DEVELOPMENT AND ANOMALIES OF MALE

AND FEMALE EXTERNAL GENITALIA

Dr Rania Gabr

OBJECTIVES For the male and female external

genitalia: a. Describe their development. a. Discuss their congenital anomalies

DEVELOPMENT OF EXTERNAL GENITALIA The cloacal membrane is surrounded by the cloacal fold which meet anteriorly to form the genital tubercle.

The cloacal membrane is divided by the urorectal septum into urogenital & anal membrane. Likewise, the cloacal fold is divided into genital (urethral) & anal folds.

A genital swelling is formed lateral to the urethral fold.

Later these swellings form the scrotal swellings in male, labia majora in female

The genital tubercle, the genital fold & the genital swelling form together the indifferent stage because male & female genitalia cannot be differentiated at this stage

In female embryo:

The genital tubercle enlarges slightly to form the clitoris.

The genital swellings form labia majora.

The urethral (genital) folds form labia minora.

The definitive urogenital sinus forms the vestibule of the vagina.

Types of Hymens 1-Microperforate hymen: A microperforate hymen is a thin membrane that almost completely covers the opening to a young women's vagina. The treatment is minor surgery to remove the extra hymenal tissue making a normal sized opening for menstrual blood to flow out.  

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2-Septate hymen: A septate hymen is when the thin hymenal membrane has a band of extra tissue in the middle that causes two small vaginal openings instead of one. 3-Imperforate hymen: An imperforate hymen can be diagnosed at birth. Rarely, the diagnosis isn't made until the teen years. An imperforate hymen is a thin membrane that completely covers the opening to the vagina. Menstrual blood cannot flow out of the vagina.Hydroclopos - Haematocolopos

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4- annular hymen:annular hymen, most common hymen variety. this type in 70% of women the hymen. annular hymen is  in the entrance of the vagina.the hole in the middle of the hymen is very large.

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5-Fimbriated hymen

6-Elastic hymen:does not tear except in labour

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7-Cribriform hymenit is very rare situation. there is more than one hole in the middle of the hymen. the hymen is not torn in the first sexual intercourse.need surgical intervention by a doctor. the hymen looks like a lace.

8-Crescentric hymen looks like  half moon. hymen torn difficult

UNIT 3: FEMALE REPRODUCTIVE SYSTEM 10

UNIT 3: FEMALE REPRODUCTIVE SYSTEM 11

In male embryo:

The genital tubercle enlarges to form the phallus (penis).

The urethral folds form the lateral boundary of urethral groove. The endoderm of the groove proliferates to form urethral plate (floor of the groove) .

The urethral folds close over the urethral plate forming the penile urethra in a posteroanterior direction.

A solid cord of ectoderm is formed in the glans then becomes canalized to form the glandular urethra.

The genital swellings form the scrotum.

Hypospadias: most common anomaly of the penis. The external urethral orifice is on the ventral surface of the glans penis (penile hypospadias)

Epispadias: The urethra opens on the dorsal surface of the penis; often associated with extrophy of the bladder; resulting from inadequate ectodermal-mesodermal interactions during development of genital tubercle

CONGENİTAL ANOMALİES

HYPOSPADIAS

EPISPADIAS

Agenesis of external genitalia: Absence of penis or clitoris; resulting from the failure of development of genital tubercle.

Bifid penis and double penis: vary rare, often associated with extrophy of the bladder or urinary anomalies; results when two genital tubercles develop.

Micropenis: The penis is so small that it is almost hidden by the suprapubic pad of fat. It results from a fetal testicular failure.

Exstrophy of bladder with epispadias

AGENESİS OF EXTERNAL GENİTALİA

Exstrophy of bladder with epispadias

DOUBLE PENIS

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