Male Reproductive Anatomy

function of male reproductive system

produce, store and deliver sperm

scrotum

2 lobes, multilayer sac enclosing testes

function of scrotum

- protection and support of testes- thermoregulation

4 layers of a scrotum

skin, tunica dartos, scrotal fascia, parietal vaginal tunic

innervated

has a nerve supply

scrotal fascia

connective tissue

tunica dartos

smooth muscle which lines scrotal wall; changes scrotal surface area; moves testes away or towards each other

parietal vaginal tunic

Thick outer layerForms a fibrous sac around each testis and spermatic cord

testis

male reproductive organ that produces sperm, hormones and proteins and fluid

visceral vaginal tunic

lies directly on the testes, epididymis, and ductus deferens

tunica albuginea

white fibrous capsule on testes

parenchyma (cortex)

outer region of the testis

seminiferous tubules

Narrow, coiled tubules that produce sperm and hormones in the testes; home of sertoli cells

sertoli cells

support spermatogenesis

interstitial cells of leydig

produce testosterone

mediastinum (medulla)

where seminiferous tubules dump into

rete testis

network of tubules between the seminiferous tubules and the epididymis

Epididymis

A long, coiled duct on the outside of the testis in which sperm is stored and matured

caput (head)

no motility or fertility

corpus (body)

little motility and fertility

cauda (tail)

motile, fertile sperm stored until sexual stimulation and ejaculation

ductus (vans) deferens

- begins at end of epididymis- surrounded by thick smooth muscle

spermatic cord

- connect through inguinal ring- provides passageway- protects testes-thermoregulation

cremaster muscle

elevates or suspends testes to control temp

pampiniform plexus

a network of testicular veins that drain the testes and absorb body heat from the testes and scrotum

ampulla

dilated portion of vas deferens; where the 2 vas deferens join to form single tube

urethra

duct that carriers semen (ampulla) and urine (ureter) outside the body through the penis

accessory sex glands

-seminal vesicles, prostate, bulbourethral glands- produce seminal fluid

seminal fluid

- sperm delivery- maintains sperm viability- slight alkaline pH

seminal vesicles

-two small glands that secretes majority of seminal fluid-released by smooth muscle-site of fructose synthesis and secretion-semenogelin

semenogelin

the main protein that causes coagulation of semen after ejaculation

prostate gland

-secretes alkaline fluid (odor)-contains Zn2+. citric acid and proteolytic enzymes-base of bladder-drain into urethra-androgen dependentonly ASG k9s have

Bulbourethral (Cowper's) gland

-covered by smooth muscle-seminal fluid-androgen dependentgel plug in rodents and boars

three parts of penis

base, shaft, glans penis

base

-root/bulb-attached to ischial arch

shaft

main portion

glans

specialized free end

two types of penis(based on erection)

-fibroelastic-vascular

Fibroelastic penis

-sigmoid flexure and retractor penis muscles-limited erectile tissue

vascular penis

erectile tissue

retractor penis muscles

-pair of smooth muscles-originates from vertebrae-holds and extends penis inside/outside sheath

corpus cavernosum penis

Larger of the two penile erectile tissues; dorsal to the urethra

corpus spongiosum penis

erectile tissue surrounding the urethra in the penis