8/24 Spinal Nerves Anatomy Flashcards
Describe the Ventral Root
This is the one way street that is going out of the spinal chord (motor neurons). epharant information!
Describe the Dorsal Root
This is the one way street that is coming into the spinal cord (sensory neurons).
How is the spinal cord and roots like dublin city center
Dublin city center has one way streets! spinal roots are like one way streets, so that things stay organized. The Dorsal Roots have ony sensory information (afferent infor) and the Ventral root has only motor info (efferent info)
Acronym Dave and the roots?!
Dorsal Afferent Ventral Efferant This will help you remember the dorsal vs. ventral.
Describe Rami
They are now two way streets for both the motor and sensory information to and from the spinal cord
Describe Ventral Ramus
To the body wall and limbs and coming from the body wall and limbs. These come segmentally from the cord levels, they often form a plexus (or a network of nerves)
What are the names of the plexuses formed by ventral rami?
from the head to the coccidual: Cervical Plexus - in the neck and to the body wall muscles of the neck Brachial plesxus- skin of the upper limbs intercostal nerves skin of the ribs lumbar plexus- body wall and lower limb saccreal plexus- lower limb
What region of the body are the plexuses of the ventral ramus located located
In the cervical region, Brachial region, Lumbar region, and the saccreal region
Describe Dorsal Ramus
The dorsal ramus: skin of the back and the deep back muscles (intrinsic, paraspinal, true deep back muscles): one-way street
The tree analogy and the nerves:
Tree: Roots/Trunk/Branches; Nerves: Roots (out of the spinal chord)/spinal Nerve Trunk (coming out of the spinal chord)/ Rami (branches into the muscles etc.
describe the pathway of the dorsal ramus and the vental ramus
coming out of the spinal cord, the dorsal ramus corse straight back through the deep back muscles to the skin of the back; The ventral ramus course out of the spinal cord and lateral along the ribs!
Why do spinal nerves in the rostral spinal cord course horizontally but will course obliquely and then vertically at the caudal spinal cord level
Becuase of the discrepancy between the length of the vetebral colomn and the spinal cord. The cord stops around L1 and L2 and then the conus medularus and the cauda equina extends below that.
describe Myotomes
The specific region of muscle controled by a specific spinal cord level:
C5: Shoulder Abduction (Deltoid)
C6: Elbow flexion (Biceps: Brachiorad)
C7: Elbow Extension (Triceps)
C8: Wrist Flexion (FDS)
T1: Finger Abduction (DABs)
L2- Hip Flexion (iliopsoas)
L4- Knee extension (quad fem)
L5- Dorsiflexion (tibialis anterior)
S1- Plantar Flexion (gastrocnemius)
Describe dermatomes
Specific regions of the skin that are innervated by specific sensory neurons:
C4(collar)
C5 (lateral shoulder)
C6 (Thumb)
C7 (no Heaven)
C8 (pinky)
T4 (teet-pore)
T7 (Xiphoid)
T10 (belly But Ten)
L1 (inguinal LLigament)
L4 (medial Malleolus)
L5 (top of foot)
S1 (heel)
What are the three parts of the ANS?
Sympahtetic Parasympathetic enteric
What are the functions of the ANS?
Sympahtetic “fight or flight” (heart rate goes up , resp. up, blood pressure up, pupils dialate, the digestive goes down etc.) Parasympathetic “Rest and Digest” (digest, parastalisis, reproductive, etc.) Enteric
Diagram the pathway pattern of the ANS:
Diagram the pathway pattern of the ANS: (Sympathetics)
Diagram the pathway pattern of the ANS: (Parasympathetics)
What do neural crest cells eventually become
They become all the peripheral nerve ganglia
how are neural crest cells like graduating medical students
They migrate or stay at the “U” like grad. med students, some go far, some not too far at all.
Where are the following located on a developing Embryo: Neural crest ells Dorsal Root ganglion paravertebral ganglia Preaortic ganglia
The neural crest cells are just lateral and dorsal to the nural tube; the dorsal root Gangian derive from the neural crest cells that don’t go very far. The Paravetebral ganglia migrate down to just below the notochord. The Preaortic ganglia migrate to just below the developing aortic and IVC. The Intramural ganglia migrate down near the gut tube. This develops the location for all of the ANS gangleons!
what are the adult derivatives for neural crest cell migration? and where are these located?
The ANS Gangleons
The ANS Gangleons are in the Dorsal root (for viseral sensory); In the pre-arotic and the sympathetic chain for the sympathetic motor and in the organs for the parasympathetic motor
what types of tissue do the ANS innervate
Cardiac muscle; smooth muscle of artery; Glandualar tissue;
What spinal colomn sections innervate the sympathetic nervous sytem
The T1-L2 levels
What organ do the Pre-Aortic Gangeons innervate:
GI Tract; Adrenal Glands; Blood Vessels; Renal System; Pelvic organs;
What organs do the Sympathetic chain gangleons innervate?
Head and Neck
Heart and Lungs
Blood Vessels
Sweat Glands
What is the name of the short nerve track connecting the ventral ramus and the sympathetic gangleon?
The White ramus communican is the road into the gangleon
The Gray ramus communicans is the road out of the gangleons.
Name the Pre-aortic ganglia from the superior to the inferior
Celiac Gangleon
Superior Mesenteric ganglion
Aorticorenal ganglion
Inferior Mesenteric ganglion
Superior Hypogastric Plexus
Hypogastric nerve
Inferior hypogastric plexus
What are the origins of he Parasympathetic nerves.
Brain Stem and S2-S4
Where do the parasympathetic neurons synapse?
Intermural ganglia
What levels of the parasympathetic innervate what sections of the body:
The midgut and up is the cranial nerve (CN 3,7,9 and expecially 10).
The hind gut and paraneum etc. is S2-S4
what neurotransmitters are used in the autonomic nervous system?
Acetyl Choline is used by both parasympathetic and sympathetic pre-gangleon;
Neuroepinephrin is used by the sympathetic system post gangleon.
Acetyl choline is used bye the parasympathetic post gagleon.
