Biol: Embryology

Front 1

cleavage

Back 1

early embrionic divisions; cleavage always results in an increasing ratio of nuclear to cytoplasmic mat and increases the surface-to-volume ratio of each cell as well

Front 2

indeterminate cleavage results in cells....

Back 2

that are still totipotent- can develop into a complete organism

Front 3

a determinate cleavage results...

Back 3

in cells with specified differentiation pathways

Front 4

The zygote divides into __ cells in approx ___ hrs; at which point it should be at the ______

Back 4

8; 72; uterus

Front 5

The first stage of the zygote; a solid ball of cells

Back 5

morula

Front 6

the morula develops a ______, beginning the process of _____

Back 6

fluid-filled cavity aka blastocoel; blastuation

Front 7

Blastocyst

Back 7

mammalian blastula

Front 8

Cell Groups of Blastocyst

Back 8

Inner cell mass--> protrudes into the blastocoel
Trophoblast--> surrounds inner cell mass and blastocoel

Front 9

When does implantation occur?

Back 9

during blastulation

Front 10

The hormone ____ prepares the uterus for implantation by....

Back 10

progestorone; thickening the endometrium

Front 11

Proteolytic enzymes

Back 11

secreted by the embryonic cells in order to enable the embryo to plant into the uterine wall. Eventually allows for the exchange of resources from mom->baby

Front 12

After implantation the blastula...

Back 12

undergoes cell migration to become a three-layered GASTRULA... 2-layers arise from an invagination; 3 from further folding.

Front 13

The fresh cavity of the gastrula?

Back 13

The archenteron- this develops into the gut (alimentary canal)

Front 14

Opening of the Archenteron?

Back 14

Blastopore; In _DEUSTEROMES_ becomes anus. in PROTOSOMES becomes mouth

Front 15

Three primary germ layers?

Back 15

Ecto(outer)derm and Endoderm arise first followed by the Mesoderm.

Front 16

WHICH DERM?
Lens of the eye

Back 16

Ectoderm

Front 17

WHICH DERM?
epithelial linings of dig/ resp tracts

Back 17

Endoderm

Front 18

WHICH DERM?
Epidermis

Back 18

Ectoderm

Front 19

WHICH DERM?
nails

Back 19

Ectoderm

Front 20

WHICH DERM?
bicep

Back 20

Mesoderm

Front 21

WHICH DERM?
bladder

Back 21

Endoderm

Front 22

WHICH DERM?
Brain stem

Back 22

Ectoderm (NS)

Front 23

WHICH DERM?
liver

Back 23

Endoderm
pancreas, thyroid

Front 24

WHICH DERM?
gonads

Back 24

Mesoderm

Front 25

Differentiation arises from

Back 25

selective transcription of genomes

Front 26

Induction, embryonically speaking is?

Back 26

The influence of a specific group of cells on the differentiation of another. Mediated by chemical _inducers_

Front 27

The rudimentary development of the NS

Back 27

Neurulation

Front 28

Neurulation begins with...

Back 28

The development of a rod of mesodermal cells, NOTOCHORD, along the longitudinal axis of the fetus; just under the ectoderm

Front 29

The notochord has an ___ effect;
expand

Back 29

inductive; the overlying ectoderm bends inwards and grow upward till they fuse, forming a _NEURAL TUBE_ , which then goes on to disconnect from the surface ectoderm.

Front 30

After the formation of the Neural tube from the ______...

Back 30

ectoderm; the cells at the tip of what were the neural folds are termed the neural _crest_

Front 31

The neural crest cells go to what end?

Back 31

They migrate laterally to become the PNS, inc the sensory ganglia, autonomic gang, schwann cells, adrenal medulla...

Front 32

After eight weeks of gestation the embryo..

Back 32

is called a fetus

Front 33

The two major components of the Fetal Respiratory System

Back 33

Placenta and Umbilical Cord

Front 34

Placenta Formation

Back 34

Begins with the CHORION, surrounding membrane of AMNION (thin,tough, membrane w/ amniotic fluid (shock absorber)). Chorion extends chorionic villi into uterine wall.

Front 35

Umbilical Cord Formation

Back 35

The _ALLANTOIS_ develops as an outpocketing of the gut. The blood cells of the allantoic wall enlarge and become umbilical vessels; The Yolk Sac, site of early development of blood vessels, and Allantois, become enveloped by the placenta and form the embryonic cord.

Front 36

Hb-F vs Hb-A

Back 36

Fetal Hemoglobin has a much higher affinity for 02 than does adult Hemoglobin; EXCHANGE of nutrients occurs via diffusion in the placenta

Front 37

So order the different cell stages of embryo:

Back 37

zygote-->8-celled ball@72hr-->morula-->blastocyst-->gastrula

Front 38

Fetal Circulation:
Blood oxygenated...

Back 38

in the placenta NOT the lungs

Front 39

Fetal Circulation:
There are three shunts whose sole purpose is to...

Back 39

divert blood from the lungs

Front 40

Fetal Circulation:
The ______ carries oxygenated blood from the placenta to the fetus

Back 40

umbilical vein

Front 41

Fetal Circulation:
The blood from the umbilical vein bypasses the liver...

Back 41

by way of the _DUCTUS VENOSUS_; converging with the inferior venae cavae

Front 42

Fetal Circulation:
The inf and sup venae cavae return deoxygenated blood...

Back 42

to the right atrium. The blood in the R atrium is only partially oxygenated as it is a mix of the umb vein and deoxy blood.

Front 43

Fetal Circulation:
From the R atrium,....

Back 43

most blood bypasses pulmonary circulation, and goes directly from the R atrium to the L atrium via the _FORAMEN OVALE_

Front 44

Fetal Circulation:
What is left in the R atrium...

Back 44

empties into the R ventricle and is pumped into the pulmonary artery. Most blood is shunted from the artery to the aorta via the _DUCTUS ARTERIOSUS_

Front 45

Fetal Circulation:
The pulmonary arteries carry...

Back 45

partially oxygenated blood to the lungs

Front 46

Fetal Circulation:
In a bebe, the pulmonary vein..

Back 46

carries fully deoxygenated blood to the left atrium, This blood mixes witg tge partially oxyg blood from the right atrium (_Foramen OVALE), before being pumped into systemic circ by the left ventricle