The Reproductive System

Flashcards on the male and female reproductive systems, including anatomy, hormones, and cycles.

External genitalia: The Penis

deliver sperm to the female reproductive tract

External genitalia: The Scrotum

housing the testes and is essential for temperature regulation of testes

• Dartos muscle (smooth muscle) - contracts to make scrotum wrinkled and thick, decreases heat loss

• Cremaster muscle (skeletal muscle) – contracts to bring scrotum and testes closer to body

testes

contains interstitial cells - produce and secrete testosterone

contains seminiferous tubules - produce sperm

Functions of the epididymis x4

Stores, nourishes and protects spermatozoa

Facilitates functional maturation

Recycles damaged sperm

Ejaculates the sperm

Ductus deferens

transport sperms from epididymis to ejaculatory tract

vas deferens and urethra

transports sperm through prostate gland to urethra

convey both urine and semen at different times

Seminal vesicles

produce and release seminal fluid, which makes up 60-70% of semen volume

contains substances that enhance sperm motility and their ability to fertilise an ovum, such as fructose (energy), prostaglandins (smooth muscle contraction) and fibrinogen (clots ejaculated semen into vagina)

Prostate gland

produces fluid that accounts for up to 30% of semen volume

contains citrate (nutrients), enzymes that breakdown seminal clot, seminalplasmin and PSA

Bulbourethral glands

Produce a thick mucus which lubricates the glans of the penis

Ejaculation

The propulsion of semen from the male duct system

Hormone for males

• GnRH released by hypothalamus

• signals release of FSH and LH

• FSH stimulates sustenocytes to produce concentrated testosterone which drives spermatogensis

• LH stimulates interstitial cells to produce testosterone

external genitalia (female)

labia majora - 2 fatty skin folds

Labia minora - Two thin, hair-free skin folds that enclose the Vestibule

vestibule - Release mucus to lubricate intercourse

clitoris - Erectile tissue, richly innervated, sexual arousal

Vagina

Provide a passageway to eliminate menstrual fluids, receive the penis during intercourse & expel fetus during child birth

• both muscular and elastic

• acidic environment - teenagers not developed this susceptible to STIs

Uterus

receives, retains and nourishes offspring

• perimetrium - Outermost layer

• Myometrium - contracts to expel baby

• endometrium - site of implantation

  • Functional layer: is shed during menstruation

  • Basal layer: regenerates functional layer following menstruation

fallopian tube

Typical site where fertilisation normally takes place.

fimbriae

ciliated finger-like projections to draw oocyte into fallopian tube

The ovaries

Produce and ovulates oocytes & secrete female sex hormones

Oogenesis

Occurs in the ovaries and Begins in the fetal period

Ovarian cycle

Events that mature an ovum

• follicular phase (1-14) - Follicle growth, ovulation occurs at the end of this stage

• luteal phase (15-28) - Period of corpus luteum activity

follicle phase

1-2 - primordial follicle to primary follicle

3 - primary follicle to secondary follicle

4 - secondary follicle to late secondary follicle

5 - late secondary follicle to vestibular follicle

6 - ovulation

luteal phase

7 - corpus luteum is formed

8a - corpus luteum degenerates (no fertilisation) - starts again

8b - corpus luteum can persist (fertilised)

Corpus Luteum

Created in the luteal phase after ovulation and surge of LH from follicle and secretes mostly progesterone

Menstrual cycle

menses phase (1-5) - Shedding of the functional layer of the endometrium - o and p low

proliferative (6-14) - Rebuilding of the functional layer of the endometrium - ovulation occurs at end

Secretory (15-28) - Endometrium prepares for implantation. if fertilisations doesn't occur, CL degenerates - low progesterone - breakdown of e - menses again

hormonal regulation of ovarian cycle

follicular phase

- GnRH is released from the hypothalamus

- releases LH and FSH

- FSH stimulates follicle growth and release of oestrogens

- stimulates surge of LH

- ovulation

luteal phase

- LH surge turns ruptured follicle into CL

- CL produces progesterone

- no fertilisation - CL degenerates and hormone levels decline

The mammary glands

Produces milk to nourish newborn