SPERMATOGENESIS PPT

SPERMATOGENESIS : 

SPERMATOGENESIS PRESENTED BY DR SURAJIT KUNDU SENIOR LECTURER DEPT. OF ANATOMY MAITHRI INSTITUTE OF DENTAL SCIENCES ANJORA, DURG CHHATTISHGARH INDIA. 1

DEFINITION : 

DEFINITION THE CONTINUOUS SERIES OF EVENTS BY WHICH THE PRIMITIVE MALE GERM CELL OR SPERMATOGONIA ARE CHANGED TO INACTIVE SPERMATOZOA OR SPERMS IS CALLED AS SPERMATOGENESIS 2

INTRODUCTION : 

INTRODUCTION DEVELOPMENT BEGINS WITH FERTILAZATION GAMETES ARE DERIVED FROM PRIMORDIAL GERM CELLS THESE CELLS MIGRATE DURING 4TH WEEK MIGRATE FROM THE YOLK SAC TOWARDS THE DEVELOPING GONADS DURING MIGRATION THEY INCREASE THEIR NUMBER BY MITOTIC DIVISION IN PREPARATION FOR FERTILAZATION, GERM CELLS UNDERGO GAMETOGENESIS AND CYTODIFFERENTIATION TROUGH GAMETOGENESIS ,EACH AND EVERY ORGANISM MAINTAIN THEIR SPECIES STRENGTH IN THE FIGHT FOR SURVIVAL OF THE FITTEST 3

MALE REPRODUCTIVE SYSTEMAN OVERVIEW : 

MALE REPRODUCTIVE SYSTEMAN OVERVIEW CONSIST OF: EXTENAL GENITAL ORGANS (SCROTUM, PENIS) INTERNAL GENITAL ORGANS (TESTIS, SEMINIFEROUS TUBULES, EPIDIDYMIS, VAS DEFERENS, SEMINAL VESICLE,EJACULATORY DUCTS,PROATATE GLAND, BULBOURETHRAL GLANDS,MALE URETHRA) THESE ORGANS CAN BE CLASSIFIED AS GONADS-PRIMARY SEX GLANDS ACCESSORY SEX GLANDS DUCTS SUPPORTING STRUCTURES 4

Slide 5: 

GERMINAL EPITHELIUM- STRUCTURE PERITUBULAR CELLS BASAL MEMBRANE SPERMATOGONIA TIGHT JUNCTION SPERMATOCYTE Ι SPERMATOCYTE ΙΙ SPERMATIDS ACROSOME RESIDUAL BODIES SPERMATOZOA NUCLEUS OF SERTOLI CELL BASAL ZONE ADLUMINAL ZONE 5

SITE : 

SITE SEMINIFEROUS TUBULAR COMPARTMENT OF THE TESTIS EPIDIDYMIS OF THE MALE REPRODUCTIVE SYSTEM 6

CHARACTERISTIC FEATURES : 

CHARACTERISTIC FEATURES ONSET- PUBERTY, CONTINUES THROUGHOUT- ADULT LIFE, DECLINES - OLD AGE MAJORITY OR SPERMATOGONIA- CONTINUOUS MITOTIC DIVISION –ADDITIONAL STEM CELLS ONLY A FEW OF THE SPERMATOGONIUM -MEIOTIC DIVISION EACH SPERMATOGONIUM- 512 SPERMATIDS SPERMATOGENESIS DO NOT OCCUR SIMULTANEOUSLY IN ALL AREAS OF TESTIS PRIMITIVE GERM CELL-MATURE SPERM- 74 DAYS SPERMATOGONIA IN THE SEMINIFEROUS TUBULE- NON MOTILE STRUCTURES SPERMATOGONIA MATURE - PASSING THROUGH THE MALE GENITAL TRACT AND UNDERGO -CAPACITATION IN THE FEMALE GENITAL TRACT 7

DEVELOPMENTAL STAGES OF SPERMATOGENESIS : 

DEVELOPMENTAL STAGES OF SPERMATOGENESIS TEMPORAL COURSE OF SPERMATOGENESIS LOCAL COURSE OF SPERMATOGENESIS- THE SPERMATOGENESIS WAVE 8

TEMPORAL COURSE OF SPERMATOGENESIS : 

TEMPORAL COURSE OF SPERMATOGENESIS 9

STAGES : 

STAGES SPERMATOCYTOGENESIS MEIOSIS Ι MEIOSIS ΙΙ /SPERMATIDOGENESIS SPERMEIOGENESIS/SPERMIOHISTOGENESIS 10

SPERMATOCYTOGENESIS : 

SPERMATOCYTOGENESIS THE TRANSFORMATION OF DIPLOID SPERMATOGONIA TO DIPLOID PRIMARY SPERMATOCYTES -MITOTIC DIVISION DIPLOID SPERMATOGONIA- 3 TYPES- DARK TYPE A, LIGHT TYPE A , DARK TYPE B HOMONYMOUS AND HETERO-NYMOUS DIVISION DARK TYPE B- 5 MITOTIC DIVISION-32 DIPLOID SPERMATOGONIA 32 SPERMATOGONIA- 64 PRIMARY DIPLOID SPERMATOCYTES (2n)- MITOTIC DIVISION 11

MEIOSIS Ι : 

MEIOSIS Ι PROCESS OF CONVERTION OF DIPLOID PRIMARY SPERMATOCYTES- HAPLOID SECONDARY SPERMATOCYTES 64 PRIMARY SPERMATOCYTES- 256 SECONDARY SPERMATOCYTES- 1ST REDUCTION OR MEIOTIC DIVISION 12

MEIOSIS ΙΙ/ SPERMATIDOGENESIS : 

MEIOSIS ΙΙ/ SPERMATIDOGENESIS PROCESS OF CONVERTION OF HAPLOID SECONDARY SPERMACYTES – HAPLOID SPERMATIDS 13

Slide 14: 

TIME TAKEN BY THESE EVENTS SPERMATOGONIA- PRIMARY SPERMATOCYTES- 8 DAYS PRIMARY SPERMATOCYTES- SECONDARY SPERMATOCYTES- 16 DAYS SECONDARY SPERMATOCYTES- SPERMATIDS- 24 DAYS 14

SPERMEIOGENESIS/ SPERMIOHISTOGENESIS : 

SPERMEIOGENESIS/ SPERMIOHISTOGENESIS SERIES OF 3 PROCESSES PROCESS OF MORPHOLOGICAL TRANSFORMATION OF HAPLOID SPERMATIDS – HAPLOID NONMOTILE INATIVE SPERMATOZOA OR SPERMS RELEASE OF THE NON MOTILE MATURE SPERMATOZOA IN TE LUMEN OF THE SEMINIFFEROUS TUBULE- SPERMIATION TRANSPORT OF THE NON MOTILE SPERMATOZOA FROM THE SEMINIFEROUS TUBULAR LUMEN TO THE EPIDIDYMIS TO GAIN MOTILITY AND TEMPORARY STORAGE ALSO KNOWN AS SPERMATELEIOSIS TIME TAKEN- ABOUT 10 DAYS 15

SPERMIOGENESIS-EVENTS ASSOCIATED : 

SPERMIOGENESIS-EVENTS ASSOCIATED CONDENSATION OF NUCLEAR MATERIAL  REMOVAL OF EXTRANEOUS CYTOPLASM CYTOPLASM REDUCTION FORMATION OF ACROSOME FORMATION OF TAIL STRUCTURES RELEASE OF SPERMATOZOA TRANSPORT OF SPERMATOZOA 16

Slide 17: 

SPERMATOGENESIS 17

Slide 18: 

18 SPERMATOGENESIS

MORPHOLOGICAL CHANGES OF SPERMATID TO SPERM : 

MORPHOLOGICAL CHANGES OF SPERMATID TO SPERM 19

Slide 20: 

AXONEMALSTRUCTURE GOLGI COMPLEX ACROSOMAL VESICLE PAIR OF CENTRIOLES MITOCHONDRION NUCLEUS FLAGELLAR PRIMORDIUM MICROTUBULES SPERM CELLS TAIL ACROSOMAL CAP MORPHOLOGICAL CHANGE OF SPERMATID TO SPERMATOZOA 20

Slide 21: 

PLASMA MEMBRANE OUTER ACROSOMAL MEMBRANE ACROSOME INNER ACROSOMAL MEMBRANE NUCLEUS PROXIMAL CENTRIOLE DISTAL CENTRIOLE OUTER THICK LONGITUDINAL FIBRES MITOCHONDRION AXONEME ANNULUS RING FIBRES HEAD (A), NECK (B), MIDDLE PIECE (C), PRINCIPLE PIECE (D), END PIECE (E) A MATURE SPERMATOZOON 21 LENGTH- 60μm (APPROXIMATELY)

SPERMATOGENESIS-CELLS INVOLVED : 

SPERMATOGENESIS-CELLS INVOLVED 22

SERTOLI CELLS- ROLE PLAYED : 

SERTOLI CELLS- ROLE PLAYED PHYSICAL SUPPORT AND NUTRITION PHAGOCYTIC FUNCTION MAINTENAINCE OF BLOOD TESTIS BARRIER SECRETORY FUNCTIONS ANTI MULLERIAN HORMONE INHIBIN ANDROGEN BINDING PROTEIN OESTROGEN TRANSPORT PROTEINS PLASMINOGEN ACTIVATOR SEMINIFEROUS TUBULAR LUMINAR FLUID SUBATANCES INITIATING MEIOSIS -ACTIVIN HORMONAL CONTROL OF SPERMATOGENESIS OPTIMUM ENVIRONMENT FOR THE GERM CELLS -DIVIDE AND MATURE 23

Slide 24: 

SERTOLI CELL OR NURSE CELL BASAL MEMBRANE 2-6. DEVELOPING GERM CELL 7. SERTOLI CELL 8. TIGHT JUNCTION 24

BLOOD TESTIS BARRIER- SIGNIFICANCE : 

BLOOD TESTIS BARRIER- SIGNIFICANCE MAINTAINS GERM CELLS IN PRIVILEGED LOCATION PREVENTS CONTACT OF GERM CELLS WITH CIRCULATING ANTIBODIES PREVENTS BYPRODUCTS OF SPERMATOGENESIS INTO BLOOD PREVENTS AUTO IMMUNE REACTIONS ALLOWS MATURING GERM CELLS TO CROSS THE BARRIER MAINTAINS LUMINAL FLUID COMPOSITION (K+,HCO3,TESTOSTERONE, (OH)TESTOSTERONE, IONOSITOL, GLUTAMIC ACID, OESTEROGEN, GLUCOSE, PROTEINS) 25

LEYDIG CELLS- ROLE PLAYED : 

LEYDIG CELLS- ROLE PLAYED SECRETION OF THE MALE SEX HORMONE-TESTOSTERONE HAVING AN IMPORTANT ROLE IN CONTROL OF SPERMATOGENESIS 26

Slide 27: 

LEYDIG CELL 2. CRYSTALLOID OF REINKE LEYDIG CELL 27

LOCAL COURSE OF SPERMATOGENESIS- : 

LOCAL COURSE OF SPERMATOGENESIS- THE SPERMATOGENESIS WAVE 28

Slide 29: 

DEVELOPMENTAL STAGES IN THE GERMINAL EPITHELIUM LEPTOTENE / ZYGOTENE OF SPERMATOCYTE TYPE Ι PACHYTENE OF SPERMATOCYTE TYPE Ι SPERMATOCYTE TYPE YOUNG SPERMATIDS OLDER SPERMATIDS SPERM CELL HEAD 29

Slide 30: 

THE SPERMATOGENESIS WAVE DEVELOPEMENTAL STAGES THREE WAVES OF SPERMATOGENESIS GENERATIONS 30

SPERMATOGENESIS- INFLUENCING FACTORS : 

SPERMATOGENESIS- INFLUENCING FACTORS ENDOCRINAL ENVIRONMENT-TESTOSTERONE TEMPERATURE POSITION OF THE TESTIS-ANATOMICAL FACTOR DIETARY FACTORS (VIT. A,B,E) ANABOLIC STEROIDS METALS- CADMIUM, LEAD RADIATION EXPOSURE DIGOXIN ALCOHOLS INFECTIOUS DISEASES 31

PURPOSE OF SPERMATOGENESIS : 

PURPOSE OF SPERMATOGENESIS PRODUCE MATURE SPERMATIDS PRODUCE HAPLOID GAMETES CELL PROLIFERATION MAINTENANCE OF RESERVE GERM CELL POPULATION GENETIC VARIABILITY – INTRODUCED 32

CONTROL OF SPERMATOGENESIS : 

CONTROL OF SPERMATOGENESIS (A) STIMULATORY CONTROL (B) FEEDBACK CONTROL 33

STIMULATORY CONTROL : 

STIMULATORY CONTROL ROLE OF HYPOTHALAMUS ROLE OF ANTERIOR PITUITARY ROLE OF FSH ROLE OF LH/ ICSH ROLE OF GROWTH HORMONE ROLE OF TESTICULAR HORMONES 34

FEEDBACK CONTROL : 

FEEDBACK CONTROL HYPOTHALAMUS +VE ANTERIOR PITUITARY SERTOLI GERM LEYDIG CELL CELL CELL TESTOSTERONE OESTRADIOL TARGET TISSUE INHIBIN GnRH -VE -VE LH FSH -VE +VE +VE -VE 35

SPERMATOGENESIS- VIDEO : 

SPERMATOGENESIS- VIDEO 36

APPLIED ASPECTS : 

APPLIED ASPECTS CRYPTORCHIDISM EXTIRPATION /CASTRATION HYPOGONADISM IN MALES HYPERGONADISM IN MALE IMPOTENCE MALE INFERTILITY 37

THANKYOU : 

THANKYOU 38