L6 SAQ - Spinal Cord

What are intersegmental spinal reflexes?

Intersegmental spinal reflexes are nerve fiber bundles with a common function that allow for the transmission of sensory and motor signals between different segments of the spinal cord.

How is blood supplied to the spinal cord?

Blood is supplied to the spinal cord via three arteries: one anterior (median) spinal artery and two smaller posterior spinal arteries.

Where is the anterior spinal artery located?

The anterior spinal artery is located along the anterior midline of the spinal cord.

What percentage of the arterial blood supply to the spinal cord does the anterior spinal artery provide?

The anterior spinal artery supplies approximately 75% of the arterial blood supply to the spinal cord. Signup and view all the answers

Where are the posterior spinal arteries located?

The posterior spinal arteries lie on each side of the spinal cord posteriorly. Signup and view all the answers

What percentage of the arterial blood supply to the posterior region of the spinal cord do the posterior spinal arteries provide?

The posterior spinal arteries supply approximately 25% of the arterial blood supply to the posterior region of the spinal cord. Signup and view all the answers

From where do the posterior spinal arteries arise?

The posterior spinal arteries arise directly from the vertebral spinal arteries or indirectly from the posterior inferior cerebellar arteries. Signup and view all the answers

How is the anterior spinal artery formed?

The anterior spinal artery is formed by the union of two branches of the vertebral arteries. Signup and view all the answers

Where do the veins of the spinal cord drain into?

The veins of the spinal cord drain into six longitudinal channels: the anterior spinal vein, the posterior spinal vein, the anterolateral veins, the posterolateral veins, and the radicular veins. Signup and view all the answers

Where do the radicular veins drain into?

The radicular veins drain into the internal vertebral venous plexus, which is divided into anterior and posterior radicular veins. Signup and view all the answers

What are the three meningeal layers that protect the spinal cord?

The three meningeal layers that protect the spinal cord are the dura mater, arachnoid layer, and pia mater. Signup and view all the answers

Where does the spinal cord terminate in an adult?

The spinal cord terminates at between L1-L2 in an adult. Signup and view all the answers

What is the purpose of the denticulate ligament?

The denticulate ligament is a continuation of the pia mater and helps to anchor the spinal cord. Signup and view all the answers

What are the two enlargements of the spinal cord and what do they correspond to?

The two enlargements of the spinal cord are the cervical enlargement, which corresponds to the origin of the brachial plexus (C3-T2), and the lumbar enlargement, which corresponds to the origin of the lumbosacral plexus (L1-S3). Signup and view all the answers

What is the purpose of the filum terminale?

The filum terminale is a prolongation of the pia mater that descends from the conus medullaris to attach to the coccyx, providing an anchor for the spinal cord. Signup and view all the answers

How many pairs of spinal nerves are there?

There are 31 pairs of spinal nerves. Signup and view all the answers

What are the two types of roots that attach to the spinal cord?

The two types of roots that attach to the spinal cord are the ventral (anterior) roots, which are motor in function, and the dorsal (posterior) roots, which are sensory in function. Signup and view all the answers

What is a dermatome?

A dermatome is an area of skin supplied by the right and left dorsal roots of a single spinal segment. Signup and view all the answers

What are the four types of nerve fibers in the PNS?

The four types of nerve fibers in the PNS are somatic efferent, somatic afferent, visceral efferent, and visceral afferent. Signup and view all the answers

What are the two main regions/columns of white matter in the spinal cord?

The two main regions/columns of white matter in the spinal cord are the anterior (ventral) funiculus and the lateral funiculus. Signup and view all the answers