Spinal Nerves Flashcards
Spinal nerves carry __ ___ fibers and ___ ___ fibers
Sensory afferent
Motor efferent
At certain levels of body, spinal nerves become fused forming a complicated latter of fibers
Nerve plexus
Peripheral nerves are wrapped in
Connective tissue
Each segment has a pair of
Spinal nerves
Each nerve is surrounded by the
Epineurium
Epineurium projects into the nerve which divides up the nerve bundles of axons
Perineurium
Perineurium divides the nerve into bundles of axons
Fascicles
Each axon is surrounded by thin and delicate
Endoneurium
Pairs of: Cervical Thoracic Lumber Sacral Coccygeal
8 C 12 T 5 L 5 S 1 Co
Dorsal root carries
Sensory fibers
Ventral roots carry
Motor fibers
Roots in the cervical region are short, but they get progressively longer inferiorly, forming the
Cauda equina
Spinal roots join to form short
Spinal nerves
In thoracic region, ventral rami are split off another ramus carrying autonomic nerve fibers
(These enter the sympathetic trunk)
Rami communicantes
Compromised of ganglia connected to each other forming a chain
Sympathetic trunk
Clusters of sympathetic neuron cell bodies
Ganglia
Somatic motor fibers leaving neurons of the ventral horn enter the rootlets combine to form
Ventral roots
What do the motor fibers do after fusing to form the spinal nerves
Motor fibers enter the dorsal/ventral rami
Ventral rami branch fuse with another lateral to the vertebral column forming
Complicated nerve plexus
Visceral sensation comes from __ from the same regions and viscera
interceptors
Somatic sensations come from __
Body wall, back, or limbs
Exteroceptors
Proprioceptors
Somatic and visceral neurons cell bodies are located in the __ and enter the __ of spinal cord
Dorsal root ganglion
Dorsal horn
It’s the only region of body that ventral rami arrange in simple segmental pattern
Thorax
Intercostal nerves lying between ribs and muscle of thorax
Intercostal nerves wrapped in CT along with artsy and vein
Neurovascular bundle
Thoracic nerves pass to
Intercostal spaces, axilla, chest, muscles of thorax, deep back and ab muscles
Nerves emanating from regions of spinal cord that control neck upper limbs and lower limbs combine to form
Complex nerve plexuses
4 nerve plexuses
Cervical
Brachial
Lumbar
Sacral
Cervical plexus formed by
Ventral rami of first 4 cervical nerves
Only nerve innervating the diaphragm
Phrenic nerve
If both phrenic nerves are severed
Diaphragm is paralyzed
Most complicated plexus of 4
Innervates the complex musculature
Situated partly in neck and axilla
C5-T1
Brachial plexus
- Axillary
- Musculocutaneous
- Radial
- Ulnar
- Median
- Deltoid and teres major
- Arm and forearm flexors
- Arm and forearm extensors, thumb
- Wrist and finger flexors, med fingers
- Forearm flexors except flexor carpi ulnaris
Trauma to the radial nerve results in
Weakness to forearm extensors
“Wrist drop”
Radial nerve wraps around
Humerus in radial groove
Lack of blood supply to tissue
Ischemia
Brachial artery being compressed leads to
Arm going to sleep
Saturday night paralysis
When brachial plexus is stretched
Erb’s Palsy
Results from reaching out when falling, someone yanking arm or pulling from above
Waiters tip
Results on damage of what nerves
Erb’s Palsy
C8-T1
Inability to pronate arm
Inability flexing wrist
Median nerve Palsy
Carpal tunnel syndrome caused by repetitive flexion pressing the nerve against
Flexor reticulum
Problems adducting or abducting fingers
Ulnar nerve Palsy
Little and ring fingers become hyperextended and knuckles and flexed at distal interphalangeal joints
Claw hand
nerve associated with hitting funny bone
Ulnar nerve
When C5-C7 is compressed
Winged scapula
Trauma to the radial nerve results in
Weakness to forearm extensors
“Wrist drop”
Radial nerve wraps around
Humerus in radial groove
Lack of blood supply to tissue
Ischemia
Brachial artery being compressed leads to
Arm going to sleep
Saturday night paralysis
When brachial plexus is stretched
Erb’s Palsy
Results from reaching out when falling, someone yanking arm or pulling from above
Waiters tip
Results on damage of what nerves
Erb’s Palsy
C8-T1
Inability to pronate arm
Inability flexing wrist
Median nerve Palsy
Carpal tunnel syndrome caused by repetitive flexion pressing the nerve against
Flexor reticulum
Problems adducting or abducting fingers
Ulnar nerve Palsy
Little and ring fingers become hyperextended and knuckles and flexed at distal interphalangeal joints
Claw hand
nerve associated with hitting funny bone
Ulnar nerve
When C5-C7 is compressed
Winged scapula
Nerve that provides sensation to genitals and inner thigh
Ilioinguinal nerve
Nerve that provides sensory to scrotum M and labia majora F
Genitofemoral nerve
Motor nerve to adductor Magnus, gracilis, and obturator externus muscles
Obturator nerve
Biggest plexus, motor nerve to the quadriceps and sartorius muscles, pectineus and iliacus
Damage to this nerve results in inability to extend leg at the knee)
Femoral nerve
Nerve that innervates the prime movers of both hip flexion and knee extension
Femoral nerve
Largest nerve of sacral plexus and in the body
This plexus is made up of __ and __ nerves
Sciatic nerve
Tibial and fibular nerve
Nerve that innervates deep to the gluteus Maximus and enters on posterior thigh to the hip joint
Sciatic nerve
Nerve that innervates posterior leg
Tibial nerve
Nerve that innervates the knee joint, fibularis longus, brevis muscles, tibialis, hallucis longus and digitorum longus and brevis
Fibular nerve
Nerve that motors gluteus medius and minimus to tensor fascia latae
Superior gluteal nerve
Nerve that innervates gluteus Maximus
Inferior gluteal nerve
Pain extending from buttocks down to back of leg means damage or pinching to
Sciatic nerve
Condition of intense stabbing pain radiating over the course of sciatic nerve from gluteal region to toes
Sciatica
Injury to fibular nerve nerve
Unable to dorsiflex while walking because they will stumble/fall
Foot drop
Calf muscles can’t plantar flex the foot
Shuffling gait
Damage to tibial nerve
Injuries to sciatic can be from
Herniated disc
Uterus pressure during pregnancy
Osteoarthritis
Area of skin innervated by a single pair of spinal nerves
Dermatome
All spinal nerves innervated dermatomes except
C1
Damage or infection of spinal nerve or dorsal root ganglion results in
Loss of sensation to region of skin supplied by the nerve
