Reproduction and Fetal Development Overview

Sexual response cycle

Four phases: excitement, plateau, orgasm, resolution.

Excitement phase

Initial arousal with physiological changes.

Plateau phase

Heightened sexual arousal before orgasm.

Orgasm phase

Peak sexual pleasure with muscle contractions.

Resolution phase

Return to resting state after orgasm.

Male sexual response

Includes erection, ejaculation, and refractory period.

Female sexual response

Involves vaginal lubrication and uterine contractions.

Capacitation

Final maturation step for sperm before fertilization.

Insemination

Introduction of sperm into the female reproductive tract.

Acrosome reaction

Sperm releases enzymes to penetrate the egg.

Cortical reaction

Prevents polyspermy after fertilization.

Zygote

Single cell formed after fertilization.

Blastocyst

Stage of embryonic development before implantation.

Uterine receptivity

Preparation of the uterus for embryo implantation.

Apposition

Initial contact of blastocyst with uterine wall.

Gastrulation

Formation of three primary germ layers.

Mesoderm

Gives rise to kidneys and gonads.

Ectoderm

Forms nervous tissue and skin derivatives.

Endoderm

Gives rise to internal organs and linings.

Placenta

Organ for nutrient exchange between mother and fetus.

Chimeric organ

Contains both maternal and embryonic tissues.

Ectopic pregnancy

Embryo develops outside the uterus.

Placenta previa

Placenta implants in the lower uterus.

Preeclampsia

Pregnancy-induced hypertension condition.

Hormones of pregnancy

Regulate various physiological changes during pregnancy.

HCG

Hormone indicating pregnancy, secreted by chorion.

Prolactin

Hormone that promotes milk production. Shifts fuel towards mother when sick.

Relaxin

Hormone that plays a role in osmoregulation and cardiovascular adaptation.

Parturition

Process of giving birth.

Cervical effacement

Thinning of the cervix during labor.

Dilation

Opening of the cervix during labor.

Contraceptives

Methods to prevent pregnancy.

Placental Lactogen (PL)

Shifts fuel away from mother, towards the fetus.

Corticotropin-releasing hormone (CRH)

Increases DHEA release, which is used to synthesize estrogen; serves as the initial signal for labor.