CMCA REPRO NOTES 2

Fertilization

The union of the ovum and a spermatozoon, marking the beginning of pregnancy.

Pre-embryonic
Embryonic
Fetal growth

Fetal growth and development is usually divided into three periods (PEF)

Pre-embryonic

first 2 weeks beginning with fertilization

embryonic

from week 3 through 8

fetal growth

from 8 week through birth

Zona pellucida

a ring of mucopolysaccharide fluid

Fimbriae

fine, and hair like structures that line the opening of the fallopian tube

Corona radiata

circle of cells

24 hours

Normally, only one ovum reaches maturity each month. Once released, fertilization must occur fairly quickly because an ovum is capable for fertilization for only _______ (48 hours at the most). 

400 million

An ejaculation of semen averages 2.5 ml of fluid containing 50 to 200 million spermatozoa per milliliter, or an average of __________ per ejaculation.

90

Sperm transport efficient close to ovulation that spermatozoa deposited in the vagina during intercourse generally reach the cervix within ___ seconds and the outer end of the fallopian tube within 5 minutes after deposition. 

Capacitation

is a final process that sperm must undergo to be ready for fertilization, this process which happens as the sperm moves toward the ovum, composed of changes in the plasma membrane of the sperm head, which reveals the sperm binding receptor cites.

Hyaluronidase

a proteolytic enzyme apparently released by the spermatozoa and acts to dissolve the layer of cells protecting the ovum. 

Zygote

The structure formed after the chromosomal material of the ovum and spermatozoon fuse during fertilization.

46

Spermatozoon and ovum carried 23 pairs of chromosomes (22 autosomes and 1 sex chromosomes) creating a total of ___ chromosomes

Female

XX chromosomes

Male

XY chromosome

Mulberry

Morula comes from Latin word morus meaning “________”

Ovum

The stage of fetal development from ovulation to fertilization   

Zygote

The stage of fetal development from fertilization to implantation 

Embryo

The stage of fetal development from implantation to 5-8 weeks.

Fetus

The stage of fetal development from 5-8 weeks until term.

Conceptus

The developing embryo or fetus and placenta structures throughout pregnancy.

Blastocyst

The structure formed by the morula that attaches to the uterine endometrium.

Trophoblast

part of the morula structure that soon will form the placenta and the membranes.

Implantation

The process in which the blastocyst attaches to the uterine endometrium, approximately 8 to 10 days after fertilization.

Apposition

A process where blastocyst brushes against the rich uterine endometrium (in the 2^nd phase of the menstrual cycle)

Decidua

Latin word “falling off”. It will be discarded after the birth of the child. The separate areas are decidua basalis, decidua capsularis, and decidua vera.

Chorionic Villi

Miniature villi that reach out from the chorionic membrane into the uterine endometrium, playing a role in nutrient exchange and hormone production.

Placenta

An organ that develops from trophoblast tissue. Latin for “pancake” which is descriptive of its size and appearance of term, and serves as the fetal lungs, kidney, gastrointestinal tract, and endocrine organs throughout pregnancy.

Cotyledons

As the number of chorionic villi increases with pregnancy, the villi form an increasingly complex communication network with the maternal blood. Intervillous spaces grow larger and larger, becoming separated by a series of a partition or septa. In a mature placenta, there are as many 300 separate segments, called _______; These compartments make the maternal side of the placenta at term look rough and uneven.

40-600g

At term, placental circulatory network is so extensive that a placenta weighs _____ (1lb) and is one sixth the weight of the baby. 

Human Chorionic Gonadotropin

The first hormone to be produced. This hormone can be found in maternal blood and urine as early as the time of the first missed menstrual period (shortly after implantation has occurred) through about the 100 days of pregnancy. Acts as a fail safe measure to ensure that the corpus luteum should fail and the level of the progesterone and estrogen. It also plays a role in suppressing the maternal immunologic response so placental tissue is not rejected.

Estrogen

Referred to as the hormone of women, primarily estriol it is produced as a second product of the syncytial cells of the placenta. It contributes to the mother’s mammary glands development in preparation for lactation and stimulates uterine growth to accommodate the developing fetus. Assessing the amount of estriol in maternal serum was used in the past to test fetal well-being. 

Progesterone

Referred to as the hormone of mother. It is necessary to maintain the endometrial lining of the uterus during pregnancy. It is present in serum as early as 4^th week of pregnancy as a result of continuation of the corpus luteum. It also appears to reduce the contractility of the uterine musculature during pregnancy, which prevents premature labor

Human Placenta Lactogen

A hormone with both growth-promoting and lactogenic (milk-producing) properties. It is produced by the placenta beginning as early as the 6^th week of pregnancy, increasing to a peak level at term.

Umbilical Cord

A cord that connects the fetus to the placenta, containing two umbilical arteries and one umbilical vein. The cord formed from the amnion and chorion that connects the embryo to the placenta, providing a circulatory pathway for oxygen, nutrients, and waste products.

53 cm

The umbilical cord is about ____ (21 in) in length at term. It is about 2 cm (3/4 in) in thickness.

Percutaneous umbilical blood sampling

A procedure where blood is withdrawn from or transfused into the umbilical vein for fetal assessment or treatment (PUBS)

Prostaglandins

The amniotic membrane not only offers support to amniotic fluid but actually produces the fluid. In addition, it produces phospholipids that initiate the formation of _______, which cause the uterine contractions and may be the “trigger” that initiates labor.

800 to 1200 ml.

At term, the amount of amniotic fluid ranges from _____________

Esophageal or anencephaly

two most common reasons if the fetus is unable to swallow

Oligohydramnios

A disturbance of kidney function may cause __________, a reduction in the amount of amniotic fluid (less than 300 mL total or n o pocket on ultrasound larger than 1 cm).

Nuchal cord

A loose loop of umbilical cord found around the fetal neck during birth.

7.2

Amniotic fluid is slightly alkaline with a pH of about ___. Checking the pH of the fluid at the time of rupture helps to differentiate it from urine, which is acidic (pH 5.0-5.5). 

Chorionic membrane

The outermost fetal membrane that supports the sac containing amniotic fluid.

Amniotic membrane

A membrane beneath the chorionic membrane that produces amniotic fluid and initiates the formation of prostaglandins.

Hydramnios

Excessive amniotic fluid, usually caused by the fetus being unable to swallow.

Oligohydramnios

A reduction in the amount of amniotic fluid, usually caused by a disturbance in kidney function.

Amniotic fluid

Fluid that surrounds the fetus, providing protection and aiding in fetal development.

Germ layer

Specific tissue layers from which organ systems develop during fetal growth: Ectoderm, mesoderm, endoderm

Endoderm

• lining of the pericardial, pleura, and peritoneal cavities

• lining the gastrointestinal tract, respiratory tract, tonsils, parathyroid, thyroid, thymus glands 

• lower urinary system (bladder and urethra) 

Mesoderm

• supporting structures of  the body (connective tissue, bones, cartilages, muscle, ligaments and tendons)

• dentin of teeth 

• upper portion of the urinary system 

• reproductive organ 

• heart 

• circulatory system 

• blood cells 

• lymph vessels 

Ectoderm

• central nervous system (brain and spinal cord) 

• peripheral nervous system 

• skin, hair and nails 

• sebaceous glands 

• sense organ 

• mucous membranes, of the anus, mouth and nose

• tooth enamel 

• mammary glands 

Volvulus of intestine

A condition where the intestine fails to rotate 180 degrees during fetal development, leading to inadequate mesentry attachment and potential twisting of the intestine.

Omphalocele

A congenital anomaly where intestinal coils remain outside the abdomen, resulting in the development of a defect in the base of the cord.

Gastroschisis

A congenital defect where the midline fusion of the abdominal wall is incomplete, leading to the protrusion of abdominal contents.

Meckel's diverticulum

A pouch of intestinal tissue that forms when the vitalline ducts do not atrophy after the return of the intestines to the abdominal cavity.

Meconium

A substance formed in the intestine during fetal development, composed of cellular wastes, bile, fats, mucoprotein, mucopolysaccharides, and a portion of the vernix caseosa.

Vitamin K deficiency

A condition that can occur in newborn infants due to the lack of bacterial synthesis of Vitamin K in the sterile gastrointestinal tract before birth.

Lipase deficiency

A condition where newborns lack the enzyme lipase, which is necessary for fat digestion.

Hypoglycemia

A condition that can occur in newborns due to the immaturity of the liver at birth, leading to low blood sugar levels.

Hyperbilirubinemia

A condition that can occur in newborns due to the immaturity of the liver at birth, leading to high levels of bilirubin in the blood.

Quickening

The moment when a mother first feels the movement of the fetus, which typically occurs around 20 weeks of gestation.

Mullerian duct

The duct that matures in the absence of testosterone secretion, leading to the formation of female reproductive organs.

Patent urachus

A condition where the lumen between the urinary bladder and umbilicus fails to close, resulting in the persistent drainage of urine from the umbilicus.

Lanugo

Fine, downy hair that covers the skin of the fetus until subcutaneous fat begins to be deposited.

Passive immunity

Temporary immunity acquired by the fetus through the transfer of maternal antibodies, primarily during the third trimester of pregnancy.

Age of viability

The gestational age at which a fetus has a practical chance of survival if cared for in a modern intensive care facility, typically around 24 weeks.

Vernix caseosa

A cream-cheese-like substance produced by subcutaneous glands that serves as a protective skin covering during intrauterine life.

Moro reflex

A reflex present in newborns that is characterized by the extension and abduction of the arms in response to a sudden loss of support or loud noise.

Lightening

The descent of the fetus into the birth canal during the last two weeks of pregnancy, indicating the end of the third trimester.