Level 2 - Skeletal System

The human skeleton is made up of 206 bones. These bones provide structure, support, and protection for the body. They also allow for movement and serve as attachment points for muscles. Each bone has a specific shape and function, and together they form the framework of the body.

The correct answer is humerus because it is the long bone located in the upper arm. The radius and ulna are bones in the forearm, while the occipital bone is located in the back of the skull.

Inversion refers to the movement of turning the soles of the feet inwards. This movement occurs at the subtalar joint, which is located below the ankle joint. When the soles of the feet are turned inwards, the medial (inner) edge of the foot is elevated, while the lateral (outer) edge is lowered. This movement is important for maintaining balance and stability during activities such as walking, running, and jumping.

The mandible is the only moveable bone in the skull. It is commonly known as the lower jawbone and is connected to the rest of the skull through a joint called the temporomandibular joint. This bone allows for important functions such as chewing, speaking, and facial expressions. The maxillae, nasal, and zygomatic bones are all part of the skull but are not moveable.

The scapula is the correct answer because it is the bone that forms the posterior part of the shoulder girdle. The clavicle is the bone that forms the anterior part of the shoulder girdle, the sternum is the breastbone located in the center of the chest, and the mandible is the lower jawbone. Therefore, the scapula is the only bone listed that is part of the shoulder girdle.

The ilium is the largest and most superior bone of the pelvis. It forms the upper part of the hip bone and helps to support the weight of the upper body when standing or sitting. The ilium also serves as an attachment point for several muscles, including those of the abdominal and gluteal regions.

The skeleton does not store vitamins. It primarily serves as a framework for the body, providing support for the weight of the body and protecting vital organs. The production of blood cells in red bone marrow is also a function of the skeleton. However, the storage of vitamins is primarily done by other organs such as the liver and adipose tissue.

The zygomatic bones are commonly known as the cheekbones. They are a pair of bones that form the prominence of the cheeks and contribute to the overall structure and shape of the face. These bones connect with the temporal bone of the skull, the maxilla bone of the upper jaw, and the frontal bone of the forehead. The zygomatic bones play a crucial role in facial expression and provide support for the soft tissues of the face.

Ligaments are tough, fibrous connective tissues that connect bones to other bones at a joint. They provide stability and support to the joint, preventing excessive movement and maintaining proper alignment. Ligaments do not join muscles to bones, as that is the role of tendons. Additionally, ligaments are not made up of articular cartilage, which is a smooth, slippery tissue that covers the ends of bones in a joint.

The palm of the hand is made up of the metacarpal bones. The metacarpals are the five long bones that connect the wrist bones (carpals) to the fingers. They are located in the middle of the hand and form the structure and support for the palm.

The vertebral column, also known as the spine, is made up of 24 movable bones called vertebrae. These vertebrae are stacked on top of each other and are separated by intervertebral discs. The vertebral column provides support and protection for the spinal cord, allows for movement and flexibility, and helps maintain the body's posture.

A bunion is a swelling of the joint between the big toe and the first metatarsal. It is a common condition that occurs when the big toe pushes against the adjacent toe, causing the joint to become misaligned and swollen. This can result in pain, discomfort, and difficulty walking.

The first cervical vertebra is called the Atlas. It is named after the Titan from Greek mythology who held up the world, as the Atlas vertebra holds up the skull. The Atlas is unique as it does not have a body like the other vertebrae, but instead consists of a ring-like structure that allows for the rotation of the head.

The bone of the skull that forms the upper sides and the back of the roof of the skull is the parietal bone. This bone is located on the top and sides of the skull, forming part of the cranial vault. It helps protect the brain and provides structural support to the skull. The parietal bone also articulates with other bones of the skull, such as the frontal, temporal, and occipital bones.

The occipital sinus is a venous channel located in the back of the head, near the occipital bone. It drains blood from the occipital region of the scalp. Therefore, the occipital sinus is indeed a sinus. The other options, frontal, ethmoidal, and maxillary sinuses, are all types of paranasal sinuses located in the skull.