BSC2086: Reproductive + Endocrine System

Major Functions of the Male Reproductive System

Production, maturation, nourishment, and storage of sperm
Transfer of sperm to female reproductive system 

Male Reproductive System (Anatomy)

Scrotum, Testis, Epididymis, Ductus (vas) deferens, Urethra, Seminal Vesicles Prostate gland, ejaculatory duct, penis, Cowpers gland

Scrotum (muscles)

Cremaster Muscle, Dartos Muscle

Cremaster Muscle (func)

Raises and lowers testi

Dartos muscle (func)

Controls surface area of scrotum to regulate temperature

Sperm exit the scrotum through…

the Ductus (vas) deferens

Spermatic Cord

Connective tissue sheath that contains a network of arteries, veins, nerves and the ductus deferens

During fetal development, the testis will…

leave the abdominal cavity and descend through the inguinal canal

Vas Deferens

Sperm highway duct that transports sperm from the epididymis through the spermatic cord and into the ejaculatory duct

Cremaster muscle

Surrounds spermatic cord

Gubernaculum

pulls testis out of the abdomen through the inguinal canal and into the scrotum during fetal development

Tunia vaginalis

Part of the peritoneum; from testes descent

Tunia albugenia

deep to the visceral vaginalis; fibrous capsule; divides testis into 250 - 300 lobules

Seminiferous tubules

net of tubes where spermatogenesis takes place

Efferent Ductules

Carries sperm from seminiferous tubules to epididymis

Epididymis

Coiled structure in which sperm starts to mature and are stored until ejactulation; feeds sperm into vas deferens

Seminiferous tubules (special cell)

Spermatogenic cells

Spermatogenic Cells (func)

Divide by meiosis to produce sperms

Interstitial (Leydig) cells (func)

Release testosterone

Seminal Vesicle

Joins vas deferent; contributes sugar, bicarbonate, and prostaglandin

Ejaculatory Duct

Passes through prostate after seminal vesicles and continues to prostatic urethra

What is the Prostate

doughnut - shaped gland at the base of the bladder surrounding the urethra

What does the Prostate do

contributes sugar, semen liquifier, and other components to sperm

What does the bulbourethral gland do

Secretes a lubricating mucus that cleans and lubricates the urethra prior to and during ejaculation

Seminal Fluid

Mixture of secretions from seminal vesicles, prostate, and bulbourethral glands

What is the composition of semen

Sperm, Fructose, Fibrinogen, Seminalplasmin, and prostaglandins

What is Fructose

Energy source for sperm

What is the purpose of Fibrinogen

Clots the semen making a bolus that is easily propelled into the vagina

What is seminalplasmin

Enzyme against bacteria

What is the purpose of prostaglandins

Reduce mucus viscosity in vagina and stimulate reverse peristalsis in uterus

What is the Penis

The male copulatory organ that transmits sperm from male to female

What are the two erectile tissues of the penis

Corpus spongiosum and corpus cavernosum

What is corpus sponguisu

A single spongy erectile tissue, surrounds the spongy urethra

What is the corpus cavernosum

Paired lateral spongy erectile tissue

The Glans Penis

The end of penis, concentration of nerves

The Prepuce

Foreskin, skin from shaft that extends over glans

How is an erection mediated

Parasympathetic Stimulation

How does parasympathetic stimulation contribute to an erection

PS stimulation leads to a release of nitric oxide which dilates penile arteries

What is the pathway of sperm during ejaculation

Epididymis, Vas Deferens, (seminal vesicle), ejaculatory duct, prostatic urethra, urethra

Sperm Anatomy

Head, Midpiece, Tail

The Acrosome…

penetrates ovum

The mid piece of sperm cells contains?

mitochondria

Which piece of the sperm whips back and forth to propel the cell forward

The flagellum

Mitosis and Meiosis (differences)

Mitosis yields two identical cells, meiosis results in four cells with ½ the chromosomes

How many nuclear divisions are in Meiosis

2, meiosis I and Meiosis II

Does synapsis occur in mitosis? Meiosis?

Synapsis does not occur in mitosis, but does in meiosis

What is Synapsis

An exchange of genetic information between chromosomes

The steps of spermatogenesis

Spermatogonia, Primary spermatocytes, secondary spermatocytes, spermatids, spermatozoon

What are spermatogonia

First stage of sperm cells, located in basal lateral in seminiferous tubules. They divide by mitosis, with one becoming a primary speratocyte

What are primary spermatocyte

Diploid cells that begin to undergo meiosis I to yield secondary spermatocytes

What are secondary spermatocytes

Haploid cells that undergo meiosis II to yield spermatids

What are spermatids

Cells that undergo spermogenesis in which they spread a tail and discard majority of cytoplasm.

What releases GnRH

The hypothalamus

What does GnRH signal? Signal to do what?

GnRH signals the anterior pituitary to produce LH and FSH

What does LH stimulate

Leydig (Interstitial) Cells to release testosterone

What does FSH stimulate

Sertoli cells to release ABP

What does ABP bind to

Testosterone, which initiates spermatogenesis

What hormone inhibits the hypothalamus and anterior pituitary

Testosterone

What aspect of male puberty does testosterone influence?

Secondary Sex Characteristics

The Main Functions of the Female Reproductive Tract are…

Produce gametes (oocytes), produce reproductive hormones, and support developing fetus

Ovaries are

Paired gonads in the female

What do ovaries produce

Oocytes, estrogen, and progesterone

What do the uterine tubes do

Transports oocytes to the uterus

What are fimbriae

muscular follicles (fingers) that sweep ovulated oocyte into the tube

The Uterus

Muscular organ that nourishes and supports the growing embryo

The Fundus

Domed superior wall of the uterus, superior to the uterine tubes

Body

Middle portion of the uterus

Cervix

Inferior portion of the cervix, projects into the vagina

The three layers of the uterus are (from superior to inferior)

Perimetrium, Myometrium, and endometrium

The Endometrium is

The inner lining of the uterus

What does the endometrium do?

Builds up during the secretory phase of the menstrual cycle, then sheds with the menses

What is the myometrium

Smooth muscle layer of the uterus

What does the myometrium do

Allows for uterine contractions during labor and expulsion of menstrual blood

What is the perimetrium

Outer epithelial layer of uterine wall

The Broad ligament

Connects the lateral uterus to the pelvic wall

The ovarian ligament

Attaches ovary to uterus

The Vagina

The copulatory organ in the female

The collective term for the external female genitalia

Vulva

The Labia Majora are the

hair covered folds of skin located behind the mons pubis

The Labia Minora are

thin, pigmented, hairless flaps of skin located medial and deep to the labia majora

The Clitoris (glans clitoris)

Nerve - rich area of the vulva that contributes to sexual sensation during intercourse

What do the ovaries produce

Eggs and sex hormones

What are follicles

The developing ovum surrounded by follicular cells

Oogenesis is

The production of eggs

How does oogenesis produce eggs

Meiosis; produzes haploid gametes

When does oogenesis take place

Before birth

Oogenesis (process before birth)

Oogonia undergoes mitosis to become a primary oocyte, which starts meiosis I and becomes stuck in prophase I until puberty

Meiosis I is completed…

On the day of ovulation

What does the Primary Oocyte divide into

Secondary Oocyte and First Polar Body

The Secondary Oocyte…

proceeds to metaphase II and stops

How does the Secondary Oocyte survive

The Secondary Oocyte will die if not fertilized, if fertilized it completes meiosis II

What is supporting cell development called

Folliculogenesis

When does folliculogenesis occur

As the egg undergoes oogenesis

Stages of Ovulation

Primordial Follicles, Primary Follicle, Secondary Follicle, Mature Follicle, Corpus Luteum, Corpus Albicans

Primordial follicles

Squamous follicular cells and basement membrane of ovary

Primary Follicle

Large granulosa cells

Secondary Follicle

2 or more layers of granulosa cells

Mature Follicle

AKA Graafian follicle, larger

What happens between mature follicle stage and corpus luteum

Ovulation 

Corpus Luteum

Post ovulation stage, a popped follicle. Provides hormones progesterone and estrogen