Lab 7 The Muscular System BIO201L
Student Name:
Access Code (located on the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and professional formatting when completing this worksheet.
Submissions without proper formatting, all required photos or sufficient responses will be
rejected. Pre lab Questions
1. How do banding patterns change when a muscle contracts?
When a muscle contracts, the myosin and actin myofilaments reduce in length, making
them to come as one and the H zones become slim and thin . Therefore, the A band
stays interchangeable.
2. What is the difference between a muscle organ, a muscle fiber, myofibril and a
myofilament?
Myofilament is the fiber that is produced of myofibrils. Myofibrils are contrived of cells
named myocytes. Myofilaments get as one to form a muscle fiber. The skeletal
muscle organs are made of bundles of muscle cells named as muscle fibers.
3. Outline the molecular mechanism for skeletal muscle contraction. At what point is ATP
used and why?
Calcium ions are let out by the sarcoplasmic reticulum in the actin filament. The calcium
ions produce bonds between actin filament and myosin head. The energy produced by
the myosin head filament allows a shift where the myosin head moves in the direction of
the actin filament. Next, skeletal muscle contraction takes place due the release of ATP.
Due to the surplus of ATP, the myosin head splits from the actin filament. At the end of
the cycle, actin filament and myosin head get back to their original position and ATPase
gets ATP back to ADP.
4. Explain why rigor mortis occurs.
Rigor mortis occurs somewhat because the collapse SR releases calcium to the ground-
plasm, and the depreciated myolemma disclose a lot of calcium from the extracellular
fluid.
Lab 7 The Muscular System BIO201L
,EXPERIMENT 1: TENDONS AND LIGAMENTS
Introduction Questions
1. How does the extracellular matrix of connective tissues contribute to its
function? The extracellular matrix gives a scaffold to the biological material.
It gives support to the cells and keeps the cellular structure. It aids to
separate one tissue from other one to perform its functions effectively.
2. Why are tendons and ligament tissues difficult to heal?
Both ligaments and tendons have limited blood supply causing indirect healing difficulties.
Lab 7 The Muscular System BIO201L
Data and Observations
1. Label the arrows in the slide images below based on your observations from the
experiment. A. Chondrocytes.
, B. collagen
C. nucleus.
D. skeletal muscle fibers
E. nuclei
F. collagen fibers
Student Name:
Access Code (located on the lid of your lab kit):
Lab Report Format Expectations
Utilize college level grammar and professional formatting when completing this worksheet.
Submissions without proper formatting, all required photos or sufficient responses will be
rejected. Pre lab Questions
1. How do banding patterns change when a muscle contracts?
When a muscle contracts, the myosin and actin myofilaments reduce in length, making
them to come as one and the H zones become slim and thin . Therefore, the A band
stays interchangeable.
2. What is the difference between a muscle organ, a muscle fiber, myofibril and a
myofilament?
Myofilament is the fiber that is produced of myofibrils. Myofibrils are contrived of cells
named myocytes. Myofilaments get as one to form a muscle fiber. The skeletal
muscle organs are made of bundles of muscle cells named as muscle fibers.
3. Outline the molecular mechanism for skeletal muscle contraction. At what point is ATP
used and why?
Calcium ions are let out by the sarcoplasmic reticulum in the actin filament. The calcium
ions produce bonds between actin filament and myosin head. The energy produced by
the myosin head filament allows a shift where the myosin head moves in the direction of
the actin filament. Next, skeletal muscle contraction takes place due the release of ATP.
Due to the surplus of ATP, the myosin head splits from the actin filament. At the end of
the cycle, actin filament and myosin head get back to their original position and ATPase
gets ATP back to ADP.
4. Explain why rigor mortis occurs.
Rigor mortis occurs somewhat because the collapse SR releases calcium to the ground-
plasm, and the depreciated myolemma disclose a lot of calcium from the extracellular
fluid.
Lab 7 The Muscular System BIO201L
,EXPERIMENT 1: TENDONS AND LIGAMENTS
Introduction Questions
1. How does the extracellular matrix of connective tissues contribute to its
function? The extracellular matrix gives a scaffold to the biological material.
It gives support to the cells and keeps the cellular structure. It aids to
separate one tissue from other one to perform its functions effectively.
2. Why are tendons and ligament tissues difficult to heal?
Both ligaments and tendons have limited blood supply causing indirect healing difficulties.
Lab 7 The Muscular System BIO201L
Data and Observations
1. Label the arrows in the slide images below based on your observations from the
experiment. A. Chondrocytes.
, B. collagen
C. nucleus.
D. skeletal muscle fibers
E. nuclei
F. collagen fibers
