lect 17. muscle relaxation and case study

Question 1

1 step of muscle relaxation

Answer 1

sarcoplasmic ca2+ atpase pumps calcium into sr

Question 2

2nd step of muscle relaxation

Answer 2

there is now less calcium so now its unable to unbind from troponin

Question 3

3rd step of muscle relaxation

Answer 3

tropomyosin recovers binding site and the head is released causing elastic elements pull filaments into relaxed position

Question 4

what is malignant hyperthermia

Answer 4

A genetic condition that only becomes obvious
when a patient is exposed to certain anesthetics
such as halothane.

Question 5

how does malignant hyperthermia cause muscle rigidity

Answer 5

• Malignant
  hyperthermia is
  caused by inherited
  mutation which
  changes the
  structure of
  ryanodine receptor
  (RyR) on the
  cytoplasmic
  reticulum.
  calcium leaks calcium

Question 6

What could be the molecular mechanism of
rigor mortis? In other words, why do the
muscles stiffen after death

Answer 6

Once all of the stored ATP is consumed,
the myosin heads remain bound to the
actin filament and the muscle is unable to
relax.