Embryology

Question 1

sex cell, haploids: oocyte (F), spermatozoan (M)  come together to form a zygote

Answer 1

Gamete

Question 2

fertilization of egg and sperm

Answer 2

Zygote

Question 2

glycoprotein layer that surrounds the egg, it hardens once the sperm enters to prevent another sperm from gaining entry (zygote), leaves after mitosis to allow for growth

Answer 2

Zona pellucida

Question 3

cell division, forms the morula (ball of cells)  (2  4  8  16) 16 total once mitosis is complete

Answer 3

Mitosis

Question 4

hollow ball of cells with blastocele (cavity)
Inner cell mass forms the embryo, multiplies and divides into 3 germ layers

Answer 4

Blastocyst (blastula)

Question 5

on exterior become the placenta (extraembryonic membranes)

Answer 5

Trophoblast

Question 6

Order of embryology

Answer 6

Gamete fertilizes, zygote forms, sona pellucida forms, mitosis, morula and blastocyst

Question 7

Formation of 3 germ layers from the inner cell mass

Answer 7

Gastrulation

Question 8

Portion of inner cell mass that is closest to the trophoblast

The cavity dorsal to the epiblast becomes the amniotic cavity

Develops into the ectoderm

Answer 8

Epiblast

Question 9

A portion of inner cell mass next to blastocoel
becomes the endoderm

Answer 9

Hypoblast

Question 10

The cells in between the epiblast and the hypoblast that become the

Answer 10

Mesoderm

Question 11

The Germ Layers

Answer 11

Ectoderm, Endoderm and mesoderm

Question 12

outer layer

Forms from epiblast cells

Becomes epidermis, hair, hooves, epithelium of sense organs, nerve tissue

Answer 12

Ectoderm

Question 13

inner layer

Forms from hypoblast cells

Grows down and forms archenteron (primitive gut)—gastrulation

Becomes epithelium of gut, respiratory tract, and lower urinary tract

Answer 13

Endoderm

Question 14

middle layer

Forms from cell in between ectoderm and endoderm

Divides into two layers coelom (precursor to body cavities.)

Becomes muscle, all connective tissue, and epithelium of gonads and joints

Answer 14

Mesoderm

Question 15

Primitive streak dorsally on embryo

Ventral

Develops from mesoderm

First support structure, rod like

Vertebrates all have one

Replaced by vertebrae of spine in later embryo

Small remnant as nucleus pulposus inside intervertebral disk

Answer 15

Notochord

Question 16

Ectoderm dorsal to notochord thickens, folds into a groove, meets to form a tube

Dorsal, hollow nerve cord

Will develop and thicken at cranial end to become brain

Hollow is filled with CSF (cerebrospinal fluid)

Spine forms

Peripheral nerves grow laterally along somites

Answer 16

Neurulation

Question 17

Adjacent to ectoderm

Gives rise to the bones, ligaments, blood vessels, and connective tissue of the limbs

Lengthwise segments called somites

Answer 17

Somatic Layer

Question 18

Coelom and mesoderm development

Answer 18

Mesoderm divides into somatic and splanchnic layer

Question 19

Adjacent to the endoderm

Forms the heart, gut muscles and blood vessels

Answer 19

Splanchnic layer

Question 20

Cavity the forms in between these two layers

Precursor to body cavities

Answer 20

Coelom

Question 21

Embryo continues to differentiate

Answer 21

Germ layers form tissues

Tissues form organs

Organs form organ systems

Fetus forms when organs are in place (1st trimester)