Introduction to the Spinal Cord and Spinal Nerves Flashcards
What two important functions do the spinal cord and its attached spinal nerves have?
1) Is a pathway for sensory and motor impulses.
2) Is responsible for reflexes.
What embryological tissue does the spinal cord develop from?
The spinal cord develops from ectoderm (neuroectoderm/neuroepithelium).
True or False:
The neural groove forms in the neural plate.
True
Is the notochord on the ventral or dorsal side of the neural plate?
On the ventral side of the neural plate. During the development, the neural tube develops between the notochord and the epidermis.
What does the alar plate develop into?
The alar plate (dorsal plate) develops into the dorsal horn (sensory).
What does the basal plate develop into?
The basal plate (ventral plate) develops into the ventral horn (motor).
What type of nerves originate from the lateral gray column (lateral horns)?
Autonomic (sympathetic and parasympathetic)
What makes up the gray matter?
Cell bodies
Is an afferent signal from a sensory or motor neuron?
An afferent signal is from the sensory nerve coming back to wards the spinal cord to synapse with the interneurons of the gray matter.
Is an efferent signal from a sensory or motor neuron?
An efferent signal is from the motor nerve travelling to whichever muscle. This efferent signal was initiated from an afferent signal that was linked to a motor neuron (efferent signal) via an interneuron in the gray matter.
What do interneurons do?
They link the communication between the sensory and motor neurons. Thus, they are located in the gray matter in-between the dorsal and ventral horns.
What makes up the white matter?
axons form white matter
What are the two enlargements of the spinal cord?
1) Cervical
2) Lumbar
How many pairs of spinal nerves are there?
31 pairs of spinal nerves
Are the cervical and lumbar enlargements visible in a 3 month old fetus?
YES
Which two important plexus originate from the cervical enlargement?
Cervical Plexus and Brachial Plexus
From which region of the spine does the intercostal nerves originate?
Thoracic Region
Which two important plexus originate from the lumbosacral enlargement?
Lumbar Plexus and Sacral Plexus
Which of the 4 regions of the spinal cord have a parasympathetic outflow?
Sacral Region –> which is the sacral parasympathetic outflow.
Which 2 of the 4 regions of the spinal cord has a sympathetic outflow?
The thoracic region (thoracic sympathetic outflow) and the lumbar region (lumbar sympathetic outflow).
Name the 3 meningeal coverings going from superficial to deep.
Dura mater –> Arachnoid mater –> Pia mater
In which space between the meningeal coverings is cerebral spinal fluid found?
Subarachnoid space