Embryogenesis and Development

Question 1

Senescence

Answer 1

The process of deterioration that happens with age.. like less cell division rounds… Occurs with telomer shortening

Question 2

Anencephaly

Answer 2

Skull does not fully develop and the brain is left open and exposed.

Question 3

Folate (vitamin B9)

Answer 3

Folate is essential for reducing the risk of neural tube defects, including anencephaly, a condition in which the brain fails to develop and the skull is left open.

Question 4

Induction

Answer 4

Signaling a tissue to grow into something…. determining the fate of something in a sense (determination).

Question 5

Prostaglandins

Answer 5

These, along with oxytocin, coordinates uterine contractions during parturition and act as inflammatory markers

Question 6

Morphogen

Answer 6

These promote development down a specific cell line in a competent cell during determination.

Question 7

Growth Factors

Answer 7

These peptides that promote differentiation and mitosis in certain tissues.

Question 8

Teratogen

Answer 8

These interfere with development, causing defects or even death of the developing embryo, like those seen in FAS.

Question 9

How does this affect Hb-O2 affinity?

• Increased 2,3-bisphosphoglycerate
• Decreased blood PaCO2
• Decreased blood pH

Answer 9

• Decrease
• Increase
• Decrease

Question 10

Germ Layers:

• Skin
• Adrenal Gland
• Small Intestines
• Central Nervous System

Answer 10

• Ectoderm - epidermis AND Mesoderm - dermis
• Mesoderm - adrenal cortex AND Neural Crest (ectoderm) adrenal medulla
• Endoderm - epithelium AND Mesoderm - muscular layer
• Ectoderm only

Question 11

Compaction

Answer 11

Compaction is an increase in cell-cell adhesion molecules that keep the embryo together

Question 12

Gastrulation

Answer 12

Gastrulation is the process of developing three distinct cell layers

Question 13

Bastulation

Answer 13

Making a hollow ball that’s a fluid filled caity (blastocoel) and outer surrounding known as trophoblast

This also is the step where the implantation into the endomertrial lining occurs.

Question 14

Cleavage

Answer 14

early mitotic cell division with NO GROWTH

Question 15

Fetal Circulation is necessary to:

Answer 15

• Move blood away from Liver because it cannot handle high blood pressure
• Avoiding Lungs allows more blood to flow upward to brain and arms
• Ductus Venosus allows heart to recieve oxygenated blood to come from placenta

Question 16

ductus arteriosus

Answer 16

shunt leftover blood from pulmonary artery to aorta

Question 17

The Ductus Arteriosus shunts leftover blood from _____ to aorta

Answer 17

Pulmonary Artery

Question 18

ductus venosus

Answer 18

shunts blood returning from the placenta via the umbilical vein directly to the inferior vena cava

Question 19

foramen ovale

Answer 19

is a one-way valve that connects the right atrium to the left atrium

Question 20

The Purpose of Fetal Circulation:

Answer 20

Shunts blood to foramen ovale, which shunts from R atria to L atria to bypass lungs –> increases oxygenated blood to brain and arms AND avoid lungs which are underdeveloped (lungs to do not develop until just before birth)

Shunts blood from placenta to Infererior Vena Cava –> get oxygenated blood to heart AND avoid liver which is underdeveloped (fetal liver is sensitive to blood pressure)

Question 21

Selective Transcription

Answer 21

The process of cells selectively up regulating and down regulating the expression of genes based on their cell type.

Question 22

Trophoblast differentiation steps:

Answer 22

trophoblast –> chorionic villi –> placenta

Question 23

Amnion

Answer 23

Shock absorber during pregnancy.. filled with amniotic fluid

Question 24

Yolk Sac

Answer 24

Site of Early Blood Development

Question 25

Allantois

Answer 25

Early fluid exchange between the embryo and yolk sac

Question 26

Paracrine Signaling

Answer 26

diffuses to local cells and stimulates cell response.

Question 27

Endocrine

Answer 27

Release of some factor (hormone, steroid, etc.) that can be uptaken and act on some other tissue in the body (i.e. adrenal on heart or brain).

Question 28

Autocrine Signaling

Answer 28

Responding to factors that have been released by the same cell.

Question 29

Totipotent

Answer 29

Cells that exsit before gatrulation (pre germ layers), and thus can have the highest rate of possible diffeerentiation

Question 30

Pluripotent

Answer 30

Cells that come after gastrulation, and can differentiate into ANYthing in their respective germ layer.

Question 31

Multipotent

Answer 31

Semi-specialized cells that can differentiate into a paticular class of cells (i.e. Hematopoteic Stem Cells can turn into different types of blood cells only).

Question 32

Nonpotent

Answer 32

Very specific cell with no more differentiation possible

Question 33

Necrosis

Answer 33

A type of cell death found only in “injury”

Question 34

Apoptosis

Answer 34

Regulation or Programming of cell death.. like dissolving a tissue inorder to make it anew (like the endometrial lining).

Also note, there is no dramatic body response (like in an infection) as seen in Necrosis.

Question 35

Blastocyst

Answer 35

Hollowed out embryo that has implanted into the endometrial lining

Question 36

Morula

Answer 36

Embryo which starts as 2 cells turns into a 16 cell mass, but does not grow in size because it undergos cleavage - rapid mitotic cell division with no growth in size (the cells are actually all smaller than the original cell).

Note that Morulation occurs before the embryo has had a chance to implant into the endometrial lining

Question 37

Zygote

Answer 37

Single cell (egg + sperm) that exist well before implantation in the endometrial lining