Rutgers Functional Human Anatomy Lec 16 (Reproductive System)

Reproductive system function

Gametes (germ cell, haploid:

sperm (male)

oocytes (female)

Fertilization

zygote

Gonads:

Testes/Ovaries

- produces gametes and hormones

Reproductive tract

Accessory glands

External genitalia

fertilization

- where: in the ampulla region of the uterine tube (fallopian tube)

- when: 12-24 hours after ovulation

- result: the formation of a diploid zygote

Gametes are _____________ by reproductive system

produced

stored

nourished

transported

Principle structures of male reproductive system

scrotum:

testis

epididymis

Ductus deferens

Urethra

Accessory Glands:

Seminal gland

Prostate gland

Bulbo-urethral gland

Penis

male testes during development

2nd month:

abdominal cavity

3rd month:

pelvic cavity

epididymis forms

4th month:

still inside body cavity

7 months:

scrotal cavity opened

-testes descending

Birth:

completely descended

testes & sperm development temp

testes:

develop at body temp

98.6 degrees F

sperm:

slightly cooler temp

96.6 degrees F

inguinal hernia

part of intestines protrudes in a weak spot in muscles of inguinal canal (wear testes droped from)

Spermatic cord

structure connected to testicles

structures in spermatic cord

- ductus (Vas) deferens - transports sperm

- testicular artery

- pampiniform plexus - venous network that helps cool arterial blood

- cremaster muscle fibers - help raise/lower the testis

- genital branch of genitofemoral nerve - innervates cremaster muscle

- lymphatic vessels

scrotum

- soft tissue surrounding testes

- chamber each testicle is in, across scrotum, anterior surface of penis

tunica vaginalis

- inner lining of serous membrane (cavity)

- reduces friction between outer and inner serous layers

Dartos muscle

- superficial

- encapsulate area around testicles

- smooth muscle

- not under voluntary control

- contracts causing wrinkling of scrotal surface (in cold weather)

cremaster muscles

- within cremaster fascia covering the testicles

- help pull testicles closer to body

cremasteric reflex

stroking the upper inner thigh causes the ipsilateral cremaster muscle to contract, raising the testis

septa testis

separating testes into lobules

lobule

contain coiled seminiferous tubules (80cm)

> mediastinum area:

- straight tubule interconnecting forming rete testis

- rete testis > efferent ductule > epididymis

leydig cells

- interconnecting endocrine cells

- between seminiferous tubules

- testosterone produced and gets released

Testosterone

- hormone

- stimulate spermatogenesis (creation of sperm)

- promotes sperm maturation

- helps maintain accessory organs

- develop secondary sex characteristics

- stimulate growth hormone/metabolism

- stimulate sexual behavior/ sex drive

FSH and LH in males

- FSH stimulates sperm production in the seminiferous tubules

- LH stimulates Leydig cells to produce testosterone

primary/secondary sex characteristics

Primary:

- appear at birth

- physical structures

Secondary:

- appear w/ puberty

- facial & body hair

- adam's apple (larger pharynx)

- increase musculature

sperm anatomy

head:

contains chromosomes & acromsone (enzyme for fertilization of egg)

neck:

mitochondria

centrioles

tail:

flagella (only flagellum in human body)

- allows to become mobile

Male reproductive tract

epididymis:

capacitation

ductus deferens (vas deferens)

urethra

epididymis

monitor composition of fluid produced by seminiferous tubules

- recycling center for damages spermatozoa

- stores spermatozoa (sperm) for maturation

how long does it take spermatozoa to pass epididymis

2 weeks

sperm present in male body

- not present from birth

- process takes few weeks

- starts after puberty

ductus deferens

- sperm and hormones pass through

- curves around urinary bladder and ureter then descends back toward prostate gland

ampulla

joins excretory duct of seminal gland to become ejaculatory duct

ejaculatory duct empties

to prostatic urethra

urethra (3)

prostatic

membranous

spongy/penile

seminal fluid

- 60% produced by seminal gland/vessels

- 30% from prostate

- 5% from bulbo-urethral glands

- 5% from epididymis

normal sperm count

- 20-300 million per milliliter of semen

- each ejaculation releases 2-5 milliliters of semen

enzymes in semen

- help dissolve vaginal mucus

- antibiotic

- prevent sperm coagulation in vagina

Capacitation of sperm

- biochemical process

- sperm is mobile & ready to fertilize an oocyte when exposed to female reproductive tract

- happens after ejaculation, inside the female body

sperm become motile when

mix w/ secretions of seminal glands

semen

= product of ejaculation

contains:

- sperm cells

- seminal fluid

- enzymes

how long does it take sperm to develop in testicles

50-60 days

how long does it take sperm to mature and move through epididymis

14 days

during spermatogenesis the testicles make _________ sperm a day

-several million

(15-hundred per second)

body maintains surplus of semen

- to ensure fresh supply for conception

seminal vesicles are producing & secreting

- alkaline viscous fluid high in and fructose and nutrients for sperm to help w/ motility

- coagulants

- prostaglandins

- to clot sperm and lubricant

Bulbo-Urethral Glands (Cowper's Glands)

releases fluid to clean acidic urine

anatomy of male reproductive system

root (to pelvic bone)

body (shaft, where erectile tissue is found)

glans penis (distal end, surround external urethral orifice)

erectile tissue & blood vessels:

- 2 posterior corpora cavernosa

- 1 anterior (underside of penis) corpus spongiosum

prepuce

foreskin

circumcision

removal of foreskin

erectile tissues of penis

posterior:

two corpora cavernosa

(deep artery)

anterior:

one spongiosum (spongnyurethra in center)

erection of penis (activation)

parasympathetic nerve activation

- smooth muscles in arterial walls relax

- arteriole muscles dilate and expand

- vascular channels in corpus cavernosa and spongiosum becomes engorged w/ blood

parasympathic and sympathetic for erection

parasympathetic

- smooth muscle relaxation

- increased blood flow to the penis

sympathetic

- controls ejaculation by stimulating contraction of smooth muscles

ejeculation activation

sympathetic activation

- sperm & semen pushed through by peristaltic actions of smooth muscle in ductus deferens

- ischiocavernosus: compresses base of penis to maintain erection

- bulbospongiosus: rhythmic contractions to eject semen

muslces both men and women have

Ischiocavernosus and bulbo-spongiosis

sensory innervation (penis)

in skin and area around penis

female reproductive system contains

ovaries

uterine tubes (fallopian tubes)

- fimbriae

uterus:

- cervix

vagina

external genitalis:

- labia minora/majora, clitoris

breasts

ovaries

- 2

- uterine tube attached by fimbriae (finger like projections)

- leads to uterus

uterus opening

cervix opens to vagina

infundibulum

curved area of uterine (fallopian) tube

ligaments of the uterus and ovaries

broad ligament:

- encloses ovaries, uterine tubes, and uterus

ovarian ligament:

- attaches ovary to uterus

mesovarium

round ligament

suspensory ligament:

- contains ovarian artery/vein

- connected to ovary by ovarian hilum

uteralsacral ligaments

broad ligament

- attaches to the lateral edges

- stabilizing structure for uterus, especially for expanding during pregnancy

processes of female reproductive system

oogenesis:

- production of female gametes (oocytes)

- initiated in embryonic stage of female

ovarian cycle:

- monthly

- development of ovarian follicles

- oocytes develop

unterine cycle:

- monthly

- prepare uterus for implantation of fertilized embyro

FSH and LH in females

- FSH and LH regulate the ovarian cycle

- FSH stimulating follicular growth

- LH triggering ovulation on day 14

- estrogen and progesterone prepare the uterus for implantation and regulate the menstrual cycle

ovarian cycle

primordial ovarian follicle:

- primordial oocyte

primary ovarian follicle:

- primordial oocyte

secondary ovarian follicle:

- primary oocyte

tertiary ovarian follicle:

- secondary oocyte

ovarian cycle hormones

Follicle stimulating hormone (FSH):

- from pituitary gland

- initiate ovarian cycle

endocrine cells:

- estrogen

> stimulating bone and muscle growth

> female secondary sex characteristics (breast, pubic hair)

> sex drive

> maintain reproductive organs

> initiate repair and growth of uterine lining

lutinizing hormone (LH)

- weaken follicular wall to release secondary oocyte in corona radiata

once oocyte is released follicle becomes

corpus luteum:

- produce progesterone (prepare body for pregnancy)

- if no fertilization, corpus luteum decomposes, 12 days after ovulation into

corpus albicans:

- marks end of 1 ovarian cycle and start of next

start of ovarian cycle

decrease in:

- hormones

- progesteron

- estrogen

stimulate release of GnRH, LH, FSH:

- start new cycle

Mensturation

The shedding of the muscosal lining of uterus

path of oocyte

frimbriae > infundibulum > ampulla > isthmus > uterus

- smooth muscle

- 13 cm long

- 5 regions

ovum

mature reproductive cell

what helps move oocyte in its path (uterine tube)

cilia and smooth muscle

(peristaltic movement)

successful fertilization occurs in

- uterine tube (ampulla region)

- within 12 - 24 hrs after ovulation

ovulation

release of ovum from ovary into tube

fertilization of egg

diploid zygote then moves into uterus

ectopic pregnancy

- when fertilized zygote fails to move into the uterus

- very painful

- must be removed from tube or death can occur

anatomy of uterus

body (pear shaped)

fundus (superior)

uterine cavity (internal opening)

isthmus (narrowing of uterus)

internal os (opening into isthmus)

cervix (cervical canal)

external os (external orifice of cervix)

uterine wall layers

- 3 layers

endometrium (inner, glandular wall)

myometrium (muscles, important for child birth)

perimetrium (outer serousal layer)

uterine cycle

menstrual cycle 3 phases:

menstrual phase

proliferative phase

secretory phase

menarche - 1st uterine cycle at puberty

menopause - ending of cycle

menstruation phase

- from day 1-7

- destruction functional layer within uterus

- decrease in progesterone and estrogen cause menstruation

- constriction of arteries and decrease of blood flow to kill off layer

proliferative phase

- day 7-14

- repair and regeneration of layer

- from end of menstruation to ovulation

ovulation day

14

secretory phase

- day 14-28

- secretion by uterine gland ( progesterone & estrogen)

- functional layer ready for implantation

vagina

- elastic muscular tube

- smooth muscle

- from cervix to vaginal canal

- 7.5 to 9 cm long

rugae in vagina

- allow for expansion of surface (child birth)

hymen

separates vagina and vestibule

- usually broken by exercise and tampons

3 main functions of vagina

- passage way for elimination of menstrual fluid

- receive penis

- passage way for fetus

bacteria in vagina

- provide nutrients in cervical mucosa

- acidic environment to prevent pathogens

- reduces sperm mobility

external gentalia of female

vulva:

- enclosing external genetila

vestibule:

- opening of vagina

- surrounded by labia minora

- moistened by greater & lesser vestibular gland

labia majora:

- surrounding labia minora

clitoris (prepuce):

- erectile tissue

urethral opening

anus

breast glands

Pressure → release of OXT from the pituitary gland → contraction of the lactiferous ducts → milk ejects

nipple

- surrounded by areola that contains large sebaceous glands

sebaceous glands

- exocrine gland

- release sebum, oily waxy substance for breastfeeding

lobules of mammary gland

- Lobules contain alveoli that produce breast milk.
- Milk flows: Lobules → ducts → lactiferous sinus → nipple.

- Prolactin makes milk, oxytocin releases it

suspensory ligament (breasts)

support:

ducts

lobes

lobules

mammary glands develop during

pregnancy

- fully develop in 6 months

- milk released when infant sucks on nipple

oxytocin release by nursing causes

- lactiferous ducts to release milk

- oxytocin from the pituitary gland stimulates milk ejection

colastrum

- first few days of nursing

- fluid filled with antibodies

- milk produced by 2-3 days

female climacteric (menopause)

decline estrogen:

- reduce size of uterus/ breast

- thinning of vaginal walls

- weakening supportive tissues of reproductive organs

- osteoporosis

- hot flashes

- typically between 45-55

male climacteric (andropause)

- testosterone levels decline ( not as rapidly as estrogen)

- avg 50-60

- reduction in sexual activity