CH 26 - Reproductive System

Gametes

sex cells

• Sperm (spermatozoon)

• Egg (ovum)

Sperm

has motility for achieving contact

Egg

has nutrition for developing embryo

Zygote

fertilized egg

Males

• XY chromosomes

• have penis for producing sperm

• Gonads: Testes

• ducts, glands, penis

Females

• XX chromosomes

• have vagina for receiving sperm

• Gonads: ovaries

• uterine tubes, uterus, vagina

Diploid

DNA combination resulting in our double stranded chromosomes (DNA from mom and dad) all cells EXCEPT sperm and egg

Haploid

DNA combination resulting in single-stranded chromosomes, ONLY cells are sperm and egg

Meiosis

Meiosis 1: First Divisions:

prophase (early diploid) → mid-late prophase I → metaphase I → anaphase I → telophase I

Meiosis 2: Second Division

prophase II → metaphase II → Anaphase II → Telophase II

Result:

4 Haploid Cells

Scrotum

pouch that contains testes

• Media septum

• Spermatic Cord

• Temperature regulation

Media Septum

perineal raphe - external seam

Spermatic cord

• ductus deferens, nerves, and vessels

• inguinal canal to pelvic cavity

Temperature Regulation

• Cremaster

• Dartos muscle

• Pampiniform plexus

Cremaster

internal oblique muscle elevates the testes

Dartos muscle

smooth muscle wrinkles the scrotum

Pampiniform plexus

a vein network of the spermatic cord

Testes Connective Tissue

• tunica vaginalis

• tunica albuginea

Testes

has hundreds of lobules of 1-3 seminiferous tubules

• germinal epithelum

  • germinal cells can become sper

  • Sustentacular (Sertoli) cells

  • Interstitial (Leydig) endocrine cells

  • Rete testis

Rete testis

beginning of sperm matruration process

Sustentacular (Sertoili) cells

help make blood-testis barrier

Interstitial (Leydic) endocrine cells

between tubules make testosterone

Spermatogenesis

Type A spermatogonium → Type B spermatogonium

Type B spermatogonium → primary spermocyte

Primary spermatocyte goes through meiosis → two haploid secondary spermatocytes

secondary spermatocytes go through meiosis 2 → four haploid spermatids

spermatids through spermiogenesis → sperm

Spermiogenesis: Stage 1

appearance of the acrosomal vesicle and flagellum in the spermatid

Spermiogenesis: Stage 3

shredding of excess cytoplasm

Spermiogenesis: Stage 4

mature sperm

Spermiogenesis: Stage 2

growth of acrosome and flagellum

Spermatozoon (Sperm)

Head:

• Nucleus

• Acrosome - Enzymes

• Flagellar basal body

Tail:

• Midpiece - many mitochondria for energy

• principal piece of tail

• end piece of tail

Efferent Ductules

posterior

Epididymis

• head, body, and tail

• sperm storage and maturation

Ductus (vas) deferens

• long tube with smooth muscle in the wall

• ampulla is widened last portion

Ejactulatory duct

• passes through the prostate

• empties into the urethra

Urethra

• prostatic, membranous, spongy

Spermatic Ducts

• Efferent ductules

• Epididymis

• Ductus deferens

• Ejaculatory duct

• Urethra

Accessory Glands

• Seminal Vesicles

• Prostate

• Bulbourethral glands

Seminal Vesicles

• Pair of glands, posterior to the bladder

• empty into ejaculatory duct

Prostate

• surrounds the urethra and the ejaculatory ducts

• empties into the urethra

Bulbourethral glands

• pair of glands near base of penis

• secretes clear fluid that neutralizes urethra, lubricates head

Components of Semen

• 2-5 mL per ejaculation

• 10% sperm

  • sperm count: 50-120 million/mL

• 30% prostatic fluid

• 60% seminal vesicle

Penis

• Internal root

• Shaft

• Glans - head

• Prepuce - foreskin

• Erectile tissue

  • corpus spongiosum

  • corpora cavernosa

Corpus spongiosum

• Glans of penis

• contains spongy urethra

Corpora Cavernosa

• contains deep arteries

Structure of the Ovary

• Tunica Albuginea

• Medulla

• Cortex

• Follicles

Tunica Albunigea

• capsule around ovary

Medulla

fibrous connective tissue with blood vessels

Cortex

contains ovarian follicles

Follicles

contain egg and supporting follicular (granulosa) cells

Oogenesis

• Primary Oocyte - (diploid) completes meiosis I, forming one secondary oocyte and one polar body (both haploid)

• Secondary Oocyte - is ovulated and will complete meiosis II IF FERTILIZED (produces and discards a second polar body)

  • ovulation of the secondary oocyte from the mature (Graafian) follicle occurs at around day 14 of the menstrual cycle

  • collapsed follicle becomes corpus luteum

    • if there is no pregnancy, it involutes and becomes corpus albacians - a scar

Folliculogenesis

• Primordial Follicle

• Primary Follicle

• Secondary Follicle

• Teritiary Follicle

• Preovulatory (graafian) follicle

Primordial Follicle

egg and one layer of follicular cells

Primary follicle

larger egg and one layer of cuboidal follicular cells

Secondary follicle

larger egg, two or more layers of granulosa cells

Tertiary Follicle

contains fluid-fluid filled pockets or single fluid-filled antrum among granulosa cells

Preovulatory (graafan) follicle

A large blister bulging from the ovary

• contains cumulus c with zone pellucida as inner layer

Uterine/Fallopian Tubes

ciliated tube from the ovary to the uterus

• fimbraie project from the infundibulum toward the ovary

  • fimbrae perform a sweeping motion over the ovary to draw the oocyte into the tube - ARE NOT CONNECTED

• Ampulla

• Isthmus

Isthmus

narrow, near uterus

Ampulla

middle segment

Uterus

muscular chamber superior to vagina for nourishment, protection, and delivery of fetus

• uterine sections

• uterine wall

Uterine Sections

• Fundus

• Body

• Cervix

  • cervical canal (with cervical glands) connects to vagina

Uterine wall

• Perimetrium

• Myomertrium

• Endometrium

  • Functional layer

  • Basal layer

perimetrium

external serosa

myometrium

smooth muscle

Functional layer

superficial, shed during menstruation

Basal layer

regenerates new lining every month

Vagina

Distensible wall of mucosa, muscularis, and adventitia

• Fornices

• Vaginal Rugae

• Hymen

Fornices

superior extensions around cervix

Vaginal rugae

friction ridges and allows for distension during sexual intercourse and childbirth

Hymen

membrane across the opening. not a sign of virginity

Vulva (pudendum)

external genitalia

• Monis pubis

• Labia majora (majus)

• Labia minora (minus)

• Vestibule

• Clitoris

Clitoris

• Erectile; area of sexual stimulation

  • Prepuce - hood over clitoris

  • Glans, body, crura

Vestibule

• Area enclosed by labia minora

Labia minora

• Hairless, thin, medial folds

Labia majora

• thick folds between thighs

Monis pubis

• Anterior mound

Vestibular bulbs

erectile tissues deep to labia majora

External vaginal glands

providing lubrication to vestibul and vagina

• Greater and lesser vestibular glands

• paraurethral glands

Breasts

• externally, the areola surrounds the nipple

• each breast contains:

  • Suspensory ligaments - attaches dermis to the fascia of pectoralis major muscle

  • adipose tissue

  • Mammary glands

Mammary glands

modified sweat glands to produce human “milk”

• Each lobe of the mammary gland is drained by a lactiferous duct

• each lactiferous duct drains into a lactiferous sinus before exiting through the nipple

External Genitalia (M&F)

Male:

• Penis

• Scrotum

Female:

• Mons pubis

• labia majora

• labia minora

• clitoris

• vaginal orfice

• vestibular bulbs

• vestibular glands

• paraurethral glands

Internal Genitalia (M&F)

Male:

• testes

• epididymis

• ductus deferens

• seminal vesicles

• prostate

• bulbourethral glands

Female:

• ovaries

• uterine tube

• uterus

• vagina

Reproductive disorders

• Prostate Cancer

• Testicular Cancer

• Breast Cancer

• Cervical/Anal Cancer

• Sexually transmitted diseases

Thelarche

testes, scrotum, breast evelopment

Pubarche

hair and sebaceous glands

Menarche

• females

• menstruation

andropause

• male climacteric

• declining reproductive function beginning at the age of 50

  • testosterone levels, sperm count, and libido decline

  • The incidence of erectile dysfunction (impotence) increases

menopause

• female climacteric

• decline of ovarian function

• cessation of menstruation occurs between ages of 45-55

  • Reproductive organs atrophy

  • Hormonal changes cause hot flashes, decreased bone mass, thinner skin, and higher cholesterol

Prostate cancer

• affects 9% of men over 50

Testicular cancer

• most common tumor in men 15-34 years old

breast cancer

occurs in 1 of every 8-9 women in america

• can also occur in males

cervical/anal cancer

• slow growing neoplasia caused by papilloma virus that can be detected by Pap smear

STD (virus)

• AIDS, Hepatitis C, Herpes Simplex 1 and 2, Genital warts

STD (bacteria infection)

• Gonorrhea, Chlamydia, Syphylis, etc