Chap 11, 18, 19, and 20 Flashcards
The growth and development of the lungs is essentially complete by about what age
20 years of age
Most of the pulmonary function indices reach their maximum levels between
20 and 25 years of age and then progressively decline
Functional residual capacity
is the volume remaining in the lungs when the elastic recoil of the lungs exactly balances the natural tendency of the chest wall to expand
What decreases with aging causing what to increase
The elastic recoil of the lungs, causing the compliance to increase. Illustrated as a shift to the left of the volume pressure curve
The decrease in lung elasticity develops because what
the alveoli progressively deteriorate and enlarge
What age do the alveoli progressively deterioate and enlarge at
after age 30
Senile emphysema or senile hyperinflation of the lungs
Structurally, the alveolar changes resemple the air sav changes associated with emphysema
What happens to the costal cartilages with aging
progressively calcify, causing the ribs to slant downward, and this structural change causes the thorax to become less compliant, causing the transpulmonary pressure difference
Transpulmonary pressure difference is responsible for
holding the airway open- diminished with age
which is greater the reduction in chest wall compliance or the increase in lung compliance
Reduction in chest wall compliance is slightly greater than the increase inlung compliance, resulting in an overall moderate decline in total compliance of the respiratory system
Work expendicture of a 60 yr old to overcome static mechanical forces during normal breathing is how much greater than in a 20 year old
20 percent greater
What essentially remains the same throughout the life retaining to the lungs
Total lung capacity (TLC), if it shall decrease it is prob due to the decreased height that typically occurs with age
Residual volume with age
increases, due to age related alveolar enlargement and to small airway closure
as the RV increases, what also increases
RV/ TLC ratio
RV/TLC ratio increases from approx what at age 20 to what at age 60
20 percent at age 20, to 35% at age 60, increase occurs predominantly at after age 40
What decreases as the RV increases
Expiratory reserve volume (ERV). FRC increases with age as well, just not as much as RV and RV/TLC
Because the FRC typically increases with age, the what decreases
Inspiratory capacity (IC)
Vital capacity is equal to what
TLC minus the RV
VC inevitably decreases as the what increases
RV
In men the VC decreases how much per year
25mL, and 20mL/year in women.
In general, the VC decreases about what percent by age 70
40-50 percent
one of the most prominent physiologic changes associated with age is
the reduced efficiency in forced air expulsion
Estimated that these dynamic lung functions decrease approx
20-30 percent throughout the average adults life
FEV in men/ women and age
decreases about 30 mL/ year in men, and about 20mL/ year in women after about age 20. Debatable why
Pulmonary Diffusion Capacity
Progressively decreases after about 20 years of age. About 20% over the course of an adult life. (2ml/min/mm Hg in men and 1.5mL/min/mm Hg in women)
Decline results from pulmonary diffusion capacity
from decreased alveolar surface area caused by alveolar destruction, increased alveolar wall thickness, and decreased pulmonary capillary blood flow, all of which are known to occur with aging
Alveolar Dead Space Ventilation
increases with advancing age. due to decreased cardiac index associated with aging and the structural alterations of the pulmonary capilaries that occur as a result of normal alveolar deterioration
Natural loss of lung elasticity results in
an increase in lung compliance, which in turn leads to an increase in dead space ventilation. Estimated that the alveolar dead space vent increases about 1mL/ year throughout adult life
Pulmonary Gas Exchange
The alveolar arterial oxygen tension difference P(A-a)O2 prog increases with age. Factors include Physiologic shunt, the mismatching of ventilation and perfusion, and a decreased diffusion capacity
In normal adult,the PaO2
should be greater than 90 torr up to 45 years of age
after 45 years of age the PaO2
generally declines between age 45 and 75, then often increases slightly and levels off
Minimum low PaO2 should be
greater than 75 torr- regardless of age
PaCO2
remains constant throughout life- greater diffusion ability of CO2 through the alveolar-capillary barrier. Then the pH and HCO3 remains constant as well
Maximum arterial venous oxygen content difference C(a-V)O2 / factors
tends to decrease with age. Contributory factors include 1. Decline in physical fitness 2. less efficient peripheral blood distribution and 3. reduction in tissue enzyme activity
Anemia
common finding in the elderly. red bone marrow has a tendency to be replaced by fatty marrow, especially in the long bones.
Gastrointestinal atrophy
commonly associated with advancing age may slow the absorption of iron or vitamin B. bleeding is also more prevelant in the elderly
Control of ventilation with age
Ventilatory rate and heart rate responses to hypoxia and hypercapnia diminish with age. Due to a reduced sensitivity and responsivenessof the peripheral and central chemoreceptors and the slowing of central nervous system pathways with age
Neural output
slowed with age to respiratory muscles and the lower chest wall and reduces lung mechanical efficiency
Ventilatory response to hypoxia is decreased
more than 50% in the healthy male over 65 years of age
The ventilatory response to hypercapnia
is decreased by more than 40%
Defense mechanisms
Rate of Mucocilliary transport system declines with age.. decreased cough reflex is more than 70 % of the elderly population
Example of defense mechanisms disease
Dysphagia (impaired esophageal motility) increases the risk for aspiration and pneumonia
What limits exercise in elderly
Oxygen transport system is critically dependent on the cardiovascular system than on respiratory function
The maximum O2 uptake peaks at
age 20 and progressively and linearly decreases with age
Major causes of death in the aging population are
diseases of the cardiovascular system
between 30 and 80 years of age, the thickness of the left ventricular wall increases by about what
25 percent
Heart with age
Fibrosis, CT increases, less elastic, compliance of heart is reduced, pumps less efficiency, heart valves thicken
Maximum heart rate equation
Max heart rate= 220 - age
Stroke volume
diminishes with age
Cardiac Output
As stroke volume diminishes, the cardiac output inevitable declines (CO= SV x HR)
As the cardiac output declines what also decreases
Cardiac index
As an individual ages the
a. Residual volume decreases
b. Exp Reserve volume increases
c. fuctional residual capacity decreases
d. vital capacity decreases
D. Vital Capacity Decreases
Most of the lung fuction indices reach their maximum levels between
20-25 years of age
With advancing age, the
- Lung Compliance decreases
- chest wall compliance increases
- lung compliance increases
- Chest wall compliance decreases
- lung compliance increases and 4. chest wall compliance decreases
As an individual ages the
- forced vital capacity increases
- peak expiratory flow rate decreases
- forced expiratory volume in 1 sec increases
- maximum voluntary ventilation increases
- Peak expiratory flow rate decreases
With advancing age, the
PaO2 decreases, C(a-V)O2 decreases
Maximum HR of a 45 year old is
175 beats/min
Over the course of life, the diffusion capacity decreases by about
20 percent
Between 30 and 80 years of age, the cardiac output decreases by about
40 percent
With advancing age the
- BP increases
- SV decreases
- CO increases
- Heart work decreases
BP increases, SV decreases, Heart work decreases
Between 20 and 60 years of age, the RV/TLC
increases from 20 to 35 percent
During Exercise
Ventilation may increase as much as 20-fold, oxygen diffusion capacity as much as 3- fold, CO as much as 6-fold, muscle blood flow as much as 25- fold, O2 consumption as much as 20 fold and heat prod as much as 20 fold
Muscle training can increase muscle size and stregnth
30-60 %
Athletes heart chambers and mass
increased by 40%
Anaerobic threshold
point at which anaerobic metabolism develops
During normal quiet breathing, an adult exchanges about how many L of gas per minute
6
During strenuous exercise adult exchanges about how much gas per minute
Can increase to 120 L/min
Why must alveolar ventilation increase
- supply sufficient O2 to the blood 2. eliminate the excess CO2 prod by the skeletal muscles
During very heavy exercise Vt and RR
Vt 60% of the vital capacity, and RR may be as high as 30 bpm
Three distinct consecutive breathing patters are seen during mild and moderate exercise.
First stage, second stage, and third stage
first stage
characterized by an increase in alveolar ventilation within seconds after the onset of exercise
Second stage
slow, gradual further increase in alveolar vent developing during approx the first 3 min of exercise
Third stage
final stage, alveolar ventilation stabilizes
Normal Oxygen consumption at rest ml
250 mL/min, the skeletal muscles account for approx 35-40 %
Oxygen consumption during exercise ml
3500 ml/min
Mean alveolar - arterial oxygen tension difference of about 10 torr because of
- mismatching of ventilation and perfusion and 2. right to left pulmonary shunting of blood
During exercise three essential physiologic responses must occur in order for the circulatory system to supply the working muscles with good amount of blood
- sympathetic discharge 2. increase in CO 3. increase in arterial blood pressure
Increase O2 demands during exercise are met almost entirely by what
an increased CO
The increased CO during exercise results from
- increased SV 2. increased HR 3. combination of both
Greater the vasodilation in the working muscles
the greater the stroke volume and cardiac output (sympathetic discharge)
Increased sympathetic stimulation causes
- increased HR 2. increased strength of contraction
There is an increase in arterial blood pressure during exercise because of
- Sympathetic discharge 2. increased CO 3. Vasoconstriction of the blood vessels in the nonworking muscle areas
at rest how much of the muscle capillaries are dilated
approx 20-25 %
Heat stroke
As much as 5 to 10 pounds of body fluid lost in 1 hour.
During strenuous exercise, an adults alveolar ventilation can increase
20 fold
The maximum alveolar ventilation generated during heavy exercise under normal conditions is about what percent of the max voluntary ventilation
50-65 %
During heavy exercise, the total cardiac output may increase as much as
8 fold
At the onset of exercise sympathetic discharge causes the
Peripheral vascular system to constrict, heart to increase its stregnth of contraction, blood vessels of the working muscles to dilate
During exercise, the SV reaches its peak when the CO is at about what percent of its maximum
50%
During exercise, heat production may increase as much as
20 fold
During exercise the oxygen consumption of the skeletal muscles may account for more than
95% of the total VO2
During very heavy exercise, the
PaCO2 decreases, PaO2 remains constant, and pH decreases
during maximum exercise, the O2 diffusion capacity may increase as much as
3 fold
During exercise the P(A-a)O2 begins to increase when the oxygen consumption reaches about what percent of its max
40 %
Peripheral chemoreceptors
when PaO2 falls low enough (to about 60torr) to stimulate the carotid and aortic bodies, kown as peripheral chemoreceptors. Which transmit signals to the medulla to increase ventilation
Hypoxic Ventilator response
when the medulla is signaled to increase ventilation
The barometric pressure is about half the sea level value of 760 torr at an altitude of
18,000 -19,000 ft
The O2 diffusion capacity of high altitude natives is about
20-25 percent greater than predicted
Acute mountain sickness is characterized by
sleep disorders, headache, dizziness, palpitation, loss of appetite
The symptoms of acute mountain sickness are generally most severe on the
second or third day after ascent
When an individual is subjected to a high altitude for a prolonged period of time which of the following is seen
An increased RBC production, A decreased PaCO2, an Increased P(A-a)O2
At high altitude the overal ventilation perfusion ratio improves T/F
true
In individuals who have acclimatized to a high altitude, an increased CO is seen T/F
false
Theres a linear relationship between the degree of ascent and the degree of pulmonary vasoconstriction and hypertension T/F
True
Natives who have been at high altitudes for generations commonly demonstrate a mild resp alk
True
The concentration of myoglobin in skeletal muscles is decreased in high altitude natives
False
At what depth below the water surface does the pressure increase to 3.0 atm
99 ft
If an indiv fully inhales to a TLC of 4.5 L at sea level (760 mmHg) and dives to a depth of 66 feet, the lungs will be compressed to about
1.5 L
Diving reflex consists of
Decreased CO, bradycardia, peripheral vasoconstriction
The half life of Carboxyhemoglobin when a victim is breathing RA at 1atm is approx
5 hours
Hyperventilation prior to a breath hold dive can be dangerous T/F
true
the fall in PAO2 as a diver returns to the surface is known as the hypoxia of ascent T/F
true
chest pain and coughing caused by decompression sickness is known as the bends T/F
false
the so called PCO2 resp drive breaking poing during a dive is about 55 torr T/F
true
approx 0.3 mL of O2 is physically dissolved in each 100 ml of blood for every PaO2 increase of 100 torr T/F
truee
Circulation during exercise
blood flow to the muscles increase, length and intensity of exercsie is limited , at the onset of exercise there is a sympathetic discharge, increase HR and strength of contraction, peripheral blood vessels contrict except for the muscles that are working which dilate
Increase in CO demands met entirely by
Blood pressure
Pulmonary vascular resistance goes down
dilates vascular bed and improves blood flow
Systemic vascular resistance goes down
peripheral constriction is less than the dilation of the muscles so the net is a decrease in SVR
Pulmonary rehab
works with patients to improve cardovascular exercise tolerance (phase 1: info gather, 2: Educate and exercise 3: output pt)
Chronic oxygen deprivation from high altitude is similar to
chronic hypoxemia from lung disease
barometric pressure goes which way as you go up
goes down as you go up
if you go from one level to another you
acclimate
acute mnt sickness starts after
6-12 hours, lasts 2-3 days, usually acclimated by 4th day
Example of high altitude pulmonary edema
CHF
Increase altitude=
Polycythemia, larger lung volumes or capacities
low oxygen=
hypoxic environment
if you hit anaerobic threshold
the minute ventilation climes more due to lactic acid which can be counteracted by a decrease in PaCO2
Lactic acid causes an increase in
pH and PaCO2
high altitude pulmonary edema
tachypnea, tachycardia, crackles in lung base (fluid). Pink frothy sputum, from increased PVR due to hypoxia and or increased permeability of membranes
Increased CO due to low oxygen
Increased PVR due to low oxygen causing vasocontriction of pulmonary vessels
