Chapter 4: Male Reproductive System
y
http://wps.aw.com/bc_marieb_happlace_7_oa/42/10973/2809187.cw/index.html
Yes?
http://www.free-anatomy-quiz.com/malereproductive1.html
yes
http://www.purposegames.com/game/testicle-anatomy-quiz
y
http://www.sciencequiz.net/jcscience/jcbiology/Reproduction/mcq/male_reprod_mcq.htm
Vas deferens
- 45 cm long tube that descends from the posterior border of each testis, penetrates the body wall via inguinal canal, enters pelvic cavity, loops over urinary bladder - Has thick muscularis which facilitates the movement of sperm - AKA ductus deferens
Interstitial (Leydig) cells
- Found in interstitial spaces outside of seminiferous tubules - Synthesize and secrete androgenic steroid hormones (testosterone) - Secretes GnIH
Testosterone
- Most important androgen in human males - 95% comes from Leydig cells in testes - 5% in the adrenal gland - 98% of plasma androgen is bound of plasma proteins 2% of plasma androgen is free
Benign prostatic hyperphasia
- Occurs in over 50% of men over 45 years old - Manifests with non-cancerous enlargement of gland
Seminal vesicles
- Paired pouch like glands at the base of the urinary bladder - Joins the ampulla of the vas deferens - secretes seminal plasma (important nutrient for sperm
Sertoli cells
- Pyramid shaped cells in seminiferous epithelium - Nurtures and provides support to spermatogenic cells - Helps sperm move to the lumen
Prostate cancer
- Second leading cause of cancer in men in USA; occurs 1 in 6 men - Diagnosis with digital exam - Biopsy gives definitive diagnosis - Increased risk in men who eat diet rich saturated animal fats - Reduced by consuming soybean products and foods rich in red carotenoid
Prostate
- Single donut shaped organ - Below urinary bladder and surrounds prostatic urethra - Secretion makes up 13-33% of seminal plasma
Estrone
Androstenedione is converted to ______ in fat cells
DHT; The prostate enlarges due to the DHT.
As men age, testosterone is converted to ____ at a faster rate in the prostate. What is the effect of this?
- Phagocytize cytoplasm that is shed during sperm formation. - Form tight junctions with each other to make a blood-testis border - Hormonal control of spermatogenesis
Aside from nurturing and providing support, what other functions (3) does the sertoli cell provide?
Testicular fluid
Aside from the Sertoli cells, what fluid aids in sperm movement through the tubule?
Spermatogonia mitosis: testosterone, FSH 1 spermatocytes--->2 spermatocytes: testosterone 2 spermatocytes---> spermatids: testosterone Spermatids--->Spermatozoa: FSH Spermatozoa--->Spermiation: LH
Connect the stimulator (FSH, LH, testosterone) to the stimulated (Spermatogonia mitosis; 1---->2 spermatocytes; 2---->spermatids; Spermatids--->Spermatozoa; Spermatozoa----> Spermiation)
Tunica albuginea
Dense covering of the testes inside the teste
Spermatic cord, inguinal canal
Each testes is suspended from the body wall by a _____ _____ which penetrates into the pelvic cavity through the ______ ______.
Ejaculatory duct
Enters into a 2 cm long ______ ____ which leads to the urethra from the vas deferens. - Joins with the duct of the seminal vesicle gland - Runs within the prostate, empties into prostatic urethra
Inhibin, ABP, aromatase, 5 alpha reductase
FSH also induces Sertoli cells to produce what other four hormones?
Sertoli, inhibin
FSH stimulates ______ cells to release _____, which suppresses FSH by decreasing sensitivity of FSH-secreting cells to GnRH
7, 5, 4, 3, 6, 2, 9, 8, 1
Place these in order: 1.Urethra 2. Tail of epididymus 3. Head of epididymus 4. Vasa efferentia 5. Rete testis 6. Body of epididymus 7. Tabuli Recti 8. Ejaculatory duct 9. Vas deferens
androgen-binding, high
Sertoli cells secrete ______-______ protein which binds to testosterone, making the testosterone levels in the seminiferous tubules _____
Urethral orifice
Sperm leave body through _____ ______
F. "Male sexual behavior" is caused by a conversion of testosterone to estrogen
T/F: Male sexual behavior is due to testosterone
20%
Testosterone and LH levels in men are ____% higher in the morning than the evening
DHT
Testosterone is converted to ___ in hair follicles on public and axillary area
aromatase
Testosterone is converted to estradiol via _______ (enzyme)
Autumn
Testosterone levels have seasonal cycles which are the highest in _______ in the Northern Hemisphere
Seminiferous; sertoli-germ
Testosterone then diffuses into _______ tubules and enters Sertoli cells to facilitate ___-____ cell interactions that stimulate steps in spermatogenesis.
negative, GnRH, LH FSH negative
Testosterone, at moderate and high levels, exerts a _______ feedback on _____ and ____ & ____ Low testosterone levels result in lack of _______ feedback which results in stimulation of GnRH, LH, FSH
Myoid cells
The layer of smooth-muscle like cells that surround the seminiferous tubules and contract to help squeeze sperm/testicular fluid out to the epididymis
Spermatogenesis
The process by which a diploid spermatogonium transforms into four haploid spermatids.
Spermiogenesis
The process by which haploid spermatids are transformed into spermatozoa (sperm cells)
Tunica vaginalis
The shiny covering on the outside of each teste
Vas deferens (duct), Testicular nerve, THREE coiled blood vessels
The spermatic cord has five (3 if you count three as a group) components. What are they?
Near wall of seminiferous tubules
The spermatogonia is produced where?
Spermatagonia
The stem cells that are positioned in the basal lamina
Urethra, sperm, semen
Tube extending from the urinary bladder, through the floor of the pelvic cavity, through the length of the penis. Transfers ____ and _____ from the ejaculatory ducts.
Testes, sex accessory (receive, store, transport sperm), sex accessory glands (add substances to ducts), external genitalia
What are four male primary characteristics made up of?
Seminiferous tubules, tabuli recti, rete testis, vas efferentia Cilia
What are the four places sperm cannot move through? If they can't move, how do they move along the epididymis?
Larger muscles, higher average height, facial hair, lower voice
What are the four secondary characteristics made up of?
Tunica vaginalis, tunica albuginea, testicular lobules, seminiferous tubules
What are the four things found within or on a testes?
Stereocilia Luminal surface Their job is to provide epithelial cells with large surface area to reabsorb testicular fluid and transfer nutrients to developing sperm.
What are the long immotile microvilli in the epididymus called? Where are they found? What is their job?
Seminal vesicles, prostate gland, bulbourethral glands
What are the three male sex accessory glands that secrete fluid into ducts so that sperm can be made into semen?
Head, body, tail Ductus
What are the three parts of the epididymus? What is the body referred to as?
Prostatic, membraneous, spongy (cavernous)
What are the three types of urethra?
Strong - Testosterone and DHT Weak - Androstenedione, DHEA
What are the two most potent androgens? What the two weak androgens?
Emotional stress (suppress GnRH and testicular function) Exogenous progesterone (suppress gonadotropin release/testosterone production)
What are the two negative factors (Not hormones) that influence testicular function? For each one, list effects to GnRH, Testosterone)
Sertoli cells, testicular fluid, stimulate phases of spermatogenesis
What cells release the DHT and estradiol? Where do these hormones go? What do they do?
Seminiferous tubules
What contains sperm stem cells?
Sperm/Spermatozoa
What do the testes produce? (not hormones)
Muscle growth at the expense of testis shrinkage and infertility
What does anabolic steroids do? At what expense?
Androgen binding protein (ABP) Inhibit Mullarian-inhibiting substance (MIS) DHT Enzymes that make testosterone into estrogen
What does the sertoli cells produce in terms of hormones (5)?
Aphrodisiac
What else can saw palmetto do?
Sperm heads are released from the sertoli cell membrane, but sperm do not swim yet.
What happens during spermiation? Do sperm cells swim yet?
Androgen
What hormone group: - Stimulates growth and maintenance in male reproductive tissues - Stimulate muscle growth - Enhances libido in both men and women
Testis, epididymis, prostate, seminal vesicle, urinary bladder
What is the male reproductive tract made up of? (5)
Primary spermatocytes, secondary spermatocytes, spermatids, sperm
What is the pathway of sperm creation? (4 steps)
1000 sperm/second >86 million sperm/24 hours
What is the rate that sperm is produced?
Seminiferous epithelium; male germ cells and sertoli cells
What lines the inside of each seminiferous tubule? What are the two types of cells inside the seminiferous tubule?
Primary diploid spermatocyte splits into two haploid secondary spermatocytes
What occurs in the first meiotic division?
Two secondary haploid spermatocytes split into four haploid spermatids
What occurs in the second meiotic division?
Adrenal glands and ovaries
What physiological structures produce androgens?
Saw palmetto inhibits the enzyme 5 alpha-reductase which converts testosterone to DHT
What plant helps to prevent the onset of BPH/how does this help in terms of 5-alpha reductase?
Ductus epididymus (body), vas deferens
What two structures have cilia and well developed smooth muscle in ducts that contract in waves to propel sperm into urethra during ejaculation
Spermiation; LH; ovulation
When mature sperm heads of spermatozoa are released from Sertoli cells in a process called ________ What hormone stimulates this process? What is it analogous to in females?
- One that produces mainly X - One that produces mainly Y - One that makes an equal number of X and Y
Given that men have a gene that determines the ratio of X and Y sperm, what are the three alleles that this gene has?
Blood-testis barrier
How are androgens kept from diffusing out of the tubules?
20 Days for maturation and motility Several months
How long do sperm usually stay in the epididymus for? How long can sperm be stored for?
75 days
How long does it take for sperm to be fully made?
6 meters On the posterior surface of each teste
How long is the epididymus when uncoiled? Where is it located?
1-4
How many seminiferous tubules are there in each testicular lobule?
lower; receptors are high Made in the sertoli cells
In comparison to androgen levels, the amount of estrogens in a male are ____. However, their receptors are ______. In what cells are the estrogens in males made?
More fat < sperm More omega-3 > sperm
In terms of sperm, What does research show on men who eat a lot of saturated fat? What about men who consume more omega-3s?
Estradiol, DHT
In the Sertoli cells, testosterone can be converted to ______ by aromatase or to ____ by 5 alpha-reductase
Testosterone, DHT, androstedione Puberty, menopause, ovulation
In women, what are the three androgens secreted? When are these secreted?
Testicular lobules
Inside each testes are 250 ______ ______ which are compartments separated from each other by septa
Number is defined at puberty (there is a defined set) and no new cells are produced. Rate of sperm prod is determined by how many cells are in testes.
Is the number of sertoli cells unlimited or defined? What is the rate of sperm production defined by?
Testosterone; Testes
Leydig cells secrete _______ in response to LH delivered in the blood flow to the ______
X,Y
Men have a gene that determines the ratio of ____ and ___ sperm
Equal; can go either way too though
On average, men in human populations produce how much X sperm in relation to Y sperm?
Male reproductive tract, bone, and brain
Where are the three places that estrogens affect men?
Hypothalamus; Produces normal functioning of the male reproductive system
Where is GnRH (and indirectly LH/FSH) made? What is its job in the male reproductive system?
Seminiferous tubule
Where is sperm produced?
Epididymus tail
With ejaculation, sperm as far down as the _______ _____ are projected through the ductus deferens, ejaculatory ducts, and urethra.
Prostate-specific antigen
With prostate cancer detection, what test is administered by blood?
Male germ cells, spermatogonia
____ ____ ____ or ______ lie next to the inner wall of each seminiferous tubule and produce sperm
LH; interstitial
____ stimulates Leydig cells to produce testosterone which enters blood circulation, diffuses from ______ spaces into seminiferous tubules and enters Sertoli cells
Blood-testis border
____-______ _____ protects spermatocytes and spermatids from autoimmune attack
DHT; 5 alpha-reductase
_____ causes growth of facial hair, prostate, penis, and scrotum. Convert testosterone to DHT with 5__-_______ enzyme
Prostatic Spongy (cavernous) Membraneous
_____ is the region of urethra surrounded by a prostate gland and an area where ejaculatory ducts enter the urethra. ______ urethra is the region of urethra passing through the penis ______ urethra is the region of urethra that passes through the pelvic cavity between prostate and penis
Spermatozoa; flagellum Sertoli cells
______ have an elongated _____ (tail) that grows out the posterior of the sperm cell. It does not beat yet. In what cell are the sperm heads embedded?
FSH, Testosterone
______, binding to Sertoli cells, functions together with _______ to maintain the germ cells and help advance them through stages of spermatogenesis.
Spermatogonium (diploid) becomes primary spermatocyte (diploid) which then splits into two secondary spermatocyte (haploid), and again to become spermatids (haploid). Spermiogenesis then occurs to produce four (haploid) spermatozoa.
_______ (diploid) becomes _____ ______ (diploid) which then splits into two secondary _______(haploid), and again to become four _______ (haploid). Spermiogenesis then occurs to produce four (haploid) spermatozoa.
Inhibin and testosterone
_______ and ________ enter the outgoing blood and exert negative feedback on GnRH
Sertoli
_______ cells are the "nurse cells" that nurture and provide structural support for sperm cells during development.
Ampulla of vas deferens
_______ of ____ ______ is expanded portion at the end next to the ejaculatory duct that serves as a sperm reservoir. Comes together with the other ductus'
Spermatogenic; 86
________ cells produce _____ million sperm per day in adult males.
