Embryology And Dermatology Flashcards
Somatic, coelom, Visceral
Somatic-“outer tube” Coelom-body cavity Visceral-“inner tube”
Body cavities
Cranial vertebral thoracic abdominal pelvic dorsal ventral abdominopelic
Development in gestation
Neural (week3) develops before heart (week 3.5)
Teeth develop week 6
Most major abnormalities are established very early in development
Embryogenesis week 1
Zygote forms day 1
Morula day 4
Blastula day 5
Blastula splits into inner embryoblast and outer trophoblast day 6
Implantation day 6
Zane met Bonnie and Bonnie had twins - Ethan and Travis
Embryogenesis week 2
Embryoblast flattens creating a bilaminar disc-gastrula
Establishes the ventral-dorsal axis
ventral layer-hypoblast
dorsal layer-epiblast
Embryogenesis week 3
Primitive streak: thickening down the midline of the epiblast-establishes cranial-caudal node
Primitive node-cranial end
Germ layers are formed:
ectoderm-replaces epiblast
mesoderm-migrates ventrally between epiblast and hypoblast
endoderm-migrates ventrally and replaces hypoblast
3 parts of ectoderm
Surface ectoderm, neural tube, neural crest cells
Surface ectoderm
Integumentary: epidermis,nails and hair, surface exocrine glands
I eat nails and hair so easily, gosh
Oral Cavity tissues:oral epithelium,enamel of teeth, salivary glands
oceans eventually engulf treasures still gold
Special sensory tissues:nasal epithelium,olfactory neurons,lens, cornea,conjunctive of eye,lacrimal gland not even
Old necks let criminals crack open every last glass
Endocrine tissue:anterior pituitary
ET took AP classes
Neural tube (neural ectoderm)
CNS-brain, spinal cord, posterior pituitary
Neural Crest cells (neural ectoderm)
PNS-sensory neurons, autonomic neurons (post-synapse)
Melanocytes,connective tissues of head, dentin of teeth,great vessels of hearts,medulla of adrenal gland
Mark called to help decide the greatest victory he made at games
4 parts of mesoderm
Axial, paraxial,intermediate, lateral plate
Axial mesoderm
Notochord-condensation of mesoderm primitive support structure signals and directs neural development
adult derivative:nucleus pulposis (intervertebral disc)
Nucleus pulposus
Intervertebral disc
Adult derivative of notochord
Paraxial mesoderm
- Somite
- sclerotome:vertebrae, ribs,occipital bone
- somite dermatome:dermis over the spine (epaxial region)
- syndetome:tendons
- Myotome: skeletal muscle
- epimere: epaxial muscles (deep back)
- hypomere:hypaxial muscles
- somites are segmented
- each somite associated with a single Spinal nerve
- skin dermatome:area of skin supplied by a sensory branch of a single Spinal nerve
Sclerotome
From paraxial mesoderm
Vertebrae, ribs, occipital bone
Somite dermatome
From paraxial mesoderm
Dermis over spine (epaxial region)
Syndetome
From paraxial mesoderm
Tendons
Myotome
- From paraxial mesoderm
- Skeletal muscle epimere:
- epaxial muscles (deep back)
- hypomere: hypaxial muscles
Intermediate mesoderm
Urinary system:kidneys, ureters, bladder
Reproductive system: gonads and reproductive ducts (vas deferent and uterine tubes)
Lateral plate mesoderm
- Somatic LPM
- connective tissues,bones (climb, sternum, pelvis),smooth muscles associated with the somatic outer tube
- Splanchnic LPM
- connective tissue and smooth muscle associated with the visceral inner tube
- endothelium of blood vessels (veins and arteries)
Endoderm
- Epithelial lining of gut tube and derivatives
- oropharynx and laryngopharynx
- larynx
- esophagus
- respiratory system-trachea and bronchopulmonary tree (lungs)
- foregut (stomach, duodenum,liver, pancreas)
- midgut (small intestine,proximal large intestine)
- hindgut (distal large intestine, anal canal)
Branchial arches
- AKA pharyngeal pouches
- Give rise to tissues of the face and neck
- Considered visceral because they form around the cranial region of the primitive gut tube
- Have mesoderm and neural crest cell components
Integumentary system-skin, hair, nails, exocrine glands v
- Epidermis
- avascular
- keratinocytes and melanocytes
- Dermis
- contains the accessory and support structures of the skin hair,glands, neurovascular
- Subcutis/superficial fascia
- loose connective tissue and fat connects skin to underlying structures
What’s in skin?
- Sweat glands
- sebaceous glands
- mammary glands
- smooth muscle
- (arrector pili muscle, controlled by autonomic nerves)
- neurovasculature
- (arteriovenous plexus-arteries and veins intertwined as they pass through dermis)
- sensory organs and nerves
- (mechanoreceptos-touch and vibration, nocioceptors-pain)
Skin development
Surface ectoderm-epidermis, glands, hair
Neural crest cells-melanocytes
Somatic LPM-hypaxial muscles, arrector pili muscles
Somite dermatome- epaxial dermis
Herpes zoster
Shingles
Skin changes in specific dermatome
