Male Physiology

Question 1

why is male physiology important to dentistry?

Answer 1

hormones impact:
salivary flow
bone loss
tooth loss
diseases
SjD (inflammation in salivary glands)

Question 2

what is the relationship between male testosterone levels and Sjögren’s disease?

Answer 2

they are inversely related
SjD = decreased testosterone

Question 3

Male reproductive organs have a dual function (2)

Answer 3

1. Production/Transmission of germ cells (gametogenesis)
2. Secretion of sex hormones

Question 4

Testes secrete a large amount of ______ and small amounts of _____

Answer 4

androgens (testosterone)

estrogen

Question 5

Male gonadotropic secretion occurs in a __-____ fashion with a slow
decrease with aging

Answer 5

non-cyclic

Question 6

males maintain the ability to produce ___ ____ as they age

Answer 6

viable gametes

*ability to fertilize last longer with age

Question 8

how many seminiferous
tubules per testis?

Answer 8

200-400 per testis

Question 9

Spermatozoa are formed in the ___ of
seminiferous tubules from the primitive germ cells

Answer 9

walls

Question 10

Spermatozoa are formed in the walls of
seminiferous tubules from the __ ___ cells

Answer 10

primitive germ cells

Question 11

spermatogenesis

Answer 11

Spermatozoa are formed in the walls of
seminiferous tubules from the primitive germ cells

Question 12

male physiology: Both ends of each loop drain into a network of ducts in the head of the ____

Answer 12

epididymis

Question 13

after drainage into the epididymis where do the spermatozoa go?

Answer 13

spermatozoa pass through the tail of the epididymis into the vas deferens

Question 14

Both ends of each loop drain into a network of ducts in the head of the epididymis. From there, spermatozoa pass through the tail of the epididymis into the __ ___

Answer 14

vas deferens

Question 15

after spermatozoa enter the vas deferens, they enter through the ___ ____ into the urethra

Answer 15

ejaculatory ducts

Question 16

spermatozoa enter through the ejaculatory ducts into the urethra in the body of the _____ at the time of ejaculation

Answer 16

prostate

Question 17

Seminiferous Tubules

Answer 17

Tubules where spermatogenesis occurs

Question 18

septa

Answer 18

Fibrous tissue that subdivides the testis into ~250 lobules

Question 19

Tunica Albuginea

Answer 19

fibromuscular connective tissue capsule of the testis

Question 20

Rete Testis

Answer 20

tubules located in the hilum of the testicle that carries sperm from the seminiferous tubules to the efferent ducts

Question 21

epididymis

Answer 21

highly coiled, single tube that is a storage reservoir for spermatozoa

Question 22

Vas Deferens

Answer 22

duct that transports sperm between the epididymis and the ejaculatory duct in anticipation of ejaculation

Question 23

Between the tubules in the testes are nests of ___ ___

Answer 23

Leydig cells

Question 24

Leydig cells

Answer 24

Secrete testosterone into the bloodstream

Question 25

Blood spermatic arteries runs _____ but in the ______ direction to blood in the spermatic veins

Answer 25

parallel opposite

Question 26

Blood spermatic arteries run parallel and opposite direction to blood in the spermatic veins which allows for ...

Answer 26

countercurrent exchange of heat and testosterone

Question 27

The composition of the fluid in the seminiferous tubules is different from plasma in what ways?

Answer 27

low protein and glucose high in androgens, estrogens, K+, inositol, and glutamic and aspartic acids. Maintenance of its composition depends on the blood testis barrier.

Question 28

Blood-Testis barrier formed by tight junctions of what cells?

Answer 28

Sertoli Cells

Question 29

Blood-Testis barrier protects germ cells from:

Answer 29

Bloodborne pathogens/toxic agents Blocks antigenic products of germ cell division from entering the circulation and generating an autoantibody response Help establish an osmotic gradient that facilitates the movement of fluid into the tubular lumen

Question 30

what issues with male reproductive system post SARS infection has been noticed?

Answer 30

Increased IgG in seminal fluid (change morphology and increased apoptosis)

Question 31

The walls of the seminiferous tubules are lined by what? (2)

Answer 31

primitive germ cells and Sertoli cells

Question 32

Germ cells must stay in contact with Sertoli cells to survive via ?

Answer 32

thru cytoplasmic bridges (CB)

Question 33

Germ cells must stay in contact with ___ to survive; thru cytoplasmic bridges (CB)

Answer 33

Sertoli cells

Question 34

Cytoplasmic Bridge functions (3)

Answer 34

* Tight junctions form a blood-testis barrier * Passing macromolecules between cells * Enables synchronous cell development

Question 35

As cells (sertoli cells/primitive germ cells) mature, they pass from ____ to the ____

Answer 35

basal lamina region to the lumen

Question 36

how do the mature cells in the blood-testis barrier move from the basal lamina region to the lumen?

Answer 36

Occurs by the coordinated breakdown of the tight junctions above the germ cells and the formation of new tight junctions below them

Question 37

What do the primitive germ cells of the seminiferous tubules mature into?

Answer 37

primary spermatocytes

Question 38

the maturing of the spermatogonia (primitive germ cells) into the primary spermatocytes occurs when?

Answer 38

during adolescence

Question 39

Each sperm is an intricate motile cell, rich in DNA, with a head that is made up mostly of ____ material

Answer 39

chromosomal

Question 40

Each sperm is an intricate motile cell, rich in ___, with a head that is made up mostly of chromosomal material

Answer 40

DNA

Question 41

Acrosome

Answer 41

Head of sperm (lysosome-like organelle rich in enzymes involved in sperm penetration of the ovum and other events associated with fertilization)

Question 42

the tail of sperm is wrapped in its proximal portion by a sheath holding many ___

Answer 42

mitochondria

Question 43

structure of sperm

Answer 43

head (acrosome - DNA rich) tail (mitochondria)

Question 44

The ability of sperm to move forward is called

Answer 44

progressive motility *acquired in the epididymis

Question 45

Spermatozoa leaving the testes are not fully ___

Answer 45

mobile

Question 46

sperm continue their maturation and acquire motility during their passage through the ___

Answer 46

epididymis

Question 47

sperm progressive motility involves the activation of cation channel proteins from the ___

Answer 47

CatSper family

Question 48

Once ejaculated into the female, the spermatozoa move up the uterus to the uterine tubes, where they slow down and undergo ____

Answer 48

capacitation

Question 49

This further maturation process involves what two components?

Answer 49

increasing the motility of the spermatozoa facilitating their preparation for the acrosome reaction

Question 50

Spermatogenesis requires a temperature considerably___ than that of the interior of the body

Answer 50

lower (about 32°C)

Question 51

how do the testis stay cool?

Answer 51

air circulating around the scrotum heat exchange in a countercurrent manner between the spermatic arteries and veins

Question 52

the fluid that is ejected during orgasm contains what? (5)

Answer 52

sperm secretions of seminal vesicles secretions of prostate secretions of Cowper glands secretions of the urethral gland

Question 53

each milliliter of semen normally contains about ___ sperm

Answer 53

100 million

Question 54

what levels of sperm/ml are standard, reduced, and sterile?

Answer 54

Standard: 100 million sperm/ml Reduced: 20-40 million sperm/ml Sterile: <20 million sperm/ml

Question 55

composition of sperm

Answer 55

sperm from seminal vesicles (60%) from prostate (20%) buffers (Ph and bicarbonate)

Question 56

Answer 56

Question 57

Answer 57

Question 58

>50% decrease in sperm count since when?

Answer 58

~1970s

Question 59

Within the next 20-40 yrs, sperm counts may be less than ____ sperm/ml

Answer 59

20 million

Question 60

male contreceptions (4)

Answer 60

hormonal control of sperm development targeting of cation channel proteins important in fertilization [e.g., CatSpers] natural compounds that limit sperm function vasectomy

Question 61

The prostate produces and secretes into the semen/bloodstream a 30-kDa serine protease generally called

Answer 61

prostate-specific antigen (PSA)

Question 62

The gene for prostate-specific antigen (PSA) has two ____ response elements

Answer 62

androgen

Question 63

PSA hydrolyzes the sperm motility inhibitor ____ in semen

Answer 63

semenogelin

Question 64

An elevated plasma PSA occurs in (3)

Answer 64

prostate cancer prostatic hyperplasia prostatitis *widely used as a screening test for prostate cancer

Question 65

Testosterone is a C__ steroid with a ____ group in the __th position

Answer 65

C19 steroid with a hydroxyl group in the 17 position

Question 66

testosterone is synthesized from what?

Answer 66

cholesterol (in the Leydig cells)

Question 67

testosterone is synthesized from cholesterol in the Leydig cells and is also formed from ____ secreted by the adrenal cortex

Answer 67

androstenedione

Question 68

Secretion of testosterone by Leydig cells is under the control of ___

Answer 68

luteinizing hormone (LH)

Question 69

testosterone in plasma is bound to proteins (3)

Answer 69

gonadal steroid–binding globulin (GBG) or sex steroid–binding globulin albumin (33%)

Question 70

Circulating testosterone is converted to

Answer 70

17- ketosteroids (majority - androsterone) estradiol (small amount)

Question 71

Testosterone and other androgens exert an inhibitory feedback effect on pituitary __ secretion

Answer 71

LH

Question 72

Answer 72

Question 73

Answer 73

Question 74

testosterone anabolic effects (3)

Answer 74

Increase synthesis proteins (increased rate of growth) increase the size of kidneys retention of Na+, K+, H2O, Ca2+, SO42−, and PO43−

Question 75

mechanism of action of testosterone

Answer 75

Testosterone and other androgens (DHT) bind to hormone responsive elements (HRE). Activation of HRE triggers nuclear localization and binding (as dimer) to DNA and facilitates transcription of genes.

Question 76

Congenital 5α-Reductase Deficiency

Answer 76

Produces pseudohermaphroditism. *Individuals are born with male internal genitalia including testes, but they have female external genitalia (increased testosterone)

Question 77

Klinefelter’s Syndrome:

Answer 77

XXY, 47 X and Y chromosomes long legs cognition deviations

Question 78

Cryptorchidism

Answer 78

one or both testes fail to descend from the abdomen Gonadotropic hormone treatment speeds descent *too warm for testis (infertility)

Question 79

Male Hypogonadism

Answer 79

decreased testosterone decreased circulating gonadotropin levels

Question 80

spermatogonium (stem cells) transition to spermatids take approx how long?

Answer 80

74 days

Question 81

t/f: cytoplasmic bridges are what maintain tight junctions in seminiferous tubules

Answer 81

true

Question 82

a condition where testes do not descend?

Answer 82

cryptorchidism

Question 83

t/f: testosterone released from Leydig cells increased LH secretion

Answer 83

false

Question 84

a majority of testosterone is converted to what before being excreted in urine?

Answer 84

androsterone etiocholanolone

Question 85

t/f: CatSper cation channels regulate sperm mobility

Answer 85

true

Question 86

what part of the sperm contains concentrated mitochondria?

Answer 86

middle piece (proximal portion of tail)

Question 87

T/F: Klinefelter's syndrome is characterized by 2 X chromosomes and 1 Y chromosome (XXY, 47)

Answer 87

true

Question 88

T/F: elevated PSA is only indicative of prostate cancer

Answer 88

false prostate cancer prostatic hyperplasia prostatitis

Question 89

vasectomy is performed by ligating what?

Answer 89

vas deferens