A&P2 CHAPT 29: DEVELOPMENT

*know the 3 stages from conception to birth

• #1: _______: first 2 weeks of development during formation of primitive germ layers

• #2: _____: weeks 3-8 is when organ systems develop; developing human is called an embryo

• #3: ____: last 30 weeks, organ systems grow, and mature developing human is called a fetus

germinal period, embryonic period, fetal period

*_____: when more than one sperm fertilizes an egg which is bad because it results in the wrong number of chromosomes → nonviable embryo. So the egg has defense mechanisms to prevent it.

a: the secondary oocyte is surrounded by two layers:

• ______: outer layer of follicular cells

• _____: glycoprotein layer just outside the oocyte membrane

b: sperm movement + binding

• sperm’s flagella propels it through the _____ ____

• _______: enzyme cap of sperm that binds to the ZP3 receptors on the zona pellucida. This initiates _______ reaction. The enzymes are released to digest the _____ ____

c: entry + blocks to the polyspermy

• when the first sperm cell enters through the _____ ____, it binds to a receptor on the oocyte that causes ________

  • this is the _____ to polyspermy: depolarization prevents additional sperm from attaching to the ooyte membrane

• the oocyte releases fluid that causes the zona pelllucida to harden and ZP3 receptors to inactivate

  • this is the ___ ___ to polyspermy: this structural change permanently prevents additional sperm entry

polyspermy, corona radiata, zona pellucida, corona radiata, acrosome, acrosomal, zona pellucida, zona pellucida, depolarization, fast block, slow block

*know the early development of the embryo form

a: ____: single cell formed after fertilization

b:_____: first division occurs within 18-36 hours

c: ____: solid ball of 12 or more cells + still surrounded by the zona pellucida

d:___ : hollow structure formed after the morula enters the uterus

• contains a fluid-filled cavity called the ______

• ______: outer single layer of cells around blastocele, becomes the placenta and extra embryonic membranes

• _____: group of thick cells inside the blastocyst, becomes the embryo proper

zygote, 2 cell stage, morula, blastocyst, blastocele, trophoblast, inner cell mass

a: _____ is the stage that implants into the uterus

blastocyst

a: ______: remains near other embryonic tissues: branches called chorionic villi protrude into the lacunae

b:_____: invades the endometrium; forms cavities called lacunae filled with maternal blood

cytotrophoblast, syncytiotrophoblast

a: _____: membrane surrounding a developing embryo and plays a key role in the exchange of nutrients, oxygen, and waste between the mother and fetus

• what is this made up of? (2 things from short phrase to long)

b: ______: forms inside blastocele from the hypoblast. Only lasts about 12 weeks, provides nourishment and gas exchange

chorion, syncytiotrophoblast layer, basement membrane of chorionic villi, yolk sac

a: ______: usually occurs in the body of the uterus

b: ______ ____: implantation near the cervix; as the _____ grows, it can extend over the internal cervical opening and tear

c: ________ ____: placental attachment is weak and tears away from the uterine wall

→ both of these conditions result in ______ and can threaten the life of the ____

implantation, placenta previa, placenta, abruptio placenta, miscarriage, mother

a: ____: epidermis of skin, lens and cornea of eye, teeth, brain and spinal cord, adrenal medulla

b: ____: dermis of skin, cardiovascular system, muscle, bones, kidneys

c: ___: lining of the digestive tract, lungs, hepatic, urinary bladder, thyroid, parathyroid, tonsils

ectoderm, mesoderm, endoderm

*know the lengths of each trimester

• ____trimester: fertilization to ____ weeks

  • Fertilized egg will change from a small grouping of cells to a fetus with human features

  • most women develop ____ ___ and ____

• ____ trimester: week 13 to week 28

  • considered the “best” part of pregnancy

  • morning sickness ends

  • start to feel movement as the fetus flips and turns in the uterus

  • can find out the sex of the baby (ultrasound at 20 weeks)

• ____ trimester: week 29 to week 40

  • more difficult to move, stand, and sleep

  • fetus gains weight quickly

  • week 36 baby turns head down

    ---

first, 12, morning sickness, fatigue, second, third

*understand parturition

a: hormones involved

• _____: rises before labor; increases uterine sensitivity to oxytocin

• _____: decreases, removing its relaxing effect on the uterus

• _____: stimulates strong uterine contraction (Positive feedback loop)

• _____: soften and dilate the cervix; enhance contractions

b: what triggers labor?

• high _____ levels overcome _____ effects

• fetal adrenal gland activity releases _____, which promotes ____ maturity and contributes to ____ onset

• stretching of uterus and cervix stimulates _____ release from maternal pituitary

• Positive feedback loop: uterine contractions > more oxytocin > stronger contractions

c: stages of labor

• #1: ______

  • from onset of contractions to full cervical dilation (10CM)

  • longest stage (can last 8-24 hours)
    amniotic sac typically ruptures [aka water breaking]

• #2: _____

  • from full dilation to birth of the baby

  • mother actively pushes

  • last minutes to a few hours

• #3: ______
  from baby’s birth to expulsion of the placenta

  • lasts about 5-30 minutes

estrogen, progesterone, oxytocin, prostaglandins, estrogen, progesterone, cortisol, organ, labor, oxytocin, dilation stage, expulsion stage, placental stage

a: ____: “sinking”/downward displacement of the uterus, where the uterine cervix moves lower into or outside the vaginal canal

• ____: cervix descend sinto the vagina, but does not reach the vaginal opening

• ____: cervix descends to the level of the vaginal opening (near the orifice)

• ____: the entire uterus protrudes outside the vaginal opening

prolapse, first degree, second degree, third degree

a: ____: occurs when a single fertilized egg (zygote) splits into two embryos early in development

• scientific term?

• can occur when a ____ cell separates from the embryo, resulting in genetically identical twins

b: ____: occurs when two eggs are released from the ovary at the same time and are fertilized by two different sperm cells

• scientific term?

c: ____: when the baby is positioned feet first/buttocks first. This increases risk during vaginal delivery + may require C-section if the abby doesn’t turn before labor

d: ____: IDEAL fetal position for birth, where the baby’s head is faced downwards + chin tucked into it’s chest

e: _____: the removal + analysis of amniotic fluid, commonly performed in the 2nd trimester. this process is typically only done when the mother is 35 years or older OR if there’s a history of some kind of disorder.

f: ____: a recalled sedative drug that was once used for pregnancy. It has caused severe birth defects when taken by pregnant women.

identical twins, monozygotic, totipotent, dizygotic, breech position, amniocentesis, thalidomide

a: _____: occurs when a pregnant female drinks alcohol, which crosses the placenta and damages the fetus. The baby is then born with a smaller-than-normal head, intellectual disability, and possibly other defects

fetal alcohol syndrome

a: ______ production of milk by mother’s breasts (mammary glands) following parturition.

b: _____: suckling by baby stimulates the surge of this hormone and stimulates additional milk production

c: benefits of breast feeding: colostrum is high in _____ and contains ____ that helps newborns from infections

d: _______: produced first few days after birth. High in protein, contains many antibodies.

lactation, prolactin, protein, antibodies, colostrum