathing?
primary motor area of cerebral cortex
Respiratory Rhythmicity Center
2 bilateral groups of neurons in the medulla oblongata
Groups of Respiratory Rhythmicity Center
- Ventral Respiratory Group
- Dorsal Respiratory Group
Ventral Respiratory Group
responsible for normal rhythmic cycle of breathing (inspiration and expiration) ;
The neurons in Ventral Respiratory Group send action potentials to _____ and _____ .
diaphragm and external intercostalsl; causing them to contract
How long does inspiration last?
2 seconds
How long does expiration last?
3 seconds; muscles relax
Dorsal Respiratory Group
center for receiving and integrating input from sensory sources;
Dorsal Respiratory Group include:
- baroreceptors
- Central chemoreceptors
- Irritant receptors
- thermoreceptors
Dorsal Respiratory Group sends action potentials to ________.
Ventral Respiratory Group; to alter breathing as the needs of the body change (accordance to sensory input).
deeper or shallower, faster or slower
Pontine Respiratory Group (PRG)
located in pons; receives input from higher brain centers.
Function of PRG
sends action potentials to DRG and VRG to modify breathing pattern. Has neurons that stimulate or inhibit DRG and VRG.
True or false: PRG alters the rate and depth of breathing
true; can either speed up or slow down transition from inspiration to expiration
Examples of PRG
adapts breathing to speaking, singing, exercise, sleep and emotional responses (crying gasping)
Chemical factors in blood and cerebrospinal fluid that affect respiration are:
- CO2
- H+
- O2
H+
by product of CO2 transport; increase CO2 concentration will increase H+ .
_________ in the medulla oblongata detect changes in H+ and CO2 in CSF.
central chemoreceptors ( sensory receptors)
True or false: central chemoreceptors are sensitive to increase in H+ and CO2.
true
______ in carotid and aortic bodies detect changes in H+, CO2 and O2 in blood.
peripheral chemoreceptors; strategically located to monitor blood going to the brain
What happens if CO2 and H+ increase in blood or CSF?
DRG stimulates the VRG to increase rate and depth of breathing; causes loss of CO2 and H+, which lowers levels of homeostasis.
What happens if CO2 and H+ decrease in blood or CSF?
breathing will be shallow, provides time for concentrations to increase back to homeostasis.
True or false: peripheral chemoreceptors in the carotid and aortic bodies are sensitive to decline in blood O2 concentration.
true
true or false: O2 levels have little effect on rate and depth of breathing unless they are very low
true
where are baroreceptors found?
- bronchi
- bronchioles
- visceral pleurae
True or false: baroreceptors are sensitive to lung inflation
true
Activation of baroreceptors (inflation reflex)
- Inspiration activates baroreceptors
- Baroreceptors send action potentials via vagus nerve to DRG
- Action potential causing inspiration are inhibited; promotes expiration and prevents excessively deep inspirations that may damage the lungs.
Irritant receptors
irritant receptors are sensitive to chemical and physical irritants in respiratory tract
smoke, dust, excessive amount of mucus
Activation of Irritant receptors (irritant reflex)
- when stimulated by irritants, receptors send action potential to the DRG.
- DRG alter VRG function which triggers a reflex contraction of the respiratory muscles to trigger a sneeze or cough to expel the irritants from the respiratory tract.
Higher Brain Centers
action potentials voluntarily generated by cerebral cortex;
When do voluntarily action potentials occur?
when a person chooses to alter the pattern of resin breathing.
true or false: voluntary control is limited
true
Involuntary action potentials from cerebral cortex and hypothalamus
created during emotional experienced that activated the autonomic division
Examples of involuntary actions
fear, anxiety, excitement can increase breathing rate
True or false: sudden emotional experience, like a sharp pain or sudden cold stimulus can cause apnea (momentarily stop breathing)
true
True or false: increase body temp, increase breathing rate
true; exercise or fever
alveolar gas exchange
gas exchange between air in pulmonary alveoli and blood in capillaries that surround them.
process of alveolar gas exchange:
- alveolar air has higher concentration of O2 and lower concentration of CO2 than blood in capillaries
diffusion across respiratory membrane
O2 moves from air into blood
CO2 moves from blood into air
Blood entering the alveolar capillaries is O2 ______ and CO2 _____.
poor and rich
Blood leaving the alveolar capillaries is O2 ______ and CO2 _____.
rich and poor
Systematic Gas Exchange ( gas exchange between blood in capillaries and tissue cells)
After blood has been oxygenated it returns to the heart and is pumped throughout the body to supply the tissue cells through systematic gas exchange.
True or false: systematic gas exchange involves diffusion across capillary wall
true
Process of systematic gas exchange :
- blood entering tissues is O2 rich and CO2 poor
- Tissue cells have lower concentration of O2 and higher concentration of CO2 than blood in capillaries.
* o2 moves from blood into interstitial fluid and then into tissue cells.
* CO2 moves from tissue cells into interstitial fluid and then into blood.
Percent of O2 that enters alveolar capillaries through RBC (alveolar gas exchange)
98.5%
Where does the O2 bind in the RBC? (alveolar gas exchange)
bind to the heme of hemoglobin to form oxyhemoglobin (1.5% dissolved in plasma)
Percent of O2 that enters resting (systematic gas exchange)
25% O2 is released so it can diffuse out of the capillary; forms deoxyhemoglobin
true or false: the bond between O2 and hemoglobin is unstable
true; reason why hemoglobin is an effective carrier of oxygen .
If surrounding O2 level is high, hemoglobin _________ binds to O2.
readily, willingly
If surrounding O2 level is low , hemoglobin _________ release O2.
readily, willingly
Modes of transportation of CO2 when it diffuses to capillary blood:
7% dissolve in plasma
23% enters RBC to combine with globin of hemoglobin to form carbinohemoglobin
70% enter RBC and combine with water to form carbonic acid
true or false hemoglobin can transport CO2 and O2 at the same time
true; have different biding sites
CO2 + H2O = carbonic acid
reaction catalyzed by carbonic anhydrase
carbonic acid rapid dissociates into H+ and bicarbonate ions
What happens whit bicarbonate ions?
diffuse out of RBCS into plasma for transport to lungs
true or false: all these reactions run in reverse in the lungs to release CO2 for diffusion into pulmonary alveoli.
true
respiratory disorders are grouped :
- inflammatory disorders
- Non- inflammatory disorders
Chonic Obstructive Pulmonary Disease (COPD) (inflammatory)
long term obstruction that reduces airflow to and from lung.
Include chronic bronchitis and Emphysema
Bronchitis (inflammatory)
inflammation of bronchi accompanied by excessive mucus production partially obstructing airflow.
Acute bronchitis:
viral or bacterial infection
Chronic bronchitis
chronic asthmatics and smokers (due to persistent exposure to irritants)
Emphysema (inflammatory)
due to long term expose to airborne irritants (tobacco)
large spaces form when pulmonary alveoli ruptured and air becomes trapped in pulmonary alveoli due to excess mucus production in bronchioles.
