MALE REPRODUCITVE SYSTEM

• do diploid cells undergo meiosis or mitosis to produce gametes?

  • the diploid cell undergoes 2 divisions = results in how many genetically different haploid daughter cells?

• meiosis

• 4

MEIOSIS 1:

1. Early prophase (___ chromosomes): each of ___ chromosomes is DUPLICATED

   • each chromosome consists of 2 ____ connected via ___

2. Middle prophase: ____ (when homologous chromosome pairs couple together) = forms ____ shape →  ____ ( exchange of material bxn mom and dad chromosomes)

   • what structure forms spindle fibers?

3. Metaphase: homologous pairs line up @ center 

   • btw this random lineup allows for?

5. Anaphase = homologous pairs moved to opposite site of cell

6. Telophase = new nuclei forms —> cytokinesis —> 2 haploid or diploid daughter cells?

   • these resulting daughter cells contain ____

• 46

• 46

• sister chromatids

• centromeres

• synapsis

• tetrad

• crossing over

• centrioles

• genetic variety

• haploid

• sister chromatids

MEIOSIS 2: when sister chromatids are pulled apart

Note: before the chromosomes (leg piece) are duplicated = called chromosome. After duplication, a leg piece is called chromatid.

1. Prophase: 2 ____condense

2. Metaphase: 2 ____ line up @ center of cell

3. Anaphase: ___ separate to opposite side of cell (so that each daughter cell receives 1 chromatid)

   • After separation = each leg piece is now called _____

4. Telophase: new nuclei forms —> cytokinesis —> cells divide into how many daughter cells?

   • each daughter cell contains ___ chromosomes)

   • these daughter cells differentiate into either ___ or ____

• sister chromatids

• sister chromatids

• sister chromatids

• chromatid

• 4

• 23

• egg cells

• sperm cells

• Diploid: cell has ___ chromosomes (2 sets homologous pairs… 1 from dad 1 from mom)

• Haploid: cell has ___ chromosomes (1 set homologous pair)

• Duplicated chromatids are also called ___ (both pieces are identical!!!)

47, 23, sister chromatids

• primary reproductive organ in males?

• accessory reproductive organs in males?

• testes

• seminal gland, prostate gland, bubo-urethral gland

• what structure houses the testes?

• testes function?

  • testes endocrine function?

  • testes exocrine function?

• ____: muscles that regulate proper temp for sperm production

• scrotum

• spem production

• testosterone'

• sperm cells

• dartus muscle and cremaster muscle

Parts of the testes:

• _____ : coverings of testes

• ____ cells: produce testosterone

• are testes located inside or outside body?

• testes contain ___ : specific location where sperm is made

• tunica albuginea + tunica vaginalis

• spermatogonia

• outside

• seminiferous tubules

• Spermatogonia (2n): aka ____; divide to form primary spermatocytes (2n)

  • where does spermatogonia come from?

• Primary spermatocytes (2n): divide via “1st division of ___ to form secondary spermatocytes (n)

• Secondary spermatocytes (n): divide via “2nd division of meiosis” to form ____ (n)

  • Spermatid(n) contains 22 autosomes and 1 sex chromosome.

• ____ (last phase of spermatogenesis): where spermatid (immature) MATURES into ____ via gaining which 3 structures?

• germ cells

• seminiferous tubules

• meiosis

• spermatids

• spermiogenesis

• spermatozoon

• acrosome, midpiece, flagella

Passage of sperm?

Seminferous tubules (@testes) > epididymis > vas deferens > ejaculatory duct > prostate (prostatic urethra) > membranous urethra > spongy urethra

• Testes formed @ embryo’s ____ → descends through ____ → into ____

• at what time-mark do testes form?

• does the descent of testes occur before or after birth?

  • at what time-mark do testes descend into inguinal canal?

• abdominopelvic cavity

• inguinal canal

• scrotum

• 8 weeks

• before birth

• 7-9 months

____: failure of both testes to descend into scrotum = prevents normal sperm development

cryptorchidism

say whether its diploid (2n) or haploid (n)

• Spermatogonia =

• Primary spermatocyte =

• Secondary spermatocyte =

• Spermatid (immature) and spermatozoa (mature) =

• 2n

• 2n

• n

• n

• __cells = produce testosterone

• ___cells (AKA ___ or ___): 

  • converts testosterone into which 2 things (helps facilitates sperm development)

  • nourishes sperm

  • Forms ____ barrier 

  • acts as ____ (which binds to sex hormone)

• leydig cells/interstitial

• substentacular cells

• sertoli cells

• nurse cells

• dihydrotestosterone (DHT) and estradiol

• blood testes barrier

• globulin

parts of the sperm and what they do:

• ___(head-piece; for penetrating egg)

• ___ (contains mitochondria)

• ___ (mobility)

• acrosome

• midpiece

• flagella

• 4 functions of epididymis?

• sperm lifespan?

• sperm maturation, sperm storage, maturation, sperm concentration, where sperm gains mobility

• 2-4 days

Sperm not only passes through the main passage stuff, but also 3 parts of urethra, which are?

• spongy/penile urethra

• membranous urethra

• prostatic urethra

3 glands that add secretions to semen?

seminal vesicles, prostate gland, bulbo-urethral gland

• Penis functions:

  • erection

  • urination

  • vehicle to inject sperm into vagina

• 3 columns of erectile tissue:

  • ____ (2 columns)

  • ____ (1 column)

    • forms the ___(aka head of penis) is covered by ___ (aka foreskin)

  • ___and___ (root of penis)

• corpora cavernosa

• corpora spongiosum

• glans

• prepuce

• crura and bulb

3 glands that secrete into semen GO:

• fibrinogen

• Makes “food” for sperm

• secreted just before ejaculation

• neutralize vagina’s acidic pH

• stimulate uterus contraction to transport sperm up fallopian tube

• clotting factors (converts fibrinogen into fibrin for coagulation)

• fibrinolysin (dissolves coagulation to release sperm)

• Mucous (to lubricate vagina during sex)

• thin-milky looking

• contributes minority secretions into semen

• contributes majority secretions into semen

• seminal vesicles

• seminal vesicles

• bulbourethral gland

• bulbourethral gland

• seminal vesicles

• prostate gland

• prostate gland

• bulbourethral gland

• prostate gland

• bulbourethral gland

• seminal vesicles

• which 4 hormones involved in regulating male reproductive system?

• are these hormones controlled via negative feedback or positive feedback?

• GnRH, FSH, inhibin, LH

• negative feedback

hormone regulation of male repro. system

• ___: increased secretion of this hormone during puberty → increased LH and FSH secretion

  • ___: promotes sperm formation 

  • inhibin: inhibits ___ secretion

  • ___: increases testosterone production

• Gonadotropin releasing hormone (GnRH)

• FSH

• FSH

• lutenizing hormone (LH)

Puberty

• Before birth, placenta secretes which hormone to stimulate testosterone secretion by FETAL testes?

• before puberty hits: is HCG secreted?

  • so is testosterone secreted?

• Puberty: age of capable sexual reproduction

  • what age range is puberty?

  • During puberty: pituitary gland becomes less sensitive to testosterone inhibition > GnRH increases = LH and FSH increases

    • LH will cause?

    • FSH will cause?

• human chronic gonadotropin hormone (HCG)

• NO

• NO

• 12-14

• sperm cell formation

• large amounts of secreted testosterone

• sperm cell formation

TESTOSTERONE

• Most of testosterone produced by what type of cells @ testes?

• is testosterone necessary initiate + maintain sexual behavior?

• Effects = secondary male characteristics…

  • Enlargement + differentiates genitals = needed for spermatogenesis 

  • Increased melanin + rougher skin + hair growth in certain areas

  • increased sebum production

  • larynx enlargement 

  • Increased metabolism

  • Rapid bone growth 

• testosterone levels remain constant levels until age _____ before declining

• interstitial cells

• YES its necessary

• 40

SERIES OF MALE SEX ACT

• Main nerve involved?

• Neurotransmitters involved?

• 3 phases of male sex act?

  1. Erection: ___ nerve sends impulses > neurotransmitters (___ and ___) cause blood vessel dilation then blood rush causes erected tissue (corpora spongiosum & corpora cavernosa) 

  2. Emission: semen empties into ___ > accumulation triggers pudendal nerve to send impulse to spinal cord > ___ response (=cause constriction of ____ to prevent semen and pee mixing)

  3. Ejaculation: contracted ___ muscle & _____ cause rhythmic motion to eject semen

• pudendal nerve

• ACH and nitric oxide

• erection, emission, ejaculation

• pudendal

• ACh and nitric oxide

• urethra

• parasympathetic

• internal bladder sphincter

• skeletal

• urogenital diaphragm

series of male sex act?

erection > emmission > ejection

erectile dysfunction

• also called?

• most common cause?

• other causes involved in temporary ED?

• other causes for chronic ED

• impotence

• parasympathetic nerves dont secrete enough nitric oxide

• psychological factors, alcohol, drugs 

• blood vessel issues or nervous system issues, diabetes mellitus

what marks the start of spermatogenesis?

1st division of meiosis (aka division of the primary spermatocyte)

• Normal sperm count = ___ million/per mL

• Normal ejaculation amt = ___ mL semen

• 75-400

• 2-5

the presence of which chromosome determines the development of male genitals?

Y chromosome

___: males born with mutation in their ___ chromosome = gives them female traits bc body resists ____)

• androgen insensitivity syndrome

• X

• testosterone

what disease can cause chronic erectile dysfunction?

diabetes mellitus

how many viable sperm are available at end of meiosis 2?

4 sperm

• what is the most common cause of male infertility?

• what sperm count is an indicator of male infertility?

• other causes include:

  • reduced sperm mobility

    damage to testes

  • Inadequate FSH and LH (possibly bc u took anabolic steroids)

  • ____: abnormal dilation of spermatic vein = reduces sperm formation

• low sperm count

• less than 20 million sperm

• varicocele

____: have testosterone-like effects 

• negative or positive feedback relationship with GnRH, LH, FSH?

• results in atrophied testes + maybe infertility

• anabolic steroids

• negative feedback