1. Order the ATP muscle kits (Carolina) to be delivered no more than seven days before the lab. One kit provides generously for eight students. Extra vials of the chemical solutions can be ordered separately (Carolina) and will reduce waiting time. Just before the lab begins, cut the muscle bundles into 2-centimeter lengths and place in a petri dish in the accompanying glycerol.
R E V I E W
S H E E T
LAB TIME/DATE _______________________
Microscopic Anatomy and Organization of
Skeletal Muscle Cells and Their Packaging into Muscles
From the inside out, name the three types of connective tissue wrappings of a skeletal muscle.
Why are the connective tissue wrappings of skeletal muscle important? (Give at least three reasons.)
They support and bind muscle fibers, strengthen the muscle as a whole, and provide a route for the entry and exit of nerves and blood vessels that serve the muscle fibers.
Why are there more indirect—that is, tendinous—muscle attachments than direct muscle attachments? (Your text may help you answer this.)
Tendons provide durability and conserve space. They are tough collagen fibers so they can cross rough, bony projections that would tear delicate muscle tissues. Because of their small size, more tendons can pass over a joint.
On the following figure, label endomysium, perimysium, epimysium, and fascicle.
(wrapped by perimysium) Endomysium
The diagram illustrates a small portion of a muscle myofibril in a highly simplified way. Using terms from the key, correctly identify each structure indicated by a leader line or a bracket. Below the diagram make a sketch of how this segment of the myofibril would look if contracted.