Cord Flashcards
What is the average length of the spinal cord?
Ends where in the adult?
45 in males
42 cm in females
Between L1 and L2
What is the junction zone between two types of tissues (glial support and Schwann cells) at the point where the dorsal nerve enters the spinal cord?
Oberseteiner- Redlich space
How does the spinal cord segment correspond with the tip of the vertebral spine?
Cervical Minus 1
Upper Thoracic Minus 2
Lower thoracic and upper lumbar Minus 3 (Eg Spine 10 = L1 cord segment)
What spinal nerves are derived from the conus medullaris?
S4 S5 and 1 coccygeal nerve
Identify the dermatome
- Back of the head
- Shoulder
- Thumb
- Middle finger
- Small finger
- Inguinal region
- Umbilicus
- Nipple
- Big toe
- Small toe
- Genitalia
- Back of the head C2
- Shoulder C4
- Thumb C6
- Middle finger C7
- Small finger C8
- Inguinal region L1
- Umbilicus T10
- Nipple T4-5
- Big toe L5
- Small toe S1
- Genitalia S4-5
In the spinal cord where is
- CSF
- Bridging veins
- Blood vessels that supply and drain the cord
- Adipose tissue and venous plexus
- CSF: Subarachnoid space
- Bridging veins: Subdural space
- Blood vessels that supply and drain the cord: Epipia mater (VS intima pia closely adherent to cord)
- Adipose tissue and venous plexus: Epidural
Identify the myotome
- Deltoid
- Bicep
- Tricep
- Hypothenar muscles
- Quads
- Extensor hallucis
- Gastrocnemius
- Rectal sphincter
- Deltoid C5
- Bicep C6
- Tricep C7
- Hypothenar muscles T1
- Quads L4
- Extensor hallucis L5
- Gastrocnemius S1
- Rectal sphincter S3-4
What side of the cord is bigger in 75% of asymmetries?
What percentage of human have asymmetric cords?
Right
75% as well!
The cuneate tract is only present above what level?
T6
The intermediolateral cell column and nucleus dorsalis of clarke extends between?
C8 to L2
Which Rexed Laminae:
- For Exteroceptive sensation
- For Proprioreception
- Main motor area
- Intermediolateral horn
- For Exteroceptive sensation 1-4
- For Proprioreception 5-6
- Main motor area 9
- IML: 7
Remember that substantia gelatinos is laminae 2 while nucleus proprius is laminae 3-4
For segments S1 to S4 what what supplementary column is present?
Onuf (Onufrowicz) nucleus
What rexed laminae are renshaw cells seen in?
What NT do they release?
9
Glycine
Why are 15% of fibers in the posterior funiculus not primary afferents?
These fibers have synapsed in the Rexed 3-5: Nucleus proprius and neck of posterior horn– they are activated by both nociceptors and mechanoreceptors unlike the 85% that are activated by mechanoreceptors alone
T or F: Lesions in the posterior funiculus decrease the threshold to painful stimuli and augment all sensation conveyed by the anterior ST pathway.
T