Reproductive system

Reproduction process by which new individuals of a species are produced and genetic material is passed from generation to generation

somatic cells diploid (2n)

\__ pairs of chromosomes
\= \___ chromosomes 23
46

paired chromosomes are \___ since contain same genes in same order

1 from \__ and 1 from\__ homologous
mom
dad

22 pairs of \____ and 1 pair of \____ autosomes and sex chromosomes

female sex chromosomes XX

Male sex chromosomes XY

a gene on Y chromosome initiates development of testis and the release of testosterone during development

gametes have \___ single set of chromosomes
haploid
23

Where are gametes produced? ovaries
testes

Gametes are made from \__ instead of \___ meiosis
mitosis

What does meiosis result in? one set of chromosomes in each gamete

how are chromosome numbers maintained? fertilization and meiosis alternate in sexual life cycles

fertilization Fusion of an egg and sperm cell

contains one set of chromosomes from each parent.. 2n now

result of fertilization zygote

what happens to the zygote? mitosis

\> identical DNA in all resulting somatic cells

what precedes meiosis? replication of chromosomes

meiosis I 2n

\> n
separating homologous chromosomes

meiosis II n

\> n
separating chromatids

results from meiosis II 4 daughter cells (only 2 in mitosis)

each daughter cell has half as many chromosomes as it would in mitosis

Gonads ovaries and testes

produce gametes and secrete hormones

reproductive ducts function transport, receive, and store gametes

accessory sex glands function produce materials that support gametes

supporting reproductive structures help in the \__ and \__ of gametes delivery
joining

what additional function is served by the female reproductive system? pregnancy

Testes function produce sperm and testosterone/inhibin

Male ducts function transport and store sperm,
assist in maturation
convey them to the exterior

Semen contains sperm and the secretions of sex accessory glands

\__ delivers sperm to female reproductive tract Penis

Scrotum cutaneous outpouching of the abdomen that supports the testes

optimal temp for sperm survival 2

3 degrees lower than core body temp

How does the scrotum control temperature of the sperm?

placement outside of the body cavities

cremaster muscle skeletal muscle

voluntary/involuntary

Dartos muscle smooth muscle
causes scrotum to become tighter/ less surface area

Testes are paired \__ oval glands

testes develop on \____ and descend into scrotum through \___ posterior abdominal wall
inguinal canals

each lobule of the testes contain \___ where sperm are formed 2

3 seminiferous tubules

Where does spermatogenesis occur? seminiferous tubules

spermatogenesis produce haploid sperm cells

testes contain 2 types of cells sertoli
spermatogenic

spermatogenic cells sperm forming cells

sertoli cells sustentacular cells

in the interstitial

spermatogonia

location stem cells

sertoli cells are \_______ to basement membrane and to \____ internal
spermatogonia

What forms the blood testis barrier? tight junctions between sertoli cells

function of blood

testis barrier protects developing sperm from immune response

spermatogenesis length 65

75 days

first step of spermatogenesis: spermatogonia (2n) undergoes mitosis

some stay as stem cells, some differentiate into primary spermatocytes(2n)

after primary spermatocytes formed, undergo meiosis I

\> secondary spermatocytes (n)

after secondary spermatocytes formed, undergo meiosis II

\> spermatids (n)

Spermatids mature into __

how? what happens? spermatazoon (sperm cells)

one primary spermatocyte produces 4 haploid spermatids

how many sperm mature every day? 300 million

sperm cell composed of head
tail

sperm head contains DNA

23 chromosomes

sperm tail microtubules for motility

mitochondria for ATP

how do hormones begin the process of spermatogenesis? Puberty

\> hypo releases gonadotropin releasing hormone

what does LH do in spermatogenesis? stimulates interstitial cells of testes to secrete testosterone

what does FSH do in spermatogenesis? acts on sertoli cells

stimulates spermatogenesis, along with testosterone

what does inhibin do in spermatogenesis?

who secretes? inhibits FSH

Effects of androgens in males(testosterone/dihydrotestosterone

DHT)

control of testosterone production Negative feedback system controls blood levels of testosterone
Receptors in hypothalamus detect increase in blood level
Secretion of GnRH slowed
Anterior pituitary (FSH & LH hormones) slowed
testosterone production by interstitial cells slowed
Blood level returns normal

path sperm takes to leave the testes seminiferous tubules
ductus epididymis
ductus deferens

what drives the movement of sperm pressure generated by the fluid created by sertoli cells pushes sperm and fluid along this path

Epididymis

description

What happens if sperm stay in the epididymis for several months? expelled or degenerate and are absorbed

Ductus deferens

description

how does the sperm travel through the ductus deferens? peristalsis

3 layers of smooth muscle

Vasectomy removal of portion of ductus deferens

incision in posterior scrotal sac, local anesthesia

what happens to the sperm and testosterone after a vasectomy? sperm: produced but can no longer reach exterior

degenerate and removed by phagocytosis

test: unchanged

ejaculatory ducts formed by union of duct from seminal vesicle and ampulla of ductus deferens (post. to urinary bladder)

Where does the ejaculatory duct end?

function? prostatic urethra

Male urethra 20cm long

passage for urine and semen

prostatic urethra passes through the prostate gland

membranous urethra passes through deep muscles of perineum

spongy urethra passes through penis

why does prostate enlargement lead to difficulty urinating? it creates a high pressure environment. bladder does not create strong enough pressure to force urine through

accessory sex glands secrete most of the liquid portion of semen

3 accessory sex glands seminal vesicles, prostate gland, bulbourethral glands

seminal vesicles

description

what produces most of the semen volume? Seminal vesicle (60%)

seminal vesicles: what does the alkaline fluid do? helps neutralize acid in the male urethra and from female reproductive tract (acidity would kill sperm)

seminal vesicle: what does the fructose do? atp production by sperm

other substances from the seminal vesicles (not alkaline/fructose) do? help with sperm motility and viability

Prostate

description

prostate: citric acid function atp production by sperm

prostate: proteolytic enzymes function liquefy coagulated semen and act as antibacterial agents

bulbourethral glands

description

Where do the bulbourethral glands empty? spongy urethra

bulbourethral glands: alkaline fluid function protects the passing sperm by neutralizing acids from urine

bulbourethral glands: mucus function lubricant

semen is a mix of sperm and seminal fluid

characteristics of the mixture of contents of semen:
seminiferous tubules _
seminal vesicles_
prostate_
bulbourethral glands_ sperm
alkaline ph, sticky
milky
sticky

volume of semen 2.5

5 mL

how many sperm per mL? 50

150 million

< \____million sperm

sperm ph 7.2

7.7
alkaline

Sperm coagulates within \___ minutes

why is reliquefying of sperm important allows sperm motility through cervix of uterus

Penis consists of root, body, glans penis