lab 3 exam: development and inheritance

first trimester involves 4 processes

1. cleavage

2. implantation

3. placentation

4. embryogenesis

cleavage

• sequence of cell divisions (mitosis) that begins immediately after fertilization

• ends with blastocysts contacts the uterine wall: zygote → 2 cell stage → 4 cell stage → morula (solid): 8, 16, 32 - cell → blastocyte or blastula

cleavage is the sequence of cell divisions (mitosis) that begins immediately after?

fertilization

how does cleavage end with blastocyst contacts with uterine walls?

zygote → 2 cell stage → 4 cell stage → morula (solid): 8, 16, 32 - cell → blastocyte or blastula (hollow)

blastomeres

identical cells produces by cleavage

zygote → 2 cell stage → 4 cell stage, is a representation of which term?

blastomeres

morula

soild ball of cells resembling mulberry

blastocyte or blastula

• hollow ball

• inner cell mass: will form embryo

• trophoblast: outer later of cells of blastocyte, provide nutrients to developing embryo

• inner cavity is called blastocoele

trophoblast

outer layer of cells of blastocyte, provides nutrients to developing embryo

blastocoele

inner cavity of blastocyte/blastula

implantation

• begins with attachment of blastocyte to endometrium of uterus

• set stage for formation of embryonic structures

in implantation, it begins with?

attachment of blastocyte to the endometrium uterus

what does the implantation set the stage for?

formation of embryonic structures

placentation

• occurs as blood vessels form around periphery of blastocyst

• placenta develops to permit exchange between maternal and embryonic blood

placentation, occurs as the blood vessels form around the?

periphery of the blastocyst

placentation, importance of the development of the placenta?

permit exchange between maternal and embryonic blood

embryogenesis

• formation viable embryo

• establishes foundation for all major organ systems

what is the importance of the 4 extra embryonic membranes?

support embryonic and fetal development

4 types of extra embryonic membranes

• yolk sac

• amnion

• allantois

• chorion

yolk sac

• primary nutrient source for early embryonic development

• blood cell formation

what is the primary nutrient course for early embryonic development?

yolk sac

what plays part in blood cell formation?

yolk sac

amnion

• surrounds and cushions developing embryo/fetus

• amniotic fluid produced

what surrounds and cushions developing embryo/fetus?

amnion

where is amniotic fluid produced?

amnion

allantois

• part of connecting stalk/umbilical cord

• waste storage, later gives rise to urinary bladder

allantoic is part of?

connecting stalk/umbilical cord

allantois, has waste storage, later gives rise to?

urinary bladder

chorion

• chorionic villi forming fetal portion of placenta

• exchange platform between mother and fetus

what is the exchange platform between mother and fetus?

chorion

what forms fetal portion of placenta?

chorionic villi - chorion

what forms the maternal portion of placenta

basal decidua (decidua basalis)

basal decidua (decidua basalis)

• disc shaped area deep in endometrium

• maternal portion of placenta

placental circulation includes?

• umbilical arteries

• umbilical veins

umbilical arteries

blood flow from fetus to placenta through paired (deoxygenated blood)

umbilical arteries carries which type of blood?

deoxygenated blood

umbilical vein

blood returns to fetus in single umbilical vein

umbilical vein carries which type of blood?

oxygenated blood

incomplete dominance

when phenotype of heterozygote is an intermediate between both homozygotes

disease caused by recessive alleles on the X chromosomes (X-linked gene) are more likely to happen in?

males since they only have 1 copy of X chromosomes whereas females have 2

in order for females to exhibit a recessive phenotype for an X-linked gene, she must?

have 2 copies of the mutant allele

females that have only 1 copy on one her X chromosomes are called?

carriers

• for the disease and does not exhibit the phenotype

3 germ layers

• ectoderm

• mesoderm

• endoderm

ectoderm

• integumentary system (epidermis, nail, hair follicles, and hair)

• glands communicating with skin (sweat, mammary, sebaceous glands)

• nervous system (brain, spinal cord, etc)

mesoderm

• skeletal system (bones)

• muscular system (muscle)

endoderm

mucous membranes lining respiratory, digestive, urinary, and reproductive system

gastrulation

form gastrula with 3 germ layers: ectoderm, mesoderm, and endoderm

cleavage includes?

• fallopian tube

• uterine cavity

fallopian tube

• fertilization to zygote

• 2 cell stage

• 4 cell stage

• morula (solid): 8, 16, 32 cells

• uterine cavity

• blastula/blastocyst (hollow) with:

• inner cell mass

• trophoblast

• blastocoele (blastocyst cavity)

blastula/blastcyst adhere to?

uterine lining

trophoblast cell divide rapidly, creating layers of?

• cytotrophoblast

• syncytiotrophoblast

cytotrophoblast

cells closest to interior of blastocyst

syncytiotrophoblast

outer layer, erodes path through uterine epithelium by secreting hyaluronidase (digestive enzymes)

uterine wall is modified as?

decidua basalis