Dermatomes And Signal Innervation (4) Flashcards
What does the dermatomyotome develop into?
- Dermis (skin)
- Muscle
What does the sclerotome develop into?
- Vertebral column
- Ribs
How does the dermatomyotome develop a nervous supply?
- Dermatomyotome develops in association with a neural level of embryonic neural tube tissue.
- Takes neural supply with it when migrates.
Where does the spinal chord start & end?
- Starts where medulla of brain ends
- Ends at conus medullaris (membranes taper into a ligament - filum terminale
- Ends at L2/3 of vertebral column
Explain how the spinal chord runs through the vertebral column.
- Runs through vertebral foramina of vertebrae
- Cord gives off a pair of nerves at each vertebral column (L&R)
- Spinal nerve leave spinal chord via intervertebral foramina
What is segmentation?
Mention sensory and motor nerves
- Each segment of nervous tissue has independence of connection to periphery.
- Sensory nerves serve discrete territories of skin
- Motor nerves serve myotomal territories
What are segments also known as?
- Neural level
How is the spinal chord split, from rostral to caudal ends?
- Cervical
- Thoracic
- Lumbar
- Sacral
What are the two functional areas of segmental areas?
- Dorsal (sensory/afferent)
- Ventral (efferent)
What are the two types of ventral roots?
- Motor (skeletal)
- Autonomic (smooth muscle/glands)
In the upper limb, which segments are the following supplied from?
- Radial: C5/6/7/8/T1
- Musculocutaneous: C5/6/7
- Ulnar: C7/8/T1
- Median: C6/7/8/T1
What segments supply the lower limb?
- Lumbar plexus: L1-L4 (not all of L4)
- Sacral plexus: L4-S4
Where is the lumbar plexus situated in the body?
- Behind psoas major
Which are the nerves that emerge lateral to psoas?
- Femoral (L2-L4)
- Iliohypogastric
- Ilioinguinal
- Lateral cutaneous of thigh
Which are the nerve that emerge medially to the psoas?
- Obturator
- Lumbosacral
