Ernie 2
Transcript of Ernie 2
Ch 27: Reproductive SystemCh 27: Reproductive 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.
General OrganizationGeneral Organization
GonadsGonads gametes & hormonesgametes & hormones
DuctsDucts transport of . . . ?transport of . . . ?
GlandsGlands secrete fluidsecrete fluid
Perineal structures = external genitaliaPerineal structures = external genitalia
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
Fig 27-1
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”
CryptorchidismCryptorchidismFigs 27-2/3
4 month
ScrotumScrotum
Function: supports and protects Function: supports and protects testes testes
Structure: Skin & underlying Structure: Skin & underlying superficial fascia superficial fascia
Dartos muscleDartos muscle in dermisin dermis Cremaster muscleCremaster muscle - - continuous
with abdominal wall muscles (?)
Involuntary contraction Involuntary contraction (cremasteric reflex) in (cremasteric reflex) in response to ________response to ________
Scrotal sac forms 2 Scrotal sac forms 2 separate chambersseparate chambers
Cremaster muscle
Structure of TestesStructure of Testes
Fibrous capsule Fibrous capsule – – tunica albugineatunica albuginea – – surrounds testes surrounds testes
Scrotal cavity – Scrotal cavity – lined by lined by tunica tunica vaginalisvaginalis – parietal – parietal and visceral layers and visceral layers
200-300 lobules200-300 lobules
3 seminiferous 3 seminiferous tubulestubules
Figs 27-4/5
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 27-6
EpididymisEpididymis
~ 7 m long~ 7 m long
HeadHead - superior, receives - superior, receives spermatozoaspermatozoa
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) urethraFig 27.8
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)
Fig. 27.8
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
seminalplasminseminalplasmin
PenisPenisRootRoot - fixed to ischial ramus - fixed to ischial ramus
BodyBody with with erectile tissueserectile 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 circumcisioncircumcision))
Preputial glands - produce Preputial glands - produce smegma (supports bacterial smegma (supports bacterial growth, such as growth, such as E. coliE. coli))
Fig 27.9