Male reproductive system

When are nipples formed

early in fetal development (7 weeks),

When are gentila formed

12 weeks

Human chromosome count

23 pairs but 46 total (23 from mom and 23 from dad)

XX set of chromosome

female

XY set of chromosome

Male

x chromosome contains how many genes

900

y contains how many

50

each gene codes for what

a protein with a specfic function

SRY gene

provides instructions for making a protein called the sex-determining region Y protein

How does the SRY Protein function

as a transcription factor, meaning it alters transcription (DNA into RNA). Simply, it turns genes ON or OFF

what does SRY Gene Alter

gene expression on specific tissues at specific times resulting in development of male sex organs

without SRY what does the undifernated organs become

female

with SRY what does the undifferented organs become

male

what tissues are homologus

penis head with clitoris, shaft of penis and labia minora, and scrotum and labia majora

Undifferentiated genitals

wolfarin ducts and mullerian ducts

undifferentiaed genitals to female genitals

wolfian ducts degrade and mullerian ducts become uterine tubes and uterus

undifferentiaed genitals to male genitals

wolfian ducts form epididiymis and vas deferns and mullerian ducts degrade

Swyer Syndrome

is classified as a disorder of sex development and XY children (typically biological men) appear as normal and healthy with external female genitals but internal structures are unlike typical males or females (cryptorchidism).

who was a famous olympic runner who had swyer syndrome

stella walsh

when do symptoms manifest for for swyer syndrome

at puberty and breasts fail to develop and no menstratuion.

common treatments include

Hormone replacement (estrogen & progestogen) and Removal of cryptic internal organs due to cancer risk.

why are female hormones theraptuic for swyer syndrome

because testerone is a precursor for estrogen

what converts testerone to estrogen

aromatase

Functions of Male reproductive system (1)

Produce androgens, sex hormones, such as testosterone.

Females have what

testerone, but 1/8 that of males

Functions of Male Reproductive system (2)

Reproduction through the formation of sperm (spermatogenesis) (Sperm are homologous to the ovum (egg).)

Functions of Male Reproductive System (3)

Delivery of Sperm during sexual intercourse

whats located within scrotum

Testis, Epididymis, Ductus (vas) deferens

what are the glands in the male reproductive system

Prostate, Seminal, Bulbo-urethal

what makes up your penis

Shaft/body, Head/glans, Prepuce/foreskin, External urethral orifice

Prostate Cancer facts

2nd most common cancer, Cancer of the prostate kills over 30K men a year, with around 270K new diagnoses each year, 1 in 8 men will be diagnosed with prostate cancer in their lifetime with 1 in 41 dying from it.Cases under 40 are rare and men over 65 are most at risk.

Early detection of prostate cancer

prostate exam or blood test is key to survival. Men over 40 should get annual prostate exams, younger if there is a family history

Blood Test for prostate exam

measure levels of Prostate-specific antigen (PSA) . This is a poor predictor for cancer as PSA levels levels vary across populations and can fluctuate within an individual. If PSA levels are suspicious a biopsy will be done. Depending on stage of prostate cancer, it can be treated by chemotherapy or surgical removal.

coiled sperm forming tubes

seminiferous tubules

what encloses the seminferous tubules

External tunica albuginea

repeated lobules contain what

coiled seminiferous tubules

within tubules are what

5 types of developing sperm cells called germ cells + supporting Sertoli cells

How do sperm develop

superficial to deep

Spermatogenesis

the process by which sperm cell production occurs.

Sertoli cells

support and protect germ cells, and form the blood-testis barrier. Also called “nurse” cells for their supportive role.

Five stages of germ cell development (1)

Spermatogonia – most primitive and superficial

Five stages of germ cell development (2)

Primary Spermatocyte - formed by spermatogonia.

Five stages of germ cell development (3)

Secondary Spermatocyte – formed by primary spermatocyte.

Five stages of germ cell development (4)

Spermatid – formed by secondary spermatocyte

Five stages of germ cell development (5)

Sperm - formed by spermatid

order of formation from wall to lumen

Spermatogonium (2n), Primary spermatocyte (2n), Secondary spermatocyte (2n), Spermatid (n), and Sperm (n)

Structure of Sperm

Head contains DNA, mid-piece mitochondria, and tail provides motility.

Volume of a sperm cell

85,000 times less than that of the female gamete. Approximately 100 to 300 million sperm are produced each day, whereas females typically ovulate only one oocyte per month.

Gametogenesis

Similar process between sexes with different outcomes (sperm or egg)

Egg

1 per menstrucal cycle, largest cell, haploid, 100-200,000 mitochondria, zona pellucida (outer glycoprotein coat) and cortical granules (enzyme packets within cell).

Sperm

250-280 million per ejaculation, smallest cell in body, haploid, 75-100 mitochondria, tail for propulsion, mitochondria in the middle for energy, and acrosome is a packet of enzymes in the head.

Testoerone

is the primary male hormone responsible for regulating sex differentiation, producing male sex characteristics, spermatogenesis, and fertility.

Leydig Cells

are located outside of the seminiferous tubules and are responsible for producing the steroid hormone, testosterone. This begins at week 7 of pregnancy and contributes to development of male structures.

Functions of Testoerone

increases libido, increased muscle mass, body hair, bone strengthing, sperm production, voice change, penile development, and development of phenotypic characterstics

Leydig cells produce how much testerone

6-7mg of test a day.

In females where is testerone seceretd

the ovaries but it is converted to estradoil

A small amount of testoerone is secreted where by both sexes

adrenal glands

Control of Testerone (1)

Hypothalamus releases GnRH and GnRH stimulates the anterior pituitary gland to release FSH and LH

Control of Testerone (2)

LH stimulates the leydig celss to release testerone. FSH stimulates the sertoli cells to release ABP. ABP binds to testerone, keeping the latter at a high concentration.

Control of testerone (3)

Inhibitin negativly feeds back to the anterior pituatry, inhibiting further release of FSH. Testerone negativly feeds back to the hypothalamus and pitutary, inhibiting further release of GnRH, FSH, and LH