Download Human Development

HUMAN DEVELOPMENT
Human sperm have typical sperm structure. The human testis
looks like the primate testis you looked at in lab.
http://www.lab.anhb.uwa.edu.au/mb140/CorePages/MaleRep
ro/malerepro.htm
www.DennisKunkel.
http://www.ich.ucl.ac.uk/ich/html/postcards/
The human ovary has the same structure as the cat ovary
you have looked at in lab.
Fertilization and early cleavage.
The second cleavage in a human zygote.
Figure on P. 171 of your text.
Human cleavage
40-50 hr
60 hr
compaction
Figure similar to that on P. 170 of your text.
http://arbl.cvmbs.colostate.edu/hbooks/pathphys/reprod/fert/cleavage.html
http://www.alphascientists.com/embryology_images/index.html
Strypsin protease
digests hole in zona
pellucida
“Hatching” from the zona pellucida.
Human blastocyst - pre-implantation
Plasminogen activator will be secreted by the
trophoblastic cells that form the
syncytiotrophoblast.
See figure of 6 day human blastocyst in lecture packet
See figure of implanting 6-7 day human blastocyst in lecture
packet
Plasminogen activator will be secreted by the
trophoblastic cells that form the
syncytiotrophoblast.
Heuser’s membrane is an ephemeral
combination of extracellular matrix and
hypoblast cells.
See figure of 8 day human embryo in lecture packet
See figure of end of second week human embryo in lecture
packet
See beginning of 3rd week human embryo in lecture
packet - primitive streak forming.
Figure illustrating spread of mesoderm between epiblast and
hypoblast - like what happens in chicken embryos.
Movements in Gastrulation figure in lecture
packet.
Human neurulation figure in lecture packet.
By the end of the 3rd week, chordin and
noggin secreted by the chordamesoderm
have blocked BMP-4. As a result,
neurulation occurs.
Figure of human primitive streak and neurulatiopn at web
link below
http://www.biology.iupui.edu/biocourses/n100/2k4ch39repronotes.html
“Sequence of flexion in
longitudinal section” figure in
lecture packet.
Fourth week human embryo figure in lecture packet.
Eighth week human embryo figure in lecture packet.
Carnegie stages of human embryos
The Virtual Human Embryo
Project
Carnegie stage 13 - human embryo
The Virtual Human Embryo
Project
Carnegie stage 13 - human embryo
The Virtual Human Embryo
Project
Carnegie stage 13 - human
embryo
CLASSIFICATION OF THE HUMAN
PLACENTA
* Chorioallantoic placenta - chorion
and allantois form placenta
*Hemochorial placenta - villi that are
formed from the chorion are bathed
in blood.
Figure on page 290 of your text
*Deciduous placenta - tears away
from the uterine wall at birth causing
hemorrhaging.
Figure on page 284 of your text
Figure of 13th day blastocyst in lecture packet.
Syncytiotrophoblast and Cytotrophoblast
Development of the human placenta
Figure of placental development passed out in class
Figure of placental development passed out in class
Figure of placental development passed out in class
Figure of placental development passed out in class
Figure of placental development passed out in class
Figures on pages 284 and 290 of text.
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Turn on pic-in-pic
Conjoined twins
• May be caused by both genetic and environmental factors
• 1 in every 40,000 births, but often still born
• 1 in every 200,000 live births
• 75% are still born or die within 24 hr of birth
• More often female than male (3:1)