Embryology Lecture

Question 1

Mitosis

Answer 1

Asexual reproduction, forms 2 identical daughter cells with no mechanism for genetic diversity, undergoes Interphase, prophase, etc

Question 2

Meiosis

Answer 2

Sexual reproduction, forms 4 haploid gametes with diverse spread of genes through crossing over and homologous recombination to create egg and sperm

Question 3

Sex hormone release pathway

Answer 3

Hypothalamus -> GnRH -> pituitary gland -> gonadotropin -> FSH/LH

Question 4

Embryonic age

Answer 4

Number of days since fertilization (Clinically relevant right now)

Question 5

Gestational age

Answer 5

Number of days since start of ovarian cycle (Don’t worry about this) (embryonic age + 2 weeks)

Question 6

Zygote

Answer 6

One cell stage of fertilized ovum before first cleavage occurs

Question 7

Morula

Answer 7

Ball of cells composing the early embryo that produces both the embryo and the placenta and membranes - each cell is totipotential

Question 8

Blastocyst

Answer 8

The stage that follows the morula stage. It consists of a fluid filled cavity surrounded by trophoblasts with embryoblast cells at one pole.

Question 9

Trophoblast

Answer 9

Cells outside the blastocele, becomes the placenta

Question 10

Embryoblast

Answer 10

Inner cell mast inside blastocele, becomes the embryo

Question 11

Embryoblast

Answer 11

Inner cell mast inside blastocele, becomes the embryo

Question 12

Fertilization occurs in the…

Answer 12

…distal third of the fallopian tube

Question 13

What occurs 3-4 days after ovulation

Answer 13

Entrance in the uterine cavity

Question 14

What occurs 5-6 days after ovulation

Answer 14

HCG levels rise, tropoblast releases enzymes that erode the uterine lining for implantation

Question 15

What occurs 7-12 days post ovulation

Answer 15

Trophoblast cells engulf and destroy cells of the uterine lining to create blood pools, stimulate capillary growth and develop placenta

Question 16

Where do ectopic pregnancies occur?

Answer 16

Implantation in the distal third of the fallopian tube, sometimes elsewhere as well

Question 17

***Epiblast vs hypoblast

Answer 17

f

Question 18

***The first week of fertilization is…

Answer 18

…all or none - you either implant or misscarry

Question 19

What does ectoderm form?

Answer 19

Epithelium and communicating (nervous tissue) structures

Question 20

What does mesoderm form?

Answer 20

Moving structures bone, cartilage, muscle, ligament, blood

Question 21

What does endoderm form?

Answer 21

Excretory structures, GI, respiratory, urinary

Question 22

Sacrococcygeal teratoma

Answer 22

Leftover primary streak containing all 3 cell types, easily removed without issue

Question 23

Why do dermatomes form the way they do?

Answer 23

They are lined up linearly on the neural fold, but projection of the limbs causes distortion of them

Question 24

Why do dermatomes form the way they do?

Answer 24

They are lined up linearly on the neural fold, but projection of the limbs causes distortion of them

Question 25

Female develops due to ________ of hormones

Answer 25

Absence

Question 26

Female develops due to ________ of hormones

Answer 26

Absence

Question 27

Exposure to toxins within first 9 weeks causes… exposure beyond that causes…

Answer 27

…greatest damage during development…minor or small changes in the infant

Question 28

Meconium

Answer 28

product of cell loss, digestive secretion and swallowed amniotic fluid in an embryo (essentially feces)

Question 29

By 24-26 weeks, what can the fetus do?

Answer 29

Live outside of the body

Question 30

What point do doctors consider inducing labor?

Answer 30

40 weeks or more

Question 31

What point do doctors consider inducing labor?

Answer 31

40 weeks or more

Question 32

Week 3 major points

Answer 32

Primitive streak, neural plate development

Question 33

finish it

Answer 33

f