1.
A foramen is:
Correct Answer
C. A hole for blood vessels and nerves
Explanation
A foramen is a hole for blood vessels and nerves. It is a passageway through a bone that allows blood vessels and nerves to pass through and supply the surrounding tissues. This is an essential feature of the skeletal system as it ensures proper circulation and innervation to different parts of the body.
2.
Normal skulls have two of each of the following except
Correct Answer
D. Sphenoid bones
Explanation
Normal skulls have two of each of the following bones: parietal bones, nasal bones, temporal bones, and maxillae. However, there is only one sphenoid bone in a normal skull. The sphenoid bone is a single bone located at the base of the skull, behind the eye sockets. It is an important bone that helps form the floor of the cranium and provides support to the brain.
3.
Tears pass into the nasal cavity through a tunnel formed in part by the:
Correct Answer
B. Lacrimal bone
Explanation
The lacrimal bone is one of the bones that form the tunnel through which tears pass into the nasal cavity. Therefore, it is correct to say that tears pass through a tunnel formed in part by the lacrimal bone.
4.
Which of the following bones is correctly matched with its process?
Correct Answer
A. Zygomatic bone-temporal process
Explanation
The zygomatic bone is correctly matched with its process, which is the temporal process. The zygomatic bone is also known as the cheekbone and it forms part of the orbital rim and the lateral wall of the eye socket. The temporal process of the zygomatic bone extends backward and articulates with the temporal bone, forming the zygomatic arch.
5.
All of the following articulate with the maxilla except the:
Correct Answer
D. Mandible
Explanation
The mandible is the only bone listed that does not articulate with the maxilla. The mandible is the lower jawbone, while the maxilla is the upper jawbone. The other bones listed - nasal bone, frontal bone, palatine bone, and zygomatic bone - all articulate with the maxilla and are part of the facial structure.
6.
Which of the following is not a component of the orbit?
Correct Answer
A. Temporal
Explanation
The temporal bone is not a component of the orbit. The orbit is made up of several bones, including the ethmoid bone, zygomatic bone, and maxilla bone. The temporal bone is located on the side of the skull and houses the middle and inner ear structures, but it does not contribute to the formation of the orbit.
7.
The nasal septum is formed by parts of the
Correct Answer
E. Both a and c are correct
Explanation
The nasal septum is a structure that divides the nasal cavity into two halves. It is formed by parts of the ethmoid bone and the vomer bone. The ethmoid bone is located at the midline of the skull and contributes to the formation of the nasal septum. The vomer bone is a thin, flat bone that forms the lower part of the nasal septum. Therefore, both options a and c are correct as they both contribute to the formation of the nasal septum.
8.
Which of the following does not contain a paranasal sinus?
Correct Answer
A. Zygomatic
Explanation
The zygomatic bone does not contain a paranasal sinus. The paranasal sinuses are air-filled spaces located within the bones of the skull, and they include the sphenoid, ethmoid, frontal, and maxillary sinuses. The zygomatic bone, also known as the cheekbone, does not have a paranasal sinus.
9.
The skeleton of the thorax:
Correct Answer
E. Is described by all of the above
Explanation
The skeleton of the thorax is formed by 12 pairs of ribs and costal cartilages, the sternum, and 12 thoracic vertebrae. It protects the internal chest organs, including the liver. It is narrower at its superior end and aids in supporting the bones of the shoulder girdle. Therefore, all of the statements mentioned describe the skeleton of the thorax.
10.
The meninges (coverings) of the brain attach to the crista galli, which is part of the:
Correct Answer
E. Ethmoid bone
Explanation
The meninges (coverings) of the brain attach to the crista galli, which is a bony ridge located in the ethmoid bone. The ethmoid bone is a small, delicate bone located between the eyes and forms part of the nasal cavity and the orbit of the eye. It has several important structures, including the crista galli, which serves as an attachment point for the meninges.
11.
The first cervical vertebra is the _____, and the second cervical vertebra is the ____
Correct Answer
atlas, axis
Explanation
The first cervical vertebra is known as the atlas, while the second cervical vertebra is called the axis. The atlas is responsible for supporting the skull and allowing for nodding movements, while the axis allows for rotation of the head. These two vertebrae are crucial for the stability and mobility of the neck and head.
12.
According to shape classification, phalanges are ____ bones, carpals are _____ bones, and ribs are ______ bones.
Correct Answer
long, short, flat
Explanation
According to shape classification, phalanges are long bones because they are longer than they are wide. Carpals are short bones because they are roughly equal in length and width. Ribs are flat bones because they are thin, flat, and curved, providing protection to the vital organs in the chest.
13.
Bones located in sutures are called sutural or _______ bones
Correct Answer
Worminian
Explanation
The correct answer is "Worminian". Sutural bones are small bones that are found within the sutures, which are the joints between the bones of the skull. These bones are also known as Worminian bones.
14.
The only nonarticulating bone of the axial skeleton is the _____
Correct Answer
hyoid
Explanation
The hyoid bone is the only nonarticulating bone of the axial skeleton. It is located in the neck, just above the larynx. Unlike other bones in the body, the hyoid bone does not directly connect to any other bones. Instead, it is suspended by muscles and ligaments, serving as an attachment point for various muscles involved in swallowing and speaking. Its unique structure and position make it an important bone in the functioning of the throat and voice box.
15.
The opening in the occipital bone through which the medulla oblongata connects with the spinal cord is the foramen magnum.
Correct Answer
T
Explanation
The statement is true. The foramen magnum is indeed the opening in the occipital bone through which the medulla oblongata connects with the spinal cord. It is a large opening that allows the passage of the spinal cord, blood vessels, and other structures. The medulla oblongata is an important part of the brainstem that controls vital functions such as breathing, heart rate, and blood pressure.
16.
The sagittal suture joins the parietal bones.
Correct Answer
T
Explanation
The sagittal suture is a dense fibrous joint that connects the two parietal bones of the skull. It runs along the midline of the skull, from the anterior fontanelle (soft spot) to the posterior fontanelle. This suture allows for slight movement between the parietal bones during childbirth and skull growth in infants. In adults, the sagittal suture becomes completely fused, providing stability and protection to the brain. Therefore, the statement that the sagittal suture joins the parietal bones is correct.
17.
Sesamoid bones protect tendons from wear and tear and may improve the mechanical advantage at a joint by altering the direction of pull of a tendon.
Correct Answer
T
Explanation
Sesamoid bones are small bones that are embedded within tendons. They act as protective shields, reducing friction and preventing excessive wear and tear on the tendons. Additionally, sesamoid bones can alter the direction of pull of a tendon, which can improve the mechanical advantage at a joint. This means that the tendon can exert more force and have a greater effect on joint movement. Therefore, the statement that sesamoid bones protect tendons from wear and tear and improve the mechanical advantage at a joint is true.
18.
The sacral promontory projects anteriorly from the apex of the sacrum
Correct Answer
base of the sacrum
Explanation
The sacral promontory is a prominent bony ridge that projects anteriorly from the apex of the sacrum. It is located at the uppermost part of the sacrum, forming the anterior boundary of the pelvic cavity. The base of the sacrum, on the other hand, refers to the broad, upper surface of the sacrum that articulates with the last lumbar vertebra. Therefore, the correct answer is "base of the sacrum" because the sacral promontory does not project from the base but rather from the apex of the sacrum.
19.
The tubercle of a rib articulates with demifacets on the bodies of adjacent vertebrae
Correct Answer
head of a rib
Explanation
The head of a rib articulates with demifacets on the bodies of adjacent vertebrae. The head of a rib is the rounded end that connects to the vertebral column. It has two facets, one that articulates with the superior demifacet on the body of the vertebra above, and another that articulates with the inferior demifacet on the body of the vertebra below. This allows for a stable and flexible connection between the ribs and the vertebrae, facilitating movements such as breathing.