Shape Of The Skeleton System

The axial skeleton is formed by the skull, vertebral column, sternum, and ribs. The humerus, on the other hand, is a bone in the appendicular skeleton, which consists of the bones of the limbs. Therefore, the humerus is not part of the axial skeleton.

The norma frontalis is a view of the skull from the front. In this view, the frontal bone is visible, as well as the two nasal bones. The mandibular body and its ramus are also seen. The orbital and nasal cavities occupy most of the middle third of the norma frontalis. However, the good part of the temporal bone is not visible in this aspect.

The pterion is a point on the side of the skull where four bones meet: the parietal bone, the sphenoid bone, the frontal bone, and the temporal bone. The zygomatic bone, also known as the cheekbone, does not meet at the pterion. Therefore, the correct answer is the zygomatic bone.

The central part of the middle cranial fossa is formed by the body of the sphenoid bone. The middle cranial fossa is one of the three major divisions of the cranial cavity and houses important structures such as the temporal lobes of the brain, the pituitary gland, and the cavernous sinuses. The body of the sphenoid bone is a butterfly-shaped bone located at the base of the skull, and its central part contributes to the formation of the middle cranial fossa. The greater and lesser wings of the sphenoid bone also play a role in forming the middle cranial fossa, but the central part is primarily formed by the body of the sphenoid.

The anterolateral fontanelle and the posterolateral fontanelle are both formed by the temporal and parietal bones.

The neurocranium is formed by several singular bones, including the frontal, ethmoid, sphenoid, and occipital bones. However, the lacrimal bone is not part of the neurocranium. The lacrimal bone is a small, fragile bone located in the medial wall of the orbit, and it contributes to the formation of the nasal cavity rather than the neurocranium.

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Norma lateralis refers to the lateral view or side view of an object. In this case, it is referring to the lateral view of bones. The statement "Norma lateralis presents 7 bones" means that when viewing the bones from the side, there are a total of 7 bones visible. Therefore, the correct answer is TRUE.

The sacral region of the spine consists of five vertebrae, which are fused together to form the sacrum. These vertebrae are located below the lumbar region and above the coccyx. The sacrum plays a crucial role in providing stability and support to the pelvis and connecting the spine to the hip bones. Therefore, the correct answer is 5.

The term "Anatomical Position" refers to a standardized position in which the body is erect, the face is directed forward, the palms are directed forwards, and the feet are together. Therefore, the statement "The feet are apart from each other" is incorrect as it contradicts the definition of anatomical position.

The mandibular nerve leaves the skull through the foramen ovale. This is a large opening located in the sphenoid bone, towards the back of the skull. The mandibular nerve is one of the three branches of the trigeminal nerve and it carries sensory information from the lower jaw, teeth, and gums. It also innervates the muscles responsible for chewing. Exiting through the foramen ovale allows the mandibular nerve to reach its target structures in the face and jaw.

Delayed closure of the fontanelle refers to the late fusion of the soft spots on a baby's skull. This condition is commonly associated with rickets, a disorder caused by a deficiency in vitamin D, calcium, or phosphate. Rickets affects the development of bones, leading to weak and soft bones. The delayed closure of the fontanelle is one of the clinical manifestations of rickets. Therefore, rickets is the most likely cause of delayed closure of the fontanelle among the given options.

The external auditory meatus does not lie below the posterior part of the temporal process of the zygomatic bone. It is actually located in the temporal bone, closer to the middle ear. Therefore, the statement is false.

The primary curve of the vertebral column is concave anteriorly. This means that the curve of the spine is inward towards the front of the body. This curve is present in the thoracic and sacral regions of the spine. It helps to distribute the weight of the upper body over the lower limbs and allows for better balance and posture.

The mandibular canal extends from the mental foramen. This statement is not true because the mandibular canal actually extends from the mandibular foramen, not the mental foramen. The mental foramen is located on the anterior surface of the mandible, below the 2nd premolar tooth, and it serves as an opening for blood vessels and nerves to pass through.

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The correct answer is that the internal carotid artery foramen lies in the posterior cranial fossa. The posterior cranial fossa is a depression at the back of the skull that contains the hindbrain, including the cerebellum and brainstem. It is formed by the occipital bone, one part of the temporal bone, and the parietal bone. The foramen magnum, which is the large opening at the base of the skull, is also located in the posterior cranial fossa. However, the internal carotid artery foramen is not found in the posterior cranial fossa; it is located in the middle cranial fossa.

The sphenoid bone can be seen in an anterior, inferior, and lateral view of the skull. It is a complex bone located at the base of the skull, forming part of the cranial floor and the sides of the skull. It is visible in these views due to its position and shape, which allows it to be seen from multiple angles. The other options, such as the frontal, occipital, nasal, and vomer bones, may be visible in other views but not in all three specified views.

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The frontal bone articulates with two other bones in the pterion.

The correct answer is 4. The hard palate is the bony structure that forms the roof of the mouth. It contains several foramina, which are small openings. The foramen incisivum is located in the midline and transmits the nasopalatine nerve and vessels. The greater palatine foramen is located towards the back and transmits the greater palatine nerve and vessels. The lesser palatine foramina are located on either side and transmit the lesser palatine nerves and vessels. Therefore, there are a total of 4 foramens in the hard palate.

The shape of the posterior fontanelle is rhomboidal.

The submandibular fossa is the correct answer because it is the surface located above the mylohyoid. The mylohyoid is a muscle that forms the floor of the mouth, and the submandibular fossa is a depression in the mandible bone where the submandibular salivary gland is located. This fossa is situated above the mylohyoid muscle, making it the surface above it.

The norma lateralis refers to the lateral view of the skull. The frontal bone, parietal bone, and the greater wing of the sphenoid are all visible in this view. The mandibular fossa and mental foramen are also visible. Therefore, the only bone that is not seen in the norma lateralis is part of the temporal bone.