Biology Sample Page

Student Manual Week 3: The Muscular System

1. Is body movement solely muscular?

2. Know the location of the names of at least the following main muscles (you can learn more muscles, too):

Trapezius	pectoralis major
Biceps	rectus abdominus (the “6-pack”)
Triceps	gastrocnemius
gluteus maximus	latissmus dorsi
external oblique	quadriceps (the rectus femoris)
hamstring (a combination of a few muscles)

 

3. What are the types of muscles, what is the importance of each type, and give an example of each.

4. Research ligaments and tendons and what the difference is between them.

5. Research how muscles work, get as detailed as you can.

6. What are ways to build muscle endurance? Why is it important to build muscle endurance?

7. What are some disorders of the muscular system?

 Parent Manual Week 3: Muscular System

If anything sparks an interest in your child, please let him spend extra time researching those areas of interest.

1. Is body movement solely muscular?

Body movement does not involve only muscles, it is the nervous system, muscular system and the skeletal system all working together.  The muscles are contractile (produce movement), have extensibility (can stretch when its muscle pair is contracting) and elasticity (when relaxed it will go back to its original length).  All skeletal muscles work in pairs, opposite each other: when one contracts, the other relaxes and vice versa (example: biceps and triceps)

2. The student should learn AT LEAST these major muscles:

Trapezius	pectoralis major
Biceps	rectus abdominus (the “6-pack”)
Triceps	gluteus maximus
gluteus maximus	latissmus dorsi
external oblique	quadriceps (the rectus femoris)
hamstring (a combination of a few muscles)	Gastrocnemius deltoids

 

3. What are the types of muscles, what is the importance of each type, and give an example of each.

The types of muscles are the smooth, skeletal and cardiac. 

• Smooth muscles (also called the visceral muscles): are the involuntary muscles, the diaphragm is an example, so we don’t have to use all of our conscious thought time thinking about breathing and all the other necessary functions that the rest of our involuntary muscles do. We cannot control the smooth muscles.  There are no striations, or banding, in the cells.
• Skeletal muscles (also called striated muscles) do our conscious movement: walk, talk, smile, wave, etc...  We can control the skeletal muscles (are voluntary muscles).  The cells have striations, or bands (light and dark bands), and are attached to the bones of the body.
• Cardiac muscle: only one muscle in the body has this type of tissue and that is the heart. It is unique in structure and in function: it is solely responsible for moving the blood through the body.  The cells are a network of interconnecting fibers and striations.

4. Research ligaments and tendons and what the difference is between them.

Ligaments attach bone to bone, and tendons attach the muscles to bone.  Both are connective tissue.

5. Research how muscles work, get as detailed as you can.

Minimum research: muscles work by a nerve giving the muscle tissue an impulse, causing the muscle to contract.

Maximum research: get into more detail, even to the biochemistry of muscular contraction: the ions move out of the muscle, causing the muscle cells to shorten.

Each muscle is made up of bundles of muscle fibers.  Each fiber is made up of bundles of myofibrils.  The myofibrils run lengthwise within the muscle cell.  The myofibrils give the skeletal muscle its characteristic striations, or bands.   The muscle fibers obey the all-or-nothing rule:  when the muscle fiber contracts, it never contracts part-way, it always contracts to the full extent.

Sliding Filament Theory for muscle contraction: 1) the nerve stimulates the sarcoplasmic reticulum which releases calcium ions.  2) the ions cause the myosin part of the myofibril to break a phosphate off of ATP to release energy and ADP and the actin part of the myofibril slides into the myosin (both happens simultaneously) resulting in the muscle contracting.

6. What are ways to build muscle endurance? Why is it important to build muscle endurance?

The best way to build muscle endurance is primarily exercise.  Its importance is agility and survival; the body becomes healthier, runs more smoothly like a well-oiled machine’. 

Muscle cells do not multiply, but increase in size (diameter) during exercise.  This results in larger muscles with greater strength.  When muscles are contracted for a long period of time, the ability to contract becomes weaker and weaker until the ability to stay contracted fails (example: holding a heavy object such as a piano at the top of the stairs.  One can hold it for a bit, but before long the muscles start to shake and are soon unable to keep the object there.)

Muscle tone refers to what the muscle looks like when at rest (legs for example).Good muscle tone is when some of the muscle fibers are contracted and some are not; the muscle is ready to perform quickly.  You can see the muscles as well formed.  Poor muscle tone is when hardly any of the muscle fibers are contracted; the muscles look ‘mushy’.  The medical term of flaccid muscle is the loss of muscle tone due to a long period of inactivity.  The term muscle atrophy is where the muscle tissue becomes smaller due to not being stimulated for a short period of time, such as a broken limb.  If exercise is resumed the muscle tissue will return to normal.

 7. What are some disorders of the muscular system?

Some disorders of muscles are:

• Muscular Dystrophy: the increasingly wasting away of the skeletal muscles. The muscle tissue shrinks to a fraction of their normal size.  The muscle tissue is replaced by fatty tissue.
• Myasthenia Gravis: the skeletal muscles become weak and fatigued quickly.
• Spasms and cramps: the involuntary contraction of the skeletal muscle (or group of muscles). Spasms cause weakness and pain, are usually caused by a pinched nerve and are usually located in the back or neck.  Cramps are titanic contractions of the muscle tissue (become like a rock), may be caused by extreme cold or by severe physical exertion over a long period of time, and stretching usually relieve the pain.

Quiz Three

1) On the outline of the human body, label 8 of the major muscles.

 

2) State one type of muscle and give an example of it.

 

 

• State the difference between ligaments and tendons.

 

 

• Why is it important to exercise?

 

 

• State one disease or disorder of the muscular system.

 

 

• What system(s) is (are) involved in the movement of the body?

 

 

**Bonus**

      Explain the “Sliding Filament Theory”.

Parent Manual Quiz Three

1. On the outline of the human body below, label 8 of the major muscles. I am having trouble right now getting the properly labeled image uploaded.  For now, please know that I have the following labeled for you to be able to check your student's answers: trapezius, deltoid, pectoralis major, biceps, triceps, latissimus dorsi, external obliques, rectus abdominus, gluteus maximus, hamstrings, quadriceps (rectus femorius), tibialis anterior and the gastrocnemius.

2. State one type of muscle and give an example of it.

Cardiac muscle - heart

Smooth muscle - most involuntary muscles, such as intestines,

esophagus, diaphragm

Skeletal muscle - All voluntary muscles, such as the biceps,

triceps, deltoids,... etc...

3. State the difference between ligaments and tendons.

Ligaments attach bone to bone, and tendons attach muscle to bone.

4. Why is it important to exercise?

The importance is agility and survival.

 5. State one disease or disorder of the muscular system.

Muscular Dystrophy, Myasthenia Gravis, Spasms and cramps,

 6. What system(s) is (are) involved in the movement of the body?

The nervous system, muscular system and the skeletal system all working together

 

**Bonus**

      Explain the “Sliding Filament Theory”.

Sliding Filament Theory for muscle contraction: 1) the nerve stimulates the sarcoplasmic reticulum which releases calcium ions.  2) the ions cause the myosin part of the myofibril to break a phosphate off of ATP to release energy and ADP and the actin part of the myofibril slides into the myosin (both happens simultaneously) resulting in the muscle contracting

Lab Dissection  Week 3: Muscle Cells and Frog Muscular System

1. Microscope work:

• View prepared slides of each type of muscles: voluntary, involuntary, and cardiac.
• Make sure you draw and label the pictures of each slide you view in the space below.

 

voluntary:

 

 

 

 

 

involuntary

 

 

 

 

 

cardiac

 

 

 

 

 

2. Dissection:

• Optional: it is a Konos activity, from KONOS Volume III (used with permission). Dissection of a chicken leg- thigh. Notice the location of the ligaments and the tendons, how the muscles are situated, and where the cartilage is.  Draw and label in the space below.

Frog dissection.  Examine the frog.  Lay the frog on its back and cut the skin only making an incision from the neck to the legs, then pull the skin away observing how the skin is attached to the muscle.  Carefully remove the skin from the ventral side (the belly) of the frog and the dorsal side (the back) and the other leg.  Draw a diagram of the frog without its skin in the space below, draw in the muscles and try to label as many of them as you can.

 

Parent Manual Week 3: Muscle Cells and Frog Muscles

 

1. Microscope work:

• View prepared slides of each type of muscles: voluntary, involuntary, and cardiac.
• Make sure you draw and label the pictures of each slide you view in the space below.

 

voluntary:

Nucleus (the darker dots)   striation (the horizontal lines)

involuntary

Nucleus No striations are visible Cells are spindle-shaped

cardiac

Intercalated disks (darker horizontal bands) are more visible than the striations.  Many nuclei can be observed (none are drawn here) Muscle fibers are branched, joined by the intercalated disks.

 

2. Dissection:

• Optional: it is a Konos activity, Volume III. Dissection of a chicken leg- thigh. Notice the location of the ligaments and the tendons, how the muscles are situated, and where the cartilage is.  Draw and label in the space below.

The student should have noticed that the ligaments are white and tough, attaching the leg bone to the thigh bone at the joint and the tendons looked very similar to the tendons (white and tough), yet attach the muscle to the bone.  The student should have noticed how the muscles overlap and fit together and how the cartilage seems to wrap around the ends of the bone at the joint.

Frog dissection.  Examine the frog.  Lay the frog on its back and cut the skin only making an incision from the neck to the legs, then pull the skin away observing how the skin is attached to the muscle.  Carefully remove the skin from the ventral side (the belly) of the frog and the dorsal side (the back) and the other leg.  Draw a diagram of the frog without its skin in the space below, draw in the muscles and try to label as many of them as you can.

An example of what the student should label from his drawing of his frog is included in the Parent Manual.  As soon as I can determine how to get the picture small enough to upload I will include it here.  

I tell my students that this is not art class, to draw as best they can.  That which is most important is to LABEL as much of their drawing as possible.