Lecture 2-Dermatomes, Myotomes, Spinal Nerves Flashcards
(24 cards)
Describe the initial embryological development of a dermomyotome
- Mesodermal derivatives
- Intermediate mesoderm-what structures are derived from this?
- Kidney
- Gonads
Describe the initial embryological development of a dermomyotome
-Mesodermal derivatives-Chordamesoderm-what structure is derived from this and what does it form?
-Notochord-forms the nucleus pulposus in intervertebral disk (between vertebra)
Describe the initial embryological development of a dermomyotome
-Mesodermal derivatives-Paraxial mesoderm-what is derived from this?
- Head
- Somite
Describe the initial embryological development of a dermomyotome
- Mesodermal derivatives-Paraxial mesoderm
- Somites-what is derived from this?
- Sclerotome (cartilage)
- Myotome (skeletal muscle)
- Dermatome (epidermis)
Describe the initial embryological development of a dermomyotome
- Mesodermal derivatives-Paraxial mesoderm
- Somites-Function of cells of the sclerotome?
Cells of the sclerotome condense around the notochord and form the vertebrae
Describe the initial embryological development of a dermomyotome
-Mesodermal derivatives-Lateral mesoderm-what is derived from this?
- Splanchnic (circulatory system) and viscera
- Somatic (body cavity)
- Extra-embryonic
Describe the major components of spinal nerves
??–>spinal nerve–>??
Root–>spinal nerve–>ramus
Describe the major components of spinal nerves
-Spinal nerve–>ramus?
- Dorsal ramus
- Ventral ramus
Describe the major components of spinal nerves
-Spinal nerve–>dorsal ramus-Goes to?
Epaxial muscles
Epaxial
- Cells migrating posterior
- Making intrinsic muscles of the back and associated dermis
Describe the initial embryological development of a dermomyotome
-Mesodermal derivatives?
- Intermediate mesoderm
- Chordamesoderm
- Paraxial mesoderm
- Lateral Mesoderm
Describe the major components of spinal nerves
-Spinal nerve–>ventral ramus-Goes to?
Hypaxial muscles
Hypaxial
- Anterior migrating cells
- Make muscles of limbs and trunk and associated dermis
Describe the major components of spinal nerves
-Spinal nerve–>ventral ramus-Cutaneous nerve forms?
Dermatome
Describe the major components of spinal nerves
-Spinal nerve–>ventral ramus-Motor nerve forms?
Myotome
Compare and contrast a myotome with a dermatome
-Myotome?
- All the muscles that are innervated by a single EFFERENT anterior root
- Most muscles are composed of more than one myotome
Compare and contrast a myotome with a dermatome
-Dermatome?
-The area of skin supplied with AFFERENT (sensory) fibers by a single posterior spinal root
Describe differences between innervation maps of skin and muscle relative to dermatome and myotome maps
???
Contrast segmental innervation with innervation via plexus formation
???
What is a spinal nerve plexus?
When multiple nerves combine into one peripheral nerve
Identify the major spinal nerve plexuses.
- Cervical plexus
- Brachial plexus
- Lumbar plexus
- Lumbosacral plexus
-In what week of gestation do limb buds appear? What are the segments corresponding to the upper and lower limb buds?
-Limb buds appear in week
Name the major terminal branches of the brachial plexus.
-Acronym?
Acronym-RUMMMM
- Radial nerve (C5-T1)
- Ulnar nerve (C8-T1)
- Musculocutaneous nerve (C5-C7)
- Median nerve (C6-T1)
- Medial brachial cutaneous nerve (C8-T2)
- Medial antebrachial cutaneous nerve (C8-T11)
Name the major terminal branches of the lumbosacral plexus.
-Acronym?
Acronym-FLOPS
- Femoral nerve (L2-L4)
- Lateral femoral cutaneous nerve (L2-L3)
- Obturator nerve (L2-L4)
- Posterior femoral cutaneous nerve (S1-S3)
- Sciatic nerve (L4-S3)
