Identify the anatomical structure indicated by the blue arrow in the specimen image below:
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Options:
explanation: The image shows an axial view of a section of the spinal cord, where the anterior surface is located at the inferior aspect of the image and the posterior surface is located at the superior aspect of the image. It is a stained prosection in which the grey matter appears white and the white matter appears grey-brown. The anterior median fissure is a deep groove located in the midline of the white matter of the ventral spinal cord, in front of the central canal. However, the blue arrow points to the ventral horn which is a collection of motor neurons which emerge from the spinal cord to innervate skeletal muscles.
name: Anterior median fissure
label: c
answer: no
explanation: The image shows an axial view of a section of the spinal cord, where the anterior surface is located at the inferior aspect of the image and the posterior surface is located in the superior aspect of the image. It is a stained prosection in which the grey matter appears white and the white matter appears grey-brown. The dorsal horn is a collection of secondary neurons which receive somatosensory input from the primary afferent neurons of the body and transmit it to the brain via ascending pathways. This is longer and thinner compared to the structure indicated by the blue arrow which is the ventral horn, a collection of motor neurons which emerge from the spinal cord to innervate skeletal muscles.
name: Dorsal horn
label: b
answer: no
explanation: The image shows an axial view of a section of the spinal cord, where the anterior surface is located at the inferior aspect of the image and the posterior surface is located at the superior aspect of the image. It is a stained prosection in which the grey matter appears white and the white matter appears grey-brown. The anterior grey commissure is a component of the internal spinal cord which connects the right and left ventral horns of grey matter. However, the blue arrow points to the ventral horn which is a collection of motor neurons which emerge from the spinal cord to innervate skeletal muscles.
name: Anterior grey commissure
label: e
answer: no
explanation: The image shows an axial view of a section of the spinal cord, where the anterior surface is located at the inferior aspect of the image and the posterior surface is located at the superior aspect of the image. It is a stained prosection in which the grey matter appears white and the white matter appears grey-brown. The posterior median sulcus is a superficial groove located in the midline of the white matter of the dorsal spinal cord, posterior to the central canal and medial to the right and left dorsal columns. However, the blue arrow points to the ventral horn which is a collection of motor neurons which emerge from the spinal cord to innervate skeletal muscles.
name: Posterior median sulcus
label: d
answer: no
explanation: The image shows an axial view of a section of the spinal cord, where the anterior surface is located at the inferior aspect of the image and the posterior surface is located at the superior aspect of the image. It is a stained prosection in which the grey matter appears white and the white matter appears grey-brown. The blue arrow points to the ventral horn which is a collection of motor neurons which emerge from the spinal cord to innervate skeletal muscles. The ventral horn can be differentiated from the dorsal or lateral horns by its shape, being shorter and thicker.
name: Ventral horn
label: a
answer: yes

Correct answer: a