REPRODUCTION AND
EMBRYONIC DEVELOPMENT
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• SEXUAL AND ASEXUAL REPRODUCTION ARE BOTH
COMMON AMONG ANIMALS
– REPRODUCTION
• THE CREATION OF NEW INDIVIDUALS FROM EXISITING ONES
– ASEXUAL REPRODUCTION
• CREATION OF OFFSPRING WHOSE GENES ALL COME FROM
ONE PARENT WITHOUT THE FUSION OF EGG AND SPERM
• EXAMPLES INCLUDE
– BUDDING
– FISSION
– FRAGMENTATION
» ALWAYS
FOLLOWED BY
REGENERATION
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• SEXUAL AND ASEXUAL REPRODUCTION ARE
BOTH COMMON AMONG ANIMALS
– REPRODUCTION
• THE CREATION OF NEW INDIVIDUALS FROM EXISTING
ONES
– SEXUAL REPRODUCTION
• THE CREATION OF OFFSPRING BY THE FUSION OF TWO
HAPLOID SEX CELLS
– GAMETES
» SPERM VS OVUM (EGG)
– ZYGOTE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HERMAPHRODITISIM
– ORGANISM HAS BOTH
MALE AND FEMALE
REPRODUCTIVE SYSTEMS
– AIDS NON-MOBILE AND
SOLITARY ORGANISMS;
HELPS IN FINDING
MATES
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• EXTERNAL VS INTERNAL FERTILIZATION
– EXTERNAL FERTILIZATION
• FUSION OF GAMETES OUTSIDE OF THE BODY
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• EXTERNAL VS INTERNAL FERTILIZATION
– INTERNAL FERTILIZATION
• FUSION OF GAMETES INSIDE OF BODY
• COPULATION
– SEXUAL INTERCOURSE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN FEMALE
– OVARIES
• EACH ABOUT AN INCH LONG, WITH A BUMP SURFACE
• SITE OF EGG PRODUCTION
– FOLLICLES
• CONSIST OF SINGLE DEVELOPING EGG CELL SURROUNDED BY ONE
OR MORE LAYERS OF FOLLICE CELLS THAT NOURISH AND PROTECT
THE DEVELOPING EGG CELL
• FOLLICE CELLS PRODUCE ESTROGEN
• A WOMAN IS BORN WITH 40,000 – 400,000 FOLLICES; ONLY
SEVERAL HUNDRED GET RELEASED
– OVULATION
• PROCESS THAT EJECTS THE EGG CELL FROM THE FOLLICE; OCCURS
ABOUT EVERY 28 DAYS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
– CORPUS LUTEUM
• FORMS AFTER OVULATION, REMAING FOLLICULAR
TISSUE GROWS WITHIN OVARY TO FORM A SOLID MASS
• SECRETES PROGESTERONE; HORMONE THAT HELPS
MAINTAIN UTERINE LINING
• IF EGG IS NOT FERTILIZED, CORPUS LUTEUM
DEGENERATES
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
– OVIDUCT (A.K.A. FALLOPIAN TUBE)
• LEADS THE EGG TO THE UTERUS
• THIS IS WHERE FERTILIZATION ACTUALLY OCCURS
– UTERUS (A.K.A. WOMB)
• ACTUAL SITE OF PREGNANCY; ONLY ABOUT 3 INCHES
IN A WOMAN WHO HAS NEVER BEEN PREGNANT BUT
CAN EXPAND
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
– UTERUS
• ENDOMETRIUM
– INNER LINING OF THE UTERUS; EMBRYO GETS IMPLANTED
HERE
• EMBRYO
– TERM USED TO DESCRIBE ZYGOTE (FERTLIZED EGG) UNTIL
BODY STRUCTURES BEGIN TO APPEAR (ABOUT 9 WEEKS)
• FETUS
– TERM GIVEN TO DEVELOPING OFFSPRING FROM 9TH WEEK
UNTIL BIRTH
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
– ECTOPIC PREGNANCY
• EMBRYO IMPLANTS IN THE WRONG PLACE; SOMEWHERE
OTHER THAN THE UTERUS; CAN BE FATAL IF NOT TREATED
– CERVIX
• NECK OF THE UTERUS; OPENS TO THE VAGINA
– VAGINA
• THIN WALLED, BUT STRONG, MUSCULAR CHAMBER THAT
SERVES AS THE BIRTH CANAL THROUGH WHICH THE BABY IS
EXPELLED
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN FEMALE
– VAGINA
• ALSO ACCOMDATES MALE’S PENIS AND IS REPOSITORY FOR SPERM
DURING COPULATION
• LABIA MINORA AND LABIA MAJORA
– PROTECT THE GENITAL REGION
• HYMEN
– THIN MEMBRANE
COVERING THE VAGINAL
OPENING; FUNCTION NOT
KNOWN
• BARTHOLIN’S GLAND
– NEAR VAGINAL OPENING;
SECRETES LUBRICATING FLUID
DURING SEXUAL AROUSAL,
AS DOES THE VAGINAL LINING
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
FEMALE
– SEVERAL FEMALE REPRODUCTIVE
• VAGINA
• LABIA MINORA
• CLITORIS  SOLE FUNCTION IS SEXUAL AROUSAL
– GLANS
» ENORMOUS
NUMBER OF
NERVE ENDINGS
– PREPUCE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN MALE
–
–
–
–
–
–
–
–
–
–
TESTES
SCROTUM
EPIDIDYMIS
VAS DEFERENS
EJACULATORY DUCT
SEMINAL VESICLE
PROSTATE GLAND
BULBOURETHRAL GLAND
SEMEN
PENIS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
– TESTES
• MALE GONADS; HOUSED INSIDE THE ABDOMINAL
CAVITY
– SCROTUM
• SAC THAT HOUSES THE TESTES; MAINTAINS CURRENT
BODY TEMPERATURE FOR SPERM PRODUCTION
– EPIDIDYMIS
• COILED TUBE THAT STORES SPERM WHILE THEY
DEVELOP
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
– VAS DEFERENS
• DUCT THAT GOES FROM EPIDIDYMIS TO EJACULATORY
DUCT
– EJACTULATORY DUCT
• FUSION OF 2 VAS DEFERENS AND DUCT FROM SEMINAL
VESICLE
• EJACULATION
– EXPULSION OF SPERM-CONTAINING FLUID OUT OF PENIS,
THIS IS WHEN SPERM LEAVE THE EPIDIDYMIS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
– MALE REPRODUCTIVE SYSTEM HAS 3 SETS OF
GLANDS
• SEMINAL VESICLE
– SECRETE A THICK, CLEAR FLUID THAT PROTECTS AND
NOURISHES THE SPERM
• PROSTATE GLAND
– MILKY/ALKALINE FLUID; PROTECTION AGAIN TRACES OF
URINE IN URETHRA AND ACIDITY OF VAGINA
• BULBOURETHRAL GLAND
– HELPS LUBRICATE THE URETHRA
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
– SEMEN
• SPERM AND GLANDULAR SECRETIONS MAKE THIS
FLUID THAT IS DISCHARGED DURING ORGASM
• 95% GLANDULAR FLUID; 5% SPERM (200 – 500
MILLION)
– PENIS
• CONSISTS MAINLY OF TISSUE THAT CAN FILL WITH
BLOOD TO CAUSE AN ERECTION DURING SEXUAL
AROUSAL; MAKING INSERTION INTO VAGINA POSSIBLE,
ALONG WITH TRANSFER OF SPERM
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
– PENIS
• GLANS
– “HEAD”; MANY NERVE ENDINGS, VERY SENSITIVE
• PREPUCE
– COVERS “HEAD”; REMOVED DURING CIRCUMCISION
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE ANATOMY OF THE HUMAN
MALE
– EJACULATION OCCURS IN 2 STAGES
• SPERM AND SEMINAL FLUID ARE FORCED TOWARDS
URETHRA REGION; BLADDER SPINCHTER SHUTS TO
PREVENT URINE FROM ENTERING
• EXPULSION STAGE OCCURS WHEN URETHRA REGION
CONTRACTS AND FORCES SEMEN ALONG PENIS; THAN
MUSCLES IN PENIS CONTRACT AND EXPEL SEMEN OUT
OF BODY
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE FORMATION OF SPERM AND OVA
REQUIRES MEIOSIS
– SPERMATOGENESIS
• THE FORMATION OF SPERM CELLS
– TAKES ABOUT 65-75 DAYS
IN THE HUMAN MALE
– SEMINIFEROUS TUBULES
» COILED TUBES IN
THE TESTES WHERE
SPERM DEVELOP
» PRIMARY VS.
SECONDARY
SPERMATOCYTES
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE FORMATION OF SPERM AND OVA
REQUIRES MEIOSIS
– OOGENESIS
• THE DEVELOPMENT OF AN OVUM
• PRIMARY OOCYTE
– DORMANT DIPLOID CELL IN THE
FOLLICLE
– FSH STIMULATES MEIOSIS
• SECONDARY OOCYTE
– THE HAPLOID CELL; UNEQUAL DIVISION OF CYTOPLASM
– 1 OVUM (MOST OF CYTOPLASM); 1 POLAR BODY (ALMOST
NO CYTOPLASM)
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HORMONES SYNCHRONIZE CYCLICAL
CHANGES IN THE OVARY AND UTERUS
– OVARIAN CYCLE
• EVENTS THAT OCCUR ABOUT EVERY 28 DAYS IN THE
HUMAN OVARY
– MENSTRUAL CYCLE
• RELATED EVENTS IN THE UTERUS; CONTROLLED BY
HORMONES
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HORMONES SYNCHRONIZE
CYCLICAL CHANGES IN THE
OVARY AND UTERUS
– AN OVERVIEW OF THE
OVARIAN AND MENSTRUAL
CYCLES
• OVARIAN CYCLE HAS TWO
PHASES
– PRE-OVULATORY PHASE
» FOLLICLE GROWING
– POST-OVULATORY PHASE
» FORM CORPUS LUTEUM
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HORMONES SYNCHRONIZE
CYCLICAL CHANGES IN THE
OVARY AND UTERUS
– AN OVERVIEW OF THE
OVARIAN AND MENSTRUAL
CYCLES
• MENSTRUAL CYCLE
– MENSTRUATION
» UTERINE BLEEDING (3 – 5
DAYS)
– AFTER MENSTRUATION, THE
ENDOMETRIUM REGROWS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HORMONES SYNCHRONIZE
CYCLICAL CHANGES IN THE
OVARY AND UTERUS
– HORMONAL EVENTS BEFORE
OVULATION
• FSH AND LH ARE RELEASED;
ESTROGEN LEVEL SLOWLY
BUILDS UP UNTIL IT HITS ITS
PEAK (OVULATION)
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HORMONES SYNCHRONIZE
CYCLICAL CHANGES IN THE
OVARY AND UTERUS
– HORMONAL EVENTS AT
OVULATION AND AFTER
• LH PEAKS, CAUSING
OVULATION
• CAUSE HIGH LEVELS OF
ESTROGEN AND
PROGESTERONE WHICH
INHIBIT FSH AND LH
PRODUCTION
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HORMONES SYNCHRONIZE
CYCLICAL CHANGES IN THE
OVARY AND UTERUS
– CONTROL OF THE
MENSTRUAL CYCLE
• CONTROLLED ONLY BY
ESTROGEN AND
PROGESTERONE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE HUMAN SEXUAL RESPONSE OCCURS IN
FOUR PHASES
– EXCITEMENT PHASE
– PLATEAU PHASE
• INCREASED BREATHING AND HEART RATE
– ORGASM
• RHYTHMIC CONTRACTIOSN OF REPRODUCTIVE
STRUCTURES
– RESOLUTION PHASE
• REVERSES THE PREVIOUS RESPONSES; RETURN TO
NORMAL
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• SEXUAL ACTIVITY CAN TRANSMIT DISEASE
– SEXUALLY TRANSMISSABLE DISEASES (STDs)
• CONTAGIOUS DISEASE SPREAD BY SEXUAL CONTACT
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CONTRACEPTION PREVENTS UNWANTED
PREGNANCY
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CONTRACEPTION PREVENTS UNWANTED
PREGNANCY
– CONTRACEPTION
• THE DELIBERATE PREVENTION OF PREGNANCY
• 3 WAYS
– PREVENTING RELEASE OF GAMES FROM GONADS
– PREVENTING FERTILIZATION
– PREVENTING THE EMBRYO FROM IMPLANTING IN THE
UTERUS
• STERILIZATION
– VASECTOMY – VAS DEFERENS ARE CUT
– TUBAL LIGATION – OVIDUCT IS CUT
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CONTRACEPTION PREVENTS UNWANTED
PREGNANCY
– CONTRACEPTION
•
•
•
•
•
•
THE DELIBERATE PREVENTION OF PREGNANCY
RHYTHYM METHOD
WITHDRAWAL
SPERMICIDES
INTRAUTERINE DEVICES (IUDs)
MORNING AFTER PILLS (MAPs)
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• FERTILIZATION RESULTS IN A ZYGOTE AND
TRIGGERS EMBRYONIC DEVELOPMENT
– FERTILIZATION
• THE UNION OF SPERM AND EGG TO FORM A DIPLOID
ZYGOTE
– PROPERTIES OF SPERM CELLS
• ACROSOME
• NECK
• FLAGELLUM
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE PROCESS OF FERTILIZATION
– THE SPERM APPROACHES THE EGG
– THE SPERM’S ACROSOMAL ENZYMES DIGEST THE
EGG’S JELLY COAT
– PROTEINS ON THE SPERM HEAD BIND TO EGG
RECEPTORS
– THE PLASMA MEMBRANES OF SPERM AND EGG
FUSE
– THE SPERM NUCLEUS ENTERS THE EGG
CYTOPLASM
– A FERTILIZATION ENVELOPE FORMS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE PROCESS OF FERTILIZATION
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CLEAVAGE PRODUCES A BALL OF CELLS FROM
THE ZYGOTE
– CLEAVAGE
• RAPID SUCCESSION OF CELL DIVISIONS THAT PRODUCES
A BALL OF CELLS – A MULTICELLULAR EMBRYO – FROM
THE ZYGOTE
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CLEAVAGE PRODUCES A BALL OF CELLS FROM
THE ZYGOTE
– BLASTOCOEL
• FLUID-FILLED CAVITY IN THE
CENTER OF THE EMBRYO
– BLASTULA
• HOLLOW BALL OF CELLS THAT
RESULTS WHEN CLEAVAGE IS
FINISHED
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• GASTRULATION PRODUCES A THREE-LAYERED
EMBRYO
– GASTRULATION
• SECOND MAJOR
PHASE OF EMBRYONIC
DEVELOPMENT; ADDS MORE
CELLS TO THE EMBRYO; SORTS
THE CELLS INTO DISTINCT CELL
LAYERS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• GASTRULATION PRODUCES A THREE-LAYERED
EMBRYO
– GASTRULA
• THREE-LAYERED STAGE OF THE EMBRYO
• THREE LAYERS ARE LABELED
– ECTODERM
– ENDODERM
– MESODERM
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• GASTRULA LAYERS DEVELOP INTO…
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• ORGANS START TO FORM AFTER
GASTRULATION
– NOTOCHORD
– NEURAL TUBE
– SOMITES
– COELOM
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CHANGES IN CELL SHAPE, CELL MIGRATION,
AND PROGRAMMED CELL DEATH GIVE FORM
TO THE DEVELOPING ANIMAL
– PROGRAMMED CELL DEATH = APOPTOSIS
• TIMELY, TIDY SUICIDE OF CELLS
• NECESSARY TO CREATE SPACE BETWEEN FINGERS AND
TOES
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE EMBRYO AND PLACENTA TAKE SHAPE
DURING THE FIRST MONTH OF PREGNANCY
– GESTATION
• PREGNANCY; THE CARRYING OF DEVELOPING YOUNG
WITHIN THE FEMALE REPRODUCTIVE TRACT
– AN OVERVIEW OF DEVELOPMENT EVENTS
• BLASTOCYST  MAMMALIAN EQUIVALENT OF A
BLASTULA
• TROPHOBLAST  OUTER LAYER THAT ALLOWS UTERINE
IMPLANTATION
• PLACENTA  COMBINATION OF TROPHOBLAST AND
MATERNAL CELLS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• AN OVERVIEW OF DEVELOPMENT EVENTS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• EXTRAEMBRYONIC MEMBRANES
– AMNION  PROTECTIVE FLUID
– YOLK SAC  NO YOLK IN HUMANS, BUT SAME
NAME; NOURISHMENT FOR NON-PLACENTALS
– CHORION  BECOME EMBRYOS PART OF
PLACENTA
• RELEASES HUMAN CHORIONIC GONADOTROPIN (HCG)
– CAUSES CORPUS LUTERUM TO STAY; PREVENTS
MENSTRUATION
– ALLANTOIS  FUNCTIONS IN WASTE DISPOSAL;
WILL BECOME THE UMBILICAL CORD
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• EXTRAEMBRYONIC MEMBRANES
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• THE PLACENTA
– CHORIONIC VILLI  CONTAIN EMBRYONIC BLOOD
VESSELS
– NEAR MATERNAL BLOOD; NO DIRECT MIXTURE
OF BLOOD
– NUTRIENTS, GASES, WASTE PRODUCES ARE
PASSED THROUGH THE PLACENTA
– DRUGS, ALCOHOL, VIRUSES CAN PASS THROUGH
– ANTIBODIES CAN PASS THROUGH
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• HUMAN DEVELOPMENT FROM CONCEPTION
TO BIRTH IS DIVIDED INTO THREE TRIMESTERS
– TRIMESTERS  ABOUT 3 MONTH SEGMENTS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CHILDBIRTH IS HORMONALLY INDUCED AND
OCCURS IN THREE STAGES
– LABOR
• SERIES OF STRONG, RHYTHMIC
CONTRACTIONS OF THE UTERUS
• 3 STAGES
– DILATION OF CERVIX
– EXPULSION; DELIVERY OF INFANT
– DELIVERY OF PLACENTA
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• CHILDBIRTH IS HORMONALLY INDUCED AND
OCCURS IN THREE STAGES
– CONTROLLED BY
OXYTOCIN AND
PROSTAGLANDINS
– AFTER BIRTH,
PROLACTIN
INCREASES MILK
PRODUCTION OF
MAMMARY GLANDS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• REPRODUCTIVE TECHNOLOGY INCREASES OUR
REPRODUCTIVE SUCCESS
– ASSISTED REPRODUCTIVE TECHNOLOGY (ART)
• IN VITRO FERTILIZATION (IVF)
– THE MOST COMMON ART
– EGGS ARE REMOVED AND MIXED WITH SPERM IN CULTURE
DISHES, THEN CAREFULLY REPLACED INTO MOTHER’S UTERUS
REPRODUCTION AND EMBRYONIC
DEVELOPMENT
• NO TIME FOR FUNNY JOKES…WE HAVE TO
RACE TO THE FINISH!!!! NERVOUS SYSTEM
NEXT!!!