Question

This bone is the only movable bone of the skull. a. sphenoid b. frontal c. mandible d. maxilla e. temporal

Short answer

The correct answer is (c) Mandible, as it is the only movable bone of the human skull responsible for the motion of the lower jaw and essential functions like speech and food consumption.

Step-by-step solution

Evaluate the given options

First, let's examine each of the given options: a. Sphenoid - is a complex bone located in the base of the skull, helping to join the cranial and facial bones. b. Frontal - is located in the forehead region, making up a part of the skull's vault. c. Mandible - is the jawbone that forms the lower jaw and provides movement for actions such as chewing and talking. d. Maxilla - is the upper jawbone, forming the roof of the mouth and floor of the nasal cavity. e. Temporal - is located on the side of the skull, near the ears, and helps enclose and protect the middle and inner ear.

Identify the movable bone

Out of all the options mentioned above, the mandible is the only bone that is movable. It is responsible for the motion of the lower jaw, allowing for essential functions like speech and food consumption.

Choose the correct answer

Based on the information in the previous steps, the correct answer to the question is: c. Mandible - the only movable bone of the human skull.

Key concepts

Mandible

The mandible is an essential bone in the human skull, known primarily for being the lower jawbone. It is distinctively recognized for its ability to move, making it the only movable bone in the skull. The mandible connects to the temporal bones at the temporomandibular joints. These joints allow for the opening and closing movements crucial for daily functions.

Functions of the mandible include:

• Chewing and grinding food, aiding digestion
• Forming the lower part of the facial skeleton
• Facilitating speech and expression

It is essential for proper alignment and functioning of the teeth. Any misalignment or issue with the mandible can affect oral health and speech.

Movable Bone

The concept of movable bones in the human body refers to bones that are capable of motion at their joints. The human skull is mostly composed of fixed bones, immovably fused to each other. However, the mandible stands out as an exception being the only movable bone in the skull, allowing articulation at the temporomandibular joint.

This mobility is crucial because:

• It allows us to speak, eat, and make facial expressions
• Provides efficiency in consuming various types of food
• Supports breathing indirectly by adjusting the mouth opening

The joint involved, known as the TMJ, combines a hinge action with sliding motions, making it one of the most complex joints in the body.

Facial Bones

Facial bones form the structure of the face and serve multiple functions. In total, there are 14 bones categorized under facial bones, and they include the mandible, maxilla, and nasal bones.

These bones:

• Provide shape and form to the face
• Protect delicate organs such as the eyes and mouth
• Support the entrance to the digestive and respiratory systems

The mandible, although a part of the facial bones, offers additional functionality due to its movability, unlike the maxilla which remains fixed.

Skeletal System

The skeletal system is fundamental to human anatomy. It consists of bones, joints, and connective tissues that support and protect the body's organs.

Key roles of the skeletal system include:

• Providing structural support and shape to the body
• Facilitating movement along with muscles
• Protecting vital organs such as the brain and heart
• Storing minerals like calcium and producing blood cells

Within this system, the skull not only protects the brain but also houses sensory organs. The combination of movable and fixed bones, like the mandible and others, highlights the complexity and adaptability of the skeletal system in performing various essential functions.