Module 2

are interstitial cells located adjacent to the seminiferous tubules in the testes.

Leydig Cells

The function of Leydig cells is to produce the:

androgen, testosterone, under the pulsatile control of pituitary luteinizing hormone (LH) 

any of a group of hormones that primarily influence the growth and development of the male reproductive system.

Androgen

The predominant and most active androgen is

Testosterone

is important in maintaining these secondary male characteristics throughout a male's life. 

Testosterone

testosterone provides the main stimulus for?

sperm production

What are the external genitalia of the male?

Scrotum and penis

What area do the external genitalia occupy?

Perineum

Pouch of skin, muscle, fibrous connective tissue containing the testes

Scrotum

Which testicle usually descends lower?

Left

Why does the left testicle descend lower?

Prevent compression

What type of glands does scrotal skin have?

Sebaceous

Scrotal skin has sparse __?

hair

Scrotal skin has rich __?

Sensory innervation

Scrotal skin has _________ pigmentation compared to other skin.

darker

What divides the scrotum into right and left compartments?

Internal median septum

Testes descent starts as early as?

6 wks

In which month do testes pass through inguinal canal?

7th month

What guides the descent of testes?

Gubernaculum

Boys born with undescended testes

Cryptorchidism

Cryptorchidism occurs in what percent of male births?

3%

Treatment if testes don't descend?

Testosterone injection or surgery

Uncorrected cryptorchidism can cause?

Sterility or testicular cancer

Ovaries descend to?

Lesser pelvis

Gubernaculum becomes ligaments supporting?

Ovary and uterus

It becomes a pair of ligaments that supports the ovary and the uterus

Gubernaculum

Three mechanisms that regulate testicular temperature?

Cremaster, dartos, pampiniform.

Strips of the internal abdominal oblique

Cremaster muscle

Cremaster muscle action in cold?

contracts

Cremaster muscle action in warmth?

relaxes

Subcutaneous layer of smooth muscle

Dartos muscle

Dartos muscle action in cold? and its effects

It contracts then it wrinkles the scrotum

Is a bundle of structures that includes the vas deferens, blood vessels, nerves, lymphatics, and muscle fibers.

spermatic cord

An extensive network of veins from the testes that surround the testicular artery and spermatic cord

Pampiniform plexus

Pampiniform plexus function?

Cools blood

Type of heat exchange in pampiniform?

Countercurrent heat exchanger

Without pampiniform, arterial blood would?

Overheat testes.

Temperature drop before reaching testis?

1.5°–2.5°C cooler.

It is suspended in scrotum by the spermatic cord

Testis

Ducts where sperm are produced

Seminiferous tubules

Where is sperm produced?

Seminiferous tubules.

How many seminiferous tubules are in each lobule?

1-3

What lines the seminiferous tubules?

Germinal epithelium.

Function of germinal epithelium?

Forms sperm

Cells that support and nourish germ cells?

Sustentacular (Sertoli) cells.

Location of sustentacular cells?

Between germ cell

What do germ cells depend on sustentacular cells for?

Nutrients, waste removal, growth factors.

Cells that produce testosterone?

Interstitial (Leydig) cells.

Location of Leydig cells?

Between tubules.

refers to the formation of haploid (1N) gametes (sperm or oocytes) by diploid (2N) germ cells (primary spermatocytes or primary oocytes) through a process called meiosis.

Gametogenesis

What is the duration of spermatogenesis in humans?

74 days

What are the two phases of spermatogenesis?

Spermatocytogenesis and spermiogenesis.

What do spermatogonia (2N) produce?

Themselves and primary spermatocytes (2N).

Primary spermatocytes (2N) are produced by?

Spermatogonia

What does a primary spermatocyte (2N) produce?

Two secondary spermatocytes (1N).

What process forms secondary spermatocytes?

Meiosis I.

What do secondary spermatocytes (1N) produce?

Four spermatids (1N).

What process forms spermatids?

Meiosis II

Transformation of spermatid into a sperm

Spermiogenesis

How long does spermiogenesis take?

18 days

Formation of spermatids in seminiferous tubules

Spermatocytogenesis

Transformation of spermatozoa occurs while linked with?

Sertoli cell.

spermatozoa are released into the?

lumen

It stimulates growth and division of spermatogenic

Testerone

Stickiness of semen promotes?

Fertilization

Clotting enzyme from prostate activates?

proseminogelin

Proseminogelin converts semen into what sticky, fibrin-like protein?

Seminogelin

The process by which female germ cells (oogonia) develop into mature eggs

Oogenesis

Female germ cells present in the embryo and fetus

Oogonia

Cell formed from oogonia that is arrested in prophase I

Primary Oocyte

Phase where the primary oocyte is arrested until ovulation

Prophase I

Cell formed after meiosis I, ready for fertilization

Secondary oocyte

Small non-functional cell formed alongside the secondary oocyte

Polar body

Cell that completes meiosis II after sperm fusion

Secondary oocyte

Final product of oogenesis after fertilization

Zygote

Total number of polar bodies typically formed

Three

Ploidy of the zygote

Diploid

When size of growing follicle reaches 10mm, it is called

Graafian follicle

contain an oocyte surrounded by a single layer of flattened follicular cells, this is the resting stage

Primordial Follicle

Follicular cells become more cuboidal and are now known as

granulosa cells

granulosa cells are separated from the oocyte by a basement membrane called the 

Zona Pellucida

Stromal cells around the follicles are now called

theca cells.

this is the growing follicle

Primary Follicle

• spaces develop between granulosa cells that eventually form the follicular antrum

• stromal cells surrounding the follicle form two layers, the theca interna, and the theca externa

Secondary Follicle

 The cells of the cumulus oophorus immediately adjacent to the oocyte are known as the

Corona radiata

within antrum, the oocyte is surrounded by a layer of granulosa cells called the

cumulus oophorus.

• clearly visible zona pelucida

• close to the surface of the ovary

Tertiary (Graafian) Follicle

Outer part of the ovary

Cortex

Ovary layer containing connective tissue and stromal cells

Stroma

Ovary region with different phases of ovarian follicles

Parenchyma

As follicles started growth three things change:

• Oocyte

• Follicular Cells

• Surrounding stroma

Growing follicles include:

• Uni-laminar primary follicle

• Multi-laminar primary follicle

• Antral follicle

It stimulates the ovarian follicle, causing an egg to grow.

FSH

It triggers the production of estrogen in the follicle. 

Follicle stimulating hormone

Follicle-stimulating hormone (FSH) is produced by the

Pituitary Gland

The rise in estrogen tells your pituitary gland to stop producing FSH and to start making more ____________

Luteinizing hormone

The shift to LH causes the egg to be released from the ovary, a process called

Ovulation

is a unique type of connective tissue abundantly supplied with blood vessels, consisting for the most part of spindle-shaped stroma cells. 

stroma of the ovary

Hormone that increases follicular pressure and triggers ovulation

LH

Substance causing localized smooth muscle contractions and fluid pressure increase

Prostaglandins