A&P_CH26_REPRODUCTION__FETAL_DEVELOPMENT_AND_HEREDITY_FINAL abridged sc

sexual arousal

reflexogenic or psychogenic can incorporate all the senses

1. excitement (parasympathetic)

2. plateau

3. orgasm

4. resolution (sympathetic)

excitement male

• originates in erection reflex center of sacral spinal cord

• Erection can be reflexogenic or psychogenic

• full erection

• testes elevate

plateau male

• requires continual erotic stimulation

• prostate enlarges

• scrotum thickens

• pre-orgasmic emissions

• color deepens

orgasm male

• Loss of voluntary muscle control

• Emission and expulsion

• Followed by refractory period

• ejaculation

• penile, urethral, internal sphincter, anal sphincter, prostate, and seminal vesicles contraction
  

resolution male

• reproductive tissue return to their resting state

• erection disappears

• scrotum thinks

• tests descends

difference between female and male

• female doesn’t have refractory periods

• multiple orgasms

excitement female

• vaginal lubrication

• Uterine fibrillations

• uterus elevates

• clitoral erection

• labia swelling

• vaginal lubrication

plateau female

• External indicators of sexual arousal continue to increase

• uterus continues to elevate

• colors deepens

• vagina widens (tenting effect)

orgasm female

• Strong muscle contractions apply greater

  pressure on the penis

• Vaginal dilation to receive ejaculate

• rhythmic uterine contractions

• No refractory period

  
  

resolution female

• Reproductive tissues return to their resting state

• External cervical os dilates to aid sperm migration

semeinogelin

• coagulant produced in seminal vesicle

• Holds the sperm against the vaginal wall after ejaculation

motility inhibitor

prevents sperm from struggling in the coagulant, wasting energy

PSA

breaks down seminogelin within 20-40 minutes, freeing sperm

prostaglandins

• Induce reverse peristalsis in uterus to draw sperm inwards

• Reduce viscosity of cervical mucus

hCAP-18

anti-microbial protein that prevents bacterial growth in female reproductive tract

factor III

coagulation and abrasion healing

PSAP

potent anti-nociceptive; prevents painful stimuli from detection

fertilization

1. Insemination; introduction of sperm

2. Initial capacitation; last step of maturation of

   sperm

3. Sperm reservoir

4. Hyperactivation; activity of sperm

5. Sperm penetrates cumulus mass

6. Zona penetration

zona pellucida

species-specific barrier

acrosome reaction

rupture of acrosome and release of proteases that digest ZP

hyperactive sperm

have their plasma membranes rearranged and penetrate into the perivitelline space (PVS)

fusion of egg and sperm

• oocyte has microvilli all over its surface, except for overlying the oocyte’s pronucleus

• Microvilli serve as docking site for sperm, ensuring they dock away from pronucleus

• Oocyte is activated after sperm-egg fusion

• PLCz (a component of the sperm’s plasma membrane) triggers release of Ca2+ from oocyte’s ER

blocking polyspermy

• cortical reaction occurs directly after oocyte activation

• Cortical granules migrate towards the oocyte plasma membrane and release their contents into the PVS

• These materials form a new barrier against further sperm fusion

• Ensures against euploidy

second meiotic division, syngamy

• meiosis II and extrusion of polar body in the oocyte

• Packaging material in sperm pronucleus replaced with maternal histones

• Paternal mitochondria destroyed; maternal mitochondria activated

• Maternal RNA destroyed

• Pronuclei fusion and generation of diploid zygote

day 1

• initial cleavage

• single cell zygote division

• zona pellucida

• migrates towards uterus

day 2-3

• morula

• 2-cell, 4-cell, 8-cell stages

• blastomeres

day 4-5

• compaction and polarization

• asymmetric division

day 6-7

• blastulation

• blastocyst

• trophoblast cells

• blastocel

• inner cell mass

apposition

• first stage

• general stromal edema brings the uterine walls into close proximity

• Helps incoming blastocyst find attachment point

attachment

• second stage

• Polarity is important (blastocyst’s inner cell mass must be next to uterine lining)

• Development of cytotrophoblast and syncytiotrophoblast

penetration

• stage 3

• Blastocyst burrows into endometrial stroma for access to uterine nutrients

• A barrier is generated between the blastocyst and maternal cells

  

hypoblast

layer of inner cell mass closest to blastocoel; will eventually form the extraembryonic endoderm

epiblast

layer of inner cell mass farther from blastocoel; gives rise to embryo proper

two layers together form

blastodisc: gives rise to yolk sac, amnion, chorion

cephalic-caudal axis folding

resulted in embryo divided into cephalic and caudal regions

transverse axis folding

results in embryo divided into three distinct layers (ectoderm, endoderm, mesoderm)

fate of mesoderm

kidney and gonads

fate of ectoderm

• nervous tissue

• Epidermis and its derivatives

• Sense organs

• Lens of the eye

• Teeth enamel

• Mouth and anus

• Pituitary and adrenal glands

fate of endoderm

• Internal lining of respiratory, GI, urinary and reproductive tracts

• Portions of the liver, gallbladder, and pancreas

• Palantine tonsils

• Thyroid and parathyroid glands

• Thymus

stricture of placenta

• chimeric organ (organ 2 sets of DNA) consisting of uterine and embryonic tissue

• Consists of several lobes called cotyledons, fed by umbilical vessels

functions of placenta

• organ of material exchange between the mother and developing embryo/fetus

• Endocrine organ; produces hormones required for pregnancy

ectopic pregnancy

Development of the embryo or fetus outside of the uterus• Occurs when something blocks the passage of the fertilized ovum

placenta previa

The placenta implants in the inferior uterus, near to/covering the internal os of the cervix, leading to spontaneous abortion or premature birth

preeclampsia

Sudden pregnancy-induced hypertension

dystocia

Difficult labor due to an abnormal fetal position or inadequate vaginal canal; may lead to cesarean section

delivery of physiologically immature baby

• Classified as a baby that weighs less than 2,500 g at birth

• Carries substantial risk to the baby
  

growth of the uterus during pregnancy

• primarily due to hypertrophic and hyperplastic growth of the uterine myometrium

• Grows all the way to the xiphoid process of the sternum by term

development of mammary glands

• Grow in response to placental hormones

• Areola and nipple become darker in response to melanocyte-stimulating hormone (MSH)

hCG

• produced by the chorion

• Detectable ~10 days after ovulation (hormone detected by at-home pregnancy kits)

estrogen/progesterone

• produced by corpus luteum, then placenta

• Estrogen promotes uterine contraction/parturition, while progesterone prevents uterine contractions

placental lactogen

• Produced by syncytiotrophoblast cells

• Shifts fuel away from mother, towards fetus (anti-insulin properties)

prolactin

• Produced by placenta and mother’s anterior pituitary gland

• Shifts fuel towards mother in periods of insult/illness

relaxin

• Produced by syncytiotrophoblast cells

• Plays important roles in osmoregulation and cardiovascular adaptation

corticotropin releasing hormone

• Produced by syncytiotrophoblast cells

• Increases DHEA production, which is used to synthesize estrogen

• Serves as initial signal for parturition

cervical effacement and dilation

• effacement contractions → dilation of cervix → transitions

• dilate up to 10 cm

dilation stage

• cervix partially dilated

• uterus

expulsion stage

• baby crowning

• placenta

placental stage

• umbilical cord

• placenta separates from uterus

more effective contraceptive devices

• implant (0.05%)

• intrauterine device (LNG-0.2%,Copper-0.8)

• male vasectomy (0.15%)

• female sterilization (0.5%)

less effective contraceptive devices

• male condom (18%)

• female condom (21%)

• withdrawl (22%)

• sponge (24%, 14%)

• spermicide (28%)