Chapter 28 (Part 1)

Male Reproductive System

sperm

male sex cells

oocytes

female sex cells

testes

produce sperm and testosterone

ducts

transport, store, and assist in maturation of sperm

accessory sex glands

secrete liquid portion of semenpe

penis

contains urethra, passageway for urine and semen

Scrotum

a pouch of looses skin and underlying subcutaneous tissue
supporting structure for the testes

dartos muscle

smooth muscle that surrounds each testicle

cremaster muscle

skeletal muscle that extends from the abdomen to the testes

tunica vaginalis

partially covers the testes

seminiferous tubules

where spermatogenesis occurs

spermatogenesis

sperm production

spermatogenic cells

sperm forming cells

sustentuacular cells

support spermatogenesis, form the blood-testis barrier

interstitial cells

cells that produce testosterone

testosterone

promotes development of male characteristics

spermatogonia

beginning of spermatogenesis
stem cell
diploid

primary spermatocytes

diploid
second step in spermatogenesis

sperm

enter the lumen of the seminiferous tubule and eventually the ducts of the reproductive tract

secondary spermatocytes

haploid
primary spermatocytes undergo meiosis I to make these

spermatids

haploid cells that result from the second meiotic division of secondary spermatocytes, eventually developing into sperm.

head

contains a nucleus with 23 chromosomes
(sperm)

acrosome

covers the head and contains enzymes
(sperm)

neck

contains centrioles
(sperm)

centrioles

from the microtubules that make up the rest of the tail
(sperm)

middle piece

contains mitochondria that make ATP for locomotion of sperm

principle piece and end piece

make up the tail used for movement
(sperm)

Gonadotropin-releasing hormone (GnRH)

treleased by the hypothalamus
triggers the production of the gonadotropins from the anterior pituitary

Luteinizing hormone (LH)

stimulates interstitial cells to produce testosterone in the testes

follicle stimulating hormone (FSH)

along with testosterone, stimulates spermatogenesis

inhibin

released by sustentacular (nurse) cells in response to spermatogenesis
prevents the release of FSH from the anterior pituitary

androgens

male sex hormones are called

epididymis

a tightly coiled tube that lies adjacent to the testis and is about 6 meters long
immature sperm enter here where they become mature and are stored until ejaculation
becomes the ductus deferens

ductus deferens

lead from the epididymis to the ejaculatory duct

spermatic cord

passage in the lower abdominal wall to enter the pelvic cavity

ejaculatory duct

just outside the prostate gland, the ductus deferens unites with the duct of the seminal vesicle to the this, which passes through the prostate gland and empties into the urethra

urethra

a shared terminal duct of the reproductive and urinary systems

prostatic urethra

portion that passes through the prostate gland

intermediate urethra

portion that passes through the deep muscles of the pelvic floors

pongy urethra

portion that passes through the sorpus spongiosum of the penis

seminal vesicles

sac-like glands near the base of the urinary bladder
contribute about 60% of the volume of semen
secrete an alkaline, viscous fluid

prostate gland

a chestnut-shaped structure that surrounds the proximal portion of the urethra
secretes a milky, slightly acidic fluid that contains enzymes and help with the mobility of sperm

bulbourethral glands

small structures located inferior to the prostate gland
secrete an alkaline fluid that neutralizes the acidic environment of the urethra
secrete mucus that libricates the lining of the urethra

penis

sylindrical organ that conveys urine and semen through the urethra to the outside

glans penis

at the distal end of the penis and is covered by a loose fold of skin

prepuce

foreskin

nitric acid

parasympathetic division causes its release
causes relaxation of smooth muscle in the walls of the arterioles supplying erectile tissue

sympathetic division

causes contraction of the ejaculatory ducts and ejaculation