Male Reproductive System Flashcards
what are 4 primary sex characteristics of men
testes
penis
scrotum
prostate gland
what 3 functions does the penis combine
erotic
reproductive
excretory
what are the male external genitalia
penis
scrotum
scrotum
sac of skin outside the body, behind the penis.
contains the testicles, which are the gonads and main source of testosterone, and sperm production.
testicles are suspended in scrotum to be kept at slightly cooler temperature than rest of the body for proper function.
has muscles that contract and relax, which help to move testicles closer or farther from the body, to maintain optimal temperature for sperm production
basic parts of the penis
the head: glans
foreskin: loose fold of skin that covers the glans
what is circumcision in men?
removal of foreskin
what sort of structure do penises have that keeps them erect?
hydrostatic skeleton
what are the erectile structures of the penis?
shaft contains pair of corpora cavernosa, and a corpus spongiosum
corpus spongiosum
extends from shaft into the glans
urethral meatus
opening at the end of the penis, semen or urine exit the body
tip of the glans penis
the point of entry for urethral sounding, a medical procedure where a thin tube is inserted into urethra to diagnose or treat certain conditions
the glans of the penis
aka. the head
sensitive, rounded tip of the penis
important in sexual response, rich in nerve endings. very sensitive to touch and stimulation.
high concentration of sensory receptors make it a key part of male sexual response, contributing to arousal, erection and orgasm
what are 2 muscles associated with the penis and what do they do?
the ischiocavernosus and bulbospongiosus
assist with erection and ejaculation
the corona of the penis
area that separates the glans from the shaft
ridge like structure around base of glans
a transition area, no specific function but can be sensitive due to presence of nerve endings and blood vessels
crus of the penis
aka. crura
two masses of erectile tissue that extend from base of penis, attached to pubic bone
main support structure during erection. keep penis upright and maintains erection by providing strong base for blood filled corpora cavernosa and corpus cavernosum
contains deep dorsal vein, which drains blood and helps to maintain erection
bulbourethral glands
aka. Cowper’s glands
located near base of penis. secrete thick, clear fluid called pre-ejaculate (precum)
fluid is released into urethra before ejaculation to help lubricate the urethra and neutralize any acidity from urine to make it more hospitable for sperm
also has enzymes and proteins to help sperm survival
the prostate gland
small, muscular gland that surrounds urethra (tube that carries semen and urine from the body)
main function is to secrete fluid that makes up part of semen
the fluid has enzymes that help nourish and protect sperm. prostate gland also helps propel sperm out of body by contracting rhythmically
prostatic urethra
portion of urethra that passes through the prostate gland. tube that carries urine and semen from the body
look at penis anatomy and cross section!
ok bestie!
dorsal vein
vein that runs along top surface of penis. responsible for carrying blood away from penis, back to the heart. during erection the dorsal vein becomes compressed to prevent blood from flowing back out. the vein also helps transport semen out of the penis during ejaculation
superficial fascia
layer of connective tissue that surrounds the penis and is located beneath the skin.
aka Buck’s fascia
main function is to provide support and to hold blood vessels, nerves and muscles in place. allows penis to expand and become rigid when filled with blood
tunica albuginea
dense fibrous sheath that surrounds the corpora cavernosa
main function is to maintain structural integrity and allow it to become erect while not letting the corpora cavernosa fill too much and also prevents excessive blood loss when ejaculating
medial septum
structure that divides two corpora cavernosa
provides structural support and maintains shape of penis during erection. prevents over expansion of corpora cavernosa and leakage of blood during ejaculation.
corpora cavernosa
columns of erectile tissue in the penis that fill with blood during erection, causing penis to become rigid and erect. also help maintain the erection by trapping blood in penis
urethra
tube that carries urine and semen out of body
urine is stored in the bladder
semen is a fluid that contains sperm and other substances, produced in prostate and other glands
corpus spongiosum
column of erectile tissue around the urethra along underside of penis. fills with blood during erection, but main function is to protect urethra and provide passage for urine and semen.
provides necessary rigidity to head of penis, during erection
how common is penile cancer?
not common. other conditions are more common though
balanitis
inflammation of the glans/tip
phimosis
inability to retract foreskin to expose the glans
paraphimosis
trapment of retracted foreskin behind glans
peyronie’s disease
curvature of penis caused by scarring of corpora cavernosa
penile cancer
rare. when caught early it can be treated with minor surgery
peep male side view anatomy on slide 28!
ok bestie
look at and review scrotum anatomy!!
ok bestie!
epididymis
a structure behind each testis, through which sperm pass after leaving the testes
the spermatic cord
a bundle of nerves, blood vessels and ducts that run from the abdomen into the testes. has a sheet like covering of connective tissue and a layer of striated muscles called CREMASTER muscle
cremaster muscle slings around testicle
vas deferens
within the spermatic cord, the vas deferents runs through, which is a tube that carries mature sperm away from epididymis. has a star shaped lumen with lots of surrounding smooth muscle
seminiferous tubules
dominate internal structure of testes
site of sperm production. in the testes. lined with lots of serotoli cells (sustentacular cells) that develop the sperm and provide nourishment and support. Leydig cells are also present.
mature sperm move from seminiferous tubules into epididymis, where they mature and are stored until they are expelled from the body during ejaculation. as they mature the sperm are sent to centre.
sperm development
through meiosis
- 2 sets of cell division
- makes a haploid chromosome number
development from stem cell to sperm takes ~64 days
average person makes ~150million sperm/day
what do the leydig cells do?
they secrete testosterone
testosterone stimulates sperm production, promotes development of secondary sex characteristics, maintains muscle mass and bone density
what do sertoli cells do?
convert testosterone to estradiol
estradiol is anti-testosterone, helps regulate hormone balance in testes.
high estradiol levels inhibit production and secretion of testosterone
low estradiol levels stimulate testosterone production
estradiol also regulates sperm production and maturation within the seminiferous tubules.
orchitis
inflammation and swelling of one or both testes. can be caused by viral or bacterial infections or autoimmune disease
symptoms: pain and swelling in affected testicle, tenderness, redness and heat over the affected area, fever, discomfort and pain when touching or moving affected testicle
diagnosis is made based on symptoms and physical examination, with lab tests performed to identify underlying cause of inflammation
treatment depends on cause, but can include antibiotics, anti inflammatory medications and bed rest. in severe cases surgery may be necessary to drain any fluid that has accumulated in the affected testicle.
syphilitic orchitis
syphilis is an STI caused by bacterium treponema pallidum. it is spread thru sexual contact with an infected person
it has 4 stages:
Primary- symptoms appear 2-3 weeks after exposure and include a painless sore at the site of infection
Secondary- symptoms include a rash, flu-like symptoms, and fever
Latent- there may not be any symptoms during this stage, but the disease is still present and can cause damage to the heart, brain and other organs if left untreated.
Tertiary- serious, potentially life threatening symptoms can occur, like dementia, paralysis and blindness
diagnosed with blood test and treated with antibiotics in early stages.
where can Dr’s go look if they want to search for something quickly
medscape
Is infectious syphillis on the rise or decline?
166% incline, mostly in women
which syphillis is most on the rise?
congenital syphillis, passed from mother to child. has increased a lot, but the numbers are low
why is syphilis on the rise?
lack of public health investment in surveillance, prevention and testing
mistrust of health system among indigenous people, black peoples and habitual drug users
epididymitis
inflammation of the epididymis
caused by bacterial infection like STI, or UTI, injury, or enlarged prostate
symptoms include pain and welling in one testicle, heavy/dragging sensation in the scrotum, discomfort or pain during urination and a low grade fever
diagnosed though physical exam, semen analysis, or ultrasound/MRI
treatment involves antibiotics to clear bacterial infection and pain relievers. if left untreated it can lead to infertility or a spermatocele (fluid filled painful lump in testicle)
varicocele
enlargement of veins that drain testicles
similar to varicose veins in legs. blood is not flowing properly in scrotum which causes swelling and discomfort.
varioceles are a common cause of infertility, they can interfere with the normal temperature regulation of the testicles and lead to reduced sperm production. can also cause discomfort like heavy or aching feeling in scrotum.
diagnosis of varioceles can be made through a physical exam, but ultrasound can confirm diagnosis.
treatment can be surgical removal of affected veins or minimally invasive procedures to block veins. treatment may not be necessary if varioceles do not cause symptoms or fertility problems
hydrocele
collection of fluid in the membrane space surrounding one testicle
they are common in newborns, can develop later in life due to injury, infection or other conditions.
fluid around testicles can cause visible swelling in the scrotum, which may feel heavy or painful. hydroceles can also cause discomfort or pain during physical activity.
diagnosis of hydrocele is typically made through a physical exam, but further tests like ultrasound can confirm diagnosis.
treatment options include draining the fluid with a needle or having surgery to remove the fluid and repair the area. in some cases the hydrocele may resolve on its own without treatment
testicular torsion
twisting of the testicle
occurs suddenly and causes intense pain and swelling and tenderness in scrotum. testicular torsion is a medical emergency, and it can lead to loss of affected testicle if not treated properly
cause is unknown, believed to occur when the testicles rotate and twist the spermatic cord. can be from congenital abnormality or injury
diagnosis through physical exam and medical history, may be confirmed through ultrasound or imaging tests.
Treatment involves surgically untwisting the spermatic cord to restore blood flow to the affected testicle. testicle may need to be removed if it has suffered permanent damage. prompt treatment is crucial to prevent loss of affected testicle and maintain fertility
is testicular cancer common?
Not really. ~1000 Canadians diagnosed and 45 died in 2017
what are the main tumor types associated with testicular cancer?
seminoma: develop from germ cells that produce sperm
classical seminomas are more likely to occur in people 30-50
spermatocytic seminomas are less common and are found in people 55+
non-seminoma: develop from germ cells, but these are non-seminomatous germ cell tumors (NSGCTs). often more aggressive and require combo of treatments, including surgery, chemo, radiation.
ex. embryonal carcinoma: rapidly growing cells similar to speed seen in early embryonic development. usually malignant and can spread to lungs, lymph nodes, liver. contain mix of cell types and can be accompanied by presence of other types of tumors.
ex. yolk sac carcinomas: presence of cells that resemble yolk sac, which is a structure that forms during early embryonic development and produces hormones needed for fetal development. hormones produced by yolk sac carcinomas vary. common are alphafetoprotein (AFP) and human chorionic gonadotropin (hCG). elevated levels of these hormones in blood can indicate yolk sac carcinoma and can be used to monitor condition. (NOT ALL PRODUCE HORMONES, NOT 100% CERTAINTY THING. need imaging and biopsy to confirm diagnosis)
ex. choriocarcinoma, germ cell tumor that develops in the uterus, rarely arises in men
ex. teratoma, can occur in testes or ovaries. can be benign or malignant
OR
stromal tumors: aka gonadal stromal tumors. include leydig or sertoli cell tumors. rare, 5% of testicular cancers. stromal cells produce hormones. most are benign, but if they spread they sometimes dont respond to conventional treatments.
what is an immune profile?
immunostain is a lab technique used in pathology to detect specific proteins within tissue samples.
uses immunohistochemistry
antibodies bind to specific antigens in tissue
how are cancer and age related?
typically seen in canadians 50+ since cancer risk increases with age
nearly 90% of new cases and 96% of cancer deaths are in people 50+
most deaths occur in ppl 80+
what are the 3 cancers of the male reproductive system?
penile
testicular
prostate
describe prostate cancer
occurs in prostate gland
surrounds top portion of urethra
what are some prostate cancer risk factors?
age: increases with age
ethnicity: men of west african ancestry are at higher risk. more likely to be aggressive or advanced
family history: family history of prostate cancer, of BRCA mutations, or strong history of of breast cancer
obesity: obese men with prostate cancer may be more likely to have advanced disease that’s more difficult to treat
how to detect prostate cancer?
urologist inserts gloved and lubed finger into rectum and feels back wall of prostate gland for enlargement, tenderness, lumps or hard spots
PSA test (prostate specific antigen): 50+ years old (or soon to be 50), have a family history of prostate cancer or have african ancestry, have symptoms of prostate cancer
explain the PSA test
prostate-specific antigen is a protein produced by normal and malignant cells of prostate gland
measures PSA levels in blood
reported in nanograms/mL
elevated PSA associated with prostate cancer
originally made to monitor progression of prostate cancer in those already with the disease, then in the 90s it was approved to be used to test for prostate cancer
but high PSA levels can also mean:
- enlarged prostate due to benign prostatic hyperplasia
- an inflamed or infected prostate
- UTI
- recent medical test or procedure on prostate like an ultrasound or biopsy
- urinary catheter use for bladder exam
- sexual activity that includes cumming
- bike riding often
what is HPV?
Human Papillomavirus, most common STI in Canada
affects 3/4 sexually active Canadians get it at least once. spread by direct epithelial-epithelial contact.
double stranded DNA virus
more than 100 kinds, 40 can infect human genital tract.
symptoms of HPV
genital warts
itchiness
no signs
cancers can cause itchiness, bleeding and pain
complications of HPV
cancer of cervix, vagina, anus, penis, mouth, throat
lesion on nose, tongue, mouth
some people it goes away on its own and they never knew they had it.
what are risk factors for HPV
higher lifetime number of sexual partners
previous other sexually transmitted infections
history of sexual abuse
early age of first intercourse
partner’s body count
tobacco/marijuana use
immune suppression
HIV infection
what is best way to prevent complications from HPV?
early vaccination in childhood (11 or 12)
what is the HPV vax timeline?
ages 9-14: 2 doses
ages 15-26: 3 doses
ages 21-26: 3 doses
age 27+: approved by not really recommended
what is the most common cause of cervical cancer?
HPV
reasons for HPV vax refusal
side effects
not necessary
not recommended
lack of knowledge
not sexually active
Who is Dr. Mike Evan’s?
founded reframe health lab, important scicomm initiative to inform patients
