Spinal Cord, Nerves, ANS Flashcards
Conus medullaris
Terminal Portion of Spinal Cord
Cauda Equina
Location=Lumbar Cistern (subarachnoid space)
- Includes conus medullaris and filum terminale
- Dorsal and Ventral Rootlets located with the subarachnoid space are directed towards the intervertebral column
Dura Mater
Tough mother…epidural space
Arachnoid Mater
Subarachnoid space
-lumbar cistern
Pia Mater
Denticulate Ligaments (anchor cord) Filum Terminale -extends down from conus and give longitudinal support
Rootlets
within subarachnoid space directed toward intervertebral foramen
Dorsal Root
Sensory neurons
-has ganglion outside spinal cord (Dorsal root ganglion-in the intervertebral foramen)
Ventral Root
Motor neurons contained in connective tissue sheath
-cell bodys in ventral horn of spinal cord
Endoneurium
Inner most connective tissue covering mixed nerves
Cover Nerve Fiber and enclose myelin
-Fluid here indicates injury in part of periphery
Perineurium
Enclose a fasicle (bundle of fibers)
Epineurium
Surround Multiple Fascicles and blood vessels
-dura and arachnoid sleeve invaginate
Vasa Nervorum
Small arteries that supply blood to peripheral nerves …interior nerves and their coverings
Dorsal Primary Ramus
Synovial joints of vertebral column
Deep muscles of back
Overlying skin of back
Ventral Primary Ramus
Remaining areas of trunk, upper and lower limbs
Form Plexus
- Cervicle Plexus (C1-C5)
- Brachial Plexus (C5-T2)
- INtercostal Nerves (T1-T11)
- Lumbar Plexus (T12-L4)
- Sacral Plexus (L4-S5)
- Coccygeal Nerve (Co)
General Sensory (General Somatic Afferent)
Transmits pain, temp, touch, pressue and proprioception to spinal cord
Somatic Motor (General Somatic Efferent)
Tranmits impulses from spinal cord to skeletal muscle
Visceral Sensory (General Visceral Afferent)
Transmit reflex pain from viscera, glands, mucous membranes and blood vessels to spinal cord
Visceral Motor (General Visceral Efferent)
Transmit impulses from CNS to smooth muscle and glandular tissue (ANS)
Sympethetic Division of ANS-Presynaptic
Fight or Flight=Norepinephrine
LATERAL HORN=Cell bodies = presynaptic (preganglionic) neurons located INTEROMEDIOLATERAL CELL COLUMN of the spinal cord T1-L2/3
Sympethetic Division-Postsynaptic (paravertebral)
Paravertebral ganglion
-Sympathetic trunk (chain)= extend from C1 where the right and left chains join at the ganglion impar at sacrococcygeal vertebral junction
Sympethetic Division-Postsynaptic (prevertebral)
Surround origins of the main branches of the abdominal aorta
White Rami Communicans
Connection of sympathetic trunk to spinal nerve
- Myleninated presynaptic axons
- T1-L2
Gray Rami Communicans
Connection of sympathetic trunk to spinal nerve
- unmyelinated postsynaptic axons
- Thoughout sympathetic chain
Courses of Presynaptic Sympathetic Fibers
Enter spinal nerve via VENTRAL ROOT
- Enter sympathetic trunk via WHITE RAMI Communican
- Can choose to synapse immediately
- Can choose to ascend or descend the sympathetic trunk w/o synapsing….splanchnic nerve to prevertebral ganglion
Course of Postsynaptic Sympathetic Fibers
Run through GRAY MATTER Communicans
Postsynaptic fibers of Head
-Head: follow branches of the carotid artery
Postsynaptic fibers of Gut
-Splanchnic Nerves follow branches of abdominal aorta
Postsynaptic Fibers-Visceral Afferent Neurons
Run with the sympathetic division of ANS in a dermatomal pattern
Head and Neck
T1-T4 (Visceral Afferent-Symp)
Heart and Lungs
T1-T7 (Visceral Afferent-Symp)
Upper Extremity
T5-T7 (Visceral Afferent-Symp)
GI System
T2(esophagus) -L2 (rectum) (Visceral Afferent-Symp)
Liver and Gall Bladder
T6-T9 (Visceral Afferent-Symp)
Pancreas and Splean
T5-T11 (Visceral Afferent-Symp)
Urinary System
T10-L2 (Visceral Afferent-Symp)
Testes/Ovaries
T10-T11 (Visceral Afferent-Symp)
Uterus and Cervix
T10-L2 (Visceral Afferent-Symp)
Prostate
L1-L2 (Visceral Afferent-Symp)
Lower Extremities
T10-L2 (Visceral Afferent-Symp)
Parasympathetic (CranioSacral)
Rest and Digest=Acetylcholine
Parasympathetic-Presynaptic
Cell Bodies=
- CN III, VII, IX, X (salivate, and see food)
- Sacral Segments 2-4
Parasympathetic-Postsynaptic
Within the wall of the organ it innervates
Shoulder
C3/4 Dermatome
Thumb
C6 dermatome
Armpit
T1/2 dermatome
Nipple
T4 (always) dermatome
Inguinal
L1 dermatome
Big toe
L4 dermatome