CHAP 29 Flashcards
The prenatal period begins with _____ and ends _____.
FERTILIZATION, BIRTH
Oxytocin:
RESPONSIBLE FOR MILK EJECTION
Prolactin:
RESPONSIBLE FOR MILK PRODUCTION
Where does fertilization take place?
WIDEST PART OF UTERINE TUBE, AMPULLA
Know the “life span” of an oocyte following ovulation and the “life span” of sperm in the female reproductive tract.
OOCYTE: 24 HRS FOLLOWING OVULATION. SPERM: 3-4 DAYS
Capacitation:
PHYSIOLOGICAL CONDITIONING UNDERGONE BY SPERM TO BECOME CAPABLE OF FERTILIZING THE SECONDARY OOCYTE
Acrosome reaction:
RELEASE OF DIGESTIVE ENZYMES FROM ACROSOMES; ALLOWS SPERM TO PENETRATE ZONA PELLUCIDA
Zygote:
SINGLE DIPLOID CELL FORMED
Cleavage:
SERIES OF MITOTIC DIVISIONS OF ZYGOTE; INCREASES IN CELL # (not size!)
If one sperm passes thru the zona pellucida, what happens to the zona pellucida? What is the purpose of this?
IMMEDIATE HARDENING OF ZONA PELLUCIDA TO PREVENT OTHER SPERM FROM ENTERING SO ONLY ONE SPERM FERTILIZES THE OOCYTE
Placenta function?
SITE OF EXCHANGE OF NUTRIENTS, WASTES, & RESPIRATORY GASES; TRANSMITS MATERNAL ANBITBODES
What is the connecting stalk?
CONNECTS EARLY EMBRYO TO PLACENTA; PRECURSOR TO UMBILICAL CORD
hCG:
SIGNALS REPRODUCTIVE SYSTEM THAT IMPLANTATION OCCURRED; PROMOTES MAINTENANCE OF CORPUS LUTEUM; PRODUCES ESTROGEN & PROGESTERONE TO BUILD UTERINE LINING
Progesterone & estrogen–first produced by:
CORPUS LUTEUM
Progesterone & estrogen–later produced by:
PLACENTA
Extraembryonic membranes–what are the three membranes?
YOLK SAC, AMNION, & CHORION
YOLK SAC:
1ST TO DEVELOP; SITE FOR EARLY BLOOD CELL & VESSEL FORMATION
AMNION:
ENCLOSES ENTIRE EMBRYO IN FLUID-FILLED SAC (AMNIOTIC CAVITY); PROTECTS MEMBRANE FROM DRYING OUT
CHORION:
OUTERMOST; EVENTUALLY FORM PLACENTA; CELLS BLEND W/FUNCTIONAL LAYER OF ENDOMETRIUM
The fetal period lasts from _____ to _____.
BEGINNING OF 3RD MONTH, BIRTH
Know the three phases of fertilization.
PHASE 1: SPERM PENETRATES CORONA RADIATA. PHASE 2: SPERM UNDERGOES ACROSOME REACTION & PENETRATES ZONA PELLUCIDA. PHASE 3: SPERM & OOCYTE PLASMA MEMBRANES FUSE
Know the two distinct cell areas of a blastocyst and what those cell areas eventually form.
EMBRYOBLAST: FORM EMBRYO PROPER. TROPHOBLAST: FORM CHORION (MEMBRANE)
Where and when does the blastocyst begin to implant?
INTO THE ENDOMETRIUM; END OF THE 1ST WEEK INTO 2ND WEEK
Direction of gas diffusion between mother and fetus.
O2 DIFFUSING FROM MATERNAL BLOOD TO FETUS; CO2 DIFFUSING FROM FETAL TO MATERNAL BLOOD
What happens during gastrulation?
CELLS OF EPIBLAST FORM 3 PRIMARY GERM LAYERS
What are the three embryonic tissues/primary germ layers?
ECTODERM, MESODERM, & ENDODERM
ECTODERM:
EPIDERMIS, SENSE ORGANS, NERVOUS SYSTEM, ENAMEL OF TEETH, LENS OF EYE, PITUITARY GLAND
MESODERM:
AXIAL SKELETON, SKELETAL MUSCLE TISSUE, REPRODUCTIVE SYSTEM, KIDNEYS, DERMIS, CT, CARDIOVASCULAR SYSTEM
ENDODERM:
LININGS OF ORGANS
Organogenesis: by week 8, what structures are in place?
UPPER/LOWER LIMBS & MOST ORGAN SYSTEMS HAVE RUDIMENTARY FORM
Brief understanding of what occurs in each trimester.
1ST: ZYGOTE INTO EARLY EMBRYO, THEN FETUS. 2ND: FETUS GROWTH & EXPANSION OF MATERNAL TISSUE. 3RD: FETUS GROWS RAPIDLY; MOTHER PREPARES FOR DELIVERY
