Male Reproductive System Flashcards
Gonads
primary sex organs
- Male: testes
- Female: ovaries
Gamete
sex or reproductive cells made in the gonads
- Males: sperm
- Females: ova/egg
sex hormones for males
androgens
sex hormones for females
- estrogens
- progesterones
path of sperm
epididymis -> vas.ductus deferens -> ejaculatory duct -> urethra
two muscles of the scrotum
- dartos
- cremaster
dartos
smooth muscle; wrinkles scrotal skin; pulls scrotum close to the body
cremaster
skeletal muscle; bands of muscle that elevate the testes
2 tunics of the testes
- tunica vaginalis
- tunica albuginea
tunica vaginalis
outer layer; forms fibrous capsule
tunica albuginea
inner layer; form fibrous capsule
sustentocytes
- seminiferous tubules have thick, stratified epithelium surrounding a central, fluid-containing lumen
- epithelium contains spermatogenic cells embedded in support cells called sustentocytes
what is made by the interstitial endocrine cells in the testes
- interstitial endocrine cells are in the soft tissue surrounding the seminiferous tubules
- interstitial cells produce androgens, such as testosterone, and secrete them into the interstitial fluid
What is the functional importance of the pampiniform venous plexuses?
- Testicular veins arise from the pampiniform venous plexuses surrounding each testicular artery
- Cooler blood in the venous plexus absorbs heat from the testicular arteries and keeps the testes cool
spermatic cord
- encloses the autonomic nerve fibers, blood vessels, vas deferens, and lymphatic vessels that supply the testes
- travels through the inguinal canal
anatomy of the penis
- root + shaft + glans penis
- prepuce
circumcision
surgical removal of the foreskin
- can lead to a reduction in the risk of contracting HIV or other reproductive infections
during an erection, the vascular spaces in erectile tissue fill with
blood, penis enlarges, becomes rigid
epididymis
site of sperm maturation
how long do sperm cells typically remain in the epididymis
several months
The vas deferens merges with a duct from what gland to form the ejaculatory duct?
joins the duct of the seminal vesicle
vasectomy
cutting and ligating the vas deferens
3 regions of male urethra
- prostatic
- intermediate/membranous
- spongy
What is contained in the secretions made in the seminal vesicles/glands?
viscous, alkaline seminal fluid - account for 70% of the volume of semen
What is contained in the secretions made in the prostate gland
Secretes milky, slightly acid fluid that contains citrate, enzymes, and prostate-specific antigen (PSA)
benign prostatic hyperplasia (BPH)
benign growth of the prostate that constricts the urethra and male urination difficult
- incomplete bladder emptying can lead to frequent UTI and kidney damage
TURP
surgical procedures ro widen the prostatic urethra
bulbo-urethral glands
- produce thick, clear mucus during sexual arousal
- mucus lubricates the glans penis and neutralizes any traces of acidic urine in the urethra
About how many sperm cells are in a typical ejaculation (a general range)?
2-5 mL
20-150 million sperm/mL
function of prostaglandins in semen
decrease the viscosity of mucus in the female cervix and stimulate reverse peristalsis in the female uterus
function of relaxing in semen
enhance sperm motility and suppress female immune response
function of clotting factors in semen
coagulate semen initially
function of fibronolysin in semen
liquifiy it
what branch of the ANS is responsible for the formation of an erection?
activation of parasympathetic neurons and release of nitric oxide (NO)
which branch is responsible for ejaculation?
sympathetic spinal reflex
sympathetic spinal reflex
- bladder internal sphincter muscle constricts to prevent expulsion of urine or reflux of semen
- ducts and accessory glands contract, empty their contents into the prostatic urethra
- bulbospongiosus muscles undergo a series of very rapid contractions that cause expulsion of semen
- ejaculatory even is called orgasm
spermatogenesis
creation of sperm in the seiniferous tubules
how many chromosomes do humans have
46 chromosome in 23 pairs
diploid cell
cell with 46 chromosomes
haploid cells
cell with 23 chromosomes
mitosis
involves 1 replication event and 1 division event - it produces 2 identical daughter cells
meiosis
involves 1 replication event and 2 division event - it cuts the number of chromosomes in half and produces 4 genetically diverse daughter cells
3 steps of spermatogenesis
- mitosis of spermatogonia
- meiosis
- spermiogenesis
first step of spermatogenesis
mitosis of spermatogonia - forms 1 stem cells and 1 primary spermatocyte
second step of spermatogensis
meiosis - primary spermatocytes form secondary spermatocytes, which become spermatids
third step of spermatogenesis
spermiogenesis - spermatids become spermatozoa (immature sperm)
spermatogonia
stem cells in contact with epithelial basal lamina
what is the net result of mitosis of spermatogonia
each mitotic division yields 1 type A daughter cells and 1 type B daughter cell
type A daughter cell
maintain the germ/stem cells line
type B daughter cell
move towards the lumen and develop into primary spermatocytes
net result of meiosis I
primary spermatocytes (2n) undergoes meisosis I forming two secondary spermatocytes (n)
net result of meiosis II
each secondary spermatocytes (n) rapidly undergoes meisosis II to become two spermatids
what happens during spermiogenesis
streamlining process where each spermatids elongates, loses excess cytoplasm, and forms a tail - becomes a spermatozoa (sperm)
be prepared to label the parts of the mature cell (slide 32)
slide 34-36
effects of testosterone
- appearance of public, axillary, chest and facial hair
- deepening of voice
- thickening of skin + increased oil production
- bone growth + increased bone density
- increase in skeletal muscle size and mass
- increase in basal metabolic rate
where are androgens produced
adrenal glands
