Chapter 10

Question 1

what is the relationship between cardiorespiratory structure and function and how it is framed to support exercise respiration

Answer 1

The cardiorespiratory system’s structure fundamentally dictates its function by providing the physical pathways and mechanisms necessary to meet the body’s demand for oxygen during exercise. The structure is framed to support exercise respiration through a highly integrated system of lungs, heart, and blood vessels that adapt to enhance efficiency and delivery of oxygen to working muscles and removal of waste products like carbon dioxide.
Structural and Functional Integration
The relationship is one of mutual dependence, where the structure of one component enables the function of the other.
Respiratory System (Lungs/Airways): The lungs’ structure features millions of tiny air sacs called alveoli, which provide a vast surface area for gas exchange. This structure allows oxygen to diffuse into the bloodstream and carbon dioxide to diffuse out efficiently.
Cardiovascular System (Heart/Blood Vessels): The heart, a powerful dual-pump structure, moves deoxygenated blood to the lungs (pulmonary circulation) and oxygenated blood to the rest of the body (systemic circulation). The extensive network of blood vessels, from large arteries to microscopic capillaries, ensures oxygen and nutrients reach every tissue.
Framing for Exercise Respiration
During exercise, muscles need significantly more oxygen to produce energy (ATP), and the cardiorespiratory system is ‘framed’ to scale up its function dramatically to meet this demand.
Increased Ventilation: The respiratory muscles (diaphragm and intercostals) contract more frequently and forcefully, increasing both breathing rate and depth (tidal volume), which moves more air in and out of the lungs.
Enhanced Circulation: The heart rate and stroke volume (amount of blood pumped per beat) increase, resulting in a significantly higher cardiac output. This speeds up the transport of oxygen-rich blood to the working muscles.
Optimized Gas Exchange: More pulmonary capillaries are recruited and widened (vasodilation) to increase the surface area available for gas exchange in the lungs and muscles, optimizing the transfer of O2 and CO2.
Blood Flow Redistribution: Blood flow is shunted away from less active areas (like the digestive system) and directed towards the active skeletal muscles.
Muscular Adaptations: The working muscles themselves develop increased capillary density and more mitochondria, enhancing their structural capacity to utilize the delivered oxygen efficiently.
Why It Matters
The ability of the cardiorespiratory system to adapt structurally and functionally is known as cardiorespiratory fitness (CRF). Higher CRF is a strong predictor of overall health and a lower risk of chronic diseases such as heart disease, type 2 diabetes, and certain cancers. Regular physical activity leads to chronic adaptations (e.g., a stronger heart, increased blood volume, more efficient lungs) that improve this functional capacity, making the body more resilient and efficient during physical demand

Question 2

Discuss the mechanics of breathing at rest and during exercise

Question 3

identify the muscles involved in inspiration and expiration at rest and during exercise? What happened when we change resistance?

Answer 3

airflow = delta P /resitiance

Question 4

identify the pressures important to ventilation? quantify the pressures of oxygen and carbon dioxide? central control –> brain control that drives ventilation

Answer 4

partial pressure
systemic pressures

Question 5

describe the primary function of the pulmonary system

Answer 5

the pulmonary function of the pulmonary system is to provide ,sans of gas exchange between the atmosphere and the body

Question 6

outline the major anatomical components of the respiratory system

Answer 6

lungs
diaphgram
espophicus
tracea

Question 7

list the major muscles involved in inspiration and expiration at rest and during exercise

Answer 7

rest inspiration - digrapham
expiration - voluntary b/c lungs are elastic
exercise
inspiration - digrapham –. anything at increase chest volume, increase throatic space
expiration - abdonimal wall, decrease throatic space

Question 8

discuss the importance of matching blood flow to alveolar ventilation in the lung

Answer 8

alveolar ventilation - volume of gas that reaches respiratory zone
ventilation/perfusion ratio - 1 for ideal
if they do not match gas exchange does occur
effiencit gas exchange between the blood and the lung requires proper matching of blood flow to ventilation (called ventilation-perfusion relationship)
the ideal ratio of ventilation to perfusion is 1.0 or slightly greater, because this ratio implies a perfect matching of blood flor to ventilation

Question 9

describe the major transportation modes of O2 and CO2 in the blood

Answer 9

o2 - hemoglobin
C02 - bicarbonate
oxygen hemoblobin dissociation curve –>factors to determine direction
- PO2 of blood
- affinity/bond strength beteen o2 an dHb
increase PO2 shift right (loading)
decrease PO2 shift left ( unloading)
exercise –> mixed venous PO2 is lowered
rest –> O2 resuirements low

Question 10

discuss the effects of increasing temperature, decreasing pH, and increasing levels of 2-3 DPG on the oxygen - hemoglobin dissociation curve

Answer 10

temp inversly proportionate to O2-Hb –> decrease temp shift legt (strengthens bonds and hinders relase) , increase temp weakens bonds and imrpoved unloading shift left
decrease pH, decrease affinity to bond b/c H bonds to hemoglobin therefore shift right (unloading) , increase pH shift left (loading)
2-3 DPG combines with Hb and decreased affinity –> shift right (unloading) –> increase alitude increase 2-3 DPG

Question 11

describe the ventilatory response to constant loss, steady-state exercise. What happens to ventilation if exercise is prolonged and performed in a hot environment?

Answer 11

Ve dirft upward during prolonged exercise due to increase in blood temp which affects respiratory contorl center
increase Ve at hot temp due to increase breathing frequency and dead-space ventilation

Question 12

describe the ventilatory response to incremental exercise. What factors contribute to the linear rise in ventilation at work rates about 50% of VO2 max? further discuss the change in breathing pattern that occur when going form rest to exercise at varying intensities.

Answer 12

Ve increase linearly until ventilation threshold (Tvent) is reached then it becomes expoenntial
Low PO2 values casue hypoxemia
changes in breathing patterns: increae pulmonary ventillation by increase frequency breathing and/or tidal volume
breathing pattern @exercise - minimuze work of breathing and reduced respiratory fatigue

(look at graph)

Question 13

Discuss the neural components involved in the generation of the rhythm of breathing

Answer 13

muscle chemoreceptors
muslce mechanoreceptors

the normal rhythm of breathing is generated by the interaction between celebrate respiratory rhythm centres located in the medulla oblongata and pons. At rest, the breathing rhythm is dominated by pacemakers neruson
during exercise the respiratory control centre receives input from both neural and humeral sources
neural input to the respiratory control centre can come from high bring centres and from receptors in the exercising muscle
humoral chemoreceptor input to the respiratory control centre comes from both central chemoreceptors and peripheral chemoreceptors. the central chemoreceptors are sentive to increase PCO2 nd decrease in Ph. The peripheral chemoreceptors (carotid bodies are the most important) are sensitive to nicer in PCO2 and decrease in PO2 in ph. a primary drive to increase ventilation during exercise comes from higher brain centres (central command) importantly humeral chemorecpertos and neural feedback from working muscles act to fine-tune ventilation and plan a signifact role in controlling breathing during moderate intensity exercise

Question 14

identify the location and function of chemoreceptors and mechanoreceptors that contribute to the regulation of breathing

Answer 14

chemoreceptors decrease pH and increase potassium
mechanoreceptors increase muscle contraction activity

both lead to increase breathing

Question 15

discuss the neural-humoral theory of ventilatory control during exercise

Question 16

alveolar ventilation(Va)

Question 17

alveoli

Question 18

anatomical dead space

Question 19

aortic bodies

Question 20

bohr effect

Question 21

bulk flow

Question 22

carotid bodies

Answer 22

is a small sensory organ located at the bifurcation of the common carotid artery that acts as a chemoreceptor to monitor blood chemistry, primarily oxygen, carbon dioxide, and pH levels

Question 23

cellular respiration

Question 24

deoxyhemoglobin

Question 25

diaphragm

Question 26

diffusion

Question 27

hemoglobin

Question 28

myoglobin

Question 29

oxyhemoglobin

Question 30

partial pressure

Question 31

pleura

Question 32

pulmonary respiration

Question 33

residual volume (RV)

Question 34

respiration

Question 35

spirometry

Question 36

tidal volume

Question 37

total lung capacity (TLC)

Question 38

ventilation

Question 39

ventilatory threshold (Tvent)

Question 40

vital capacity (VC)

Question 41

cellular respiration

Question 42

pulmonary respiration

Question 43

big picture of gas exchange happened in 4 continuous and simultaneous processes

Answer 43

conduction zone and respiratory zone ventilation alveolar gas exchange circulatory transport systemic gas exchange

Question 44

intrapleural pressure

Answer 44

pressure in plural cavity less than atmospheric pressure which prevents lungs from collapsing

Question 45

define TV, IRV, ERV, RV, VC, IC, FRC, TLC

Answer 45

Tv - tidal volume - amount of air inhaled or exhaled in one breath during rest breathing IRv - inspiratory reserve volume - amount of air in excess of tidal volume that can be inhaled with max effort ERV - expiratory reserve volume - exhaled with max effort RV - residual volume - amount left in lungs after max expiration VC - vital capacity - amount of air that can be forcefully exhaled during max inspiration IC - inspiratory capacity - man inhaled after normal expiration FRC - functional residual capacity - air remaining in lung after resting exhale TLC - total lung capacity - max in lung after max inspiration

Question 46

fricks law and how it changes based on the parameters (ie increase or decrease due to thickness..)

Answer 46

V gas = A/T x D x (P1-P2)

Question 47

ventilation -perfusion relationship (ratio)

Answer 47

ventilation to perfusion ratio V/Q - the amount of law flowing through the lung vs the amount of O2 being loaded to the tissues higher moderate exercise improved V/Q ration but intense exercise decrease the ratio

Question 48

causes of respiratory muscle fatigue

Answer 48

amount of work done by diaphragm limited amount of blood flow Respiratory muscle fatigue occurs when the work of breathing exceeds the capacity of the respiratory muscles, often during high-intensity or prolonged exercise. Causes include high ventilatory demand, impaired oxygen delivery to the diaphragm and accessory muscles, accumulation of metabolites such as lactate and H⁺, depletion of glycogen, and neuromuscular limitations. V̇/Q̇ mismatch can contribute by increasing the work of breathing, but the primary determinants are workload and muscle metabolic capacity.

Question 49

what is the primary function of the pulmonary system? what secondary functions does it serve?

Answer 49

primary function gas exchange with in the body secondary function it to regular blood pH

Question 50

list and discuss the major anatomical components of the respiratory system

Question 51

what muscle groups are involved in ventilation during rest? during exercise?

Answer 51

during resit inspiration is diagpharm expiration is inactive during exercise inspiration is diaphragm expiration is a mixture of muscle including the abdominal wall

Question 52

what is the functional significance of the ventilation-perfusion ratio? How would a highV/Q ratio affect gas exchange in the lung?

Answer 52

a high V/Q ratio would indicate a large ventilation compare to perfusion this means that there would be a lot of air moving past the tissue but not a low being diffused - results in poor gas exchange

Question 53

Discuss those factors that influence the rate of diffusion across the -blood-gas interface in the lung.

Answer 53

Po2 in blood affinity/strongth of O2 and Hb bond

Question 54

graph the relationship between hemoglobin- O2 saturation and the partial pressure of O2 in the blood. what is the functional significance of the shape of the O2-HB dissociation curve? what factors affect the shape of the curve?

Answer 54

see graph - increase O2Hb affinity/bond strength shift curve left (loading) decreae O2Hb affinity shift curve right (unloading) temperature --> inverse increase temp decrease affinity therefore shift right (unloading) decrease temp increase affinity therefore shift left (loading) pH linear increase pH increase affinity shift left (loading) decrease pH increase H decrease affinity shift right (unloading) 2-3 DPG inverse increase 2-3 DPG decrease affinity shift right (unloading) increase altitude increase 2-3 DPG

Question 55

discuss the modes of transportation for the CO2 in the blood

Answer 55

CO2 transported by bicronabate

Question 56

Graph the ventilatory response in the transition from rest to constant-load submaximal exercise. What happens to ventilation if the exercise is prolonged and performed in a hot/humid environment? Why?

Answer 56

Ve jumps when exercise starts exercise in hot environment increase Ve due to increase in blood temp due to increase breathing frequency and dead space ventilation

Question 57

Graph the ventilatory response to incremental exercise. Label the ventilatory threshold. What factor(s) might explain the ventilatory threshold?

Answer 57

Ve start to slowly rise as exercise begins then exponentially as VO2 max is reached . ventilatory threshold with when Ve starts to rise exponentially The ventilatory threshold occurs when ventilation rises disproportionately to oxygen uptake due to increased anaerobic metabolism. As exercise intensity rises, lactate production increases, producing H⁺ ions. The bicarbonate buffering system neutralizes H⁺, generating CO₂, which stimulates chemoreceptors and triggers increased ventilation. This hyperventilation helps expel CO₂ to maintain acid-base balance. Catecholamines and neural feedback from muscles also contribute to the ventilatory response.

Question 58

“List and identify the functions of the chemoreceptors that contribute to the control of breathing.”

Answer 58

central chemoreceptors - medulla affected by increase PO2 and H+ to increase ventilation peripheral chemoreceptors - aortic bodies respond to increase in h+, decrease pH, increase PCO2 --> increase breathing - carotid bodies respond to increase in h+, decrease pH, decrease PO2 , increase PCO2 --> increase breathing

Question 59

“What neural afferents might also contribute to the regulation of ventilation during exercise?”

Answer 59

high brain centers respiratory muscle --> lung stretch receptors skeletal muscle - chemoreceptors --> increase muscle contraction activity --> increase breathing - mechanoreceptors --> decrease pH or increase potassium --> increase breathing

Question 60

Discuss the control of ventilation during exercise.

Answer 60

moderate exercise - increase Ve --> both neural and chemoreceptors heavy exercise - increase vE decreae pH --> see notes