Skeletal Muscle

1. David’s body temperature rises above normal during the surgery (hyperthermia). How does skeletal muscle tissue contribute to body temperature?

Skeletal muscle tissue contributes to body temperature by contracting which generates heat. When the body is shivering and forming goosebumps, this is the body’s way of generating heat.

2.During malignant hyperthermia, there is an increased amount of calcium released into the sarcoplasm of skeletal muscle cells.

a.What organelle stores calcium in muscles cells?

The organelle that stores calcium in muscle cells in the sarcoplasmic reticulum.

b.Describe the events that must occur in the muscle cell before calcium is released from this organelle.

The events that occur in a muscle cell before calcium is released is: when an action potential reaches the synaptic terminal, acetylcholine is released into the synaptic cleft, Ach molecules land on receptors on the motor end plate, an action potential is generated and travels across the sarcolemma surface, the action potential travels down the t tubules, and finally; calcium ions are released into the sarcoplasm.

3.Jaw muscle contraction (masseter spasm) is one of the key physical findings seen in David’s case of malignant hyperthermia. Explain how calcium functions to cause contraction of a skeletal muscle cell.

Calcium binds to troponin, this causes the unwinding of the tropomyosin-actin complex, which uncovers the myosin-head binding sites. The Myosin head binds to actin at those sites and forms a cross-bridge. Finally, ATP generates a series of steps on the myosin head for contraction

4.Dr. Hodges notes that David’s exhaled carbon dioxide levels are elevated. List all the metabolic pathways that function to synthesize ATP for skeletal muscle contraction. Which of these pathways produces carbon dioxide as a by-product?

Glycolysis and the TCA (also known as Citric Acid and Kreb's) Cycle. TCA produces 6 CO2's per glucose.