9/15 Dermatomes, Myotomes, and Spinal Nerve Plexuses - Dennis Flashcards
What receives stimulus from joints, skin, and skeletal muscle? 3
Somatosensory fibers (afferent, sensory)
what sends stimulus to skeletal muscle? 3
Somatomotor fibers (efferent, motor)
What receives stimulus from viscera and vessels? 3
Viscerosensory fibers (afferent, sensory)
What sends stimulus to glands, smooth muscle, and cardiac muscle? 3
visceromotor fibers (efferent, motor)
What embryonic tissue are the kidney and gonads derived from? 4
Intermediate mesoderm
What embryonic tissue is the splanchnic (circulatory system) derived from? 4
lateral plate mesoderm
What embryonic tissue is the somatic (body cavity, pelvis, and limb bones derived from? 4
lateral plate mesoderm
What embryonic tissue is the notochord derived from? 4
chordamesoderm
What embryonic tissue is cartilage, tendons, skeletal muscle (myotomes), and dermis, skeletal muscle (dermatomes) derived from? 4
paraxial mesoderm (somites)
Which is the most dorsal structure: neural tube or notochord? Where is the floor plate found? 6
The floor of the neural tube is called the floor plate and is dorsal to the notochord
What does the myotome form after migrating? 8
epimere - migrates posteriorly (dorsal)
hypomere - migrates anteriorly (ventral)
What are the muscle derivatives of the epimere and hypomere? 8
Epimere - epaxial muscle
Hypomere - hypaxial muscle
What cells condense around the notochord to form the vertebrae? 9
Sclerotome cells
What contributes to the nucleus pulposus of an intervertebral disk? 9
Notochord
How many occipital myotomes are there? 11
4
How many cervical myotomes are there? 11
8
How many thoracic myotomes are there? 11
12
How many Lumbar myotomes are there?
5
How many sacral myotomes are there? 11
5
What are the dorsal (epaxial) columns of epimeres? 11
C6 - T4
What three dermatomes innervate the hands? 14
C6, 7, 8
What dermatomes innervate the foot?
L4
L5
S1
What dermatomes innervate the face?
V1, V2, V3
C2, C3, C4
What is a dermatome? 18
A unilateral area of skin innervated by the sensory fibers of a single spinal nerve