Exam I Flashcards
(83 cards)
0
Q
Period of embryo
A
3-8weeks
1
Q
Period of egg
A
2 weeks
2
Q
Period of fetus
A
9-40weeks
3
Q
Gametogenesis
A
Joining sperm and egg
4
Q
Cleavage
A
Subdividing fertilized egg; no growth in overall size
5
Q
Gastrulation
A
Flat disk of cells, axes form, endo- ecto- and mesoderm
6
Q
Morphogenesis
A
Folds into tubular embryo
8
Q
Organogenesis
A
Organ systems form
9
Q
primordial germ cells
A
Form separate from gonads
isolate in yolk sac to reduce signals from somatic cells
migrate after reducing signals
10
Q
autonomous specification
A
mature unfertilized egg has determinant molecules in cytoplasm; this region destined to become PGCs; seen in amphibians
11
Q
embryonic induction
A
signaling between cells induces PGCs
12
Q
animal pole
A
region of egg with nucleus
13
Q
vegetal pole
A
region of egg without nucleus where yolk forms
contains determinant molecules (in autonomous organisms)
damage to area leads to no PGCs
14
Q
day 0
A
pronuclear stage
15
Q
day 5
A
blastocyst
inner cell mass and trophoblast surrounded by zona pellucida
embryo must hatch before implanting
16
Q
Txn represssor factors expressed in PGCs
A
Blimp1
Prdm14
both proteins expressed=PGC
17
Q
Blimp1
A
suppress genes associated with somatic cell formation and activate pluripotency genes
18
Q
pluripotency genes
A
nanog
sox2
oct4
19
Q
Prdm14
A
activate pluripotency
20
Q
PGC migration
A
filopodia fibronectin (intercellular protein) binds integrin receptors on surface (somehow important) saf1 secreted by gonads=chemotaxis?
21
Q
stem cell factor (SCF)
A
secreted by cells surrounding PGCs during migration
22
Q
PGCs by number
A
detected in epiblast of mice: 6
end of migration: 4000
23
Q
teratomas
A
when PGCs end up in wrong location
- mediastinum (chest)
- oral
- sacrococcygeal
24
Q
inert gene hypothesis
A
PGCs demonstrate large scale gene repression (expression of somatic genes)
isolate and repress idea
25
testis structure
divided into cavities of seminiferous tubules
Pre-puberty: PGCs and sertoli cells
at puberty: PGCs begin spermatogenesis
26
BMP8b
produced by PGCs at puberty
| higher levels leads to differentiation of PGC into spermatogonia between sertoli cells
27
sertoli cell function
structure
| secretion
28
structural function of sertoli cells
basal and adluminal compartments- separate at junctions of sertoli cells
blood-testis barrier- prevents immuno attack of sperm due to expression of antigens not present in somatic cells
29
secretory function of sertoli cells
mullerian inhibiting substance- causes mullerian duct degredation in males
androgen binding protein- increses spermatogenesis
inhibitin- negative feedback to anterior pituitary
30
Hormone regulation of spermatogenesis
bypothalamus secretes GnRH
anerior pituitary releases FSH
Sertoli cells secrete androgen binding protein
increases testosterone levels
increases spermatogenesis
inhibitin=negative feedback to pituitary from sertoli cells
31
PGC=>Sperm
BMP8b high: PGC -> spermatogonia
at puberty: spermatogonia type A -> B
type B -meiosis-> 1* spermatocyte ->2* spermatocyte -> spermatid -> spermatozoa
32
GDNF
from sertoli cells
high B into more B
low B into 1*
33
Stem Cell Factor SCF
from sertoli
| promote B -> 1*
34
timeframe of spermatogenesis
A-B: 16 days
1*-spermatids: 24 days
spermatid-spermatozoa: 24 days
35
spermiogenesis
golgi phase
cap phase
acrosome phase
maturation phase
36
golgi phase
acrosomal granule from golgi forms vesicle at nucleus
proximal centriole used in egg cell division
distal centriole aides tail formation
manchette- temporary protein fibers that sort into tail
37
cap phase
acrosome forms cap by close association with nucleus
38
acrosome phase
acrosome completes development
vesicle drapes over nucleus head
tail completes development with mitochondrial sheath
39
maturation phase
nucleus compacts- protamines instead of histones
cytoplasm sloughed
tubulobulbar complex
40
sperm structure
acrosomal cap
nucleus
connecting piece with proximal centriole
Tail
41
Sperm tail
Middle- axonene surrounded by protein fibers; mitochondrial sheath gives energy for motion
Principal- fiber around axonene
End- axonene
42
Oligospermia
Low count
43
Teratospermia
Abnormal sperm %
44
Male vs female gametogenesis
Male pause at PGC until puberty
| Female pause at p1 of 1* oocyte until puberty
45
1* oocyte count
5mos fetus- 7 million
Birth- 700,000
Puberty- 400,000
Menopause- 0?
46
Menstrual cycle
Ovarian
Uterine
Cervical
47
Ovarian cycle
Oocyte and follicle maturation
48
Uterine cycle
Buildup and sloughing of uterine lining
49
Cervical cycle
Thinning of cervical mucous at ovulation
50
Menstrual phase
Days 0-5
Uterine lining shed
Some oocytes grow
51
Proliferative phase
Days 5-14
Hypothalamus releases GnRH, pituitary releases FSH and LH, estrogen incease, thickens uterine lining, G to E mucous, follicle matures
52
primary egg envelope
zona pellucida (glycoprotein)
cumulus cells
vitilline envelope in amphibians
53
factors produced by oocyte and follicle cells
oocyte: GDF9
| follicle cells: FGF2
54
yolk
platelets
| vitellogenin from liver taken up by oocyte
55
alecithal
no yolk
| humans
56
micrrolecithal
small yolk
| invrtebrates
57
megalecithal
huge yolk
| cell division confined to cytoplasmic disk
58
mesolecithal
moderate yolk
| amphibians
59
centolecithal
nuclei divide and move to periphery
60
acotex
outer cytoplasm
| more solidified
61
corticle granule
membrane bound contents near cell membrane, released during fertilization
62
protective chemicals
produced in external fertilizers; UV protection; bad taste
63
ovulatory surge
LH and FSH
| moves oocyte from M1 to M2 and leads to ovulation
64
hyaluronic acid
increased production by cumulus cells ffor uptake
65
granulosa cells
bind progesterone
| activates protease production, increased fluid, and prostaglandins for smooth muscle contraction
66
secretory phase
days 14-28
follicle ruptures
fimbria drape over ovary
villi cause fluid movement which sweeps up egg
67
corpus luteum
ruptured follicle
| produces progesterone which increases uterine lining and inhibits FSH
68
corpus albicans
degenerate follicle if no fertilization
69
isthmus
junction of uterus and oviduct
70
sperm counts
20-200 million/ ml
| 100-200 make it into oviduct
71
sperm mobility
nonmobile
non-progressively motile
non-linear motility
progressively motile
72
semen contributions
seminal vesicles: 60%: alkaline, fructose, protease, prostaglandins
Prostate: 30%: citrates; acidic, seminal plasmin
bulbourethral: 5%: alkaline, mucous
seminiferous tubules: 5%: fluid
73
pH
vaginal 3.8-4.5
semen: .2
cervix: 6-6.5
74
sea urchin fertilization
sperm to jelly which produces SAP (resact)
acrosome reaction
digestion of jelly
bind VE
fuse of acrosomal process with egg membrane
75
acrosome reaction
acrosome and nuclear membranes fuse and release vesicle contents
actin assembles to produce microfilaments for process
76
acrosomal tubule
bindin on surface binds protein on VE
| fertilization cone rises and engulfs
77
sperm movement
hyperactivation
themotaxis
chemotaxis (progesterone from mature follicle)
capacitation
78
capacitation
sperm must bind in isthmus
albumin removes cholesterol from membrane
removes some proteins and cabs to unmask binding site
change in potential
protein phosphorylation
79
acrosomal rxn of mammalian sperm
after capacitation as movin through cumulus cells
| bind and then dissolve ZP
80
zona pellucida
glycoprotein: ZP1, 2, 3 and accessory proteins
81
binding of egg and spem
CD9 of egg
| IZUMO of sperm
82
fast block
change in membrane potential
temporary
external fertilizers
-70to +20 with Na2+ influx
83
slow block
mechanical
all
release of cortical granules
