Early Embryology 1 Flashcards Preview

Exam 1 FTM > Early Embryology 1 > Flashcards

Flashcards in Early Embryology 1 Deck (10)
Loading flashcards...
1
Q

Fertilization

A

Day 0

1) Capacitation- seminal proteins pass corona radiata (outside egg)
2) Acrosomal reaction- release acrosome enzymes/pass zona pellucida (2nd layer)
3) Fusion of plasma membrane of sperm and oocyte (Sperm inside released, inactivating sperm receptors=prevents multiple pregnancies)

2
Q

Week 1: Fertilization

A

Location: Ampulla of fallopian tube

1) female pronucleus
2) Male pronucleus
3) Chromosomes condense
4) Mitotic division = zygot

3
Q

Week 1: Cleavage and Morula Formation

A

Repeased cell division

Form more blastomeres (16-32=morulas)

4
Q

Week 1: Blastocysts Formation

A

Location: Uterus fluid-filled blastocystic cavity

-Morula enters blastocystic cavity

Two layers formed:

1) Embryoblast: Embryo
2) Trophoblast: Placenta

5
Q

Week 1-2: Implantation

A

Location: Posterior wall of body of uterus close to the fundus

  • 6-10 days
  • Blastocyte enters endometrium
  • Trophoblast divides in two parts
    1) Cytotrophoblast (inner)- makes cells/mitotically active
    2) Syncytiotrophoblast (outer)- Contains human chorionic gonadotrophin (HCG), allows blastocyst to burrow into the endometrium
6
Q

Week 2: Bilaminar Disc

A

-Embryo implantated results in embryonic disc

Embryonic Disc:

1) Epiblast = forms germ layers
2) Hypoblast= Hypoblast = yolk sac (lubrication)

7
Q

Week 3: Gastrulation

A

-Germ layers form

8
Q

Mesoderm

A

Paraxial

  • Muscle
  • Skin
  • Bone

Intermediate
-Urogential organs and ducts

Lateral

  • Heart
  • Spleen
  • Adrenals
9
Q

Endoderm

A

-Lining of epithelium of gut, organs, thryroid glands, lining of bladder

10
Q

Ectoderm

A
  • Nails
  • Sweat glands
  • Epidermis
  • Sensory cells

Neuralectoderm:
1) Neural tube- CNS, retina, pineal body, posterior pituitary

2) Neural crest cells- PNS, melanocytes, cranal nerves, glial and schwann cells, connective tissue/bones, adrenal medula