Reproductive System

cremaster muscle

elevates testes when temperature drops

interstitial cells

produces testosterone

scrotum

maintains testes outside the body

seminiferous tubules

site where haploid sperm cells are produced

spermatogenesis

• process of producing haploid sperm cells

• occurs in seminiferous tubules of testes

function of testes

produce testosterone and sperm

haploid sperm cell

has 23 chromosomes

what is the spermatic cord and what does it protect?

connective tissue tube

1. blood vessels

2. nerves

3. lymphatics

4. ductus deferens

optimal temperature for testes

• 3 degrees less than core body temp

• for this reason, testes are maintained outside the body

3 parts of sperm cell

1. head

2. body

3. tail

4 parts of male duct system

1. epididymis

2. ductus deferens

3. ejaculatory duct

4. urethra

epididymis

• site where sperm cells are stored and matured

• located around testes

ductus deferens

transports sperm from epididymis to ejaculatory duct

ejaculatory duct

• transports sperm to urethra

• mixes sperm with seminal fluid

urethra

transports both sperm and urine

3 male accessory glands

1. seminal vesicles = produces seminal fluid

2. prostate gland = produces prostatic fluid and sits inferior to bladder

3. bulbourethral (Cowper’s) glands = produces mucus

seminal fluid

• viscous, yellow, alkaline fluid that contains fructose

• accounts for 60% of semen

prostatic fluid

milky white fluid containing fibrolysin and citrate

mucus

• secreted into urethra prior to ejaculation

• neutralizes any urine left

3 regions of penis

1. root

2. shaft

3. glans penis

foreskin

prepuce

3 columns of erectile tissue

• 1= corpus spongiosum,

• 2 + 3 = corpora cavernosa

ovarian follicle

• oocyte surrounded by follicle or granulosa cells

• immature ovarian follicle = primordial follicle

• mature overian follicle ready for ovulation = Graafian follicle

• found in cortex of ovary

what is ovulated

oocyte surrounded by zona pellucida and a layer of granulosa cells called the corona radiata

meiosis

• cell division of gametes (egg and sperm cells)

• oocyte will only complete meiosis if it is fertilized

• if oocyte completed meiosis it will have 23 chromosomes

corpus luteum

• temporary endocrine gland that produces progesterone

• made of granulosa cells that are left in ovary after ovulation

• if fertilization occurs corpus luteum will survive for 3 months but if not it will begin to deteriorate after 10 days

• end of corpus luteum life span = corpus albicans

2 phases of ovarian cycle

1. follicular phase = several ovarian follicles develop, but usually only one completes its development

2. luteal phase = formation of corpus luteum and production of progesterone

ovulation

• triggered by large and rapid rise of luteinizing hormone called “LH surge”

• 28 day cycle = ovulation occurs on day 14

what does luteinizing hormone + follicle-stimulating hormone trigger?

LH = production of estrogen

FSH = maturation of ovarian follicles

fimbriae

• located at distal end of fallopian tubes

• “sweep” surface of ovary trying to guide ovulated oocyte into fallopian tube

where does fertilization occur

ampulla of fallopian tubes

Uterus

• internal lining = endometrium

• provides site for implantation of fertilized oocyte

• inferior region = cervix, except at its mid-cycle canal is filled w thick mucus

menstrual phase

• endometrium sloughs, detaches from the rest of the uterus and is removed from the body

• both estrogen and progesterone are at their lowest levels

• days 1-5

proliferative phase

• new endometrium built

• estrogen levels reach peak, progesterone levels still low

• days 6-14

secretory phase

• endometrium is maintained and ready for implantation of a fertilized oocyte by progesterone

• progesterone levels reach peak, drop if fertilization does not occur

• days 15-28

vagina

• 3-4 inches in length

• internal tissue folds = rugae

• before female is sexually active, membrane partially covers external orifice = hymen

clitoris

female erectile tissue

greater vestibular glands

provides lubrication for intercourse

labia majora and minora

tissue folds

mons pubis

layer of adipose tissue over the pubic symphysis

alveoli

milk producing glands

suspensory ligaments

attach mammary glands to dermis and pectoralis major muscle

lactiferous duct

transports breast milk to nipple

areola

darkened area around nipples that contains sebaceous glands

prolactin

stimulates production of breast milk

oxytocin

stimulates release of milk; “let down reflex”

secondary sex characteristics

• effects of testosterone and estrogen outside reproductive system

• ex: development of breasts in females and increased BMR (basal metabolic rate) in males

acrosome cap

contains digestive enzymes that are needed for fertilization