Male Reproductive System Flashcards
Before what week of gestation is there no anatomical difference between male and female embryos?
7th week
Name the male gonad
Testes
What does the testes produce and where do they lie within the male reproductive system?
The tests produce sperm and lie within the scrotum
Sperm is delivered to the exterior through a system of ducts:
epididymis, ductus deferens, ejaculatory duct, urethra
Name the accessory sex glands (3) What do they do?
seminal vesicles, prostate gland, bulbourethral glands
Empty their secretions into the ducts during ejaculation
Describe the scrotum
Sac of skin that hangs outside the abdominopelvic cavity at the root of the penis. Contains paired testicles separated by a midline septum.
The scrotum’s external positioning keeps the testes how many degrees C lower than core body temp? Why?
2-3 degrees Celsius.
For sperm production
What two muscles keep intrascrotal temperature at a constant?
dartos and cremaster
Describe the dartos intrascrotal muscle
smooth muscle that contracts in response to cold
Describe the cremaster intrascrotal muscle
muscle that elevates the testes
What do the testes do?
Produce and store gametes (spermatazoa) and male sex hormones (testosterone)
What do the seminiferous tubules in the testes do?
Produce the sperm, converge to form the tubulus rectus
When sperm leaves the testes, where does it travel to and stored?
epididymus
What interstitial cells surround seminiferous tubules?
Leydia cells
What do sertoli cells do?
Provide nutrients to growing sperm
What two hormones influence spermatogenesis taking place
testosterone and FSH
Explain the process of spermatogenesis
The hypothalamus produces GnRH, which influences production of LH and FSH. LH stimulates leydig cells to produce testosterone, FSH stimulates the sertoli cells to produce sperm.
What does LH do in spermatogenesis?
stimulates the leydig cells to produce testosterone
What does FSH do in spermatogenesis?
stimulates sertoli cells to produce sperm
Name the 3 major regions of a sperm cell
head, midpiece, tail
What does the head of the sperm contain?
DNA and has a helmetlike acrosome containing enzymes that allow the sperm to penetrate and enter the ovum
What does the midpiece of the sperm contain?
mitochondria
What is the role of the sperm tail?
swimming
What is the role of the epididymis?
Stores sperm as they mature. Upon ejaculation the epididymis contracts, expelling sperm into the ductus deferens (also known as vas deferens)
Where is the epididymis situated in the system?
posterior surfance of each teste.
Where is the ductus/vas deferens situated?
Runs from the epididymus, through the inguinal canal into the pelvic cavity
What is a vasectomy?
where the ductus/vas deferens is cut, which is nearly 100% effective form of birth control
What do the seminal vesicles do?
produce seminal fluid that joins the ductus deferens to form the ejaculatory duct. Seminal fluid provides nutrition for the sperm
What do the ejaculatory ducts do?
sperm and seminal fluid mix in the ejaculatory duct and enter the prostatic urethra during ejaculation
Where is the prostate gland situated?
doughnut shaped gland that lies below the neck of the bladder
What percentage of semen volume is accounted for by prostatic fluid from prostate gland?
30%
What is the point of prostatic fluid?
stimulates the motility of the sperm
What does bulbourethral glands produce?
a fluid which lubricates and neutralises the urethra
Define the role of the penis
an organ designed to deliver sperm into the female reproductive tract
The penis consists of…
an attached root and free shaft that ends in the glans penis
Define circumcision
cutting of the prepuce/foreskin that covers the distal end of the penis
What is contained internally in the penis?
the urethra and the three columns of erectile tissue
Name the 3 erectile tissues in the penis
- corpus spongiosum
- 2x corpora cavernosa
Describe the corpus spongiosum
surrounds the urethra and expands to form the glans and bulb of the penis. Remain pliable during an erection to main urethral opening.
Describe the corpora cavernosa
two dorsal erectile bodies
What is the role of semen?
provides a transport medium and nutrients, protects and activates sperm and facilitates their movement.
What do the prostaglandins in semen do?
- decrease the viscosity of mucus in cervix making it easy for sperm to swim in
What implications does the male reproductive system have on Midwifery?
contraception infertility sexual transmitted infections fetal development hermaphrodite male neonate
What forms of contraception is progesterone found in?
Pill, injection, coil, implant
What does progesterone in contraception do to the cervix and sperm?
The progesterone increases the viscosity of the cervical mucus, preventing sperm penetration into the cervix
What does copper-ions from copper coils do to sperm?
Spermicide - detaches the sperm from its tail
What is the development of the male pill intending to do?
Includes progesterone which will inhibit LH production due to negative feedback loop
What does smoking do to male fertility?
Can significantly decrease sperm count and mobility
What can steroid use do to a males fertility?
anabolic steroids can cause erectile dysfunction and infertility. Medication use can reduce testicular size
What can long hot baths do to male fertility?
Impair sperm production temporarily
What can wearing tight underwear do to a males infertility?
can increase scrotal temperature which results in decreased sperm count
What can obesity do to a males infertility?
leads to hormonal imbalance that reduces male fertility
What environmental and lifestyle choices might effect male fertility?
Smoking
Drugs
Pollution
Radiation
What primary pathologies can effect male fertility?
- male accessory gland infections
- immature/abnormal spermatozoa
- prolonged stasis of spermatozoa in the epididymus or in transit
What system pathologies can effect male infertility?
diabetes
cancer
systemic infections - e.g. HIV
What changes can STD’s make to sperm and fertility?
Different STDs can cause varying changes to sperm
- Sperm count reduction
- Anti-sperm antibodies
- Reduced mobility
- Morphology alteration
Urogenital folds: what is the equivalent of the female labia minora?
Spongey urethra
Genital swelling: what is the equivalent of the female labia majora?
Scrotum
Phallus: what is the equivalent of the female clitoris?
Penis
Sex determination of the embryo. At what gestation is gender distinguishable?
Week 17
Up to week 14 the penis and clitoris are the same size
In determining gender of the embryo. What role do X and Y chromosomes play?
The presence of the Y (male sex cell) chromosome and testosterone promotes the development and the differentiation of the primary gonad.
Female sex occurs in the absence of any male genetic determinants
