PTH618 Exam 1 With Complete Solution
Summarize important events during 1st week of pregnancy: - ANSWER - ovulation
- fertilization
- trip down fallopian tube
- uterine wall implantation
- 7 cell divisions
- increase from 1 to 100-140 cells
- formation of blastocyst
What are the 2 distinct parts of the blastocyte? - ANSWER embryoblast and trophoblast
What does the embryoblast develop into? - ANSWER embryo
What does the trophoblast develop into? - ANSWER placenta
What are some possible problems that can occur in week 1? - ANSWER genetic:
nondisjunction
ectopic pregnancy
failure of implantation
environmental influences
Summarize important events of week 2 development - ANSWER - implantation
completed
- formation of bilaminar disc
What is a possible problem that can occur during week 2 development? - ANSWER
about 35% of blastocytes are abnormal and spontaneously abort
What are the components of the bilaminar disk? - ANSWER epiblast and hypoblast
Summarize important events of week 3 development - ANSWER simultaneous formation
of:
- trilaminar embryonic disc
- notochord
- neural tube
, - somites
- cardiac tube
What are the components of the trilaminar disc? - ANSWER ectoderm, mesoderm, and
endoderm
Angiogenic cell clusters differentiate into... - ANSWER endocardial tubes (ventral) and
aorta (dorsal)
What do the endocardial tubes form? - ANSWER heart tube
Summarize important events of week 4 development - ANSWER - heart continues to
develop
- neural tube closes
- somites increase 7-28
- limb buds begin
- respiratory diverticulum forms
- eyes begin to form
- optic placode forms
- embryo is tubularly shaped
Summarize important events of week 5 development - ANSWER - head growth exceeds
other body parts
- 42-44 pairs of somites
- diverticulum begins to branch
Summarize important events of week 6 development - ANSWER - somites smooth
- elbow forms
- foot plate later than upper limb
- spontaneous movement
- trunk straightens
Summarize important events of week 7 development - ANSWER - receding of tail
- notching of hand plates
- toes webbed
Summarize important events of week 8 development - ANSWER - tail disappeared
Summarize important events during 1st week of pregnancy: - ANSWER - ovulation
- fertilization
- trip down fallopian tube
- uterine wall implantation
- 7 cell divisions
- increase from 1 to 100-140 cells
- formation of blastocyst
What are the 2 distinct parts of the blastocyte? - ANSWER embryoblast and trophoblast
What does the embryoblast develop into? - ANSWER embryo
What does the trophoblast develop into? - ANSWER placenta
What are some possible problems that can occur in week 1? - ANSWER genetic:
nondisjunction
ectopic pregnancy
failure of implantation
environmental influences
Summarize important events of week 2 development - ANSWER - implantation
completed
- formation of bilaminar disc
What is a possible problem that can occur during week 2 development? - ANSWER
about 35% of blastocytes are abnormal and spontaneously abort
What are the components of the bilaminar disk? - ANSWER epiblast and hypoblast
Summarize important events of week 3 development - ANSWER simultaneous formation
of:
- trilaminar embryonic disc
- notochord
- neural tube
, - somites
- cardiac tube
What are the components of the trilaminar disc? - ANSWER ectoderm, mesoderm, and
endoderm
Angiogenic cell clusters differentiate into... - ANSWER endocardial tubes (ventral) and
aorta (dorsal)
What do the endocardial tubes form? - ANSWER heart tube
Summarize important events of week 4 development - ANSWER - heart continues to
develop
- neural tube closes
- somites increase 7-28
- limb buds begin
- respiratory diverticulum forms
- eyes begin to form
- optic placode forms
- embryo is tubularly shaped
Summarize important events of week 5 development - ANSWER - head growth exceeds
other body parts
- 42-44 pairs of somites
- diverticulum begins to branch
Summarize important events of week 6 development - ANSWER - somites smooth
- elbow forms
- foot plate later than upper limb
- spontaneous movement
- trunk straightens
Summarize important events of week 7 development - ANSWER - receding of tail
- notching of hand plates
- toes webbed
Summarize important events of week 8 development - ANSWER - tail disappeared
