Lecture 22: Reproductive Physiology III Flashcards
Cells of the embryoblast differentiate to form what? Name the layers.
Bilaminar disc. Endoderm called hypoblast, ectoderm called epiblast.
What is special about the epiblast?
Contains cavity called enlarges to form amniotic cavity.
Cells on the edge of the _______ migrate to cover the inner surface of the _________. The former _________ cavity becomes the _____ ____.
Hypoblast, blastocyst, blastocyst, yolk sac.
What does the yolk sac do?
Supply nutrients, blood cells, primoridal germ cells, forms part of the GI tract.
____ days after fertilization, the ______ disc transforms to form which THREE layers? This process is called what?
15, bilaminar. Ectoderm, mesoderm, endoderm. Gastrulation.
During gastrulation, cells from the _______ rearrange/migrate. A ________ _______ forms on the dorsal surface of the _______. What does it do?
Epiblast, primitive streak, epiblast. Establishes tail/head, R/L, etc.
_______ cells from the primitive streak displace cells from the ________, which forms the _______.
Epiblast, hypoblast, mesoderm.
At the head of the _________ _______, epiblastic cells form the ________ ______. What does this eventually form?
Primitive streak, primitive node. Forms NS.
Describe the cells of the ecto/meso/endoderm and what they eventually form.
ecto = tight epithelia, form all NS/skin
meso = loose CT, form all muscle things
endo = tight epithelia, form all epithelia and gametes
What occurs during the 4th-8th week?
Organogenesis. By the end of the 8th week, all systems have begun to develop.
During the folding stage, the _______ ____ is incorporated into the embryo to form the ___________ _________.
Yolk sac, primitive gut.
How does the cardiovascular system adapt to pregnancy (4)?
- increased blood to placenta
- SV/CO increase
- HR increase
- blood volume increases
How does the respiratory system adapt to pregnancy (2)?
- tidal volume increases
- oxygen consumption increases
How do the GI system, urinary system adapt to pregnancy?
GI = decreased motility
Uro = pressure on bladder, ureters/kidneys enlarged
Labour onset is a complex interaction of ________ and ________ hormones, but mostly driven by ___________.
Placental, fetal, oxytocin.
_________ has been maintaining the pregnancy, preventing __________ __________. Labor cannot occur until ____________ has been diminished.
Progesterone, uterine contractions, progesterone
At the end of pregnancy, ________ levels soar. Why does this happen?
Estrogen. Increased CRH from placenta, causes fetus to release cortisol, DHEA (which is converted into estrogen).
What do increased levels of estrogens do? (2)
- increase oxytocin receptors on uterine myometrium
- uterine muscle fibers form gap junctions
During birth, __________ __________ in the cervix send impulses to the ___________ so oxytocin can be released from the _______ ________.
Stretch receptors, hypothalamus, posterior pituitary
Describe the three layers of the muscular myometrium.
Outer (long), middle (mesh), inner (circular)
Differentiate between 1st, 2nd and 3rd stage of labor.
1st - strong contractions until full dilation
2nd - full dilation until expulsion of the fetus
3rd - expulsion of fetus until placenta delivery
What is the fourth stage of labor? What does the uterus undergo?
Puerperium, involution.
Labor promoted clearance of ______ ______ fluid. Metabolism is boosted in the fetus and prepares to switch to ___________.
Fetal lung, glycogenolysis
Name the 8 cardinal movements in order.
Engagement
Descent
Flexion
Internal rotation
Extension
Restitution
External rotation
Expulsion
