6. Reproductive Day 1- Male Accessory

accessory organs

nurture and transport sperm cells

each testis has

associated epididymis, vas deferens, seminal vesicle

glands

prostate, bulbouretral

epididymis anatomy

narrow, tightly coiled tubes at top of testis, runs between testis and vas deferens, lined with pseudostratified columnar epithelium

epididymis function

promote maturation of sperm cells

epididymis stores

glycogen and produces energy for sperm transport

vas deferens (ductus deferens) anatomy

musclar tubes (45 cm), extends from epididymis to ejaculatory duct, lined with pseudostratified columnar epithelium

vas deferens function

stores and propels sperm toward urethra

seminal vesicles anatomy

pair of glands located behind urinary bladder, duct joins with vas deferens to form ejaculatory duct

seminal vesicles function

secretes think alkaline fluid for s3men with fructose and prostaglandin, nourishes sperm and enhances motility, create environment for sperm to survive

fructose

energy for sperm

prostaglandin

stimulate muscular contractions

prostate gland anatomy

single gland located below urinary bladder

prostate gland functio

secrete thin milky alkaline fluid with enzymes for sperm, helps activate and protect sperm, neutralizes acidity in urethra + female reproductive tract

bulbourethral gland (cowpers) anatomy

2 below prostate

bulbourethral gland function

secretes clear mucus fluid (pre-ejaculate), alkaline and neutralize urethra acidity, lubricates urethra, protect sperm

s3men

fluid containign sperm cells (from testes) and secretions (from accessories), discharged from male reproductive tract of ejaculation

s3men pH

7.5

volume of s3men per ejacualtion

2 to 5 mL

sperm per mL of s3men

120 million

scrotum anatomy

pouch of skin and subcutaneous tissue, behind penis, 2 chambers, dartos muscle

dartos muscle

smooth muscle tissue, contracts and relaxes in response to temp changes

testes optimal temperature

~5 degrees F below body temp

penis anatomy

contains urethra, made of erectile tissue, erect when tissue fills with blood

penis function

delivers s3men into female reproductive tract

urethra

carries urine and sperm

erection

sexual stimulation → parasympathetic neurons release nitric oxide, dilation of arteries to penis, veins compressed, reduce blood flow away from penis → blood accumulates in vascular spaces within erectile tissue of penis → penis swells and erects

emmision

sperm: epididymis → vas deferens, secretions from accessories are added (s3men enters urethra)

ejaculation

s3men expelled from urethra out of penis, rhythmic contractions of reproductive and pelvic muscle propel s3men out (s3men exits body)

orgasm

culmination of sexual stimulation

spermatogenesis

make sperm cells, sustentacular cells

sustentacular cells

large cells, span entire thickness of epithelium of a seminiferous tubule, support and nourish spermatogenic cells throughout their development into sperm

formation of sperm

in seminiferous tubes of testes, begins with diploid spermatogonia, cells undergo mitosis and meiosis to form haploid sperm, occurs until puberty

stages of sperm formation

spermatogonia → primary spermatocytes → secondary spermatocytes → spermatids → spermatozoa

sperm sturcture

head, midpiece, tail

sperm head

haploid head, acrosome

acrosome

cap over nucleus, contains enzymes that penetrate oocyte during fertilization

sperm midpiece

contains mitochondria w/ ATP for swimming

sperm tail (flagellum)

contains microtubules enclosed in extension of cell membrane, lashing movement propels sperm to egg