Reproductive System

Primary Sex Organs/Gonads

ovaries and testes

Gametes

sex cells (sperm or eggs) produced by the primary sex organs

Accessory Reproductive Organs

ducts (carry gametes), glands (secrete fluids that support gametes), external genitalia

Secondary sex characteristics

appear at puberty

External genitalia

vulva or penis

Chromosomal sex

XX or XY

Gonadal sex

ovaries or testes

Gender

This includes norms, behaviors and roles associated with being a woman, man, girl or boy, as well as relationships with each other. As a social construct, gender varies from society to society and can change over time

Gender Identity

a person's deeply felt, internal and individual experience of gender

Hypothalamus/anterior pituitary/gonadal axis

hormones originate in hypothalamus that then triggers the anterior pituitary which then triggers the gonads to excrete the hormones which affect the target cells

Gonadotropin releasing hormone (GnRH)

hormones released from the hypothalamus that activates the anterior pituitary

Testosterone

major gonadal hormone in males

Estrogen and Progesterone

major gonadal hormones in females

Diploid

chromosome pairs, one from one parent, one from another parent

Meiosis I

parent cell splits into 2 daughter cells

Meiosis II

daughter cells split into 4 gametes each with half the amount of genetic material

Haploid

single chromosomes, found in gametes

Independent assortment

increases genetic variability, orientation of sister chromatids as they line up at the mitotic spindle is random so DNA is randomly divided between daughter cells

Tetrad

pair of replicated homologous chromosomes

Crossing over

the mixing of genes between homologous chromosomes in a tetrad

Sperm

male sex cell

Eggs (Ova)

female sex cell

X Chromosome

female chromosome

Y Chromosome

male chromosome

Testes (testis, singular)

produce sperm

Scrotal sac / Scrotum

hold the testes outside the body

Seminiferous tubules

produce sperm

Sertoli cells (nurture cells, sustentacular cells)

create the walls of seminiferous tubule, nourish and support sperm development

Spermatogonia (spermatogonium)

stem cells that produce sperm that lie outside the seminiferous tubule

Spermatocyte

when a spermatogonia cells divides, one cell travels between the sertoli cells and begins meiosis

Blood

testis barrier

Spermatids

product of meiosis of spermatocytes, one set of chromosomes (haploid cells)

Sperm (head, acrosome, midpiece, tail)

spermatids that have undergone physical changes and grown a tail; 100 to 200 made per day

Spermatogenesis

the formation of sperm from spermatogonia cells, takes about 70 days to come to full maturation

Leydig cells (interstitial endocrine cells)

between seminiferous tubules, produce testosterone; reside outside the basal lamina near blood vessels

GnRH

hypothalamus hormone that stimulates the anterior pituitary to release FSH and LH

FSH (follicle stimulating hormone)

anterior pituitary hormone that stimulates Sertoli cells to foster developing sperm

LH (luteinizing hormone)

hormone from the anterior pituitary that stimulates leydig cells to make testosterone

Testosterone

spermatogenesis, development of the reproductive tract in embryonic and fetal life, expression of secondary sexual characteristics, muscle and bone growth, sex drive and aggressive behavior, erythropoiesis, increase basal metabolic rate

Androgen binding hormone

keeps testosterone levels high around developing sperm

Inhibin

produced by Sertoli cells that feeds back to the anterior pituitary

Inguinal canal

leaves a weakness in the anterior abdominal wall through which intestines can herniate

Spermatic cord

contain blood vessels, nerves, lymphatic vessels and vas deferens and descend into the testes from the abdominal wall

Vas deferens (ductus deferens)

connects to the base of the posterior bladder; carries sperm toward the urethra at the time of ejaculation

Cremaster muscle

skeletal muscle of the spermatic cord, raises the testis to bring it closer to the body when its cold

Pampiniform plexus

veins wrap around the testicular artery and cool arterial blood before it reaches the testis

Varicocele

dilation of veins in pampiniform plexus usually caused by inadequate valves

Cryptorchidism

failure of the descent of the testes, greatly increases risk of testicular cancer at puberty

Epididymis

stabilization of acrosome, sperm spend 2 to 4 weeks maturing here, storage in tail region for several months before being phagocytized

Vasectomy

surgical procedure that cuts the vas deferens tube so sperm can't be ejaculated

Semen

formed when fluids from seminal, prostate and bulbourethral glands mix with sperm during ejaculation

Seminal gland (seminal vesicle)

70% of semen, fluid is sticky and rich in mucous, contain fructose and prostaglandins

Prostate gland

20% of semen, fluid is think and milky, alkaline, contains clotting enzymes and PSA; enlargement of the gland can compress the urethra, prostate cancer in 1/6 men, elevated levels of PSA can indicate prostate cancer

Bulbourethral gland

5% of semen, lubricating mucous; pre ejaculate that washes out urine of the urethra before ejaculation

Ejaculatory duct

where the vas defers meets the seminal gland

Bulb/Corpus spongiosum

penile urethra travels through this structure

Crus/Corpus cavernosum

tissue on the left and right sides of the corpus spongiosum

Foreskin/prepuce

skin that covers the glans penis

Ovary – Cortex, medulla

follicles in the cortex are the site of egg development

Uterine tube (Fallopian tube, oviduct)

tube of smooth muscle with mucosa containing ciliated epithelium and gland cells that produce fluid to nourish oocytes

Fimbriae, Infundibulum, Ampulla

fimbria are finger like processes next to the ovaries, infundibulum is the opening at the ovary, ampulla is the central portion where fertilization occurs

Broad ligament

2 layers of peritoneum that the female reproductive organs reside within

Uterus – fundus, body, cervix

fundus is top wall, body is the main section, cervix is the bottom portion connecting to the vagina

Vagina

smooth muscle with elastic fibers, lubricated by cervical mucous and cells lining the vaginal wall, acidic pH, mucosa covers most of the external opening prior to first intercourse

Vulva

external female genitalia

Labia minora

inner hairless folds

Labia majora

outer hairy folds

Greater vestibular gland

provide lubricating mucous to vaginal orifice

Erectile tissue – bulbs of the vestibule, clitoris

bulbs on either side of the vaginal orifice, extensions of the right and left crus form the clitoris

Breast/Mammary gland – glands, ducts

glands produce milk, ducts carry milk to nipples

Menstrual cycle

about 28 days long, changes in oocyte and follicle development, hormones of the HPG axis and lining of the uterus

Oogonia

stem cells that create oocytes through mitosis, all division occurs prior to birth

Oogenesis

process of egg production

Oocyte – primary, secondary

primary are all oocytes created before birth, secondary after the first round of meiosis

Ovum

gamete formed after 2 rounds of meiosis

Polar body

3 created along with 1 ovum, all degenerate

Ovarian Follicle – primordial, developing (primary/secondary, antral), mature

oocyte grows inside a halo of support cells

Granulosa cells

outside the zona pellucida

Theca cells

outer part of follicle

Zona pellucida

glycoprotein coat immediately surrounding the oocyte

Corpus luteum

when the oocyte leaves the ovary it leaves behind the granulosa and theca cells that then enlarge and produce steroid hormones, lipids fill in follicle

Down Syndrome

genetic disorder resulting in developmental issues, 3 copies of chromosome 21 (one from paternal, 2 from maternal), more common with increasing maternal age

Follicular phase

new group of follicles make estrogen, one follicle grows to maturity

Ovulation

mature follicle ejects oocyte from ovary, caused by LH surge

Luteal phase

remnants of follicle form corpus luteum, makes estrogen and progesterone, corpus luteum produces hormones for 14 days and then dies off

Gonadotropin releasing hormone (GnRH)

stimulates anterior pituitary

FSH (follicle stimulating hormone)

stimulates granulosa cells to: nurture development of oocyte, produce estrogen, produce inhibin

LH (luteinizing hormone)

stimulates thecal cells to produce androgens that are converted to estrogen, also causes mature follicles to rupture when ovulating

Estrogen

levels rise as one follicle becomes dominant and reaches maturity, provides negative feedback to AP and hypothalamus

Uterine cycle

changes in the uterus over a 28 day cycle, is dictated by changes in the ovaries, menstrual phase, proliferative phase and secretory phase

Endometrium

inner layer of the uterus

Myometrium

middle, smooth muscle layer of the uterus

Perimetrium

outer layer of the uterus

Stratum functionalis (functional layer)

inner layer of the endometrium that changes during the menstrual cycle

Stratum basalis (basal layer)

outer layer of the endometrium that is constant and provides stem cells to replace the functional layer

Menstrual phase

last month's functional layer is shed as menstrual fluid

Proliferative phase

new growth of stratum functionalis under influence of estrogen from ovary follicles

Secretory phase

enhancement of stratum functionalis and gland activity by increasing vessels and glands secreting fluid into the lumen

Ovarian Cycle

ovary grows one follicle to maturity and makes estrogen (follicular phase), mature follicle ejects oocyte from ovary (ovulation), remnants of follicle form corpus luteum, makes estrogen and progesterone (luteal phase)

Endometriosis

endometrial tissue in or on the uterine tubes/ovary/peritoneal cavity, tissue responds to gonadal hormones (grows and sheds during cycle), excessive menstrual bleeding and pain as symptoms, infertility