Reproductive System

Reproductive SystemReproductive SystemGoals:Goals:

1.1. Identify the structures of the male Identify the structures of the male and female reproductive systems, and female reproductive systems, including the gross and including the gross and microscopic anatomy of the microscopic anatomy of the organs, structures and accessory organs, structures and accessory glands and their basic functions.glands and their basic functions.

2.2. Explain meiosis, spermatogenesis Explain meiosis, spermatogenesis and oogenesis.and oogenesis.

3.3. Discuss the changes that occur in Discuss the changes that occur in the female reproductive system the female reproductive system during pregnancy.during pregnancy.www.freelivedoctor.com

General OrganizationGeneral Organization

GonadsGonads gametes & hormonesgametes & hormones

DuctsDucts transport of . . . ?transport of . . . ?

GlandsGlands secrete fluidsecrete fluid

Perineal structures = external genitaliaPerineal structures = external genitalia

www.freelivedoctor.com

Male Reproductive AnatomyMale Reproductive Anatomy

Primary reproductive organs produce Primary reproductive organs produce gametesgametes

Secondary reproductive organs . . . Secondary reproductive organs . . .

Male reproductive and urinary tracts Male reproductive and urinary tracts are partially sharedare partially shared


TestesTestes (paired glands)(paired glands)

Develop adjacent to kidneysDevelop adjacent to kidneys

Descend into scrotum through inguinal canal Descend into scrotum through inguinal canal (function of (function of gubernaculum testis)

Peritoneal lining is carried along Peritoneal lining is carried along lining of lining of scrotumscrotum

Spermatic cord: bundle containing all the “duct Spermatic cord: bundle containing all the “duct work”work”

CryptorchidismCryptorchidism

4 month


ScrotumScrotumFunction: supports and protects testes Function: supports and protects testes

Structure: Skin & underlying Structure: Skin & underlying superficial fasciasuperficial fascia

Dartos muscleDartos muscle in dermisin dermis Cremaster muscleCremaster muscle - - continuous with

abdominal wall muscles (?)

Involuntary contraction (cremasteric Involuntary contraction (cremasteric reflex) in response to ________reflex) in response to ________

Scrotal sac forms 2 Scrotal sac forms 2 separate chambersseparate chambers

Cremaster musclewww.freelivedoctor.com

Structure of TestesStructure of Testes

Fibrous capsule – Fibrous capsule – tunica albugineatunica albuginea – – surrounds testes surrounds testes

Scrotal cavity – lined Scrotal cavity – lined by by tunica vaginalistunica vaginalis – – parietal and visceral parietal and visceral layers layers

200-300 lobules200-300 lobules

3 seminiferous 3 seminiferous tubulestubules


From Spermatocyte to SpermatozoonFrom Spermatocyte to Spermatozoon

Spermatogenesis: Meiosis of primary spermatocytes spermatids

Spermiogenesis: Spermatid maturation into spermatozoa within Sertoli cells

Spermiation: Spermatozoon released into lumen


Sustentacular (Sertoli) CellsSustentacular (Sertoli) Cells

Maintenance of blood testis barrierMaintenance of blood testis barrierspecial lumen fluid high in sex hormones, Kspecial lumen fluid high in sex hormones, K++ and aa and aa

protection from immune attack (due to sperm specific ag)sperm specific ag)

Suspend spermatids and support and support spermatogenesis and spermiogenesisspermatogenesis and spermiogenesis FSH and Testosterone work via Sertoli cellsFSH and Testosterone work via Sertoli cells

Secretion of inhibin to Secretion of inhibin to slow sperm production

Secretion of androgen-binding Secretion of androgen-binding protein (ABP)protein (ABP)


Anatomy of a SpermatozoonAnatomy of a Spermatozoon

Mature sperm has 3 Mature sperm has 3 portions:portions:

1.1. Head with acrosome Head with acrosome (containing _______ )(containing _______ )

2.2. Middle piece with Middle piece with nucleus and lots of ?nucleus and lots of ?

3.3. Tail - flagellum Tail - flagellum - (rotating - (rotating in corkscrew fashion)in corkscrew fashion)

See fig 27-6www.freelivedoctor.com

EpididymisEpididymis

~ 7 m long~ 7 m long

HeadHead - superior, receives spermatozoa - superior, receives spermatozoa

BodyBody - distal and inferior - distal and inferior

TailTail - leads to ductus deferens - leads to ductus deferens

Functions:Functions:

1) Monitors and adjusts tubular fluid 1) Monitors and adjusts tubular fluid (stereocilia!)(stereocilia!)

2) Recycles damaged spermatozoa2) Recycles damaged spermatozoa

3) Stores sperm and facilitates 3) Stores sperm and facilitates maturationmaturation

Rete testis and Efferent ductules


Pathway of Sperm

Seminiferous tubules

Rete testis

Epididymis

Vas (ductus) deferens

Ampulla of vas deferens

Ejaculatory duct

Prostatic urethra

Membranous urethra

Penile (spongy) urethra


Accessory GlandsAccessory Glands

Provide for 95% of the seminal fluidProvide for 95% of the seminal fluid

1) Seminal Vesicles1) Seminal Vesicles Paired, on back wall of urinary bladderPaired, on back wall of urinary bladder Tubular Tubular (~ 15 cm)(~ 15 cm)

Produce 60% of semen, hormones, fructose, Produce 60% of semen, hormones, fructose, etc.etc.

Activate sperm (leading to motility)Activate sperm (leading to motility)


Prostate GlandProstate Gland

20 - 30% of seminal fluid 20 - 30% of seminal fluid

Single, doughnut-shapedSingle, doughnut-shaped

Secretion contains:Secretion contains: Citrate Citrate Seminal plasmin (mild Seminal plasmin (mild

antibiotic)antibiotic) Prostate specific antigen Prostate specific antigen

(PSA) – blood test for ?(PSA) – blood test for ?


Bulbourethral glands Bulbourethral glands (Cowper’s glands)(Cowper’s glands)

Pea size, Pea size, paired, at base of penis

Produce about 10% of semen

Alkaline mucus - Alkaline mucus - function??function??


SemenSemen

2-5 ml ejaculate2-5 ml ejaculate

Ejaculation of semen by pelvic floor and penile Ejaculation of semen by pelvic floor and penile muscles (Sympathetic division induces muscles (Sympathetic division induces peristalsis in tract)peristalsis in tract)

Constituents:Constituents:1. sperm - 20 - 100 million sperm/ ml1. sperm - 20 - 100 million sperm/ ml2. seminal fluid - see above glands2. seminal fluid - see above glands3. enzymes - proteases and 3. enzymes - proteases and

seminalplasminseminalplasminwww.freelivedoctor.com

PenisPenisRootRoot - fixed to ischial ramus - fixed to ischial ramus

BodyBody with erectile tissues with erectile tissues

GlansGlans – enlargement of – enlargement of corpus spongiosumcorpus spongiosumPrepucePrepuce - foreskin – partially - foreskin – partially

covers glans and surrounds covers glans and surrounds external urethral meatus external urethral meatus (may be removed in (may be removed in circumcision)circumcision)

Preputial glands - produce Preputial glands - produce smegma (supports bacterial smegma (supports bacterial growth, such as growth, such as E. coliE. coli))


Female Reproductive SystemFemale Reproductive System

All organs are internal and closely associatedAll organs are internal and closely associated– Primary reproductive organs: ?Primary reproductive organs: ?

– Secondary reproductive organsSecondary reproductive organs: ?: ?

Female repro system must produce gametes AND maintain developing embryo

OvariesOvaries

Suspended by ovarian Suspended by ovarian ligament & suspensory ligament & suspensory ligamentligament

Functions:Functions: 1.1. Ova production Ova production 2.2. Hormone productionHormone production

Oogenesis Oogenesis ((= ovum production)= ovum production)

takes place inside takes place inside ovarian follicles in ovaries as ovarian follicles in ovaries as part of ovarian cyclepart of ovarian cycle

OogoniaOogonia (= stem cells) complete mitotic (= stem cells) complete mitotic divisions before birthdivisions before birthAt birth: ~ 2 mio primary oocytesAt birth: ~ 2 mio primary oocytes

At puberty: ~ 400,000 primary oocytesAt puberty: ~ 400,000 primary oocytes

40 years later: 0 (even though only ~ 500 used) 40 years later: 0 (even though only ~ 500 used) Atresia Atresia

OogensisOogensisOvarian cycles start at puberty under influence of ___Ovarian cycles start at puberty under influence of ___

Primordial folliclePrimordial follicle

Primary folliclePrimary follicle

Secondary follicleSecondary follicle

Tertiary (Graafian follicle)Tertiary (Graafian follicle)

Each month some proceed

Few proceed

Few proceed

(simple squamous layer)

Primordial Follicle or Egg Nests

in cortex

Present at birth

Primary Follicle

OocytesFollicle cells

Follicles enlarge in response to FSH and

produce estrogens

Few relative to number of primary follicles

Produce follicular fluid

Rapid enlargement

= Clear glycoprotein layer

Secondary Follicle

Tertiary or Graafian Follicle

Spans entire width of cortex

First meiotic division being completed: 1oocyte divides into one 2 oocyte and one polar body

Ovulation

Happens in tertiaryfollicle

OogenesisOogenesisSuspended in prophase I

Stops in Metaphase II

Oocyte and follicular cells shed into abdominal cavity

then1. Empty follicle forms corpus luteum which produces progesterone

2. Corpus luteum degenerates and becomes corpus albicans

3. GnRH increases under low estrogen and progesterone levels

Ovulation

Uterine Tube

= Fallopian tube = oviduct = Fallopian tube = oviduct = salpinx= salpinx

Two muscular tubesTwo muscular tubes infundibuluminfundibulum with fimbriae with fimbriae AmpullaAmpulla (place of fertilization) (place of fertilization) IsthmusIsthmus intramural portionintramural portion

Tubal ligationTubal ligation

Fig 27-14

Uterine Tube Histology

Ciliated and non-ciliated Ciliated and non-ciliated simple columnar simple columnar epitheliumepithelium

Ciliary movement and Ciliary movement and periodic peristaltic periodic peristaltic contractions move contractions move ovaova

Secretion of nutrient Secretion of nutrient substancessubstances

The Uterus

Uterine wallUterine wall ~ 1.5 cm ~ 1.5 cm

made up ofmade up of

1.1. Endometrium, Endometrium,

2.2. Myometrium, Myometrium,

3.3. Incomplete perimetriumIncomplete perimetrium

Blood supplyBlood supply Uterine arteries from internal iliacUterine arteries from internal iliac Ovarian arteries from abdominal Ovarian arteries from abdominal

aorta (inferior to renal arteries)aorta (inferior to renal arteries)

Fig 27-16

Histology of Endometrium

Functional zoneFunctional zone – – deciduum, sheds during deciduum, sheds during menses menses menstruation - flow sheds functionalis layer of menstruation - flow sheds functionalis layer of

endometriumendometrium proliferative phase - under influence of estrogen proliferative phase - under influence of estrogen

basal cells proliferatebasal cells proliferate secretory phase - progesterone maintains secretory phase - progesterone maintains

functionalisfunctionalis

Basilar zone Basilar zone – – permanent layer, deep to permanent layer, deep to functionalisfunctionalis

Functions of UterusFunctions of Uterus

Protection of embryo/fetusProtection of embryo/fetus

Nutritional supportNutritional support

Waste removalWaste removal

Ejection of fetus at birthEjection of fetus at birth

Cervix and Vagina

CervixCervix attaches to vagina at ~ 90° angle attaches to vagina at ~ 90° angle

FornixFornix – – pocket surrounding uterine cervixpocket surrounding uterine cervix (surgical (surgical access to pelvic cavity; location of birth control device)access to pelvic cavity; location of birth control device)

VaginaVagina – – fibro-muscular organ serving asfibro-muscular organ serving as receptacle for intercoursereceptacle for intercourse passageway for menstrual productspassageway for menstrual products birth canalbirth canal

The Mammary GlandModified sweat glandModified sweat gland

Overlaying the ____________ muscleOverlaying the ____________ muscle

15-20 separate lobes separated by suspensory 15-20 separate lobes separated by suspensory ligaments; each lobe contains several secretory ligaments; each lobe contains several secretory lobuleslobules

Lactiferous ducts leaving lobules; converge into 15-20 Lactiferous ducts leaving lobules; converge into 15-20 lactiferous sinuseslactiferous sinuses

Milk stored in lactiferous sinus until released at tip of nippleMilk stored in lactiferous sinus until released at tip of nipple

Lymphatic Drainage of Mammary Glands . . . . . . is of considerable clinical . . . is of considerable clinical

importance, why ??importance, why ??

Health & Medicine

Reproductive System