Which term describes the fibrous connective tissues that cover the brain and spinal cord?

Choice A rationale

Rigidity is characterized by a continuous resistance to passive movement in any direction and does not specifically occur during abrupt dorsiflexion of the foot.

Choice B rationale

Flaccidity refers to decreased muscle tone or limpness, which is the opposite of hyperactivity or spasticity, and would not be observed with abrupt dorsiflexion.

Choice C rationale

Ataxia involves uncoordinated or erratic movements and is related to cerebellar dysfunction. This is not specifically triggered by abrupt dorsiflexion of the foot.

Choice D rationale

Clonus is the correct term for rhythmic, involuntary contractions of a muscle that occur when it is suddenly stretched, such as with abrupt dorsiflexion of the foot. It is a sign of hyperactive reflexes and upper motor neuron lesions.

Choice A rationale

Irregular bones have complex shapes that do not fit into the other categories (long, short, or flat bones). They include bones such as the vertebrae and facial bones, which have specialized functions but are not primarily responsible for protecting vital organs.

Choice B rationale

Flat bones, such as the sternum, ribs, and skull bones, are designed to protect vital organs. They provide broad surfaces for muscle attachment and serve as protective barriers for organs like the brain, heart, and lungs.

Choice C rationale

Long bones, such as the femur and humerus, are primarily responsible for supporting the weight of the body and facilitating movement. While they contribute to the overall structure of the body, they are not specifically designed for organ protection.

Choice D rationale

Short bones, such as the carpals and tarsals, provide support and stability with limited movement. They are not primarily involved in the protection of vital organs.