Reproductive System and Development

Figure 27.4A

Seminalvesicle(behindbladder)

Urethra

Scrotum

Glans ofpenis

Testis

Epididymis

Vas deferens

Erectile tissueof penis

Bulbourethralgland

Prostate gland

Urinary bladder(excretorysystem)

Figure 27.4B

TesticleScrotum

Testis

Epididymis

Vas deferens

Bulbourethral gland

Prostate gland

Ejaculatoryduct

Vas deferens

Seminal vesicle

Rectum(digestivesystem)

Anus(digestive system)

Urinary bladder(excretory system)

Pubic bone(skeletal system)

Urethra(excretorysystem)

Erectiletissue

Penis

Glans of penis

Prepuce

Figure 27.5A_1

EpididymisPenis

Testis

Scrotum

Seminiferoustubule

Testis

Cross section ofseminiferous tubule

Figure 27.5A

EpididymisPenis

Testis

Scrotum

Seminiferoustubule

Testis

Cross section ofseminiferous tubule

Diploid cell

Primaryspermatocyte

Secondaryspermatocyte

(haploid)

(haploid)

(diploid; in prophaseof meiosis I)

Developingsperm cells

Sperm cells

Mature sperm released into center ofseminiferous tubule

Differentiation andonset of meiosis I

Meiosis I completed

Meiosis II

Differentiation

2n

2n

n n

n n n n

n n n n

Figure 27.4C

2

1

Contractionsof vas deferens

Contractionsof seminalvesicle

Contractionsof prostategland

Sphinctercontracts

Urinarybladder

Urethral region hereexpands and fillswith semen

Sphinctercontracts

Contractionsof epididymis

Sphincter remainscontracted Semen expelled

Contractionsof musclesaround baseof penis

Sphincter relaxes

Contractionsof urethra

Figure 27.4DStimuli from otherareas in the brain

Releasinghormone

Anteriorpituitary

Androgenproduction

Spermproduction

Hypothalamus

FSH LH

TestisN

eg

ati

ve f

eed

back

Figure 27.3A

Follicles

Oviduct Ovaries

Corpus luteum

Wall of uterus

Endometrium(lining of uterus)

Vagina

Uterus

Cervix(“neck” of uterus)

Figure 27.3C

Oviduct

Ovary

Uterus

Urinary bladder(excretory system)Pubic bone(skeletal system)Urethra(excretory system)

ShaftPrepuce

Glans

Clitoris

VulvaLabia minora

Labia majoraVaginal opening

Vagina

Cervix

Anus(digestive system)

Rectum(digestive system)

Figure 27.5B_1

Ovary

Beforebirth

Diploid cell

Differentiationand onset

of meiosis I

Primary oocyte

(arrested in prophaseof meiosis I; presentat birth)

Primaryoocytewithinfollicle

Figure 27.5B_2

Growingfollicle

Maturefollicle

Completion of meiosis Iand onset of meiosis II

Ovulatedsecondary oocyte

Firstpolar body

Secondary oocyte

(arrested at metaphaseof meiosis II; releasedfrom ovary)

Rupturedfollicle

Figure 27.5B_3

Ovulatedsecondary oocyte

Firstpolar body

Secondary oocyte

(arrested at metaphaseof meiosis II; releasedfrom ovary)

Rupturedfollicle

Corpus luteum

Degeneratingcorpus luteum

Entry of sperm triggerscompletion of meiosis II

Secondpolar body

Mature egg(ovum)

Figure 27.9C

12

3

4

5

6Sperm

Nucleus

Acrosome

Plasma membrane

A sperm touchesthe egg’s jellycoat, and its acrosomereleases enzymemolecules.

The sperm’sacrosomalenzymes digest theegg’s jelly coat.

Acrosomalenzymes

Proteins on thesperm head bindto egg receptors.

The plasma membranesof sperm and egg fuse.

The sperm nucleus entersthe egg cytoplasm.

The vitellinelayer separatesand becomesimpenetrable.

Spermnucleus

7

Zygote nucleus

The nuclei of spermand egg fuse.

Eggnucleus

2n

nnn

n

Receptor proteinmolecules

Cytoplasm

Plasmamembrane

Vitellinelayer

Jellycoat

Egg cell

Figure 27.10_s1

Zygote 2 cells

Figure 27.10_s2

Zygote 2 cells

4 cells

8 cells

Figure 27.10_s3

Zygote 2 cells

4 cells

8 cells

Many cells (solid ball)

Figure 27.10_s4

Zygote 2 cells

4 cells

8 cells

Many cells (solid ball)

Blastocoel

Blastula(hollow ball)

Cross sectionof blastula

Table 27.11