male reproductive Flashcards
what are the primary sex organs called?
gonads
what are the primary sex organs for males?
testes
what are the 2 major function of the reproductive system?
- produce sex cells (gametes)
- sperm - male
- oocytes - females
- secrete steroid (sex hormones)
- testosterone
- estrogen and progesterone
how many autosomes are in our DNA?
22 pairs
what are the 2 sexes?
male and female gametes combine their genes to form a zygote
what is the difference between diploid and haploid?
diploid: most body cells (2n)
- contain 2 sets of chromosomes
haploid: gametes
- thinks half (23 chromosomes)
what type of division do gametes participate in?
meiosis - number of chromosomes cut in half
- 2 rounds
produce 4 haploid daughter cells
where do the human testes reside?
in the scrotum because its cooler
- 35 C
what is the spermatic cord?
bundle of fibrous connective tissue containing the ductus deferens, blood and lymphatic vessels, and testicular nerve
What are the three mechanisms to regulate temperature of testes?
- cremaster: strips of the internal abdominal oblique muscle (cold temps, contracts up; warm temps, relaxes far)
- Dartos fascia: subcutaneous layer of smooth muscle (cold temps, contracts, reduces surface area)
- pampiniform plexus: an extensive network of veins from the testes that surrounds the testicular artery and spermatic cord (countercurrent heat exchanger)
what are the testes?
combines endocrine and exocrine glands that produce sex hormones and sperm
what is the tunica albuginea?
white fibrous capsule on testes
what are seminiferous tubules?
ducts where sperm are produced
what are nurse cells?
thick germinal epithelium
- lay in between germ cells
- protect the germ cells and help them grow
what produces testosterone?
interstitial endocrine cells between tubules
what is the blood-testis barrier?
formed by tight junctions between nurse cells
- separates sperm from immune system
- prevents antibodies and other large molecules in the blood from getting to germ cells
What are the three spermatic ducts?
Duct of the epidermis:
- site of sperm maturation and storage
Ductus (vas) deferens:
- thick wall of smooth muscle well innervated by sympathetic nerve fibers
Ejaculatory duct:
- passes through prostate to empty into urethra
what are the male accessory glands?
seminal vesicles:
- pair of glands posterior to bladder
- empties into ejaculatory duct
- 60% of semen
prostate:
- surrounds urethra and ejaculatory duct just inferior to the bladder
- 30% of semen
bulbourethral glands:
- near bulb of penis
- pre-ejaculatory secretion
- neutralize the acidity of residual urine in the urethra
what is Benign prostatic hyperplasia?
- noncancerous enlargement of the prostate
- compresses urethra and obstructs flow of urine
- promotes bladder and kidney infections
what is prostate cancer?
- tumors tend to be near the periphery of the gland where they do not obstruct urine flow
- Digital rectal exam
- diagnosed from elevated levels of serine protease and acid phosphatase in blood
what is the penis?
it is a three cylindrical bodies of erectile tissue fill with blood during sexual arousal and account for erection
- single corpus spongiosum along ventral side of penis
- two corpora cavernosa
sympathetic vs parasympathetic?
symp: ejaculation
para: erection
adolescence?
period from onset of gonadotropin secretion and reproductive development to when a person attains full adult height
- testosterone sustains the male reproductive tract, sperm production, and libido
puberty?
first few years of adolescence until the first ejaculation of viable sperm in boys
- growth of sex hormones
- DHT
- stimulates sperm production and libido
what does the hypothalamus produce?
GnRH: stimulates anterior pituitary cells to secrete:
- Follicle-stimulating hormone: stimulates nurse cells to secrete androgen-binding protein that bind testosterone, keeping it in seminiferous tubule lumen to stimulate spermatogenesis
- luteinizing hormone: stimulates interstitial endocrine cells to produce testosterone
things that change when men age?
- testosterone secretion declines with age (peak at 7mg/day at age 20; declines to 1/5 by age 80)
- Andropause (male climacteric): declining reproductive function, age related drop in testosterone and triggers rise in FSH & LH
- erectile dysfunction: the ability to produce or maintain an erection sufficient for intercourse
treatments for erectile dysfunction?
- Viagra, Levitra, and Cialis
- phosphodiesterase inhibitors
- Sexual stimulation triggers nitric oxide secretion, which activates cGMP, which then
increases blood flow into erectile tissue
what is spermatogenesis?
process of sperm production in seminiferous tubules
what are the three principal events of spermatogenesis?
- division and remodeling of large germ cells into small, mobile sperm cells with flagella
- reduction of chromosome number of one-half
- shuffling of genes so each chromosome contains new gene combinations that did not exist in parent
- ensures genetic variation in the offspring
what is a spermatozoon?
head:
- nucleus contains haploid set of chromosomes
- acrosome - enzymes cap over the apical half of the nucleus that contains enzymes that penetrate the egg
Tall in 3 regions:
- midpiece contains mitochondria around axoneme of the flagella, produces ATP for flagella movt
what is semen?
a mixture of seminal fluid and sperm - fluid expelled during orgasm
- func: provide a nutrient pH protected, enzyme containing, fluid medium for the sperm to travel in
Prostate: thin milky white fluid
- calcium, citrate and phosphate ions
- clotting enzyme
seminal vesicle: contribute viscous yellowish fluid
- causes retentions of sperm in vagina
