TOPIC: LocomotionAim: Explain the structure and

functions of the 3 types of muscles.

Do Now: Compare/Contrast Organizer for Nervous and Endocrine Systems

HW: CL Nervous and Endocrine Systems

1. Identify the process taking place in the diagram. Support your answer.

2. Identify the life process this is involved in.

3. Identify the system and gland that secretes insulin.

Identify the graph that represents homeostasis. Support your answer.

Identify the purple structures in the diagram. Explain

their function.

Did you know…………….•You have over 30 facial muscles

which create looks like surprise, happiness, sadness, and frowning.

•Eye muscles are the busiest muscles in the body. Scientists estimate they may move more than 100,000 times a day!

•The largest muscle in the body is the gluteus maximus muscle in the buttocks.

1. Identify the three types of muscles.

•Skeletal •Cardiac•Smooth

a. Skeletal Muscle

•Voluntary

•Attached to bones

•Striated

•Work in pairs.–One contracts while the other relaxes

When fibers of skeletal muscle involuntarily contract a spasm occurs. If only a few fibers contract and the spasms are short lived, just a twinge or twitch, you’ve lucked out. However, when the spasm is strong and prolonged you’re experiencing a muscle cramp. A cramp is defined as an involuntary, forcibly contracted muscle that does not relax. The pain can be abrupt and intense in the involved muscle with visible hardening or a knot when palpated.

The most common sites of muscle cramps seem to be the calf, thigh and arch of the foot. There are different theories on the cause of muscle cramps, but the exact reason why a cramp develops is uncertain. It is generally agreed that an over firing of the nerves that stimulate the muscles are the primary cause of “true” cramps.

Factors that may lead to muscle cramping include muscle fatigue, lack of flexibility, exercising in the heat and imbalances of the electrolytes in the blood. A diet lacking in minerals such as potassium, calcium and magnesium also may contribute to spasms and cramps. Vigorous exercise and repetitive movements can result in cramping during the activity or even much later. An injury or sudden blunt trauma to the muscle, such as getting hit with a baseball, can cause a persistent muscle spasm. Holding a position for a prolonged time can cause muscle fatigue and cramping. Muscle cramps may occur at rest or during the night when the muscle is shortened by sleeping in an awkward position. Simply lying with the toe pointed downward can cause shortening of and a cramp in the calf muscle

•Involuntaryb. Smooth Muscle

•Line your internal organs (stomach, small and large intestines, trachea, blood vessels…)

•Non-striated (no stripes)

c. Cardiac Muscle

•Involuntary•ONLY in the HEART

•Striated•Branched fibers

3. What supplies energy for muscle contraction?

•Glucose is used to make ATP

Glucose +

Energy

Oxygen

Carbon Dioxide

Water ++

4. Identify what controls muscle contraction.

•Nervous systemAs the axon of a motor neuron approaches a muscle that it innervates, it divides into multiple branches, each of which makes a synapse called a neuromuscular junction with an individual muscle fiber. It thus follows that any one muscle fiber is innervated by only one motor neuron.

Let’s summarize…

1. Identify the 3 types of muscles.

2. Describe where each type of muscle is located.

3. Describe whether each type of muscle is involuntary or involuntary.

4. Describe whether each type of muscle is striated or non-striated.

Review: Identify the muscle being described.

1. Involuntary

2. Striated

3. Found in the heart

4. Lines internal organs

5. Voluntary

6. Branched fibers

7. Attached to bones

MUSCLES TYPES

A

B

C

D

E

F