Embryo for Practical Flashcards
What degenerates as the vertebral bodies form and gives rise to the nucleus pulposus (intervertebral discs) in embryo, fetus and young children?
Notochord
What germ layers form the epithelium?
ALL 3!
What is derived from the Ectoderm?
- Epidermis of the skin & epidermal derivatives (ex. hair follicles, nails, glands)
- CNS
- PNS
- Neural crest cells
- Eyes
- Internal ears
What is derived from the Mesoderm (intraembryonic)?
- All skeletal muscle
- Visceral smooth muscular coats
- Serosal linings of all body cavities
- Urogenital organs (i.e kidneys)
- Most of the cardiovascular system – blood cells, lining of vasculature
- Cartilage
- Bones
- Tendons
- Ligaments
- Dermis
- Stroma of internal organs in the trunk
What is derived from the Endoderm?
- Epithelial linings of the respiratory & digestive tracts
- Glands opening into the GI tract
- Glandular cells of accessory GI organs (liver & pancreas)
What part of the notochord grows into the sacral, coccygeal and tail regions?
Caudal notochord
Primary neurulation is associated with __-__ spine formation
Cervical-Lumbar
What is derived from neural crest cells?
- Melanocytes
- Odontoblasts
- Schwann cells
- Spinal & autonomic ganglia
- Enteric nervous system
- Suprarenal (adrenal) medulla
What gives rise to spinal epidural space?
Spinal Ectomeninx
What does the PNS develop from?
- Neural crest cells
- Neuroectoderm
- Ectodermal Placodes
Where does the spinal cord end in a fetus?
S1
Where does the spinal cord/medullary cone end in an adult?
L1
What does the spinous process and lamina of the vertebral arch arise from?
Dorsal Sclerotome
What does the vertebral body arise from?
Ventral Sclerotome
What does the pedicles of vertebral arch, transverse processes & proximal ribs arise from?
Central Sclerotome
What do the distal ribs arise from?
Lateral Sclerotome
A single vertebrae forms from adjacent __/__ segments of sclerotome
caudal/cranial
What caudal/cranial sclerotomes form C1?
Caudal half of C1 + Cranial half of C2
What caudal/cranial sclerotomes form T1?
Caudal half of C8 + Cranial half of T1
Paired sternal bars arise in body wall from somatic layer of ___ ___ ___
Lateral Plate Mesoderm
Nucleus Pulposa arises from what?
Notochordal Cells
Annulus Fibrosus develops from what?
Annulus Fibrosus
What forms from the Epaxial division (Epimere)?
Extensor muscles of the neck & vertebral column (ex. Iliocostalis, longissiums, spinalis, rotatores brevis, rotatores longus, multifidous, rectus capitis posterior major and minor. obliquus capitis inferior and superior, semispinalis capitis and cervicis)
What forms from the Hypaxial division (Hypomere)?
Muscles of lateral and ventral body walls in the thorax and abdomen (ex. diaphragm, intercostal muscles, serratus anterior and posterior, abdominal muscles, limbs)
