BI 233 Reproductive System Test

Scrotum

Dartos muscle

Cremaster muscle

Testes

Seminiferous tubules

Epididymis

Vas deferens

Urethra

Urogenital diaphragm

Glans penis

Corpora cavernosa

Corpus spongiosum

Prostatic urethra

Membranous urethra

Spongy urethra

Urethral orifice

Seminal vesicles

Prostate gland

Bulbourethral gland

Ovaries

Broad ligament

Ovarian ligament

Suspensory ligament

Fallopian tubes

Infundibulum

Fimbriae

Ampulla

Isthmus

Uterus

Fundus

Body

yellow part

Isthmus

blue part

Cervix

Vagina

Fornix

Mons pubis

Labia majora

Labia minora

Clitoris

Vaginal orifice

Vestibule

External urethral orifice

second line on left

Oocytes

Vesicular follicle

bottom left follicles

Corpus luteum

top middle thing

Corpus albicans

Primary sex organs =

Gonads, produce gametes and sex hormones

Male gonads

Testes, produce sperm

Female gonads

Ovaries, produce ova

Accessory reproductive organs

support gametes via ducts, glands, and external structures

store, transport, nourish, and protect gametes

scrotum

protects the testes and maintains optimal temperature for spermatogenesis (2-3°C below core body temperature)

dartos muscle

smooth muscle in scrotal wall, produces wrinkling to reduce heat loss

cremaster muscle

extension of internal oblique, raises/lowers testes in response to temperature or arousal

testes

coverings, = tunica vaginalis and tunica albuginea

tunica vaginalis

serous membrane lining scrotal cavity

tunica albuginea

dense fibrous capsule, forms septa that divide testes into lobules

seminiferous tubules

site of spermatogenesis, lined by spermatogenic cells (least mature near basement membrane, most mature near lumen)

sustentacular (sertoli) cells

in seminiferous tubules, support, protect, nourish developing sperm, secrete ABP, inhibin, and testicular fluid

interstitial (leydig) cells

located between seminiferous tubules, secrete testosterone

ducts of the testes

tubulus rectus, rete testis, epididymis, ductus deferens, spermatic cord

tubulus rectus/straight tubules

receive sperm from seminiferous tubules

rete testis

network of channels leading to efferent ductules

efferent ductules

rete testis → E.D. → epididymis

Epididymis

site of sperm maturation and storage

Ductus deferens (vas deferens)

stores and transports sperm from epididymis to ejaculatory duct, travels through inguinal canal within spermatic cord

spermatic cord

contains vas deferens, testicular artery, autonomic nerves, lymphatics

urethra

shared by urinary and reproductive systems, 3 regions

prostatic urethra

~2 in

membranous urethra

~.5 in

spongy/penile urethra

~6 in, within corpus spongiosum

accessory sex glands

produce the liquid portion of semen

1. seminal vesicles

2. prostate gland

3. bulbourethral (cowper’s) glands

seminal vesicles

posterior to bladder, secrete alkaline, fructose-rich fluid, prostaglandins, fibrinogen

prostate gland

inferior to bladder, secretes citrate, proteolytic enzymes, and clotting factors

bulbourethral (cowper’s) glands

produce alkaline mucus to neutralize urine and lubricate urethra

semen

mixture of sperm and glandular secretions

pH 7.2-7.6 to neutralize acidic male urethra and vaginal environment

penis

3 cylindrical erectile tissues

1. 2 corpora cavernosa (dorsolateral mass)

2. 1 corpus spongiosum (midventral mass, surrounds urethra)

Hypothalamic-Pituitary-Gonadal (HPG) Axis

the hypothalamus secretes GnRH → stims anterior pituitary to release FSH and LH

Follicle stimulating hormone (FSH)

targets: sustentacular (Sertoli) cells in seminiferous tubules

major actions

1. stimulates spermatogenesis and spermiogenesis (indirectly, by supporting Sertoli cell function)

2. Induces Sertoli cells to synthesize and release androgen-binding protein (ABP), which concentrates testosterone in the seminiferous tubules to support developing sperm

3. stimulates inhibin release, which provides negative feedback on FSH secretion from the anterior pituitary

luteinizing hormones (LH)

stimulates interstitial (Leydig) cells to produce testosterone

Testosterone

primary male sex hormone, essential for spermatogenesis, development of secondary sex characteristics, and maintenance of libido

regulation of testosterone

a classic negative feedback loop: inc GnRH → inc LH → inc testosterone → feedback inhibition → dec GnRH and dec LH

Ovaries

female gonads

Ovaries are anchored in place by the

broad ligament, ovarian ligament, suspensory ligament

broad ligament

part of the parietal peritoneum

ovarian ligament

anchors the ovaries to the uterus

suspensory ligament

attaches the ovaries to the pelvic wall

ovarian follicles

consists of the oocytes in various stages of development and their surrounding epithelial tissue

primordial follicle

single layer squamous cells

primary follicles

cuboidal granulosa cells

secondary follicles

multiple granulosa layers, small fluid spaces

tertiary (vesicular/graafian) follicles

large antrum, oocyte with corona radiata

corpus luteum

remnant of ruptured follicle, secretes progesterone and estrogen

corpus albicans

fibrous scar of degenerated corpus luteum

uterine tubes (fallopian tubes)

transport oocyte to uterus, lie between the folds of the broad ligament

contain: infundibulum, fimbriae, ampulla, isthmus

infundibulum

open funnel shaped distal end of tube

fimbriae

finger-like projections of the infundibulum that drape over the ovary, contain cilia that create a current in the peritoneal fluid during ovulation to draw the released oocyte toward and into the fallopian tube

ampulla

widest and longest portion of the fallopian tube

isthmus

short, narrow, thick-walled portion that joins the uterus

uterus

located between the urinary bladder and the rectum, in anteverted position (normally)

fundus is most anterior while the body lies over the posterior top half of the bladder

parts: fundus, body, isthmus, cervix

fundus

dome shaped portion above the uterine tubes