Question | Answer |
What 2 functions are separated in the nervous system? | Sensory and Motor |
Give 2 names for fibers carrying information to the CNS/neurons | Sensory, afferent |
Give 2 names for fibers carrying information from the CNS/neurons | Motor, efferent |
Rostral/anterior= | Towards the tip of the head |
Caudal/posterior= | Towards tip of tail/human feet |
Dorsal= | "Upper surface of body" (back) |
Ventral= | "Bottom surface of body" (stomach) |
Medial vs. Lateral= | Close to midline vs farther from midline |
How many pairs of spinal nerves branch off from spinal cord? | 31 pairs |
Each single spinal nerve has 2 roots, name them and their respective locations and functions | Dorsal roots= sensory, afferent. Ventral roots= motor, efferent. |
What is the DRG and where is it located? | Dorsal Root Ganglia= cell bodies for all sensory neurons entering spinal cord. Located on Dorsal root outside of CNS in Peripheral Nerv. System |
Each spinal nerve receives info from/sends info to specific striped regions in body called what? | Dermatomes |
What are cauda equina? | Long nerves that dangle down from spinal cord and branch off to the legs |
A cold sore on your lip is a sign that what is infected? | The nerve connected to your lip |
Translucent CNS tissue is called ___, whereas opaque CNS tissue is called ___ | Gray matter, white matter |
White matter in the CNS is also called what? (3 names) | Tract, fasciculus, or pathway |
White matter consists of afferent and efferent fibers running which direction and in what form in spinal cord? | Up and down, in myelinated axons |
Gray matter is the collection of what in the spinal cord? In what form? | Cell bodies, unmyelinated structures |
Where is the gray matter located and what does it look like? | Central region of spinal cord (Central Gray Region), 4 lobes |
What is gray matter home to? | Spinal (sensory)dorsal and (motor) ventral function |
Where is the first cell in sensory pathway's soma located and what is it called? | In the DRG (PNS), first-order neuron (1*) |
Where is second-order (2*) neuron located in sensory pathway? | Spinal cord (CNS) |
Where is the third-order neuron (3*) located in sensory pathway? | Brain (CNS) |
Define decussation | Nerve fibers cross midline to innervate structures on other side of body, therefore left brain controls right side of body and vice versa |
What is it called when a projection crosses? | Contralateral |
What is it called when a projection stays on the same side? | Ipsilateral |
Sensory function uses two types of fibers, name them. | Mechanoreceptors and Nociceptors |
Mechanoreceptors carry what type of sensory information? | All except pain (pressure, touch) |
Nociceptors carry what type of sensory information? | Pain. Activated by tissue damage stimuli. |
Which fibers are larger and quicker; mechanoreceptors or nociceptors? | Mechanoreceptors |
After mechanoreceptors enter the spinal cord, where does it go? (Be specific) | Ascends ipsilaterally in dorsal column of cord without synapsing |
(Mechanoreceptors) Where does the 1* cell connect with 2* cell? | In the brainstem |
(Mechanoreceptors) What does the 2* cell do/where does it go? | Decussates and projects onto 3* neuron in Thalamus |
What is considered the 'Grand Central Station' for all sensory information? | Thalamus |
What is the likely transmitter in 1* nociceptors? | Substance P (pain neurotransmitter) |
Where are the nociceptors' 1* cells located? | DRG |
(Nociceptors) Where does 1* cell synpast onto 2* cell? | Dorsal horn of spinal cord |
(Nociceptors) What does the 2* cell do/where does it go? | Deccusate and project to brainstem onto 3* cell in thalamus and reticular formation |
An epidural is an injection of a substance into spinal cord which blocks what? | Sodium channels so calcium is not released |
Where is the origin for motor commands? (2 names) ____ motor neurons are housed here. | Cerebral cortex/Motor cortex, upper |
Where are lower motor neurons located? | Ventral horn of Spinal Cord |
Describe pathway of motor neurons | Upper MNs project axons to contact lower MN, lower MNs project axons which exit CNS and innervate skeletal muscles |
Cell bodies of lower MNs are found where in ventral horn? | Gray matter |
How/where do axons leave SN? | Ventral roots |
Synapse of LMNs to muscles exclusively uses what NT? | Acetylcholine |