Male Reproductive System

Primary sex organs

Testes and Ovaries

accessory sex organs

glands and external genitalia

Structure of testes

1. tunica vaginalis: surround testes in a serous sac

2. tunica albuginea: fibrous capsule of the testes (divides testes into 250-300 lobules)

3.Epididymis: posterior of testes

Function of testes

produce sperm and testosterone

function of seminiferous tubules

produce sperm through spermatogenesis inside tunica alibuginea

function of epididymis

store and mature sperm; gain ability to swim

20 day journey

function ductus deferens

stores and transports sperm

layers:

1. inner mucosa

2. thick muscularis

3. adventitia

function of spermatic cord

suspends the testes in the scrotum, provides pathway for sperm transport

contains:

-ductus deferens

-testicular vessels

-nerves

function the seminal glands

secrete 60% of the volume of semen (fluid component of sperm)

fluid contains:

-fructose for nourishment

-sperm mobility enhancement

-prostoglandins (suppress immune response)

-clotting and liquifying enzymes

function of the prostate (gland)

secretes about 1/3 of the volume of semen, enhances motility, clotting/liquifying enzymes

-encircles urethra

function of bulb-urethral glands

produce a mucus

-enters spongy urethra prior to ejaculation to neutralize traces of acidic urine and lubricates urethra

internal structures of the penis

3 erectile bodies:

ONE corpus spongiosum (surrounds spongy urethra)

TWO corpora cavernosa (makes up most of the penis)

external structures of the penis

1. shaft/body

2. glans penis (distal expanded end)

3. prepuce (foreskin)

boundaries of perineum

Anterior: pubic symphysis

Posterior: coccyx

Lateral: Ischial Tuberosities

contains: scrotum, root of penis, anus

Spermatogensis stages

1. formation of spermatocytes

2. Meiosis I and Meiosis II

3. Spermiogenesis

Stage 1 spermatogenesis

1. formation of spermatocytes

-Type A: maintain germ cells (stem cells/spermatogonia)

-Type B: differentiate into primary spermatocytes

Stage 2 spermatogenesis

Meiosis I and Meiosis II

I: froms 2 secondary spermatocytes

II: each spermatocyte forms 2 spermatids

Stage 3 spermatogenesis

Spermiogenesis

-four spermatids differentiate into sperm

-each one sheds cytoplasm and grows tail

muscles of the testes

dartos muscle: smooth muscle & wrinkling

Cremastor muscle: skeletal & elevating

scrotum

skin and superficial fascia surrounding the testes

positions testes to be 3 degrees cooler

spermatogenic cells

sperm-forming

begin at puberty

make spermatogonia

columnar sustentocytes

support cells surronding spermatogenic cells

secrete testicular fluid to push through tubules

myoid cells

contract rhythmically to move sperm out of testes, surround seminiferous tubules

interstitial cells

secrete testosterone by LH