PRIN 1 The Body Flashcards
Endoderm
Lungs & Alveolar walls
Lining of GU
Liver
Bladder
How does endoderm form?
Epiblast cells push hypoblast cells and create new layer in its place
Hypoblast cells become lining of yolk sac and give rise to germ cells
Trimesters of Pregancy
(1) 0-14
(2) 14-27
(3) 28-40
note: 42+ = post-term
GTPAL
(G) # of times preg
(T) # preg carried to term 37-42 GA
(P) # of preg delivered preterm 20-36 GA
(A) # of preg <20
(L) # of living
Intermediate Mesoderm
forms between somite and lateral plate mesoderm
gives rise to urinary & genital systems
Primitive Streak
GASTRULATION
*Prim Streak = region where cells are detaching from epiblast layer (migrating in)
Pregnancy Dating Methods
(1) LMP
(2) Early Pre US
8 -14 weeks - most accurate
(3) Blood (7 days), Urine (2 wks)
Detect hcG: diagnostic for preg only (not for dating)
(4) Physical Exam (grapefruit …)
What does the obstetrical history include?
(1) Previous Preterm Deliveries
(2) Previous C-sections
(3) GTPAL
Where is C8?
Below C7
Above T1
Somite Mesorderm gives rise to …
spinal cord
dermis
muscles of back, body walls, limbs
Somatic Mesorderm gives rise to ..
peritoneum
pleura
Lateral Plate Mesoderm is comprised of:
SOMATIC M.
peritoneum
pleura
SPLANCHNIC M.
Mesenteries
Muscles of GI
Splanchnic Mesoderm gives rise to …
Mesenteries
Muscles of GI
Mesoderm
Bone, Blood, Muscle, Kidneys, Gonads, Dermis of Skin
Inner Cell Mass becomes …
Epiblast (top)
Hypoblast (bottem)
What is the susceptible period for a fetus to teratogens?
2-10 weeks embryonic age
What is Nuchal-translucency?
- method to detect DS
- US: 11-14 weeks
- looking at thickness of skin at back of neck
Normal Symptoms & Signs in 1st Trimester
Fatigue
Bloating
1 to 2 kg weight gain
- 12 weeks: Fetal Heart detectable by Doptone
- 16-40 weeks: Feel fetal movements
Nagele’s Rule
Est Due Date = First day of LMP - 3 months \+ 7 days \+1 yr
Ectoderm
CNS & Neural Crest
PNS
Epidermis of Skin
Teeth
When does sex determination occur in developing fetus?
8th week
How does mesoderm form?
Some Epiblast cells lose their attachment. Results in 2 different layers:
(1) Mesoderm
(2) Ectoderm
What is located between the two products of the Lateral Plate Mesoderm?
(somatic mesoderm)
Cavity: COELOM:
*forms body cavities: pericardial, pleural, abdominal
(splanchnic mesoderm)
Diaphragm arises from …
Septum Transversum
Anatomy of Blastula
Trophoblast around outside
Inner Cell Mass (inside)
Inner yolk sac (inside)
What surrounds the blastula?
Zona Pellucida
What does the Trophoblast eventually become?
Placenta
Ectopic Pregnancy
Implantation outside of the uterus
Epiblast turns into …
Ectoderm, Mesoderm, Endoderm
Hypoblast turns into …
Germ Cells
“When should I feel my baby move?”
about week 16
When is the gender of the fetus determined?
Week 8
What is the mid-gut herniation?
- Normal event during pregnancy
- gut grows FIRST and abdominal cavity then catches up
- can possibly cause congenital problems
Even for the normal, healthy 25 yr old mom having a baby, there is always WHAT risk of abnormalities?
3-5%
What are the developmental Periods?
0-2 weeks is preembryonic
2-8 is embryonic
8+ is fetal
When does the the zona pellucida finally break down?
When it is the correct time for implantation
What induces neurulation?
Notocord
What happens if mom doesn’t get enough folate during pregnancy?
Neural tubes won’t close on either end and we get spina bifida
What is Anacephaly?
“without head”
actually, does have head, but it is the brain that is missing
What does the Neural Crest become?
PNS
In the gastrulation diagram, what is the long line that is seen?
TOP (1) Primitive Node (round thing) (2) Primitive Pit (3) Primitive Streak BOTTOM
What does the notocord become?
becomes the intervertebral discs
When do we get the Trilaminar Embryo?
Gastrulation (week 3)
What is the notocord derived from?
Mesoderm
What are the 3 “tomes” of the Somites?
MYOTOME
skeletal muscles
DERMATOME
CT, dermis
SCLEROTOME
vertebrae, ribs
In the Blastula, what is above and below the inner cell mass (but surrounded by the trophoblast)?
Potential Amniotic Cavity (above)
Potential Yolk Sac (below)
How often do prenatal care visits occur?
- Every 4 weeks until 28 weeks
- Every 2 weeks 28-36 weeks
- Every week until delivery
(aka, 1/month during Trimesters 1&2. Every other week for first 2 months of Tri3, followed by every week for last month)
Drug Exposure Classification System
A = NO risk B = No evidence of human risk C = Risk cannot be ruled out D = Positive evidence of risk E = Contraindicated (methotrexate, accutane)
When does screening for structural abnormalities occur?
Weeks 18-22
2nd trimester US
What is amelia?
Absence of limbs
When is Chorionic Viili Sampling performed?
10-12 weeks
end of first trimester
When is Amniocentesis performed?
15 - 20 weeks
What does the Notocord do?
Induces overlying ectoderm to form the neural plate, the initial event in the process of neurulation
Brain is derived from …
Ectoderm
Epidermis of skin is derived from …
Ectoderm
Spinal Cord is derived from …
Ectoderm
Heart is derived from …
Mesoderm
smooth muscle of intestinal wall is derived from …
Mesoderm
skeletal muscle is derived from …
Mesoderm
intestinal epithelium is derived from …
Endoderm
When does the neural tube close?
Week 6
The kidneys are derived from what primary germ layer?
Mesoderm
The lungs are derived from what primary germ layer?
Endoderm
The intestinal epithelium is derived from what primary germ layer?
Endoderm
Which organ starts to differentiate first during development?
Brain
Liver is derived from ….
Endoderm
When I have rolled my ankle in the past, it has been due to what movement?
Inversion
Thumb flat on the table … now lift up the thumb. What movement is that?
Abduction
Order of Speed of Receptors from Fast to Slow
(1) Ion Channel
(2) G-Protein
(3) Receptors coupled to Enzymes
(4) Intracellular
