Embryo for test Flashcards
Where does sperm fertilize the egg?
Ampulla of fallopean tube
Define fertilization
fusion of the male and female pronucleus
What part of the egg hardens during block of polyspermy?
zona pellucida
What are the first 2 layers that the sperm penetrates?
Corona radiata, then zona pellucida
How many blastomeres are found in the morula?
16-32
Where is the site of implantation?
Superior lateral uteral wall
What is an ectopic pregnancy?
Fertilized egg develops outside uterus
What is placenta previa?
Placenta forms too low and blocks uterine cervix, leading to bleeding and death of fetus
During the 2nd week of pregnancy, what layers form?
Embryoblast: epi and hypoblast
Trophoblast: cyto and syncytiotrophoblast
2 cavities: amniotic cavity and yolk sac
Which of the 3 germ layers do brain and spinal cord arise from?
Ectoderm
Which of the 3 germ layers do kidneys and gonads arise from (specifically)?
Intermediate mesoderm
What are the 2 types of lateral plate mesoderm?
Somatic mesoderm and splanchnic mesoderm
What do somites give rise to (generally)?
Schlerotome, dermotome, myotome
What germ layer does the notochord arise from?
Mesoderm
What germ layer does hair, nails, and glands of skin arise from?
Ectoderm
What does schlerotome come from and what does it give rise to?
- Comes from somites
- Gives rise to vertebrae and ribs
(“schler” = hard)
What does the notochord give rise to?
Nucleus pulposis of intervertebral discs
What does myotome come from and what does it give rise to?
- Comes from somites
- Gives rise to trunk and limb musculature
What does somatic mesoderm come from and what does it give rise to?
Comes from lateral plate mesoderm
- Parietal serosa
- Ventral dermis (dermotome gives dorsal)
- CT of limbs (bones, ligaments, joints)
What does splanchnic mesoderm come from and what does it give rise to?
Comes from lateral plate mesoderm
- Walls of dig/resp tracts (but not epithelium)
- Visceral serosa
- Heart
- Blood vessels
What does dermatome come from and what does it give rise to?
- Comes from somites
- Gives rise to dorsal dermis –“dermatome gives dorsal dermis”
(somatic mesoderm gives ventral dermis)
Describe the pharyngeal apparatus’s layers.
CAP:
Clefts,
Arches,
Pouches
What do the children tend to do at the Golden Arches (McDonalds)?
Chew Smile Stylish Swallow Speak
What pharyngeal arch is associated w/what CN?
Arch: 1 -- V 2 -- VII 3 -- IX 4/6 -- X
What are the fates of the pharyngeal pouches?
Ear, Tonsils, Bottom To Top (4)
- Tympanic cavity and auditory tube (ear)
- Palatine tonsils and tonsillar fossa (tonsils)
- Inferior parathyroid (bottom)
- Thymus (to)
- Superior parathyroid (top)
What is the fate of the 1st pharyngeal cleft?
External auditory meatus
What is the fate of the 2nd, 3rd, and 4th pharyngeal clefts?
Obliteration via growth of a cervical sinus
- If this persists, forms a branchial cyst/fistula!
What layer do phayngeal pouches comprise?
endoderm
What layer do phayngeal clefts comprise?
ectoderm
What layer do phayngeal arches comprise?
mesoderm
