Intense Exercise- Lactate and H+ W2

Question 1

What relationship does muscle force have with lactate and H+?

Answer 1

Decreased muscle force
Increased intracellular concentrations of lactate and H+

Question 2

What is muscle pH like at rest?

Answer 2

7.05

Question 3

How low can pH drop during exhaustive exercise?

Answer 3

6.5

Question 4

What does low pH reduce?

Answer 4

Direct activation of Ca2+ release channel to stimulation by Ca2+ and caffeine

Question 5

What happens to lowered pH in intact fibres?

Answer 5

Maximum tetanic force is reduced by no more than the expected amount

Question 6

What are the deleterious effects of transmission of the action potential along the sarcolemma?

Answer 6

Increased K+
Increased Na+

Question 7

What are the deleterious effects of inward conduction of the Action Potential in T-Tubule?

Answer 7

Increased K+
Increased Na+

Question 8

What inhibits the reuptake of Ca2+ by the Sarcoplasmic Reticulum?

Answer 8

Increased Pi, ADP and ROS
Decreased ATP

Question 9

What reduces Ca2+ sensitivity of myofibrillar proteins?

Answer 9

Increased Pi and ROS
Decreased pH

Question 10

What reduces Maximum Ca2+ activated force in muscle?

Answer 10

Increased Pi

Question 11

What reduces shortening velocity in muscle?

Answer 11

Increased ADP

Question 12

What does Ca2+ releasement via SR have an direct effect on?

Answer 12

Pi on RyR
RyR phosphorylation or oxidation