Question

Laboratory 8: Muscle Lecture & Case Study Rigor Mortis (Muscle Contraction) Braude, S., Goran, D., and Maxfield, S. 2011. Case Studies for Understanding the Human Body, 2nd Edition. Boston: Jones and Bartlett Publishers. pp 141-145. Emma Louise, RN, started her morning rounds in Mrs. Weitzel's room. Mrs. Weitzel was to have surgery later in the week, and Emma had an order to draw some blood for lab work. Because the patient appeared to be sleeping, Emma took her time tidying up the room. As Emma approached the side of the bed, Mrs. Weitzel suddenly moved her leg. Emma looked over at Mrs. Weitzel and noticed she was not breathing. She punched the code-blue button and checked Mrs. Weitzel's airway to begin artificial respiration and cardiopulmonary resuscitation (CPR). Several of Emma's colleagues rushed into the room with the crash cart. Mrs. Weitzel was not breathing, was ashen in color, and was very cold. The emergency team could not find a pulse or a heartbeat, and they could not detect respiration. On closer examination, the resident found every joint in her body was stiff. Just then Mrs. Weitzel's son, Josh, entered the room. He had come to visit his mother and was shocked to see so many people in her room. He couldn't believe his cars when the resident declared his mother deceased. Josh remembered that Emma had been taking care of her and demanded that she explain what had happened.

Answer 1

Rigor mortis is the stiffening of muscles after death due to the cessation of ATP production, which prevents the detachment of myosin heads from actin, leading to sustained muscle contraction.

• The phenomenon of rigor mortis affects a body after death due to biochemical changes in the muscles.
• During life, muscle contraction and relaxation cycles depend on the continual synthesis and utilization of adenosine triphosphate (ATP).
• In live individuals, the detachment of myosin heads from actin-binding sites is a process that requires ATP, leading to muscle relaxation.
• However, after death, ATP production ceases, causing myosin heads to remain attached to actin, which prevents relaxation and results in the stiffening of muscles, known as rigor mortis.
• This process is a clear indication that the subject has passed away, as observed with Mrs. Weitzel.