Endocrinology - Overview 9

Front 1

2 purposes of the male reproductive system

Back 1

Produce sperm and deliver sperm to the female

Synthesis of male sex hormones

Front 2

Purpose of the male reproductive system is achieved in 3 processes:

Back 2

Spermatogenesis

Testicular production

Delivery system (male reproductive tract)

Front 3

Semen contains ______________ and ______________

Back 3

gametes

seminal plasma

Front 4

Male accessory sex glands include:

Back 4

prostate

seminal vesicles

cowper's gland

Front 5

Sperm is stored in the:

Back 5

epididymis

Front 6

Sperm is transported in the:

Back 6

vas deferens

Front 7

Sperm and hormone synthesis occurs in the:

Back 7

testis

Front 8

Blood testis barrier

Back 8

physical barrier between the blood vessels and the seminiferous tubules

Front 9

The blood testis barrier is formed by:

Back 9

tight connections between the sertoli cells

Front 10

2 functions of the sertoli cell

Back 10

Provides nutrients to the developing sperm

Provides immunological protection

Front 11

Fetal testis differentiates at the ______ fetal week

Back 11

7th

Front 12

Testosterone synthesis occurs at the _____ fetal week

Back 12

8th

Front 13

Genetic sex

Back 13

Interaction of sex chromosomes

XX = genetic girl

XY = genetic boy

Front 14

Gonadal sex

Back 14

Comparison of ovaries with testes

XX fetus = ovary

XY fetus = testes

Front 15

Phenotypic sex

Back 15

Comparison of the external genitalia and secondary sex characteristics: male, penis, beard; female, vulva, breasts

Steroid hormones (T, DHT) and MIF (H)(AMH)

Front 16

Birth certificate

Back 16

Legal document usually certified by the physician present at birth, but may not correctly state the gonadal or genetic sex of the individual

Front 17

Somatic

Back 17

Comparison of the internal sex organs in the male and female

Front 18

Sequential events

egg + sperm

--> _________ sex

--> _________ sex

--> _________ sex

Back 18

genetic

gonadal

phenotypic

Front 19

SRY

Back 19

sex-determining region of the Y chromosome

Front 20

What gene is expressed only in cells that develop into Sertoli cells?

Back 20

SRY

Front 21

In the absence of SRY, cells develop into ____________ cells

Back 21

follicle

Front 22

Sertoli cells express ___________ and other transcription factors and the autocrine factor ______________ that lead to differentiation and multiplication of Sertoli cells

Back 22

SOX 9

FGF9

Front 23

Recruitment of mesenchymal cells and differentiation into Leydig cells occurs in response to _____ and ______

Back 23

DHH

PDGF

Front 24

Newly differentiated Sertoli cells secrete __________ and ____________

Back 24

AMH

inhibin

Front 25

____________ stimulates development of the wolffian duct

Back 25

Testosterone

Front 26

________________ inhibits development of the mullerian duct

Back 26

Mullerian-inhibiting substance

aka Mullerian-inhibiting hormone (MIH)

aka Antimullerian hormone (AMH)

Front 27

Internal male genitalia include:

Back 27

Vas deferens

Seminal vesicle

Epididymis

Front 28

External male genitalia include:

Back 28

Glans penis

Shaft of penis

Scrotum

Front 29

Testosterone is converted to DHT by what enzyme?

Back 29

5 alpha-reductase

Front 30

The wolffian ducts, when stimulated with testosterone, become the:

Back 30

epididymis

vas deferens

seminal vesicles

ejaculatory ducts

Front 31

The mullerian ducts, in the absence of Sertoli cell mullerian-inhibiting substance (AMH/MIF/MIH), become:

Back 31

fallopian tubes (oviducts)

uterus

cervix

upper one third of the vagina

Front 32

In the presence of _____________, the genital tubercle, genital fold, genital swelling, and urogenital sinus become the penis, scrotum, and prostate

Back 32

dihydrotestosterone (DHT)

Front 33

In the absence of ___________, the genital tubercle, genital fold, genital swelling, and urogenital sinus become the labia majora, labia minora, clitoris, and lower two thirds of the vagina

Back 33

dihydrotestosterone (DHT)

Front 34

Until the ____ week of gestation, each sex has potential

Back 34

7th

Front 35

Fetal ovaries produce __________, which supports follicular maturation

Back 35

estradiol

Front 36

Each primary spermatogonium ultimately give rise to _____ sperm cells

Back 36

64

Front 37

A second meiotic division changes secondary spermatocytes into ___________

Back 37

spermatids

Front 38

Spermatogenesis takes ______ days in men

Back 38

64

Front 39

Asynchrony among germ cells ensures:

Back 39

a continuous production of sperm

Front 40

Testosterone --> ___________

Estrone

Estradiol

Back 40

Estradiol

Front 41

Androstenedione -->__________

Estrone

Estradiol

Back 41

Estrone

Front 42

FSH acts directly only on ___________ cells

Back 42

Sertoli

Front 43

LH acts directly only on __________ cells

Back 43

Leydig

Front 44

Testosterone concentration in the Sertoli cell is ______ x greater than in serum

Back 44

100

Front 45

LH enters the Leydig cell and activates ____________, which goes on to activate PKA

Back 45

cAMP

Front 46

Activation of _________ in the Leydig cell triggers the beginning of cholesterol transport to the mitochondria

Back 46

PKA

Front 47

In the Leydig cell, cholesterol is converted to pregnenolone by what?

Back 47

StAR

Front 48

Testosterone is regulated by _________ in the Leydig cell

Back 48

LH

Front 49

In the Leydig cell, pregnenolone is converted to testosterone by ____________

Back 49

P450

Front 50

The interstitial leydig cells in the testis are equivalent to _________________ in the ovary

Back 50

interstitial theca cells

Front 51

The sertoli cells in the testis are equivalent to _______________ in the ovary

Back 51

granulosa cells

Front 52

Sex steroids are transported bound to ___________________ and ____________________

Back 52

sex steroid-binding globulin

albumin

Front 53

______% of sex steroids are free

Back 53

1-3

Front 54

Metabolism of sex steroids occurs primarily in the ___________

Back 54

liver

Front 55

Testosterone enters its target cell and can bind to its androgen receptor in which 2 ways?

Back 55

Directly

After being converted to 5 alpha-dihydrotestosterone (DHT) by 5 alpha-reductase

Front 56

Both testosterone and ________ may bind to the nuclear androgen receptor

Back 56

DHT

Front 57

Which binds more tightly to the androgen receptor?

Testosterone

DHT

Back 57

DHT

Front 58

During the prepubertal phase, does testosterone or DHT affect external genitalia (growth and differentiation-scrotum and penis)?

Back 58

DHT

Front 59

Prepubertally, which hormone affects wolffian duct differentiation and growth?

Back 59

Testosterone

Front 60

Estrogen resistance

Back 60

Mutation in estrogen receptor resulting in non-functional estrogen receptor

Front 61

What does bone age assess?

Back 61

Closure of epiphyseal plates

Front 62

Is DHT higher in men or women?

Back 62

Men

Front 63

___________ mediates Inhibin B production

Back 63

FSH

Front 64

Which is the major circulating form in men?

Activin A

Activin AB

Inhibin A

Inhibin B

Back 64

Inhibin B

Front 65

Inhibin B is comprised of:

Back 65

an alpha subunit and a beta B subunit

Front 66

Activins are comprised of:

Back 66

two beta subunits

Front 67

Nocturnal GnRH begins around what age?

Back 67

10

Front 68

What is used to assess pubertal development?

Back 68

Tanner Staging

Front 69

What is the number range used for Tanner Staging?

Back 69

1-5

Front 70

Prepuberty age range (in men)

Back 70

birth-10 years

Front 71

Puberty

Back 71

10-13 years

Front 72

Adulthood

Back 72

Starts at the completion of puberty, usually 16-18 years

Front 73

Senescence

Back 73

Healthy elderly men maintain reproductive capacity

>70 years men have a decrease of testosterone although levels remain within the normal range

Front 74

Sperm production may decrease by ____% between the ages of 50-80

Back 74

30

Front 75

Three peaks of testosterone levels are observed throughout life (in males):

Back 75

Fetal

Neonatal

Pubertal