Muscle Cells

Lesson Plan - Get It!

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• Do you feel the burn after exercising?

That sensation is occurring in your muscle cells!

You have muscles spread throughout your body, working to help you move, breathe, and grow. Your body has three types of muscle tissue: skeletal, cardiac, and smooth. Each type has a specific function to carry out in the body.

Skeletal muscles are found attached to the skeletal system and assist the body with movement.

These specialized cells are long and thin with multiple nuclei. These many nuclei help the cell carry out the process of contraction and release based on directions from the brain.

Skeletal muscle cells have stripes on the outer membrane to assist with muscle contraction. These cells look like thin fibers bundled together.

Smooth muscle cells are much shorter than skeletal muscles and only contain one nucleus.

These cells perform involuntary functions, such as moving nutrients through the digestive system using contraction and relaxation.

Cardiac muscle cells are found in the heart.

These cells have a single nucleus and membrane strips to help contract during heartbeats. They are long and branched together, creating a network of muscle cells.

All these types of muscles help your body function daily.

Muscle cells rely on an organelle called the mitochondria. Mitochondria is considered the energy provider in animal cells because it converts food and sugar into cellular energy.

Adenosine triphosphate molecules are used to power cell processes, like cell transport. Muscle cells have many more mitochondria than other body cells because they constantly convert sugar into energy for movement and muscle contractions.

• Have you ever felt tired or weak after having eaten less food?

This sensation occurs because your body does not provide enough energy to your muscles and cells to function.

• Have your muscles felt sore the day after heavy exercise?

This chemical reaction occurs in your muscle cells when there is a buildup of lactic acid. This molecule is produced by changing food into energy during cell respiration.

Muscle cells require oxygen to carry out respiration, and lactic acid builds up when the body can't supply muscle cells with enough oxygen. It can cause painful cramps and aches the following day!

Your muscle cells are different from other cells in your body because they constantly utilize mitochondria to convert food into quick energy. The three types may differ in several nuclei and cell structures, but they are all part of the muscular system that allows you to play and run!

• How might a reduction in mitochondria impact the function of muscle cells?
• Which type of muscle cell do you think has the most mitochondria?

Continue to the Got It? section to exercise your intellectual muscles with in-depth research!