EXB 101 final Question and answers
correctly solved 2026
Define a Stressor vs Stress - correct answer ✔- Stressor = an environmental factor that takes the body
away from equilibrium
--> eg. going on a run
- Stress = a passive and unwanted bodily displacement
--> eg. increased HR
Define controlled vs regulated variables - correct answer ✔- Controlled variables = are altered as a
response to exercise and can be placed into a new steady state
--> eg. HR, SV, RR
- Regulated variable = kept at a constant rate throughout exercise
Define feed forward system - correct answer ✔- enzymes are sent throughout the body as a response
to exercise that enhance responses prior to the stress
Define central command - correct answer ✔- works to regulate many responses within the body to
maintain homeostasis
Define physiological response vs adaptation - correct answer ✔- response = a quick onset change that
does not last very long
--> temporary increase in heart rate during exercise
- adaptation = a slow developing change showing structural changes that can be measured
--> increased heart size as a response to repeated exercise
Does muscle contractile activity play a role in gene activation? - correct answer ✔YES! Mammals
require physical activity, otherwise they become sick and die
,How is energy stored? - correct answer ✔- stored in very small amounts as ATP in all cells in skeletal
muscle
How is energy generated? - correct answer ✔- activation of skeletal muscle (mostly)
--> produced in the mitochondria and utilized with movements
- sliding filament theory = thin and thick filaments slide past one another causing a change in muscle
length
--> decrease length of I band and H zone
--> no change in A band
Where does energy utilization occur? - correct answer ✔- in metabolic pathways, ATP is the main
source of energy (fat oxidation, carbohydrate oxidation, anaerobic glycolysis and phosphorylation)
What metabolic pathways are utilized during acute and chronic exercise? - correct answer ✔- acute
exercise (resistance training) utilizes phosphocreatine and anaerobic glycolysis
- chronic exercise (endurance training) utilizes carbohydrate and fat oxidations
How do skeletal muscles adapt to changes in activity? - correct answer ✔
What determines muscle cross sectional area? - correct answer ✔- the number of myofibrils in the
muscle fiber (make up the size of muscle fibers)
-->can change throughout lifetime
What two cells are found in skeletal muscle? - correct answer ✔- myonuclei: lie beneath/inside the
sarcolemma, are post mitotic and lie at the periphery of the fiber (85%)
- satellite cell: are undifferentiated and lie between the sarcolemma and the basal membrane. Are
thought of as 'adult stem cells' because of their ability to regenerate (15%)
, What proteins are associated with sarcomeres and what do they do? - correct answer ✔- contractile
proteins (actin and myosin) = generate force
- regulatory proteins (MLC, troponin, tropomyosin) = turn contractile apparatus on and off, monitor
activity of MHC
- structural proteins (desmin, nebulin) = maintain the structure of thick and thin filaments and aligning
the sarcomeres
Describe the role of costomeres, alpha actinin, titin and nebulin within a sarcomere - correct answer ✔-
Costomeres = allow for communication and transmission of force between sarcomeres
- alpha-actinin and nebulin hold the sarcomeres together
- titin = attaches to myosin filaments and aids in passive force
Define Excitation-contraction coupling - correct answer ✔- how skeletal muscle is activated: the fibers
are activated by a release of calcium that signals acetylcholine to flood the cell at the neuromuscular
junction. Acetylcholine activates DHP receptors in the T-tubules, opening ryanodine receptors in the SR
leading to a release in Ca2+ into the cell. Ca2+ binds to troponin and allows the muscle to contract.
- this process is stopped as a result of a re-uptake of Ca2+ into the SR
Describe the Frequency - Tension relationship - correct answer ✔- As frequency of stimulus increases,
tension also increases until max tension is produced and the muscle enters tetanus
Describe the Length- tension relationship - correct answer ✔- optimal length of a muscle fiber is when
myosin and actin are overlapping but are not overstretched or under stretched
Describe the Force - velocity relationship - correct answer ✔- the speed of a muscle contraction
depends on the amount of force resisting a muscle
- most force with an eccentric contraction
correctly solved 2026
Define a Stressor vs Stress - correct answer ✔- Stressor = an environmental factor that takes the body
away from equilibrium
--> eg. going on a run
- Stress = a passive and unwanted bodily displacement
--> eg. increased HR
Define controlled vs regulated variables - correct answer ✔- Controlled variables = are altered as a
response to exercise and can be placed into a new steady state
--> eg. HR, SV, RR
- Regulated variable = kept at a constant rate throughout exercise
Define feed forward system - correct answer ✔- enzymes are sent throughout the body as a response
to exercise that enhance responses prior to the stress
Define central command - correct answer ✔- works to regulate many responses within the body to
maintain homeostasis
Define physiological response vs adaptation - correct answer ✔- response = a quick onset change that
does not last very long
--> temporary increase in heart rate during exercise
- adaptation = a slow developing change showing structural changes that can be measured
--> increased heart size as a response to repeated exercise
Does muscle contractile activity play a role in gene activation? - correct answer ✔YES! Mammals
require physical activity, otherwise they become sick and die
,How is energy stored? - correct answer ✔- stored in very small amounts as ATP in all cells in skeletal
muscle
How is energy generated? - correct answer ✔- activation of skeletal muscle (mostly)
--> produced in the mitochondria and utilized with movements
- sliding filament theory = thin and thick filaments slide past one another causing a change in muscle
length
--> decrease length of I band and H zone
--> no change in A band
Where does energy utilization occur? - correct answer ✔- in metabolic pathways, ATP is the main
source of energy (fat oxidation, carbohydrate oxidation, anaerobic glycolysis and phosphorylation)
What metabolic pathways are utilized during acute and chronic exercise? - correct answer ✔- acute
exercise (resistance training) utilizes phosphocreatine and anaerobic glycolysis
- chronic exercise (endurance training) utilizes carbohydrate and fat oxidations
How do skeletal muscles adapt to changes in activity? - correct answer ✔
What determines muscle cross sectional area? - correct answer ✔- the number of myofibrils in the
muscle fiber (make up the size of muscle fibers)
-->can change throughout lifetime
What two cells are found in skeletal muscle? - correct answer ✔- myonuclei: lie beneath/inside the
sarcolemma, are post mitotic and lie at the periphery of the fiber (85%)
- satellite cell: are undifferentiated and lie between the sarcolemma and the basal membrane. Are
thought of as 'adult stem cells' because of their ability to regenerate (15%)
, What proteins are associated with sarcomeres and what do they do? - correct answer ✔- contractile
proteins (actin and myosin) = generate force
- regulatory proteins (MLC, troponin, tropomyosin) = turn contractile apparatus on and off, monitor
activity of MHC
- structural proteins (desmin, nebulin) = maintain the structure of thick and thin filaments and aligning
the sarcomeres
Describe the role of costomeres, alpha actinin, titin and nebulin within a sarcomere - correct answer ✔-
Costomeres = allow for communication and transmission of force between sarcomeres
- alpha-actinin and nebulin hold the sarcomeres together
- titin = attaches to myosin filaments and aids in passive force
Define Excitation-contraction coupling - correct answer ✔- how skeletal muscle is activated: the fibers
are activated by a release of calcium that signals acetylcholine to flood the cell at the neuromuscular
junction. Acetylcholine activates DHP receptors in the T-tubules, opening ryanodine receptors in the SR
leading to a release in Ca2+ into the cell. Ca2+ binds to troponin and allows the muscle to contract.
- this process is stopped as a result of a re-uptake of Ca2+ into the SR
Describe the Frequency - Tension relationship - correct answer ✔- As frequency of stimulus increases,
tension also increases until max tension is produced and the muscle enters tetanus
Describe the Length- tension relationship - correct answer ✔- optimal length of a muscle fiber is when
myosin and actin are overlapping but are not overstretched or under stretched
Describe the Force - velocity relationship - correct answer ✔- the speed of a muscle contraction
depends on the amount of force resisting a muscle
- most force with an eccentric contraction
