2.4: Activity 2

Identification of Key Spinal Cord Structures

The objective of this lab activity is to identify and understand key anatomical structures related to the spinal cord and associated nerves, including the phrenic nerve, cervical enlargement, sympathetic trunk (chain), thoracic nerve, brachial plexus, cervical plexus, sympathetic trunk ganglion, femoral nerve, conus medullaris, sacral plexus, lumbar enlargement, lumbar plexus, and sciatic nerve. Students will use a labeled images Figure \(\PageIndex{1}\), Figure \(\PageIndex{2}\) and a 3D laboratory model to enhance their anatomical understanding. Some of the key structures are shared in the images.

Instructions

• Review the basic anatomy of the cervical and thoracic regions to familiarize yourself with the context of these structures.
• Carefully analyze the colored image provided, noting the numbered structures (1 to 7). 
• Observe the 3D model to gain a spatial understanding of each structure's location and orientation.
• Compare the model with the image to visualize how these structures appear in three dimensions.
• Describe Functional Roles of each key structure identified.

Figure \(\PageIndex{1}\) shows a posterior (back) view anatomical model of the vertebral column with the spinal cord and spinal nerves. The model includes multiple numbered labels (1 through 7) placed near structures on the left and right sides of the spine. The purpose is to be identification of spinal nerve structures as they exit the vertebral column. Model depicts:

• A central vertical structure representing the spinal cord within the vertebral canal.
• Repeating paired openings along the spine where spinal nerves emerge.
• Multiple nerve branches extending laterally from the spinal cord region into the body.
• Surrounding tissues of the back and trunk shown as layered anatomical structures.

Table \(\PageIndex{1}\): Identifying anatomical features of the spinal cord in the cervical and thoracic regions labeled 1 through 7 in Figure \(\PageIndex{1}\)

Number	Key Anatomical features of spinal cord	Describe Functional Role(s)
	Phrenic nerve
	Cervical enlargement
	Sympathetic trunk (chain)
	Thoracic nerve
	Brachial plexus
	Cervical plexus
	Sympathetic trunk ganglion

Instructions

• Carefully analyze the colored image provided, noting the numbered structures (8 to 15). 
• Observe the 3D model to gain a spatial understanding of each structure's location and orientation.
• Compare the model with the image to visualize how these structures appear in three dimensions.
• Describe Functional Roles of each key structure identified.

 Figure \(\PageIndex{2}\) shows a posterior (back) view anatomical model focused on the lower thoracic to lumbar region of the spine and the spinal nerve pathways extending laterally into the surrounding tissues. 

• A central vertical structure representing the spinal cord and/or lower spinal canal region within the vertebral column.
• Multiple paired spinal nerves emerging from the vertebral column and branching outward.
• Surrounding anatomical structures of the posterior trunk, including layered tissues adjacent to the spine.

Table \(\PageIndex{2}\): Identifying Anatomical features of spinal cord 8 through 15.

Number	Identifying Anatomical features of spinal cord	Describe functional role(s)
	Femoral nerve
	Conus medullaris
	Sacral plexus
	Lumbar enlargement
	Cauda equina
	Lumbar plexus
	Filum terminale
	Sciatic nerve