Duchenne Muscular Dystrophy: Muscle Cell Structure and Systemic Effects

AXON

Sends signal to contract to the muscle cell

EXTRACELLULAR MATRIX (ECM)

helps cells attach to, and communicate with, nearby cells, and plays an important role in cell growth, cell movement, and other cell functions

DYSTROPHIN

Connects the myofibrils to the cell membrane

MYOFIBRILS

Fibers that contract within a muscle cell

DMD Duchenne Muscular Dystrophy

) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact.

Structural Changes in DMD:

Missing or fewer Dystrophin proteins.

Normal myocytes have proteins that connect the myofibrils to the cell membrane. These proteins are lacking in a patient with DMD.

Functional Changes in DMD:

Muscle cells cannot contract properly.

Myofibrils are not fully connected to the outer layer of the cell (the cell membrane), when the myofibrils contract, the force is less because they are contracting within the cell and not causing the cell as a whole to contract.

There is a decrease in muscle strength and activity in a person with DMD.

The lack of dystrophin due to DMD causes the force of muscle contractions to decrease.

RESPIRATORY SYSTEM how does it change with DMD

Smooth muscles contract in the respiratory system which affects breathing. Due to the weakening of the muscles, DMD patients may have a harder time breathing due to a weakening diaphragm. Shallow breathing could cause the muscular and circulatory systems to not get enough oxygen.

CIRCULATORY SYSTEM: how does it change with DMD

Weaker muscles would make it more difficult for the heart (circulatory system) to pump blood. Lack of blood flow could cause the muscular and circulatory systems to not get enough oxygen.

DIGESTIVE SYSTEM how does it change with DMD

Smooth muscle is responsible for movements of the digestive tract. A decrease in muscle contraction in the digestive system can result in problems digesting food which in term can prevent the muscular system from getting necessary nutrients.

How does DMD happen

results from alterations to a protein called dystrophin that helps keep muscle cells intact.