Applied embryology Flashcards
Does FSH increase or decrease at the beginning of the hormone cycle?
Increase
Stimulate more follicles to develop
What does follicular oestradiol do?
Stimulates endometrial thickening
Negative feedback to FSH
What produces oestradiol?
Follicles
What happens with oestradiol levels at day 12?
Rising levels trigger an LH surge
Triggers ovulation
How do sperm cells penetrate an egg?
Sperm acrosome reacts with zona pellucida Hydrolytic enzymes released Acrosome reacts with perivitelline space Plasma membranes of each fuse Sperm nucleus enters egg
What are the functions of the placenta?
Immunological barrier Gas exchange Nutrient exchange Waste excretion Endocrine function
What defines the orientation of the embryo?
Primitive streak
Where does the primitive streak form?
Caudal end of embryo
What does the ectoderm give rise to?
Epidermis Nervous system Hair Nails Neuroendocrine organs Teeth enamel
What does the mesoderm give rise to?
Dermis MSK structures CV system Kidneys Ureters Trigone of bladder Gonads Adrenal cortex Visceral and parietal linings
What does the endoderm give rise to?
GI tract lining Liver parenchyma Pancreas Thyroid Parathroid Tonsils Thymus Bladder Urethra
Where does most of the urinary system originate from?
Mesoderm
Apart from urethra and all areas of the bladder apart from trigone which arise from from the endoderm
What does the intermediate mesoderm give rise to?
Kidneys
Ureters
Gonads
What does the lateral plate mesoderm give rise to?
Pleura Pericardium Peritoneum CV system Connective tissue and smooth muscle of GI and resp systems
When do the pharyngeal arches form?
Week 4
When do the fingers begin to separate?
Week 7
When does the gut herniate into umbilical cord?
Week 7
When does the embryonic period transition into the fetal period?
End of week 8
Where does the urinary tract develop?
Intermediate mesoderm
What is the SRY gene?
Sex determining region Y gene
What role do sertoli cells play in testis development?
Formation triggered by TDF
Produce Anti-Mullerian Hormone
What causes development as a male?
Androgens from Leydig cells
Anti-Mullerian Hormones from Sertoli cells
What forms the ovarian follicles?
Cortical cords develop and surround germ cells
What is another name for the mesonephric duct?
Wolffian duct
What is another name for the paramesonephric duct?
Mullerian duct
How does the AMH affect the growth of mesonephric and paramesonephric ducts?
Presence of AMH in males causes paramesonephric ducts to regress
Absence in females cause paramesonephric ducts grow and enter pelvis, grow medially and fuse
What do the fused portions of the paramesonephric ducts form?
Vagina and uterus
What do the unfused portions of the paramesonephric ducts give rise to?
Fallopian tubes
What do the paramesonephric ducts fuse with and what forms at this place?
They fuse together and then with the sinus tubercle
Hymen forms here
What structure does the penis form from?
Genital tubercle
What structure does labia majora form from?
Labiosacral folds
What structure does labia minora form from?
Urogenital folds
What structure is the clitoris form from?
Genital tubercle
What is the most recent classification of uterine abnormality?
ESHRE classification
