Muscles (Pg 12-22, Nelson)

All work to be completed in your workbooks. Full sentence answers or stick this page in your book.

1.  Spend some time looking at pictures of the muscles on page 11. Try and work out where these muscles are on your own body. Get to know the major muscle groups (chest, back, arms, legs, torso).

2.  Compare and contrast the 3 types of muscles. Draw up a table that includes purpose, appearance, and whether they are voluntary/involuntary.

Muscle / Purpose / Appearance / Voluntary/Involuntary
Cardiac Muscles / Line heart wall – Beat/pump / Striped appearance / Involuntary
Smooth Muscles / Digestion, blood movement / Spindle cells / Involuntary
Skeletal Muscles / Skeletal movements / Striped cells / Voluntary

3.  Summarise the other functions of muscle

All skeletal movements result from muscles pulling on bone. They also provide support and allow an upright posture. Many muscles contract statically/isometrically also known as muscle tone. Muscles also produce heat when energy is produced from foods/fuels to allow contractions. Skeletal muscles can also contract involuntarily – shivering.

4.  Differentiate between

a)  ligaments and tendons

Ligaments connect bone to bone. Tendons connect muscle to bone

b)  origin and insertion

Origin attaches to a stable or flat bone. Insertion attaches to a bone it pulls on.

c)  agonist prime mover and antagonist Opposite muscle

5.  Accurately describe the process of reciprocal inhibition, use an example to assist your answer.

Reciprocal inhibition occurs when one muscle contracts and its opposite relaxes to allow movements to occur. Flexion of the Elbow – Biceps contracts – Triceps Relax

6.  What is a prime mover – causes movement (biceps responsible for flexing elbow) and a stabiliser – provides stability to the origin – Traps stabilize the scapula during elbow flexion.

7.  Complete ‘Student Activity’ on page 14. You may complete one or all tasks, ask teacher for sticky labels for activity 1.

8.  Complete Thinking Things Through on Page 16.

1. List 4 examples of fusiform muscles

Any four of the following: biceps, sartorius, rectus abdominus, brachioradialis, tibialis anterior, illiopsoas, soleus, plantaris or palmaris longus.

2. Pennate muscles have a larger cross sectional area and number of fibres than fusiform muscles and as such can generate more force and power. Pennation allows more fibres to be packed into any given length of muscle when compared to fusiform arrangements.

3. Fusiform muscles are able to generate greater contractile velocities, which are traded off for lower force outputs. This occurs because longer muscles can contract over a greater distance and develop higher shortening velocities.

4. a Ligaments connect bones to bones and if they are ‘stretched’ will often lead to immediate inflammation and pain at the site. This will often also be associated with joint instability because the ‘fit’ or ‘bone association’ has been compromised, and can lead to dislocations and further injuries because the joints are able to move in excess of their normal range of motion.

b Ligaments connect bones to bones, whereas tendons connect muscles to bones.

c Ligaments have poorer blood supply than tendons, and are often subjected to greater stress/force because of the fact that they span a joint.

9.  Read Page 16-22. Familiarise yourself with the following terms: myofibrils, sarcomere, myosin, actin, mitochondria, enzymes, I-band, A-band, H-zone, motor unit, neurons, synapse.