Exam #1 Flashcards
Urogenital anatomy begins to develop at the _____ developmental week. Development begins with formation of the ________ _______.
4th
Urogenital ridge
The urogenital ridge contains a _________ region, a ________ region, and a ________ region.
Pronephric region
Mesonephric region
Metanephric region
The pronephros forms at ____ weeks. It functions, very minimally, as the ________. It differentiates into one long _________ on each side.
3
Kidney
Nephron
By ___ to ____ weeks, the embryo needs more filtration. The pronephros begins to die by ________, as the _________ takes over.
4-4.5 weeks
Apoptosis
Mesonephros
The mesonephros develops from ________ to _________, and performs filtration from about ____ to _____ weeks gestation
Superior to inferior
4 to 10 weeks
Eventually the mesonephros is replaced by the ___________, which becomes the adult _________. This structure begins to form at week ____ of development and becomes functional around week _______.
Metanephros
Kidney
Week 5
Week 9-10
Gonads begin to form during week ____ and ______
5 and 6
The gonads develop from a thickening of the _________ ________, called the _______ _______.
Urogenital ridge
Gonadal Ridge
The gonads contain: (1) (2) and (3)
- Coelomic epithelium (lining)
- Inner mesenchyme (mesoderm)
- Primordial germ cells
Early in the ____ week, the primordial germ cells migrate to the ________ ________, traveling along the bowel mesentery via _______ ________. By the end of week _____, the PGC become incorporated into the ______ ______ _____.
6th
Genital ridge
Amoeboid movement
Primary sex cords
Before ____ weeks (known as the _______ stage), both male and female genital ducts are present. The male duct system develops from the ____________ / ____________ ducts, and the female duct system develops from the ____________ / ____________ ducts.
10
Indifferent
Mesonephric / Wolffian
Paramesonephric / Mullerian
The mesonephric and paramesonephric ducts form the __________ genital structures. This process begins around the _____ month of gestation.
Internal
3rd month
The SR-Y region of the Y chromosome codes for a protein called ____________, which causes __________ ducts to differentiate into male genital structures, and _____________, which causes the __________ ducts to regress.
TDF (testis determining factor)
Wolffian/Mesonephric
MIS (mullerian inhibiting substance)
Mullerian/Paramesonephric
Without an SR-Y region, there is no ____________, therefore the _________ ducts regress and the gonads become __________, and since there is no ______________, the _________ ducts develop into female internal genitalia.
TDF (testis determining factor) Wolffian Ovaries MIS (mullerian inhibiting substance) Mullerian/Paramesonephric
The primary sex cords of testes (also known as the _________ ______), contain the ________ _____ _____. The cords contain two types of cells: 1. ____________ (“Nurse” cells for developing sperm) and 2. ___________ (developed from primordial germ cells)
Spermatic Cords
Primordial germ cells
1. Sertoli cells
2. Spermatoblasts
The spermatic cords canalize to form the ____________ _________, which are separated by mesenchyme to form the ________ ______ (cells of _________), which make testosterone.
Seminiferous tubules
Interstitial Cells
Cells of Leydig
In males, the sex cords become _________ ________, while in females, the sex cords become _________ _________.
Seminiferous tubules
Primordial follicles
What two substances do the fetal testes produce?
- Androgens - stimulate the Wolffian ducts
2. MIS - suppress the Mullerian ducts
A __________ is a common opening shared by the digestive, reproductive, and the urinary tracts. Humans develop this in utero, but it becomes divided by week ____ of gestation
Cloaca
Week 7
In cloacal separation, the genital tubercle develops and elongates to form the ________. ________ folds then appear, and the cloacal membrane divides into two, creating a _______ _______ By week 7, separate urogenital and rectal openings have formed, called ________. The phallus elongates to form the ________, and the ________ swellings meet and form ________.
Phallus Urogenital Urorectal septum Sinuses Penis Labioscrotal swellings Scrotum
Incomplete fusion of the urethral folds. Typically more distal, though proximal variations can occur.
Hypospadias
The penis is homologous to the:
Clitoris
The phallic shaft is homologous to the:
Clitoral body
The foreskin is homologous to the:
Clitoral hood and labia minora