Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histo > Pregnancy > Flashcards

Pregnancy Flashcards

1
Q

Lactogenesis vs Milk let-down response

A

Lactogenesis: milk production

Milk letdown response: release of stored milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Milk let down / ejection reflex

A
  1. Baby suckling sends impulses from the nerves of the nipple to the hypothalamus
  2. Anterior pitutiary releases prolactin: secrete milk into alveoli
  3. Posterior pituitary releases oxytocin: causes the myoepithelial cells to squeeze alveoli
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Lactational amenorrhea

A

prolactin inhibits GnRH –> amenorrhea

This is why your period stops during pregnancy - to stop ovarian follicle development

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Regression of mammary gland after lactation

A

Resorption of glandular tissue & reestablishment of c.t. and adipose tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How does the mamary gland change after menopause?

A

Connective tissue decreases (less cellular, more fibrous)

Involution of ducts & secretory units

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Things leading up to implantation

A

Fertilization in the ampulla > 2,4, 8, cell stage > blastocyst rolls along the endometrium> implantation into the endometrium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

When does implantation occur?

What important things happen during implantation?

A

Occurs during the secretory phase (days 21-24 of cycle)

  • Syncytiotrophoblasts secrete hCG to rescue and maintain the corpus luteum
  • Decidual reaction: hypetrophy of endometrial stromal cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why do we need so much progesterone and estrogen during pregnancy?

A

To maintain the thickness of the endometrial lining

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q
A

25 days

We’re at day 40. Conception is day 15. Thus, conception occured 40-15 = 25 days ago.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Decidual reaction

A

the continued produciton of progesterone & estrogen cause endometrial stromal cells to hypertrophy and fill with glycogen & lipid

–> fibroblasts look more round

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Functions of decidua

A
  • Source of nutrients for embryo until vascular connections between mother and embryo are developed
  • Barrier to further invasion of the uterine wall by the mebryo
  • Endocrine function: prolactin, relaxin, and prostaglandins act on uterine muscle, cervix, and embryo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Relaxin

What produces it?

What is it stimulated by?

What are its funcitons?

A
  • Produced by decidua, corpus luteum of pregnancy, and placenta
  • Stimulated by hCG
  • Fxns:
    • Early pregnancy: suppress myometrial contractions
    • Late pregnancy: soften cervix in preparation for parturition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Prolactin

What makes it?

Function?

A

Major source: maternal pituitary and decidua

Function: depress immune response to fetus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Prostaglandins

what makes it

function

A

Decidua

In late pregnancy, it contracts uterine smooth muscle and softens the cervix.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the blue arrows pointing at?

A

Decidual cells / Stroma cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What changes do we see in the endometrium and myometrium in the pregnant uterus?

A

Decidual reaction: endometrial stroma becomes decidua

Myometrium: hyperplasia & hypertrophy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Tissue layers of the blastocyst (inner to outer)

A
  • Cytotrophoblast (inner)
  • Synctiotrophoblast (outer)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Describe the trophoblast

A

Peripheral cells of the blastocyst that attach the fertilized ovum to the uterine wall and contribute to the placenta

Cytotrophoblast (inner): mitotically active trophoblast-producing cells that fuse with the syncytiotrophoblast

Syncytiotrophoblast (outer): not mitotically active; multinucleate cytoplasmic mass invades the epithelium and underlying stroma of the endometrium

19
Q

Syncytium

A

a multinucleate cellular mass produced by the fusing of cells.

20
Q

Functions of the placenta

A
  • Endocrine
    • Synthesizes & secretes hormones for maternal & fetal metabolism
    • Independent; not subject to regulation by maternal or fetal signals!
  • Fetal gut supplying nutrients
  • Fetal lung exchanging gases
  • Fetal kidney eliminating waste products & regulating fluid volume
21
Q

Describe the components of placenta

A
  • Fetal portion - chorion
    • Chorionic plate
    • Chorionic villae
    • Cytotrophoblastic shell
  • Maternal portion - decidual basalis
    • Basal plate
    • Placenta septa
22
Q

What is the blue bar?

A

The chorion: contains the secondary villus, the cytotrophoblast, and the syncytio trophoblast

23
Q

What is the blue line pointing at?

A

Cytotrophoblastic shell

24
Q

Establishing placental circulation

A

The chorion (fetal criculation) sends out villi into the placenta, wher eit will capture maternal blood in the decidual basalis

25
Q

Where is the maternal blood vs the fetal blood?

A

This is chorionic villi

The fetal blood supply would be within the villi (BV)

The maternal blood supply would be in the interstitial space (IS)

26
Q

Histologically how do cytotrophoblasts look diff from syncytiotrophoblast?

A

Syncytiotrophoblasts look like packs of nuclei

Cytotrophoblasts have one fat nucleus

27
Q

Free vs anchoring villi

A

Free villi dont connect to the decidual basalis

Anchoring villi do

28
Q

Describe the placental barrier that blood, gas, and nutrients have to cross to get to the fetus

A

Syncytiotrophoblast

Cytotrophoblast

Connective tissue (extraembryonic mesenchyme)

Fetal endothelial cell of blood vessel

29
Q

What crosses the placental barrier?

A
  • Exchange of gases & nutrients (glucose, aa, proteins)
  • Transferrin (iron to fetus)
  • Steroid hormones
  • Fetus eliminates CO2 and waste
  • Maternal antibodies (esp igG) provides passive immunity to the newborn
  • Alcohol, drugs, some viruses (birth defects)
30
Q

The placenta secretes numerous steroid & protein hormones that affect maternal AND fetal metabolism

How is it regulated?

A

Independent!

not subject to regulation by maternal or fetal signals

31
Q
A

Urinary estriol & serum hCG

Fetus is responsible for estriol

hCG is only ever produced by the placenta by syncytiotrophoblast only (whereas, progesterone can come from corpus luteum of pregnancy AND placenta).

32
Q

Cytotrophoblast hormones

A

​IGF-I and IGF-II to stimulate proliferation/differentiation

GnRH, CRH, TRH, and somatostatin to act on the syncytiotrophoblast

33
Q

Syncytiotrophoblast hormones

A
  • hCG, human chorionic ACTH, human placental GH, and human chorionic thyrotropin
  • Progesterone
  • Estradiol
  • Inhibin A: suppress mother’s FSH
  • Human chorionic somatomammotropin (hCS)/hPL: shunts nutritional substrates to fetus
34
Q

Funcitons of progesterone secretion from placenta

A
  • Inhibits maternal immune responses
  • provide precursors to fetal adrenal glands
  • quiets uterine contractions
  • stimulates mammary gland development
35
Q

Function of estrogens released from sycytiotrophoblast

A
  • Stimulates growth of uterine smooth muscle
  • Stimulates mammary gladn development

Can’t synthesize androgen precursors for estradiol synthesis; must use fetal adrenal glands

36
Q

Function of human chorionic somatommaotropin (hCS) aka hPL

A

Shunt nutritional substrates to fetus

37
Q

Where do androgen precursors for estradiol synthesis come from in placenta?

A

androgen precursors come from the fetal androgen gland

38
Q

describe the process of placental steroidogenesis

A
  1. Mother sends cholesterol to the placenta
    1. Make pregnenolone to be sent to the fetus
    2. Make progesterone
  2. ​Fetus makes DHEA from pregnenolone and then creates the androgen precursor to be sent back to the placenta for it to then make estriol
39
Q

Progesterone & Estrogen synthesis

Which occurs independently of the fetus? Which can be used to assess fetal health?

A

Progesterone synthesis tells us about placental health

40
Q

How long does hCG maintain estrogen & progesterone secretion until?

A

Until the end of the 1st trimester, then placenta takes over

41
Q

High levels of sex steroids from the placenta suppress __ to prevent __.

A

the hypothesis/pituitary axis to prevent ovulation

42
Q

Prolactin’s action on the mammary gland during prengancy is blocked by ____. What causes the lactogenic effect to start?

A

Blocked by E & P during pregnancy

Extrusion of placenta during birth –> drop in E & P –> lactogenic effect commences

43
Q

Review of pregnancy hormone levels

A

Histo (20 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions