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Home , Membranous urethra, Root of penis, Spermatogonium, Spongy urethra

Seminal vesicle Prostatic Ampulla of ductus deferens Rectum Erectile tissue of the Bulbo-

Shaft of the penis Ductus (vas) deferens Testis Prepuce External urethral (a) orifice

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Urinary bladder Ureter Ampulla of ductus deferens Seminal vesicle

Ejaculatory Prostate duct Prostatic Bulbourethral urethra gland

Membranous Ductus urethra deferens Erectile tissues

Epididymis Shaft (body) of penis Testis Spongy urethra Glans penis

Prepuce External urethral (b) orifice © 2018 Pearson Education, Inc. 2

Blood vessels and nerves

Seminiferous

Rete testis

Ductus (vas) deferens

Lobule Septum Tunica Epididymis albuginea

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Seminiferous tubule Basement membrane

Spermatogonium 2n 2n Daughter cell () type A (remains at basement 2n membrane as a stem cell) Growth Daughter cell type B Enters (moves toward tubule prophase of lumen) meiosis I 2n Primary Meiosis I completed Meiosis n n Secondary Meiosis II

n n n n Early

n n n n Late spermatids

Sperm n n n n

Lumen of

© 2018 Pearson Education, Inc. 4 (n = 23)

n Egg

n Meiosis Fertilization

Multicellular adults Zygote 2n (2n = 46) (2n = 46)

Mitosis and development

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Provides genetic Provides instructions and a energy for means of penetrating mobility the follicle cell capsule and Plasma membrane oocyte membrane

Neck Provides Tail for mobility Head Midpiece

Axial filament Acrosome of tail Nucleus Mitochondria

Proximal centriole

(b) © 2018 Pearson Education, Inc. 6 Hypothalamus 1 The hypothalamus releases gonadotropin-releasing hormone 1 (GnRH). GnRH 2 Anterior GnRH stimulates the anterior pituitary to release gonadotropins pituitary —FSH and LH. 3 FSH stimulates spermatogonia to produce sperm. 5 2 4 LH stimulates the interstitial cells to release , FSH LH which serves as the final trigger Testosterone for spermatogenesis. 3 4 Testosterone then enhances 5 spermatogenesis. 5 The rising level of testosterone exerts negative feedback control on the hypothalamus and pituitary. Testosterone Primary and secondary sex characteristics

Supporting cell Seminiferous tubule in testis FSH and testosterone stimulate sperm production

Spermatogonia Spermatogenesis

KEY: Stimulates Inhibits © 2018 Pearson Education, Inc. 7

Suspensory ligament of ovary (part of broad ligament) Infundibulum Uterine tube Ovary Fimbriae Uterus (fundus) Uterosacral ligament Round ligament

Urinary bladder Rectum Mons pubis Cervix Urethra Vagina Anus Hymen Greater vestibular gland Labium minus Labium majus

(a)

© 2018 Pearson Education, Inc. 8 Primary follicle Growing follicles

Degenerating corpus luteum

Blood vessels Antrum Corona radiata

Mature vesicular (Graafian) follicle

Germinal epithelium Corpus luteum

Developing Ruptured Secondary oocyte corpus luteum follicle

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Suspensory Uterine (fallopian) tube ligament of ovary Fundus Lumen (cavity) Ovarian of uterus of uterus blood vessels Ovary Broad Infundibulum Uterine ligament Fimbriae tube

Ovarian ligament Round ligament of uterus

Body of Endometrium uterus Myometrium Wall of Perimetrium uterus Ureter Uterine blood Cervical canal vessels Uterosacral ligament Vagina Cervix (b)

© 2018 Pearson Education, Inc. 10 Mons pubis Labia majora

Prepuce of clitoris Clitoris Vestibule Urethral orifice Vaginal orifice Opening of duct of greater vestibular gland Labia minora Anus

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Oocyte

© 2018 Pearson Education, Inc. 12 Meiotic Events Follicle Development Before birth in Ovary 2n Oogonium (stem cell) Follicle cells Mitosis Oocyte Primary 2n Primary oocyte follicle Growth

2n Primary oocyte Primary (arrested in prophase I; follicle present at birth)

Childhood (ovary inactive) Monthly from Primary to follicle 2n Primary oocyte (still arrested in prophase I) Growing follicle

Mature vesicular Meiosis I (completed by one (Graafian) primary oocyte each month) Secondary oocyte follicle (arrested in First polar body n metaphase II) Ovulation

Sperm Ovulated secondary Meiosis II of polar body oocyte (may or may not occur) Meiosis II completed (only if sperm penetration occurs) Polar bodies n n n n (all polar bodies Second Ovum degenerate) polar body © 2018 Pearson Education, Inc. 13

LH

FSH Plasma Plasma hormone level

(a) Fluctuation of gonadotropin levels: Fluctuating levels of pituitary gonadotropins (FSH and LH) in the blood regulate the events of the ovarian cycle.

© 2018 Pearson Education, Inc. 14 Primary Secondary Vesicular Ovulation Corpus Degenerating follicle follicle follicle luteum corpus luteum

Follicular Ovulation (Day 14) phase (b) Ovarian cycle: Structural changes in the ovarian follicles during the ovarian cycle are correlated with (d) changes in the endometrium of the uterus during the uterine cycle.

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Estrogens

Progesterone Plasma hormone Plasma level

(c) Fluctuation of ovarian hormone levels: Fluctuating levels of ovarian hormones (estrogens and progesterone) cause the endometrial changes of the uterine cycle. The high levels are also responsible for the LH/FSH surge in (a).

© 2018 Pearson Education, Inc. 16 Endometrial Blood vessels glands

Menstrual flow Functional layer

1 5 10 15 20 25 28 Days Menstrual Proliferative Secretory phase phase phase Basal layer

The menstrual and proliferative phases occur before ovulation and together correspond to the of the ovarian cycle. The secretory phase corresponds in time to the luteal phase of the ovarian cycle.

(d) The three phases of the uterine cycle: • Menstrual: Shedding of the functional layer of the endometrium. • Proliferative: Rebuilding of the functional layer of the endometrium. • Secretory: Begins immediately after ovulation. Enrichment of the blood supply and glandular secretion of nutrients prepare the endometrium to receive an embryo.

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Skin (cut)

Pectoralis major muscle

Connective tissue suspensory ligament

Adipose tissue

Lobe

Areola Nipple

Lactiferous sinus

Lactiferous duct

Lobule containing alveoli

(a) © 2018 Pearson Education, Inc. 18 First rib Skin (cut)

Pectoralis major muscle

Connective tissue suspensory ligament

Adipose tissue

Lobe

Areola Nipple

Opening of lactiferous duct

Lactiferous sinus

Lactiferous duct Lobule containing alveoli Hypodermis (superficial ) Intercostal muscles

(b) © 2018 Pearson Education, Inc. 19

Embryo

Fertilization 1-week 3-week 5-week embryo conceptus embryo (10 mm) 8-week embryo (3 mm) (22 mm)

12-week fetus (90 mm)

© 2018 Pearson Education, Inc. 20 (a) Zygote (b) 4-cell stage (c) Morula (d) Early blastocyst (e) Implanting (fertilized egg) 2 days (a solid ball of (morula hollows out blastocyst blastomeres) and fills with fluid) (consists of a sphere 3 days 4 days of trophoblast cells and an eccentric cell cluster called the inner cell mass) Zona 7 days pellucida Inner cell Blastocyst mass Fertilization cavity (sperm Sperm meets and enters egg) Uterine tube Blastocyst Ovary cavity Oocyte Trophoblast (egg)

Uterus Ovulation Endometrium

Cavity of uterus

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4 Hypothalamus sends efferent impulses to posterior pituitary, where oxytocin is stored

5 Posterior pituitary releases oxytocin to blood; oxytocin targets mother’s uterine muscle 6 Uterus responds by contracting more vigorously

1 Baby moves deeper into mother’s birth canal

3 Afferent impulses to hypothalamus

2 Pressoreceptors in cervix of uterus excited Positive feedback mechanism continues to cycle until interrupted by birth of baby

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