1 Embryology/Histology Flashcards
What are the 3 stages of development of the embryo?
- early development (fertilization-day 16)
- Embryonic period (weeks 3-8)
- Fetal period (week 9-38)
Most organ systems are susceptible to damage during the ____________ period
embryonic
What body parts are most susceptible during the fetal period?
CNS (brain, ear, eye)
palate+teeth
external genitalia
Describe the genetic makeup of daughter cells in mitosis vs meiosis.
Mitosis: daughter cells are clones
Meiosis: crossing over (pachytene of meiosis I) creates genetically different daughter cells
Meiosis in females results in __________ while meiosis in males results in __________
ONE ovum (and 3 polar bodies)
4 spermatids
By week 12 of a female embryo, her Oogonia halt during _________ phase and are now known as _____________
halt @ PROPHASE I
known as PRIMARY OOCYTE
Primary oocytes are diploid _______
4N (have 4 copies of each chromosome)
Simple squamous covering+primary oocyte= ?
Primordial follicle
the capsule of the primordial follicle is composed of what?
simple squamous epithelium (Follicular cells)
Once puberty begins, __________ automatically begin to grow a cuboidal capsule around the primary oocye
primordial follicles
When we have a Primary follicle, it begins secretion of a glycoprotein coat around the oocyte called?
zona pellucida
The change from squamous cells to cuboidal cells gives it the name ____________ follicle
Primary Follicle (unilaminar)
Upon conversion from a Multilaminar Primary Follicle to a Vesicular Follicle, what happens inside?
accumulation of fluid (Antrum)
duh, ‘vesicle’ means bladder
A vesicular follicle has an outer CT layer. What’s it called?
theca externa (fibrous capsule)
theca interna (will become steroid cells)
When does this oocyte that’s been stuck in Prophase I for years ever get to complete its FIRST meiotic division?
-FSH SURGE
The presence of a Secondary Oocyte tells us the oocyte has done what?
completed its first meiotic division
The FSH SPIKE causes the primary oocyte within the Vesicular Follicle to do 2 things. What are they?
- complete the FIRST meiotic division
- as it divides, oocyte moves into the ANTRUM
Now that the secondary oocyte is floating in the antrum, what are we ready for?
OVULATION bitchesssssss
Ovulation occurs when the follicle is pushed to the surface of the ovary and what 3 things are squirted out
secondary oocyte (duh)
liquor folliculi (fluid in antrum)
cumulus oophorus cells (clumps of follicular cells)
After squirting out the secondary oocyte thru the peritoneum, the ruptured follicle becomes the ?
corpus luteum (yellow body)
What the hell is the function of the corpus luteum?
it secretes Progesterone, which MAINTAINS THE UTERINE ENDOMETRIUM
If progesterone levels are not sufficient, what happens to the endometrium?
it sloughs off (i.e. during MENSES)
To go from a Primary follicle to a secondary Follicle, we require ?
FSH (not spike)
A female presents with complete Anterior Pituitary insufficiency. Her menstrual cycle has stopped due to cells not being able to progress past a ______________
Primary follicle
FSH is REQUIRED for primary to secondary conversion
