Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OB > 2.4 Conception and Fetal Development > Flashcards

2.4 Conception and Fetal Development Flashcards

1
Q

Conception

A
  • Union of single egg and sperm
    1. Gamete (Egg and Sperm Formation)
    2. Ovulation
    3. Fertilization
    4. Implantation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mitosis

A
  • Body cells replace and repair themselves.

- Cell division supports diploid number of 46 and facilitates growth and development or cell replacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Meisosis

A
  • Divide and decrease chromosomal number by half from diploid (46) to haploid (23) to produce gametes
  • DNA replication and cell division in meiosis allow different alleles (genes) to be distributed at random by each parent and then re-arranged on the paired chromosome.
  • Random mixing of alleles are responsible for the variation in traits seen in offspring.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Gametogenesis

A
  • Oogenesis is the process of egg formation (ovum) Begins during fetal life of female
  • Spermatogenesis is the process of sperm formation.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Ovum

A
  • Each month 1 ovum matures.
  • During ovulation the ovum is released from the ruptured ovarian follicle.
  • High estrogen increases motility of uterine tubes so cilia can capture and propel ovum through the tube towards the uterine cavity.
  • Ovum is fertile for 24 hours after ovulation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Ovum Protective Layers

A

Zona Pellucida - Inner thick layer, acellular

Corona Radiata - Outer layer, elongated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Capacitation

A
  • Physiological change that removes protective coating from head of sperm.
  • Necessary for sperm to penetrate the protective layers of ovum
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Fertilization

A
  • Takes place in ampulla (outer 3rd) of the uterine fallopian tube.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Conception

A
  • Formation of zygote (the first cell of new individual)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Cleavage

A
  • Begins within 30 hours after fertilization and ends with the formation of a blastocyte
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Morula

A
  • Solid ball of cells that is produced within 3 days and is still surrounded by protective zona pellucida
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Trophoblast/Embryoblast/Blastocyte

A

Trophoblast - Creates placenta
Embryoblast - Creates embryo
Blastocyte - Whole structure of the developing embryo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Implantation

A
  • Occurs when zona pellucida degenerates.
  • Trophoblasts displace endometrial cells at implantation site
  • ## Blastocyte embeds into endometrium and trophoblast secretes enzymes that enable it to borrow into endothelium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Chorionic Villi

A
  • Fingerlike projections that develop from trophoblasts and extend into blood filled space of endometrium
  • This is what obtain oxygen and nutrients from maternal bloodstream and dispose of carbon dioxide and waste products into maternal blood.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Decidua

A
  • Term for endometrium after implantation.
  • Decidua basalis forms the maternal portion of the placenta.
  • Decidua capsularis is the portion covering the blastocyte.
  • Decidua vera lines the rest of the uterus.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Length of pregnancy

A
  • 9 months, 40 weeks, 280 days.

- Lasts from first day of last menstrual period until day of birth.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Conception

A
  • Occurs about 2 weeks after first day of last menstrual period.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Embryo Layers

A

Ectoderm - Outside layer with skin, pigment, and neuron cells of the brain
Mesoderm - Skeletal, cardiac, smooth, RBC and bone cells
Endoderm - Stomach, pancreatic, lung cells.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Post Conceptual Age

A
  • Used in discussion of fetal development

- This is 2 weeks less for a total of 266 days, or 38 weeks.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Embryonic Stage

A
  • Lasts day 15 until 8 weeks after conception
  • Most vulnerable to teratogens (substances or exposure that causes abnormal development)
  • Developing areas have rapid cell division making it vulnerable to malformations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Chorion

A
  • Chorion develops from the trophoblast and contains chorionic villi on the surface.
  • Contains major umbilical blood vessels and formation of placenta.
  • Outermost membrane surrounding the embryo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Amnion

A
  • Develops from interior cells of blastocyte

- Space between inner cell mass and outer layer of cells (trophoblast) is the amniotic cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Amniotic Fluid

A
  • Liquid found within 12 days of conception

- Contained within amniotic sac that surrounds the growing embryo/fetus within the uterus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Amniotic Fluid Fun Facts

A
  • 800 mL by 32 weeks of gestation
  • By 39 weeks the volume is stable around 700-800 mL
  • Volume steadily decreases after term. 500 mL at week 41
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Amniotic Fluid Function

A
  • Maintains fetal temperature
  • Source of oral fluid
  • Repository for waste
  • Maintains electrolyte homeostasis
  • Allows movement for musculoskeletal development
  • Cushions fetus from trauma
  • Allows face/body to form symmetrically
  • Antibacterial Factors
  • Prevents embryo from tangling with membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Oligohydramnios

A
  • Less than 300 mL of amniotic Fluid

- Associated with fetal renal abnormalities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Hydramnios (polyhydramnios)

A
  • More than 2L of amniotic fluid

- Associated with GI and other malformations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Lecithin/Sphingomyelin (L/S)

A
  • L/S ratio determines health and maturity of fetus.

- L/S ratio of 2:1 means baby has developed lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Yolk Sac

A
  • Another blastocyte cavity that forms on the other side of a developing embryonic disc.
  • Helps transfer maternal nutrients and oxygen through chorion to the embryo
  • Blood vessels form to aid transportation
  • Blood cells and plasma are manufactured in the yolk sac during second and third weeks.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Umbilical Cord

A
  • Embryonic Disk, Amniotic Sac, and Yolk Sac attach to chorionic villi by the connection of a stalk.
  • Blood vessels develop to supply embryo with maternal nutrients and oxygen.
  • Two arteries carry blood from embryo to chorionic villi and one artery returns blood to the embryo
  • Umbilical cord rapidly increases in length at term it is 40-70 cm.
31
Q

Wharton Jelly

A
  • Connective tissue that surrounds the vessels preventing compression of the blood vessels.
  • This ensures the embryo continues receiving nourishment
32
Q

Nuchal Cord

A
  • Umbilical cord gets wrapped around babies neck
33
Q

Vasa Previa and Battledore Insertion

A
  • Variations in cord insertion that increase risk of fetal hemorrhage
34
Q

Placenta Structure

A
  • Begins to form at implantation
  • Chorion is embryo side of placenta
  • Intervillous spaces is where maternal blood supplies oxygen and nutrients to the embryonic capillaries
  • Waste products and CO2 diffuse into maternal blood
35
Q

Human Chorionic Gonadotropin (hCG)

A
  • Detected in maternal serum 8-10 days after conception
  • This hormone is the basis for pregnancy tests
  • This hormone ensures continued supply of progesterone and estrogen to maintain pregnancy
  • Ovarian Corpus Luteum releases progesterone and estrogen to maintain pregnancy
  • Between 100-130th day the placenta becomes the primary source of estrogen and progesterone
36
Q

Human Placental Lactogen (hPL)

A
  • Chorionic Somatotropin
  • Growth hormone that stimulates maternal metabolism to supply nutrients for fetal growth
  • Increases resistance to insulin and facilitates glucose transport across placenta
  • Stimulates breast development for lactation
37
Q

Progesterone

A
  • Maintains the endothelium
  • Decreases contractility of uterus
  • Stimulates maternal metabolism
  • Stimulates development of breast alveoli
38
Q

Estrogen

A
  • By 7 weeks, placenta produces most of maternal estrogen
  • Steroid Hormone
  • Stimulates uterine growth and uteroplacental blood flow.
  • Onset labor is caused by decline in progesterone and increase in estrogen
39
Q

Isoimmunization

A
  • Fetal erythrocytes leak into maternal circulation causing mother to develop antibodies to fetal red blood cells
  • rH negative mother becomes sensitized to rH positive fetus
40
Q

Circulatory Effects of Placental Function

A
  • Placental function relies on maternal blood pressure supplying circulation
  • Vasoconstriction diminishes uterine blood flow (hypertension and cocaine)
  • Decreased maternal blood pressure or cardiac output also diminishes uterine blood flow
  • Lying on back with pressure on uterus compressing vena cava, blood return to right atrium is diminished
41
Q

Braxton Hicks Contractions

A
  • Painless contractions that occur intermittently after first trimester.
  • Enhances the movement of blood through intervillous spaces, aids placental circulation,
  • Prolonged contractions or too short intervals between contractions reduce blood flow to placenta
42
Q

Embryonic Stage

A
  • Day 15 until 8 weeks
  • Critical time for organ development and external features
  • Rapid cell division makes this the most vulnerable time to malformations caused by environmental teratogens
43
Q

Placenta Development

A
  • Week 12 placenta is formed

- Completely mature by week 34

44
Q

Role of Placenta

A
  • Protects fetus from detrimental substances in maternal blood (glucocorticoids and toxins)
  • Protected by multidrug-resistant protein (transport protein)
  • Toxins from fetus are processed in mothers liver and kidneys for elimination
45
Q

Teratogens

A
  • Drugs, chemicals and infections that cause abnormal fetal development.
  • Pesticides, fungicides, rodenticides, harsh cleaning products.
46
Q

Fetal Circulatory System

A
  • Cardiovascular system first organ to function
  • Week 3 blood vessels and cells form
  • By the end of week 3 heart beat forms
  • CVD links embryo, connecting stalk, chorion and yolk sac
47
Q

Fetal Heart Beat

A
  • Usually detectable by week 6.5-7
  • Heart develops into 4 chamber organ by week 4-5
  • 5.5-6.5 is the earliest that cardiac activity can be detected by vaginal ultrasound
48
Q

Birth Defects due to Teratogens

A
  • Neural tube defects
  • Intellectual impairment
  • Cardiac Anomalies (truncus arteriosus)
  • Atrial and Ventricular septal defects
  • Amelia/Meromelia in upper/lower limbs
  • Cleft lip/palate
  • Low set malformed ears
  • Deafness
  • Eye anomalies (cataracts, glaucoma)
  • Staining of teeth
  • Masculinization of female genitalia
49
Q

Yolk Sack

A
  • First extra-embryonic membrane to appear
  • Produces chorionic fluid to help cushion and protect embryo
  • Chorion develops and functions to nourish the developing embryo
50
Q

Amniotic Fluid and Membranes

A
  • Insulates baby to keep it warm

- Contains antibodies

51
Q

Umbilical Cord

A
  • Serves as blood source for neonate

- Allows fetus to obtain oxygen

52
Q

Placenta

A
  • Immunologic functions, respiratory, excretory, endocrine, barrier function.
  • Supplies oxygen, output of CO2 (via diffusion)
  • Supplies nutrients via umbilical cord
  • Clears out waste such as urea, creatinine, uric acid
  • Metabolizes and releases food substances required into maternal/fetal blood
  • Protects fetus from xenobiotics (food/drug/environmental pollutants)
  • Produces steroids and peptide hormones that help in growth and development of baby.
53
Q

Fetal Maturation

A
  • Fetal stage lasts 9 weeks until end of pregnancy
54
Q

Viability

A
  • Capability of fetus to survive outside uterus
  • Defined by fetal weight and pregnancy duration
  • Standard is at least 20 weeks of gestation
  • Birth weight of 350,400, or 500g depending on state
  • Limitations on survival at an early stage depend on CNS function and oxygenation capability
55
Q

Ductus Arteriosus

A
  • Fetal artery connecting aorta and pulmonary artery. (allows blood to detour away from lungs). Closes within first few days of life
56
Q

Fetal Respiratory Characteristics

A
  • Fetal hemoglobin has high affinity for oxygen
  • Can carry 20-30% more oxygen than maternal hemoglobin
  • 50% higher hemoglobin concentration in fetus than mother
  • Fetal heart rate is 110-160 bpm
57
Q

Hematopoietic System

A
  • Formation of blood (occurs in yolk sack)
  • Blood type is determined in the 6th week
  • rH negative women are at risk for isoimmunization in pregnancy lasting longer than 6 weeks after fertilization
58
Q

Respiratory System

A
  • 32 weeks is when sufficient surfactant is present in developed alveoli.
  • Surface-active phospholipids in amniotic fluid determine lung maturity
  • Once L/S ratio reaches 2:1 infant lungs are mature.
59
Q

Gastro-intestinal System

A
  • Fetus swallows amniotic fluid at 5th month
  • Gastric emptying and peristalsis occur
  • Fetal waste products accumulate in intestines called meconium, black tar.
60
Q

Hepatic System

A
  • Glycogen and iron are stored in fetal liver
  • Coagulation factors cannot be synthesized in the liver due to GI sterility and lack of Vitamin K synthesis.
  • This is why vitamin K is given prophylactically to a newborn.
61
Q

Renal System

A
  • Kidneys are fully developed at term
  • GFR is low and kidneys lack ability to concentrate urine
  • Newborns are more susceptible to overhydration and dehydration
  • Most newborns void within the first 24 hours
62
Q

Neurologic System

A
  • Originates from ectoderm during 3rd week after fertilization.
  • Open neural tube occurs during 4th week
  • Neurologic insults can cause cerebral palsy, neuromuscular impairment, intellectual disability, learning disabilities.
  • Fetus can feel pressure and pain
  • Fetus responds to sound at 24 weeks.
63
Q

Endocrine System

A
  • Insulin produced at week 20
  • Mothers with uncontrolled diabetes can pass hyperglycemia to fetus
  • This causes a rise in insulin and islet cell hyperplasia.
  • This produces a macrosomic (large) fetus.
  • Increased insulin also blocks lung maturation
  • This puts neonates at risk for respiratory distress and hypoglycemia when maternal glucose is lost at birth.
64
Q

Reproductive System

A
  • Sex differentiation begins at 7th week
  • Distinguishing characteristics appear around 9th week and fully differentiated by the 12th week.
  • Pseudomenstruation - Vaginal discharge at birth
  • High level of maternal estrogen stimulate secretion of “witch’s milk”
65
Q

Musculoskeletal System

A
  • Can be perceived by mother at 16-20 weeks

- Fetus sucking thumbs, somersaults, arm and leg movement

66
Q

Integumentary System

A

12th week - Fine hairs (lanugo) appear on eyebrows and upper lip
20 week - covers whole body

67
Q

Immune System

A
  • 3rd trimester albumin and globulin are present
  • IgG is the only immunoglobin that passes placenta providing passive immunity to specific bacterial toxins
  • Fetus produces IgM by end of first trimester
  • Normal term neonate can fight infections but pre-term is at much greater risk.
68
Q

Dizygotic Twins (Fraternal)

A
  • Multiple eggs fertilized by separate sperm.
  • Results in 2 zygotes
  • 2 Amnions, 2 chorions, 2 placentas that may fuse.
  • Most often happens with African Americans least with Asians
  • Not genetically similar
  • Separate placenta
69
Q

Monozygotic Twins (Identical)

A
  • Develops from 1 fertilized egg.
  • Placentation varies depending when zygotic division occurs
  • Shared placenta
70
Q

Siamese Twins

A
  • Cleavage is incomplete and occurs after 13 days of conception
71
Q

Triplets and Higher-Order Birth

A
  • Triplets occur when 1 zygote divides into 2 and then divides again (identical)
  • Triplets can also occur from 2 zygotes (fraternal) and 1 zygote dividing into a monozygotic (identical).
  • Triplets can also be 3 fraternal zygotes
72
Q

Teratogens

A
  • Substances that cause physical harm to embryo or fetus
  • Can cause pre-term labor or spontaneous pregnancy loss
  • Medications
  • Recreational drugs
  • Chemicals
  • Hormones
  • Viruses in maternal system that transfer to fetus
  • Maternal Stress
73
Q

Folic Acid

A
  • Women who are planning pregnancy should avoid taking folic acid daily before contraception to avoid neural tube defects.
    High Risk
  • Had child with neural tube defect before
  • If mom was a neural tube defect baby
  • If partner was a neural tube defect baby
  • Coeliac disease (immune system attacks your own tissue when eating gluten) or epilepsy

OB (96 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions