Unit 3

ventilation

mechanical movement of air into and out of the lungs (breathing)

diffusion

random movement of molecules from an area of high concentration or partial pressure to low concentration or partial pressure

upper

the ______ (upper/lower) respiratory tract is made up of nose, nasal cavity, pharynx, larynx

lower

the ______ (upper/lower) respiratory tract is made up of trachea, bronchi, bronchioles, terminal bronchioles, respiratory bronchioles, alveolar duct, alveoli

conducting zone

which zone is in charge of moving the air to the gas exchange region, filter debris, and humidifies the air?

respiratory zone

which zone is in charge of performing gas exchange?

thin walls, large surface area, surfactant

why is gas exchange efficient? 3 reasons

760 mmHg

what is the value or atmospheric pressure at sea level?

intrapulmonary pressure

the force exerted by gases inside the alveoli of the lungs, changes during breathing to move air

intrapleural pressure

the force exerted by fluid within the pleural cavity between the lung and the chest wall

below

during inspiration intrapulmonary pressure goes ______ (above or below) atmospheric pressure causing air to flow into the lungs

decrease

according to Boyles Law if there is an increase in lung volume will intrapulmonary pressure increase or decrease?

increase

according to Boyles Law if there is an decrease in lung volume will intrapulmonary pressure increase or decrease?

diaphragm

what structure performs most of the work for inspiration during rest?

active

during exercise, is expiration passive or active?

diameter

resistance to airflow is based primarily on the _____ of the airway

airflow

______ = pressure difference/resistance

decrease

if there is an increase to airway resistance will there be an increase or decrease in airflow?

tidal volume

the amount of air inhaled or exhaled in one breath

minute ventilation

the total volume of air moved into and out of the lungs in one minute

anatomical dead space

VD or _______ ___ _____ is the air that never reaches the alveoli for gas exchange

alveolar ventilation

VA or ______ _____ is the the air that reaches the alveoli and is available for gas exchange

IRV

Amount of air in excess of tidal volume that can be inhaled with maximum effort

ERV

Amount of air in excess of tidal volume that can be exhaled with maximum effort

residual volume (RV)

Amount of air remaining in the lungs after maximum expiration; that is, the amount of air that can never be voluntarily exhaled

vital capacity (VC)

Amount of air that can be forcefully exhaled following a maximum inspiration

total lung capacity (TLC)

Maximum amount of air in the lungs at the end of a maximum inspiration

inspiratory capacity (IC)

Maximum amount of air that can be inhaled following a normal expiration

functional residual capacity (FRC)

Amount of air remaining in the lungs following a normal expiration

ventilation-perfusion ratio

measures how well the amount of air reaching the alveoli matches the amount of blood available to exchange gases

1.0

what V/Q ratio represents optimal gas exchange matching?

base

is blood perfusion highest at the apex of base of the lungs?

closer

during moderate exercise does V/Q move closer or further from 1?

partial pressure

the pressure contributed by an individual gas within a mixture of gases

Daltons Law

what law states the total pressure of a gas mixture equals the sum of the partial pressures of the individual gases

Ficks Law of Diffusions

what law describes what makes gas diffusion faster or slower?

increase

does a higher partial pressure difference and higher surface area increase or decrease diffusion?

membrane/tissue thickness

what decreases diffusion?

hemoglobin

99% of O2 is transported by ______ inside red blood cells

4

how many O2 can 1 Hb carry?

males

do male or females have a higher oxygen capacity?

loading

does a high PO2 cause O2 loading or unloading?

unloading

does a low PO2 cause O2 loading or unloading?

more

if there is an increase in PO2 will there be more or less binding to Hb

flat portion

during what portion of the oxygen-hemoglobin dissociation curve does hemoglobin stay highly saturated even when PO2 changes somewhat?

steep portion

during what portion of the oxygen-hemoglobin dissociation curve causes large release of O2 from Hb due to small drops of PO2?

decrease

does PO2 increase or decrease during exercise?

true

true or false: during intense exercise, working muscles consume more oxygen, causing tissue PO₂ to fall

90%

up to what percentage of bound O2 can be unloaded to working muscle tissues during intense exercise?

increased temp, decreased pH, increased 2,3 DPG

what three metabolic conditions cause a right shift in the oxyhemoglobin dissociation curve (promoting unloading)?

glycolysis

2,3 DPG is a byproduct of what process?

bicarbonate

70% of CO2 is transported via ______

plasma

10% of CO2 is transported via ______

hemoglobin

20% of CO2 is transported via ______

decrease

a ______ in blood pH reduces hemoglobins affinity for O2.

carbonic anhydrase

Which enzyme inside red blood cells catalyzes the formation of carbonic acid (H2​CO3​) from CO2​ and H2​O?

gravity

While standing at rest, what is the main reason as to why the base of the lung is overperfused (V/Q<1.0) compared to the apex?

myoglobin

does hemoglobin or myoglobin have a higher affinity for O2?

skeletal muscle

where is myoglobin found?

Hydrogen ion (H+) and bicarbonate ion (HCO3−​)

into which two ions does carbonic acid (H2​CO3​) dissociate inside the red blood cell?

Carbonic acid (H2​CO3​)

what intermediate weak acid is formed when carbon dioxide reacts with water in the blood?

red blood cells (RBC)

in which blood component is the enzyme carbonic anhydrase primarily located?

chloride shift

what process maintains electrical neutrality when HCO3−​ leaves the RBC at systemic tissues?

CO2 ​+ H2​O —> H2​CO3​ —> H+ + HCO3-

what is the complete chemical equation for the bicarbonate buffer system?

CO2​ and H2O

what two molecules are generated when carbonic acid (H2​CO3​) is broken down by carbonic anhydrase at the lungs?

carbonic anhydrase

which enzyme accelerates the reversible conversion of CO2​ and H2​O into carbonic acid (H2​CO3​)?

false

true or false: During exercise, expiration is facilitated by the elastic recoil of the diaphragm.

pulmonary capillaries

When considering the diffusion of gasses at the lung and the equation for Fick’s Law of Diffusion, where would P₂ be located?

false

true or false: The flat portion of the curve at the top of the oxygen-hemoglobin dissociation curve indicates the small changes in PO₂ will have a large effect on oxygen binding to hemoglobin.

false

true or false: Excess CO₂ produced in the skeletal muscle immediately combines with carbonic acid to become bicarbonate.

true

true or false: During incremental exercise, ventilation increases first because of an increase in V_T and second because of an increase in breathing frequency.

reduce

does exhaling CO2 reduce or increase PCO2 and H+ levels?

lactic acid

________ dissociates into lactate and H+

right

which direction does high tissue PCO2​ shift the bicarbonate reaction at active contracting muscle?

left

which direction does low alveolar PCO2​ shift the bicarbonate reaction at pulmonary capillaries?

stays constant

what happens to arterial partial pressure of oxygen (PaO2​) during continuous moderate exercise below the lactate threshold? Does it increase, decrease or stay constant

ventilatory drift

The gradual upward rise in minute ventilation over time despite a constant exercise workload

VT1

The exercise intensity point where minute ventilation (VE​) first begins to increase non-linearly (curvilinearly) relative to oxygen uptake (VO2​).

anaerobic metabolism

What metabolic event triggers the non-linear increase in minute ventilation at VT1?

VT2

The second non-linear breakpoint in minute ventilation (VE​) occurring at high exercise intensities due to severe metabolic acidosis.

severe lactic acid accumulation

What physiological condition causes the steep non-linear rise in VE​ at VT2?

Exercise-induced hypoxemia

What phenomenon occurs in elite endurance athletes characterized by a severe drop in arterial partial pressure of oxygen (PaO2​) at near-maximal exercise?

elite runners

Do untrained individuals or elite runners experience a sharp drop in arterial PO2 at high work rates?

tidal volume

by expanding ___ _______ the body primarily increases minute ventilation during light to moderate exercise (~50%V˙O2​max)?

tidal volume

does tidal volume or breathing frequency plateau when exercise intensity transitions from moderate to heavy/maximal

increases

What happens to breathing frequency as exercise intensity progresses from rest to 100% VO2​max?

acid

is an acid or a base a molecule that can release hydrogen ions, thereby increasing the H+ of a solution and decreasing its pH

base

is an acid or a base a molecule that can accept hydrogen ions, thereby decreasing the H+ of a solution and increasing its pH

lactic acid

which strong acid is heavily produced in muscle tissue during anaerobic glycolysis?

bicarbonate

which strong base serves as a major physiological buffer during exercise?

false

true or false: oxidative phosphorylation produces O2​, which reacts with water to form carbonic acid, dissociating into H+ and HCO3−​

45

High-intensity exercise lasting at least _____ seconds produces large quantities of H+ ions

PFK

which rate-limiting enzyme in glycolysis is inhibited by high hydrogen ion concentrations?

isocitrate dehydrogenase

which rate-limiting enzyme in the Krebs cycle is inhibited by elevated H+?

true

true or false: intracellular acidosis directly interferes with muscle contraction mechanics.

intracellular

is intracellular or extracellular buffers the first line of defense against muscle pH drops during exercise?