Conception and Normal Fetal Development Flashcards
What is the difference between embryonic development and fetal development?
By week 9, thats when the fetus is referred to as a fetus and not an embryo
During the embryonic period, it is the most critical time in the development of organ systems and main external features
by 8 weeks, all organ systems and external structures are present
What organs FINISH developing during the state of the embryo? (by week 8)
Major congenital anomalies occur here
Heart, Upper limbs, lower limbs
What organs develop during the state of the fetus?
Eyes teeth,
palate (by end of week 9)
xternal genetitalia,
ear (by end of week 16)
functional defects and minor congenital anomalies
What is a teratogen?
An agent that acts directly on the developing fetus, causing abnormal embryonic or fetal development
What are the effects of teratogens dependant on? (3)
- Birth person and fetal genotype
- Stage of development when exposure occurs
- Dose and duration of exposure of the agent
What is toxoplasmosis?
Toxoplasmosis is when a parasite that invades tissues and fetal brain
no cleaning cat litter
caution when gardening
no eating RAW or partially cooked meat
What are the symptoms and signs of toxoplasmosis?
fever
fatigue
headaches
swollen
lymph glands
muscle aches/pain
What diseases are fatal for pregnant women (TORCH)
T toxoplasmosis gondii
O ther (VZV, HIV, Listeria, syphalliz, herpes)
R rubella
C cytomegalovirus
H herpes simplex-virus-1 (HSV-1) and HSV-2
What disease is the most common perinatal infectious agent? and the long-term health problems
Cytomegalovirus ; hearing loss, development and motor delay, vision loss, microcephaly, seizures
Talk about HSV in pregnancy
it is a viral infection causing painful, recurrent lesions on oral and genital
passed to infant through vaginal birth
high mortality rate
put woman on antiviral mediation towards the end of pregnancy
What are the two parts of the fetal membrane
Chiron - Outside ; toward uterus
- Develops from trophoblast
- Contains chorionic villi on the surface
- becomes the COVERING OF FETAL SIDE OF PLACENTA
- CONTAINS MAJOR UMBILICAL BLOOD VESSELS
Amnion
- Inner cell membrane develops from blastocyst
- COVERS THE UMBILICAL CORD
- covers chorion of the fetal surface of the placenta
they fuse to form the amniotic sac
What are the mechanics of the amniotic fluid
Fluid diffuses from the maternal blood
( increases as pregnancy progresses)
- fetal urine increases the fluid
- the fetal swallows fluid (because the fetal lungs dont work)
What are the 5 functions of amniotic fluid?
- maintains temperature (warm)
- source of oral fluid
- respiratory for waste
- protects fetus from trauma
- allows for freedom of movement assisting musculoskeletal development and growth
What does the placenta do for the baby?
Produces hormones:
hCG , progesterone, estrogens, hPL, relaxin, inhibin
metabolic functions: respiration, nutrition, excretion, storage
What are the parts of the cardiovascular system
FIRST system to function
two arteries : carry deoxygenated food
FETUS to PLACENTA
one vein: carries oxygenated blood from PLACENTA to FETUS
What is the pathway of oxygenated blood from placenta to the fetus
Placenta
Umbilical Vein
DUCTUS VENOSUS (bypasses the liver)
IVC
Right atrium (bypasses the right ventricle through the FORAMEN OVALE to left atrium
left ventricle
aorta
blood to body of fetus
What is the pathway of blood from the fetus to the placenta
IVC and SVC
Right Atrium
Right ventricle
Pulmonary artery
AVOID LUNGS:
Ductus Arteriosus to aorta
umbilical arteries
placenta to be cleared by the patient
What is the function of chorionic villi?
Fingerlike projections that extend into the endometrium and obtain O2 and nutrients from maternal blood
What happens
What is the name of fraternal twins vs identical twins?
Dizygotic twins vs monozygotic twins
Fraternal twins vs Identical twins
Fraternal twins : two ova produced at one time
Fertilized by separate sperm
2 chorions, amminons, placentas
higher in AA’s
Identical:
One fertilized ova
same sex and genetic material
10% LOWER SURVIVAL RATE
2 placentas and 2 amniotic sacs
(30% dichorionic, diamniotic)
2 amnion, one chorin (70% : monochorioni/ diamoniotic)
monochorinic and mono amniotic (1% _
When does a multi-fetal pregnancy occur
When division occurs late and cleavage did not complete so conjoined twins occurs (typically around 10 days after fertilization, which is late)
how to calculate naegles rule
(last menstrual period + 7 days) - 3 months + one year
Talk about the respiratory system in a developing fetus. pulmonary surfactants, RDS
pulmonary surfactants are used to determine fetal lung maturity and their ability to function after birth
two biggest ones:
Leeithin (L) - MOST CRITICAL FOR LUNG EXPANSION
sphingomyelin (S) - remains constant
ratio: of L/S is 2:1 for a mature baby (35 weeks gestation)
RDS- alveoli collapse - decreased gas exchange – hypoxemia
- begins immediately after birth
- leads to death
signs and symptoms: grunting, increased respiratory rate , retracting muscles when trying to inhale and get oxygen
treat with steroids?
What is isoimmunization?
A condition that happens when a pregnant woman’s blood protein is incompatible with the baby’s, causing her immune system to react and destroy the baby’s blood cells.
Talk about Rh and ABO incompatibility
If the blood of a mother contains antibodies which do not suit the blood type of the baby, blood incompatibilities happen for the newborn. The blood of the mother is transfused to the fetus through umbilical cord, which breaks down the red blood cells in the infant.
when does the hemapoiteic system develop
6 weeks
when does the hepatic system develop? bile?
4 - 5 weeks
week 12
Where does blood formation start? where does it get most of its blood supply??
in the fetal liver ; from the umbilical vein
What does the liver metabolize?
Bilirubin
What is bilirubin ? how does it relate to jaundice? why are infants so supsectible to jaundice?
a brownish yellow substance found in bile; it is produced when the liver breaks down old RBSs.
The pathway for a newborn is not at an adult level and the placenta is the main route for its elimination
when bilirubin does not get released, it stores up in the liver, leading to jaundice
When does the gastrointestinal system change shape? What are its three sections?
It changes from a straight line to a C-shpre during week 4
3 sections:
Foregut - produces pharynx, lower respiratory tract, esophagus, stomach, 1ST half of duodenum, gall bladder
(UPPER HALF TO MIDDLE)
Midgut - becomes distal half of duodenum, jejunum, ileum, cecum , appendix, proximal half of colon
Hindgut - Forms distal half of colon , rectum, anal canal, bladder, urethra
What is there to note about fetal waste products are the fetus nears term
products collect in the intestines as dark green/ black meconium (mec)
Talk about the renal system, when does it major organs form and function? what is important to note about urine in the uterus
Kidneys form by week 5
Begins to function at week 9
fetal urine contributes to amniotic fluid volume after 23 weeks
How early does the neurological system develop? Why is this importantly related to folic acid?
3 weeks after fertilization
nerve fibers traverse body by the end of week 8
This why folic acid is important to take pre conception because it affects fetal neural development
What happens during week 11-12 in relation to the CNS
during week 11-12 the fetus:
makes respiratory movement
moves extremities
changes positions
sucks their limb
swims in the amniotic fluid
What happens to the endocrine system? When do the relating organs develop? When does insulin produce?
Thyroid: 3 - 4 week
Adrenal cortex : week 6
produces hormones by: week 8-9
(more cortisol produces as fetus nears term)
Pancreas: week 5 -8
Insulin produced by week 20
Islets of Langerhans develop week 1?
What are the implications if the mom has hypothyroidism or is diabetic ?
Pregnant women with autoimmune (subclinical) hypothyroidism have an increased risk of developing gestational diabetes mellitus (GDM).
which increases the risk of premature delivery and PROM at term, and has certain influence on the intellectual development and psychomotor development of infants
What are the Islets of Langerhans?
A pancreatic cell that produces hormones (e.g., insulin and glucagon) that are secreted into the bloodstream
When does sex differentiation begin? distinguishing characteristics?
week 9 ; week 9 characteristic start, complete by week 12
XY - male
XX- female
When do bones and muscles develop?
week 4
What are the soft spots of the infants skull?
Anterior fontanels- closes 15 - 18 months
Posterior fontanels- closes 3 - 6 months
Talk about the integumentary system
*Skin thins and wrinkles with visible blood vessel say week 17
when born: Vernes : cheesy substance that naturally moisturizes the baby
*the more creases on the foot, the older the age
*hair covers body by week 20
(nugol) - helps body maintain heat
*nails form by week 10
Talk about the antibodies involved in the immunologic system
IgG - passively acquired immunity from the mother, ONLY one that crosses the placenta
IgM - Fetus produces by itself at the end of the 1st trimester
What is colostrum? What antibody is present?
The first human milk that a person produces (liquid gold) ;
IgA - helps prevent GI problems
