reproductive system(s). osu physio 3200

Gonads

Primary reproductive organs producing gametes which are testes in males and ovaries in females

Spermatogenesis

Process of sperm development occurring in seminiferous tubules that requires temperatures slightly cooler than body cavity

Testes

Male gonads located in the scrotum that produce sperm and synthesize testosterone

Epididymis

Structure attached to testes where sperm undergo maturation in the head and storage in the tail

Seminiferous Tubules

Microscopic packed tubules in the testes where sperm are produced before moving to the epididymis

Leydig Cells

Endocrine cells located between seminiferous tubules that produce testosterone

Vas Deferens

Smooth muscle lined tubule that connects epididymis to ejaculatory duct and stores sperm

Seminal Vesicles

Secretory glands joining vas deferens behind the bladder that contribute fluid to semen

Prostate Gland

Secretory gland surrounding the urethral junction that contributes fluid to semen

Bulbourethral Glands

Secretory glands attached to the urethra that contribute fluid to semen

Semen

Ejaculated fluid made of ninety percent gland secretions and ten percent sperm

Vasectomy

Male birth control method of cutting the vas deferentia to block sperm from entering semen

Gametes

Mature reproductive cells with half the genetic material such as sperm or ova

Spermatogonia

Undifferentiated stem cells near the outer tubule wall that start sperm formation

Primary Spermatocytes

Cells formed from spermatogonia that undergo the first meiotic division

Secondary Spermatocytes

Haploid cells generated after the first meiotic division of primary spermatocytes

Spermatids

Immature haploid cells created after second meiotic division that mature into spermatozoa

Spermatozoa

Fully differentiated motile male gametes with head midpiece and flagellum

Replenishment

Process where some spermatogonia divide without differentiating to preserve stem cells

Sertoli Cells

Tubule wall cells forming the blood testis barrier that nourish sperm consume defective ones and release inhibin

Acrosome

Lysosome like structure on the sperm head filled with enzymes needed to penetrate an egg

Flagellum

Tail structure of sperm that moves in a whiplike motion to propel it forward

GnRH

Hypothalamic hormone released in pulses to trigger pituitary release of FSH and LH

FSH

Pituitary gonadotropin that acts on Sertoli cells in males to stimulate sperm production and inhibin

LH

Pituitary gonadotropin that acts on Leydig cells in males to stimulate testosterone production

Inhibin

Hormone secreted by Sertoli or granulosa cells that provides negative feedback to decrease FSH

Testosterone

Main male hormone produced by Leydig cells that drives sperm production sex traits and libido

5 Alpha Reductase

Enzyme in peripheral tissues that converts testosterone into dihydrotestosterone

Dihydrotestosterone

Highly potent androgen converted from testosterone by 5 alpha reductase

Aromatase

Enzyme converting testosterone into estradiol which is present in high amounts in ovaries

Nitric Oxide

Gas signaling molecule released in penile blood vessels causing dilation and erection

Erectile Dysfunction

Consistent inability to achieve or maintain an erection adequate for sexual performance

Cryptorchidism

Condition where one or both testes fail to descend into the scrotum

Hypogonadism

Abnormally low or absent testosterone production from the testes

Benign Prostatic Hyperplasia

Noncancerous enlargement of the prostate in older men causing urinary blockage

Uterus

Muscular organ located above the bladder where embryonic and fetal development occurs

Vagina

Muscular canal leading from cervix to outside of the body

Cervix

Lower narrow neck of the uterus opening into the vagina

Vulva

External female genitalia structure

Ovaries

Female gonads producing eggs plus estrogen and progesterone hormones

Fallopian Tubes

Tubes connecting ovaries to uterus where egg fertilization occurs

Fimbriae

Fingerlike projections at fallopian tube ends that sweep ovulated eggs inside

Oogonia

Immature female germ cells that divide in fetal life and convert to primary oocytes before birth

Primary Oocytes

Egg cells arrested in early meiosis from birth until puberty activation

Secondary Oocyte

Large cell formed after first meiotic division receiving almost all cytoplasm prior to ovulation

Polar Body

Small nonfunctional cell generated during meiotic divisions that degrades

Ova

Fully mature female egg cell formed only after fertilization by sperm

Primordial Follicle

Immature follicle containing a small oocyte surrounded by one layer of granulosa cells

Primary Follicle

Growing follicle with larger oocyte proliferating granulosa cells and zona pellucida

Zona Pellucida

Gel coating surrounding the egg with receptors for sperm binding

Granulosa Cells

Follicular cells surrounding the egg that convert androgens to estrogen nourish egg and release inhibin

Theca

Outer endocrine cell layer surrounding maturing follicles that produces androgens

Antrum

Fluid filled space formed within maturing secondary follicles

Cumulus Oophorous

Mound of granulosa cells supporting the egg inside a mature follicle

Dominant Follicle

Single follicle selected each cycle to reach full maturity and ovulate

Atresia

Natural programmed death of non dominant follicles occurring throughout life

Corpus Luteum

Temporary gland formed from ruptured follicle remnants that secretes progesterone and estrogen

Follicular Phase

First half of cycle where follicles mature under FSH until ovulation

LH Surge

Rapid spike in LH triggered by high estrogen levels causing ovulation

Luteal Phase

Second half of cycle where corpus luteum secretes progesterone and estrogen

Progesterone

Steroid hormone secreted by corpus luteum and placenta to maintain uterus for pregnancy

Progestin

Synthetic form of progesterone used in birth control products

Myometrium

Thick muscular outer layer of uterine wall

Endometrium

Inner lining of uterus that thickens for implantation and sheds during menstruation

Menstrual Phase

Days one to five of cycle when endometrial lining sheds causing bleeding

Proliferative Phase

Days five to fourteen of cycle when estrogen regrows the endometrial lining

Secretory Phase

Days fourteen to twenty eight of cycle when progesterone prepares lining for embryo

Dysmenorrhea

Menstrual cramps and pain caused by uterine prostaglandin release

Premenstrual Syndrome

Physical and emotional symptoms occurring during late luteal phase before period

Premenstrual Dysphoric Disorder

Severe and debilitating form of premenstrual syndrome

Endometriosis

Condition where endometrial tissue grows outside uterus causing pain and scarring

Puberty

Developmental period of hormone increases leading to gamete maturation and reproductive ability

Menarche

First menstrual period occurring during female puberty

Amenorrhea

Absence of menstrual periods classified as primary or secondary

Perimenopause

Transition years around age fifty when periods become irregular as follicle counts drop

Menopause

Permanent stop of menstruation defined as twelve consecutive months without a period

Hormone Replacement Therapy

Treatment providing estrogen and progesterone to ease menopause symptoms

Capacitation

Process sperm undergo in female tract to become fully motile and capable of fertilization

Corona Radiata

Outer ring of granulosa cells surrounding an ovulated egg

Acrosome Reaction

Release of enzymes from sperm head to digest zona pellucida

Cortical Reaction

Release of granules from egg after sperm entry that hardens zona pellucida blocking polyspermy

Polyspermy

Fertilization of an egg by more than one sperm cell

Zygote

Single fertilized egg cell before uterine implantation

Embryo

Developing human from uterine implantation through eighth week of pregnancy

Fetus

Developing human from ninth week of pregnancy until birth

Cleavage

Rapid early cell divisions of zygote without overall cell growth

Morula

Solid ball of twelve to fifteen identical totipotent cells formed three days post fertilization

Totipotent

Ability of early embryonic cells to develop into any cell type or complete individual

Blastocyst

Hollow fluid structure formed at six days with inner cell mass and trophoblast

Inner Cell Mass

Internal group of cells in blastocyst that becomes the embryo

Trophoblast

Outer layer of blastocyst that implants into uterine wall and forms placenta

Ectopic Pregnancy

Dangerous condition where zygote implants outside uterus such as in fallopian tube

Placenta

Organ made of fetal and maternal tissues that exchanges nutrients gases and wastes

Chorion

Outer embryonic membrane derived from trophoblast forming fetal side of placenta

Chorionic Villi

Fingerlike projections extending into maternal blood pools for substance exchange

Placental Barrier

Membrane formed by chorionic villi cells separating maternal and fetal blood

Teratogens

Harmful substances or drugs that cross placental barrier causing birth defects

Amnion

Membrane surrounding embryo enclosing amniotic fluid

Amniotic Fluid

Protective fluid cushioning the fetus and enabling movement

Human Chorionic Gonadotropin

Hormone secreted by early placenta that preserves corpus luteum and confirms pregnancy