Reproductive Part 2

Question 1

What are the 3 fertilization steps called

Answer 1

#1: Capactitating
#2: Acrosmal Reaction
#3: Fertilization

Question 2

What is Capactitating and what happens here

Answer 2

First step of fertilization.

• acidic vagina causes acrosomal pores to open
• sperm membrane receptors detect chemicals released by the egg

Question 3

What is acrosomal reaction and what happens

Answer 3

Second step of fertilization.

- enzymes realeased by acrosome digest the outer membrane of egg

Question 4

What is fertilization and what happens

Answer 4

Final step of fertilization

• sperm fuses with plasma membrane of the ovum
• sperm goes into cytoplasm causing electrochemical reactions in egg
• membrane of egg becomes impermeable

Question 5

How does pregnancy happen

Answer 5

Zygote undergoes mitosis while moving down the oviduct. 8 cells make a morula which is undifferentiated. By the time it goes to uterus it’s differentiated.

Zygote is now called a blastocyst with embryo in the middle

Question 6

What is a morula

Answer 6

8 undifferentiated cells which differentiate upon reaching uterus

Question 7

What is blastocyst, where does it embed

Answer 7

Zygote becomes blastocyst, and it has embryo in the middle. It embeds in endometrium

Question 8

What happens during implantation

Answer 8

During implantation, blastocyst embeds in endometrium and the outer layer releases hCG

Question 9

hCG function

Answer 9

• stops corpus luteum from degenerating for 3 months.
• makes progrestrone/estrogen despite the lack of FSH and LH
• prevents contractions of uterus, endometrium maintained

Question 10

Define chorion

Answer 10

• Outermost membrane secreting hCG

- Part intermingling with endometrium forms placenta

Question 11

define placenta

Answer 11

Specialized part of chorion

• contains meternal & feternal vessels
• allows diffusion of gasses, nutrients, and water
• continues production of hCG, progesterone, and estrogen
• maintains endometrium

Question 12

define amnion

Answer 12

Innermost membrane next to baby

• has amniotic fluid to cushion baby
• protects embryo from trauma & temp fluctuations
• allows baby freedom to move so limbs don’t stick to body

Question 13

define allantois

Answer 13

Helps embryo exchange gasses & handles wastes

- sends umbilical blood vessels to placenta

Question 14

define umbilical cordà

Answer 14

Connects mother to baby
Connects from belly button to placenta
- carry blood to and from placenta

Question 15

define umbilical cord

Answer 15

Site of early blood cell formation, contributes to permative digestive tract

Question 16

Embryonic development (gastrulation)

Answer 16

Happens when embryonic cells start producing 3 layers

Question 17

What do layers produced by embryonic cells do

Answer 17

Ectoderm - outer layer: skin cells & nervous systems
Mectoderm - middle layer: keleton, muscles, and reproductive structures
Ectoderm - inner layer: digestive, respitory, and endocrine systems

Question 18

define human gestation

Answer 18

Human gestation are pregnancy months divided into 3 trimesters

Question 19

What happens during 1st trimester of human gestation and how long is it

Answer 19

It’s from fertilization to week 12

• zygote become blastocyst
• organs are developed
• heart starts beating by week 4
• testosterone is produced by week 7 if Y chromosome
• all basic adult structures developed by week 8
• embryo becomes fetus, about 9cm long
• really sensitive

Question 20

What happens during 2nd trimester of human gestation and how long is it

Answer 20

From week 13 to week 24

• rapid growth
• fetus really active
• hair growth
• skeleton carriage replaced by bones
• 30cm at the end

Question 21

What happens in 3rd trimester of human gestation how long is it

Answer 21

From week 25 to week 38

• rapid growth
• fetus activity decreases due to lack of room
• mature and ready to come out
• 50cm at the end, 3kg

Question 22

Steps of pasturation

Answer 22

#1: labour
#2: delivery
#3: childbirth

Question 23

What happens during labour

Answer 23

• involuntary rythmic contractions of uterus

- cervix opens up and diallates

Question 24

What happens during delivery

Answer 24

• involuntary uterine contractions
• voluntary abdominal contractions
• mother forces baby out of cervix and vagina

Question 25

What happens during afterbirth

Answer 25

• placenta blood vessels contract immediately after delivery
• placenta seperate from uterine walls due by muscle contractions
• progesterone decreases allowing uterine to contract
• oxytocin: from posterior pituitary stimulating uterine contractions
• relaxin: from the placenta causing pelvis pigments to loosen
• prostaglandins do uterine contractions

Question 26

What is lactation

Answer 26

Milk being secreated from mammary glands.

Question 27

How are breasts prepared for lactation

Answer 27

During pregnancy, progesterone and estrogen prepare breasts for milk production. Breasts also inlarge to prepare for lactation

Question 28

How do breasts produce milk

Answer 28

Each breast has 20 glands connecting to nipple through ducts

Question 29

How is milk secretion initaited

Answer 29

After placenta leaves the body, pituitary starts secreating prolactin

Question 30

Prolactin function

Answer 30

Prolactin inhibits LH = no more ovulation = no more menstrual cycle. Prolactin secreats milk

Question 31

define colostrum

Answer 31

First milk realeased from mammary glands

- contains lactose, proteins, and antibodies, there is no fat

Question 32

How does oxytocin keep getting produced

Answer 32

Due to positive feedback, suckling causes hypothalamus to produce more oxytocin

Question 33

Why does prolactin not get produced during pregnancy

Answer 33

Estrogen and progesterone inhibit release of prolactin

Question 34

Define ultrasound

Answer 34

Detecting body structures using soundwaves

Question 35

Define amniocentesis

Answer 35

Removes amnitonic fluid using needle and fetal cells in fluid are cultured for 2-4 weeks.
- karyotype produced allows to analyze genetic disorders

Question 36

Chorionic Villi Sampling (CVS)

Answer 36

• fetal part of placenta is removed to test for disorders
• can perform this earlier than amniocentesis
• greater risk of spontaneous abortion

Question 37

In-vitro fertilization

Answer 37

• ova surgically removed from women with blocked oviducts

- ova fertilized in petri dish & embryo inserted in mother’s uterus

Question 38

Difference between prolactin and oxytocin

Answer 38

Prolactin produces milk, oxytocin releases milk

Question 39

What is vasectomy

Answer 39

Vas defences in males are cut and tied off, so sperm is produced but dosent get too uterus

Question 40

What is tubal ligation

Answer 40

Oviducts are severed to stop egg movement from ovary to uterus

Question 41

Birth control pill

Answer 41

Taken for 28 days

• estrogen and progesterone given for 21 days to simulate pregnancy
• FSH and LH shit down so follicles don’t develop and no ovulation

Question 42

What is diaphragm barrier method

Answer 42

Fits over cervix to prevent semen from entering uterus

Question 43

What is IUD

Answer 43

Device placed in uterus by physician preventing blastocyst from implanting in endometrium