Chapter 23: The Reproductive System

BIOS 213

Somatic cell pairs:

23 pairs

Somatic cells are:

diploid (2n)

Gamete cell chromosome #:

23

Gamete cells are:

Haploid (1n)

Meiosis results in the:

production of genetically unique haploid daughter cells

Meosis I -

chromosomes separate

Meosis II -

chromatids separate

Prophase

synapsis of homologous chromosomes which results in 4 chromatids (tetrads); crossing over between nonsister chromatids

Metaphase

tetrads line up along the metaphase plate of the cell and homologous chromosomes pair up

Anaphase

homologous chromosome pairs separates they are pulled to opposite poles by microtubules attached to centromere

Telophase I

resulting cell contains the haploid # of chromosomes; only one member of each pair of the homologous chromosomes present in the starting cell

Telophase II

results in four haploid gametes that are genetically different from the original diploid starting cell

testes

produce sperm and secret hormones

the ductal system includes:

epididymis, vas deferens (ductus), ejaculatory ducts, urethra

the male accessory sex glands includes:

seminal vesicles, prostate gland, bulbourethral glands

the supporting structures of the male reproductive system include:

penis and scrotum

scrotum

protects the testes and regulates their temperature

seminiferous tubules of testes -

site of sperm production

seminiferous tubules of testes contain 3 cell types:

spermatogenic cells, sertoli cells, and leydig (interstitial) cells

Spermatogenic cells are:

stem cells → spermatogonia

spermatogonium

produces four sperm

Sertoli cells are ____ receptors

FSH

Stertoli cells:

support and protect spermatogenesis, produce inhibin, part of the blood-testis barrier

Leydig cells are ____ receptors

LH

Leydig cells produce ____

testosterone

inhibin decreases:

follicle stimulating hormone

Spermatogenesis begins at:

puberty

Spermatogonia (2n) goes through ____

mitosis

Spermatogonia mitosis:

one daughter cell stays at basement membrane; one differentiates into primary spermatocyte

Spermatogonia meiosis steps:

primary spermatocyte (2n), secondary spermatocyte (1n), spermatids (1n), spermatozoa (4 sperm)

Sperm head contains:

haploid DNA, acrosome, nucleus

Acrosome contains ____

proteolytic enzymes

Proteolytic enzymes in the acrosome help to:

allow the sperm to penetrate the protective layers of the egg

Sperm midpiece contains:

mitochondria

the sperm tail provides ____

motility

Sperm tail =

flagellum

Epididymis function:

site of sperm maturation (14 days), stores sperm for months

Vas deferens (ductus defernes) function:

propels sperm to urethra, stores sperm for months

Ejaculatory duct function:

eject sperm and seminal vesicle fluid into the urethra

male urethra Function:

shared passageway for semen and urine

Male urethra regions:

prostatic, membranous, penile (spongy)

Semen, made up of sperm and fluids, is produced in ____

accessory sex glands

Male accessory sex glands:

seminal vesicles, prostate gland, bulbourethral gland

The seminal vesicle is located ____

behind the urinary bladder

Seminal vesicle secrets:

alkaline, viscous fluid (fructose, clotting protein fibrinogen, prostaglandins)

the seminal vesicle makes up ___ of semen

60%

the Prostate gland is located:

beneath the bladder, surrounding the prostatic urethra

the prostate gland is the size of a:

golf ball

the prostate gland secrets:

milky, slightly acidic solution (citric acid, clotting enzymes act on fibrinogen, proteolytic enzymes, seminalplasmin)

the prostate gland makes up ___ of semen

25%

bulbourethral glands =

cowper’s glands

bulbourethral glands are:

pea-sized structures

Bulbourethral glands secrete:

alkaline fluid and mucus

the bulbourethral glands make up ___ of semen

5%

penis function:

deposits semen into the female reproductive tract

the penis consists of two regions:

shaft, glans penis

The penis has two different erectile tissue types:

Corpora cavernosa, corpus spongiosum

Corpora cavernosa:

dorsolateral; fills with blood during erection

corpus spongiosum:

ventral; surrounds penile (spongy) urethra and keeps the urethra open during ejaculation

erection is a ____ reflex

parasympathetic

the sacral spinal cord has:

postganglionic parasympathetic neurons

nitric oxide causes:

vasodilation

Erection pathway:

corpora cavernosa fills with blood → blood sinuses expand → compress veins exciting penis → penis hardens

the penis contains:

mechanoreceptors

Female reproductive organs:

ovaries, fallopian tubes, uterus, vagina, vulva, mammary glands

ovaries produce:

gametes and secret hormones

ovaries are:

paired glands located in the pelvic cavity

Ovaries are homologous to the ____

testes

Ovaries produce various hormones:

estrognes, progesterone, inhibin, relaxin

Ovaries contain ____

ovarian follicles

Ovarian follicles:

house oocyte, primordial follicle, primary follicle, secondary follicle, mature (graafian follicle, corpus lutem, corpus albicans

Oogenesis begins in woman ___

before birth

fallopian (uterine) tubes extend from:

fundus of uterus

Fimbriae function:

sweeps oocyte into fallopian tube

the fallopian tube is the:

site of fertilization

Uterus function:

pathway for sperm, implantation of fertilized ovum, development and delivery of fetus, pathway for menstrual flow

Uterus -

pear shaped organ between rectum and urinary bladder

Regins of the uterus:

fundus, body, cervix

The uterus is composed of:

endometrium, myometrium, perimetrium

endometrium:

innermost layer

Myometrium:

middle layer

perimetrium:

outermost layer

Endometrium tissue type:

stratum basale and startum functionale

Myometrium tissue type:

smooth muscle

Perimetrium tissue type:

connective tissue

Endometrium function:

stratum functionale grows and sheds cyclically; site for implantation of zygote

Myometrium function:

contractions during labor to assist in delivery of fetus

Perimetrium function:

site of attachment to peritoneal cavity → pelvic wall

Vagina -

tubular canal that extends from the cervix of the uterus

The vagina is the female organ of ___

copulation

The vagina is the receptacle for the ____

penis

Secretions from vaginal walls are ____

acidic

Vulva =

pudendum

vulva -

female external genitalia

The vulva includes:

mons pubis, labia majora, labia minora, clitoris, vestibule, paraurethral glands, and greater vestibular gland

Mammary glands function in:

lactation

the mammary glands consist of:

15-20 lobes separated by variable amounts of adipose tissue

alveoli -

smaller lobules in the mammary glands that secrete milk

lactation -

the release of milk through the nipples

positive feedback in female system allows for ___

ovulation