Embryology And Dermatology

Question 1

Somatic, coelom, Visceral

Answer 1

Somatic-“outer tube” Coelom-body cavity Visceral-“inner tube”

Question 2

Body cavities

Answer 2

Cranial vertebral thoracic abdominal pelvic dorsal ventral abdominopelic

Question 3

Development in gestation

Answer 3

Neural (week3) develops before heart (week 3.5)

Teeth develop week 6

Most major abnormalities are established very early in development

Question 4

Embryogenesis week 1

Answer 4

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

Question 5

Embryogenesis week 2

Answer 5

Embryoblast flattens creating a bilaminar disc-gastrula

Establishes the ventral-dorsal axis

ventral layer-hypoblast

dorsal layer-epiblast

Question 6

Embryogenesis week 3

Answer 6

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

Question 7

3 parts of ectoderm

Answer 7

Surface ectoderm, neural tube, neural crest cells

Question 8

Surface ectoderm

Answer 8

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

Question 9

Neural tube (neural ectoderm)

Answer 9

CNS-brain, spinal cord, posterior pituitary

Question 10

Neural Crest cells (neural ectoderm)

Answer 10

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

Question 11

4 parts of mesoderm

Answer 11

Axial, paraxial,intermediate, lateral plate

Question 12

Axial mesoderm

Answer 12

Notochord-condensation of mesoderm primitive support structure signals and directs neural development

adult derivative:nucleus pulposis (intervertebral disc)

Question 13

Nucleus pulposus

Answer 13

Intervertebral disc

Adult derivative of notochord

Question 14

Paraxial mesoderm

Answer 14

• 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

Question 15

Sclerotome

Answer 15

From paraxial mesoderm

Vertebrae, ribs, occipital bone

Question 16

Somite dermatome

Answer 16

From paraxial mesoderm

Dermis over spine (epaxial region)

Question 17

Syndetome

Answer 17

From paraxial mesoderm

Tendons

Question 18

Myotome

Answer 18

• From paraxial mesoderm
• Skeletal muscle epimere:
  
  • epaxial muscles (deep back)
  • hypomere: hypaxial muscles

Question 19

Intermediate mesoderm

Answer 19

Urinary system:kidneys, ureters, bladder

Reproductive system: gonads and reproductive ducts (vas deferent and uterine tubes)

Question 20

Lateral plate mesoderm

Answer 20

• 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)

Question 21

Endoderm

Answer 21

• 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)

Question 22

Branchial arches

Answer 22

• 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

Question 23

Integumentary system-skin, hair, nails, exocrine glands v

Answer 23

• 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

Question 24

What’s in skin?

Answer 24

• 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)

Question 25

Skin development

Answer 25

Surface ectoderm-epidermis, glands, hair

Neural crest cells-melanocytes

Somatic LPM-hypaxial muscles, arrector pili muscles

Somite dermatome- epaxial dermis

Question 26

Herpes zoster

Answer 26

Shingles

Skin changes in specific dermatome