Embryogenesis

Question 1

Ampulla

Answer 1

Region of the Fallopian tube where fertilization occurs. It is the widest part of the Fallopian tube.

Question 2

Acrosomal Apparatus

Answer 2

When the first sperm comes into contact with the oocyte, it releases acrosomal enzymes that enable the head to penetrate the corona radiata and zona pellucida. It forms a tubelike structure known as the acrosomal apparatus that extends to and penetrates the membrane. Its pronucleus then may freely enter the oocyte once meiosis II has come to completion.

Question 3

Cortical Reaction

Answer 3

release of calcium ions after the penetration of the sperm. The calcium ions depolarize the membrane of the ovum, which serves two purposes: prevents fertilization by multiple sperms. Also increases the metabolic rate of the newly formed zygote.

Question 4

Fertilization membrane

Answer 4

Depolarizer, impenetrable membrane formed after the cortical reaction

Question 5

Stages of development of the zygote to embryo?

Answer 5

Zygote, morula, blastula gastrula

Question 6

Morula

Answer 6

Solid ball of cells after several divisions of the zygote

Question 7

Blastula

Answer 7

Hollow ball of cells with a fluid filled inner cavity known as the blastocoel

Question 8

What arises from the trophoblasts?

Answer 8

Chorion and later placenta

Question 9

What are the two parts of the blastocyst?

Answer 9

Trophoblast and the inner cell mass (ICM).

Question 10

In what stage is the embryo implanted in the uterine lining?

Answer 10

Blastula

Question 11

Chorionic villi? What are they and what do they develop from?

Answer 11

Develop from the trophoblasts, and are fingerlike microscopic projections that penetrate the endometrium.

Question 12

The 3 extraembryonic membranes?

Answer 12

Chorion, Amnion, and Allantois

Question 13

Allantois?

Answer 13

Extraembryonic membrane that is involved in the fluid exchange between the yolk sac and the embryo.

Question 14

Umbilical chord forms from what?

Answer 14

From yolk sac and Allantois.

Question 15

Ectopic pregnancy

Answer 15

If the blastula implants itself outside the uterus. 95% in the Fallopian tube. Not viable, and if not self aborted, will rupture causing hemorrhage.

Question 16

Name what you see if you move in from the uterine lining towards the embryo

Answer 16

Uterine lining, chorion, chorionic cavity, amnion, amniotic fluid, embryo.

Question 17

Arcehnteron

Answer 17

Membrane invagination into the blastocoel during the formation of gastrula

Question 18

Blastocoel

Answer 18

The opening of the archenteron.

Question 19

Deuterosome

Answer 19

The blastopore develops into the anal opening

Question 20

Protostome

Answer 20

Blastopore develops into the mouth

Question 21

Know where the ectoderm, endoderm, and mesoderm are located in gastrula

Answer 21

Just know it!

Question 22

Integument

Answer 22

Includes hair, nails, epidermis, epithelial of the nose, mouth, nose and lower anal canal.

Question 23

What does the ectoderm give rise to?

Answer 23

Integument: Hair, nails, epidermis, epithelial of the nose mouth and the lower anal canal
+
Nervous system (including adrenal medulla) and the inner ear

Question 24

Mesoderm gives rise to…

Answer 24

Musculoskeletal, circulatory systems, and most of the excretory system + gonads, adrenal cortex
+ muscular and connective layers of the respiratory and digestive systems.

Question 25

What do neural crest cells give rise to?

Answer 25

Peripheral nervous system (including the sensory ganglia, and autonomic ganglia, Schwann cells, and adrenal medulla) + Specific cell types in other tissues: calcitonin producing cells in thyroid, melanocytes in skin

Question 26

Spins bifida

Answer 26

Failure of the neural tube to close. All or parts of the spinal cord might be exposed to the outside world

Question 27

Anencephaly

Answer 27

Brain fails to develop and the skull remains open

Question 28

What chemical supplement is used to prevent anencephaly and spins bifida?

Answer 28

Folic acid

Question 29

Pancreas enzymes?

Answer 29

Trypsin, pancreatic lipase, carboxypeptidase A and B

Question 30

Pancreatic endocrine hormones

Answer 30

Insulin, glucagon, somatostatin

Question 31

Different types of cell-cell communication? Do you know what each mean?

Answer 31

Autocrine, paracrine, juxtacrine, endocrine.

Question 32

What are growth factors?

Answer 32

Peptides that induce differentiation and mitosis in certain tissues

Question 33

Example of reciprocal development? (pax6)

Answer 33

In ectoderm of the head, when optical vesicle touches the ectoderm, it induces the ectoderm to form the lens placode. The lens placode induces the optical vesicle to produce the optic cup. Optic cup induces the lens placode to develop into the lens and the cornea.

Question 34

Name three common morphogens:

Answer 34

TGF beta (transforming growth factor beta), sonic hedgehog (shh), epidermal growth factor (EGF).

Question 35

Where does the anterior pituitary gland originate from?where does it travel to?

Answer 35

A segment of the oral ectoderm and migrates to its location below the hypothalamus.

Question 36

What are the hormones produced by placenta?

Answer 36

Estrogen, progesterone, and hCG (human chorionic gonadotropin).

Question 37

Name the pathogens that can cross the placental barrier

Answer 37

TORCHES: | Toxoplasma Gondi, Rubella, Cytomegalovirus, Herpes or HIV, Syphilis

Question 38

What are the shunts in fetus? What organs do they bypass?

Answer 38

Three shunts to bypass lungs and liver. 2 for lungs: Foramen ovale (connects the right to the left atriums)**One way flap Ductus arteriosus (connects the flow from the pulmonary artery to aorta) 1 for liver: Ductus venosus Connects the umbilical vein to the inferior vena cava.

Question 39

What happens during the first trimester?

Answer 39

Development of the major organs during the first few weeks 22 days: hear beat begins Shortly after: eyes, gonads, limbs and liver By the end of week 5: 10 mm By the end of week 6: 15mm Week 7: cartilaginous skeleton hardens into bones End of week 8: most organs have formed, brain is fairly formed we start to call it a fetus! End of month 3: 9 cm.

Question 40

What happens during the second trimester?

Answer 40

``` Tremendous growth. Fingers and toes elongate Begins movement in the amniotic fluid Face gains human appearance By the end of the sixth months measures 30 to 36 cm. ```

Question 41

What happens during the third trimester

Answer 41

Growth and brain development continues during the 7th and 8th months. Antibodies transported by selective active transport from mother to the fetus. (Highest during the 9th month)

Question 42

Parturition

Answer 42

Vaginal childbirth

Question 43

What hormones are involved during parturition?

Answer 43

Oxytocin and prostaglandins.

Question 44

What are prostaglandins involved in?

Answer 44

Parturition