Pre-Lab: Comparing Limbs
Problem How is the structure of skeletal muscles and bones related to the functions of these body parts?
Materials disposable plastic gloves, chicken wing, disposable dissection tray, dissecting scissors, forceps, colored pencils or markers
Skills Focus Observe, Infer, Compare and Contrast
Connect to the The structure of your bones reflects the different functions of your skeleton. For example, your bones must be strong enough to support your body and protect internal organs. Your bones must also be rigid so that they provide a system of levers on which skeletal muscles can act.
Skeletal muscles have a structure that enables them to move bones around fixed points called joints. In skeletal muscles, the cells are long and narrow, which is why these cells are also called muscle fibers. When muscle fibers contract, they pull on the bone to which a muscle is attached. This force causes the bone to move in the direction of the contraction.
In this lab, you will observe and compare the structure and function of a human arm and leg. You will also compare the arm with a chicken wing.
Review What motion does a hinge joint allow? What motion does a pivot joint allow? Which of these joints are found in your elbows and knees?
Review What role does cartilage play in freely movable joints?
Explain How is it possible for bones to move in more than one direction around a joint?
Compare and Contrast How are a ligament and a tendon similar? How are they different?
Observe How will you observe the structure and function of your elbow and knee joints?
Relate Cause and Effect Why is it important to wear goggles and disposable gloves while examining the chicken wing?
Predict Will the arrangement of bones and muscles in a chicken wing be similar to the arrangement in a human arm? Why or why not?
Visit Chapter 32 online to test yourself on chapter content and to find activities to help you learn.
Untamed Science Video Hold onto your seats as the Untamed Science crew whisks you to NASA to learn about the effect space travel has on an astronaut's bones.
Data Analysis Collect and analyze skin cancer data, then propose some conclusions based on this data.
Tutor Tube Watch an analogy to help you learn the sliding-filament model of muscle contraction.
Art Review Review your understanding of the structures of the skin.
InterActive Art Watch how the various joints in the body move.
Art in Motion Watch the process of muscle contraction.
Visual Analogy How is the skeleton like the framework of a house?