Flashcards in Embryogenesis and Fetal Period Deck (72):
1
neurulation
ectoderm thickens and becomes known as the neural place
2
what happens on day 22 in reference to the neural plate
it begins to fold inward and makes contact with four occpital somites and the first cervical somites
3
what day does the cranial neuropore close
24 or 25
4
what day does the caudal neuropore close
26 or 27
5
the fusion of the neural folds results in the formation of what ?
neural tube
6
neural crest cells
really important, lose attachment to neural tube and form a lot of things
7
what are some examples of neural crest derivatives
parasympathetic ganglia of 3,7, 9 and 10, sensory ganglia of central nervous sytem of 5, 7, 9 and 10 and the autonomic doral root ganglia
8
surface ectoderm gives rise to what ?
epidermis, hair, nails, cutaneous, mamary glands, anterior pituitary gland, enamel of teeth, internal ear, and lens of eye
9
mesoderm immediately laterally to the notochord form cylindrical bodies called ___________
paraxial mesoderm
10
mesoderm just laterally to the notochord forms_________
intermediate mesoderm
11
futherest lateral to the notochord forms _____-
lateral plate mesoderm
12
paraxial mesoder
axial skeleton, volutary musclulatur and part of the dermis
13
intermediate mesoderm
form the urinary system and parts of the genital system
14
lateral plate mesoderm
will split into two layers splachnic mesoderm (associated with endoderm) and somatopleuric mesoderm (associated with the ectoderm)
15
the paraxial mesoderm helps form the first ________-
somite on day 20
16
how many pairs of somites are there ?
37 pairs
17
the endoderm of the embryo contributes to what structure ______________
yolk sac
18
endoderm derivatives
epithelial lining of GI tract, allantois, epithelium of repiratory tract, bladder, urethra, tympanic cavity and auditory tube, parenchyma of thyroid, parathyroid, liver and pancreas, stroma cells of the tonsils and the thymus
19
when is the fetal period
9th week til birth
20
characteristics of weeks 9-12
liver is major site of erythropoeisis, and the external genitals can be distinguished male or female
21
weeks 13-16
sites of ossification are evident, eye movements and the eyes are facing forward
22
weeks 17-20
primary ovarian follicles are formed and testes are descending
23
weeks 21-25
period of weight gain, blink and startle reflexes, surfactant is beginning to be secreted into the lungs
24
weeks 26-29
lungs are capable of breathig, CNS is capable of breathing and body temperature, spleen is still making blood cells but by 28 weeks blood formation shifts to the bone marrow
25
weeks 30-34
pupillary light reflex is present, fat is still accumulating
26
weeks 35-38
finish period involves final preparations of tissues important to the outside world
27
for the first 12 weeks of developent what is the major blood producing organ
yolk sac
28
for weeks 12-30 what organ is the major blood producing organ and weeks 12-24
liver, spleen
29
by week 30 what is the major hemopoietic organ
bone marrow
30
what is amniocentesis ?
sampling of the amnioc fluid to test for genetic disorders (must pass through chorion and amnion to get the sample)
31
by the 4th week the somites begin to differentiate into ______________ and ___________-
sclerotome and dermomyotome
32
hemangioblast
give rise to blood vessels
33
vasculogenesis
formation of blood islands, denovo vessels
34
angiogenesis
sprouting from existing vessels
35
hemangiomas
tumor like collections of blood vessels typically on the face
36
epithlium derived from the mesoderm is
vascular endothelium
37
epithelium derived from the endoderm is
epithelium of structures derived from yolk sac (gut and airway)
38
epithlium derived from the ectoderm
epidermis and ependyma
39
benign tumors of mesoderm epithelium are
angiomas
40
malignant tumors of mesoderm epithelium are
sarcomas
41
benign tumors of endoderm epithelium are
pailoma or adenomas
42
malignant tumors of endoderm epithelium are
carcinomas
43
benign tumors of ectoderm epithelium are
papiloma and ademoas
44
malignant tumors of ectoderm epithelium are
carcinomas
45
connective tissue is derived from ?
mesoderm for torso and limps and neuroectoderm (head)
46
benign tumors of connective tissue mesoderm
fibroma, lipoma, chondroma, osteoma
47
malignanty tumors of connective tissue medoderm
sarcomas
48
benign tumors of muscle mesoderm
myomas
49
malignant tumors of muscle mesoderm
myosarcomas
50
what are the two types of paraxial mesoderm
sclerotome and dermomyotome
51
what does the sclerotome give rise to
skeleton and cartilage
52
what does the dermomyotome give rise to
skeletal muscles, dermis and connective tissues
53
expected date of confinement ( EDC)
measures corwn rump length, head measurements and femur length to determine age
54
gestation age
age from last menstruation!
55
last nomrla menstrual period
with this gestation takes 40 week
56
actual date of fertilization
with this measure it takes 38 weeks
57
what is the first trimester
all major systems are developed
58
second trimester
external anatomy, many birth defects can be detected
59
third trimester
fetus becomes viable
60
if alpha fetoprotein is elevated what happens
detects of embryonic body wall
61
if alpha fetoprotein is depressed what can result
downs syndrome and trisomy 18
62
surface ectoderm gives rise to
epidermis, hair,cutaneous and mammary glands, anterior pituitary gland, enamel of teeth, internal ear, and lens of the eye
63
what does paraxial mesoderm give rise to
sclerotome which gives rise to skeleton and cartilage
dermomyotome which gives rise to skeletal muscles, dermis and connective tissue
64
what does intermediate mesoderm give rise to
urogenital system and contributions to the reproductive system
65
what does the lateral plate mesoderm give rise to
somatic(parietal) layer gives rise to connective tissue of limbs and serious membranes
splanchnic (visceral) layer gives rise to connective tissue, smooth muscle of vercera, serious membranes, primordial heart, blood, spleen, and suprarenal cortex
66
what does the endoderm give rise to
epithelium of the GI tract, liver, pancrease, liver, urachus, trachea, bronchi, longs, pharynyx, and thyroid
67
what does the neural ectoderm give rise to
neural tube (CNS, retina, pineal gland, and posterior pituitary)
neural crest (all ganglia)
68
the myotome splits into what
epaxial (intrinsic back muscleS) and hypomeres (hypaxial)
69
epithelium is derived from what layers
all three
70
connective tissue is derived from what
neuroectoderm and mesoderm
71
muscle is derived from
mesoderm
72