Male Reproductive System Flashcards Preview

Histology IV > Male Reproductive System > Flashcards

Flashcards in Male Reproductive System Deck (134):
1

what acts as the endocrine gland in the Testes?

leydig cells producing and secreting testosterone

2

what acts as the exocrine organ in the testes?

spematozoa secretion via holocrine secretion (from the seminal tubules)

3

what type of gland is the testes?

a compound tubular gland

4

What is the tunica albuginea?

dense irregular CT hat surrounds each testis in a capsule

5

what is the innermost layer of the tunica albuginea called? what does it contain?

tunica vasculosa = loose CT with blood vessels

6

what is the mediastinum testis?

a posterior thickening of the tunica albuginea

7

what divides each testis into lobules? what does each lobule contain?

the septae of CT divides each testis into lobules; each lobule contains 1-3 seminiferous tubules

8

Where do the seminiferous tubules start? end?

near the mediastinum testes

9

what does the intersitial CT (aka intersitium aka stroma) of the testes lobules contain?

lympathic vessels, blood vessels, nerves, leydig tells (interstitial cells)

10

Describe the morphology of leydig cells and staining

larger than other cells of the interstitium, have an eosinophilic cytoplasm and a VESICULATED nucleus with a prominent nucleolus; cytoplasm has lipid droplets ; contains lots of sER and mitochondria (TUBULOVESICUALR CRISTAE)

11

where are leydig cells found?

in the testicular lobules, BETWEEN SEMINIFEROUS TUBULES

12

What is the function of Leydig cells

secretion of testosterone (STEROID HORMONE)

13

Why is testosterone important in males?

it is necessary for development, maturation, and maintenance of male gamete production, reproductive tract function and male secondary sex characteristics

14

what is the tunica propria?

a layer of dense CT that surrounds each semeniferous tubule; contains MYELOID CELLS

15

what is the function of myoid cells? where are they found?

function like myofibroblasts, have characteristics of SMC and Fibroblasts;

Function = to contract and help propel secreted spermatozoa along the seminiferous tubule lumen

Found in the tunica propria -- surrounding each seminiferous tubule

16

What separates the tunica propria from the seminiferous epithelium?

basal lamina

17

Describe the seminiferous epithelium morphology; what cells can be found here?

stratified epithelium containing 1. sertoli cells (epithelial cells) and 2. spermatogenic cells (spermatogonia, spermatocytes, spermatids)

18

What is the effect of temperature of spermatogenesis?

spermatogenesis occurs at 2-3 degrees LOWER than body temperature; this is maintained by the scrotum (sac) that suspends the testes;

19

What is the relationship between infertility and body temperature?

Infertility can be caused by elevated temperature because then spermatogenesis ceases even the TESTOSTERONE SECRETION IS UNAFFECTED

20

What are the most common ways for male infertility?

1. Elevated temperature in the testes
2. crytoorchidism (undescended testicles)
3. Mutagens
4. Steroids
5. Infections
6. Radiation

21

What are sertoli cells?

seminiferous epithelial cells THAT DO NOT BECOME SPERM; instead they form compartments to organize the spermatogenic cells that are undergoing spermatogenesis

22

Describe the morphology of sertoli cells?

columnar, stretch from the basal lamina to the lumen of the semeniferous tubule; they have indistinct PM boundaries, an indented vesiculated nuclear and a prominent nucleolus

23

What is the function of the space between sertoli cells?

it creates a microenvironment needed for the development of the different types of spematogenic cells

24

what are sertoli-sertoli junctions?

specialized junctions created between 2 neighboring sertoli cells with in a semeniferous tubule

BASIS OF THE BLOOD TESTIS BARRIER

25

how does the sertoli cell divide the seminiferous epithelium?

into a basal compartment containing spermatogonium and an adluminal compartment containing spermatocytes + spermatids?

26

what is found in the basal compartment of the seminiferous epithelium? adluminal compartment?

basal = spermatogonia (+spermatocytes very briefly)
adluminal = spermatocytes + spermatids

27

Other than adjacent sertoli cells, what else do sertoli bind to? what does this form?

bind to spermatids within the seminiferous epithelium to form the sertoli-spermatid junction

28

what is the function of the sertoli-spermatid junction?

anchors spermatid to the sertoli cell during sperm development

29

How is there a high concentration of testoserone in the seminiferous tubule? why is this important?

sertoli cells produce testosterone binding protein to maintain high [testosterone] in the seminiferous tubules (200 times higher than normal blood vessels); Necessary for spermatogenesis

30

what do sertoli cells secrete?

fluid to help move the spermatozoa along the lumen of the seminiferous tubule

31

How does autoimmunity to spermatozoa occur? what happens? What patients usually have this?

if the sertoli-sertoli junctions are compromised, the immune system may detect "foreign" proteins of the spermatozoa which have a different genetic makeup than the host and mount an anti-body response to them ;

Patients who have a vasectomy usually have autoimmunity to their sperm because the vasectomy allows spermatozoa to leak out of the reproductive tract and be exposed to the immune system

32

What are the 3 stages of spermatogeneis? what their general goal?

1. spermatogonial phase: production of spermatocytes by spermatogonial cells
2. spermatocyte phase: meiotic divisions of spermatocytes to reduce the DNA content to 1 per cell (haploid)
3. Spermatid phase: differentiation of sperm

33

what is a spermatogonia?

the least developed of the spermatogenic cells that reside within the seminiferous epithelium of the testes

34

what are the 3 types of spermatogonia? how are they distinguished?

1. Ad (dark)
2. Ap (pale)
3. B

distinguished histologically by their nuclei

35

How are spematogonia IDed?

any cells resting on the basal lamina and lacking sertoli morphology = spermatogonia

36

What is true of all spermatogonia?

all are round with a round nucleus and are located next to the basal lamina (basal compartment)

37

What is the function of Ad type spermatogonia?

divide by mitosis to form another pair of Ad type or a pair of Ap type spermatogonia

38

what is the function of Ap type spermatogonia?

commit to differentation process that will produce sperm; they go through several rounds of mitosis but DO NOT COMPLETE CYTOKINESIS, forming a cohort and differentiating into type B spermatogonia

39

what is a cohort with respect to the male reproductive system?

a group of spermatogonia linked together by cell bridges; formed by type Ap spermatogonia undergoing mitosis without cytokinesis

40

what gives rise to type B spermatogonia?

type Ap spermatogonia

41

what marks the end of the spermatogonial phase of spermatogenesis?

type Ap differentiating into type B spermatogonia

42

type B spermatogonia divide via _______ to produce _______________ located in the _______ but moving to the _________.

divide via MITOSIS to produce PRELEPTOTENE PRIMARY SPERMATOCYTES located in the BASAL COMPARTMENT but moving to the ADLUMINAL COMPARTMENT

43

how do primary spermatocytes migrate from the basal compartment to the adluminal compartment?

via sertoli cells forming new sertoli-sertoli junctions beneath the primary spermatocytes and breaking down the junctions above them

44

what is the goal of the spermatocyte phase of spermatogenesis?

primary spermatocytes (2n) undergo meiosis with genetic recombination to reduce the chromosome number and amount of DNA

45

Describe the morphology of primary spermatocytes

largest nuclei of the cells in the semeniferous epithelium and nth nucleus is filled with very basophilic chromatin

46

How do primary spermatocytes prepare for meiosis? what is the result of the "prep"

they duplicate DNA such that they have normal number of chromosomes (sister chromatids = 46 chromosomes) but TWICE the total amount of DNA compared to interphase

47

what is the result of meiosis I in spermatogenesis?

two secondary spermatocytes, each with 23 chromosomes and the normal amount of DNA

48

what is another name for meiosis I?

reductional division

49

where are secondary spermatocytes located?

in the adluminal compartment

50

How do spermatocytes prep for meiosis II?

THEY DONT. DO NOT UNDERGO DNA REPLICATION, increase they just go straight into meiosis II

51

what is another name for meiosis II?

equatorial division

52

How does the time frame of meiosis I compare to that of meiosis II?

meiosis I = weeks
meiosis II = hours

53

what is the result of meiosis II?

two spermatids (4 total, 2 spermatids per secondary spermatocyte) , each with 23 chromosomes and 1/2 the normal amount off DNA

54

In general what is spermatogensis?

1 diploid spermatogonia in the basal compartment to 4 haploid spermatids in the adluminal compartment

55

describe the morphology of the early (round) spermatid

small, round, dark basophilic nucleus, NO STRANDS OF CONDENSED CHROMATIN NUCLEUS

56

Do spermatids undergo meiosis? mitosis?

NO TO BOTH, they only undergo a series of biochemical + morphological changes (spermatogenesis phase)

57

What are the 4 phases of the spermatid phase of spermatogenesis?

1. Golgi phase
2. Cap phase
3. Acrosome Phase
4. Maturation Phase

58

Describe the golgi phase of spermatogensis

1. spermatids produce acrosomal vesicles from the golgi apparatus
2. Tail microtubules (Axoneme) begin to form

59

what is the acrosomal vesicle? where is it located?

membrane bound vesicle next to the nuclear envelope (formed during the golgi phase of spermatogenesis)

60

What does the acrosomal vesicle contain?

hydolytic enzymes = hyalurinidase, acrosin, neuraminidase

61

what is the function of the acrosomal vesicle's contents?

hydolytic enzymes to help penetrate the coverings of the ovum and receptors for the zona pellucida surrounding the ovum

62

What happens during the cap phase of spermatogensis?

1. acrosomal vesicle flattens against round (early) spermatid nucleus to form a "cap"
2. Tail also elongates

63

What happens during the acrosomal phase of spermatogensis?

1. Nucleus condenses and elongates, giving the sperm head a pointed appearance
2. Mitochondria migrate to the initial portion of the axoneme, adjacent to the neck, forming a spiral wrapping to constitute the "middle piece" of the spermatozoan

64

what happens in the maturation phase of spermatogenesis?

excess cytoplasm extruded into a residual body, which is usually phagocytoized by nearby sertoli cells

65

What are the major morphological changes that occur during the spermatid phase of spermatogensis?

1. During acrosome phase, the late (elongated) spermatids with small dense triangular heads form

66

where are late (elongated) spermatids located?

very close to the lumens of seminiferous tubules

67

What happens to the late (elongarted) spermatids?

they are shed from the seminiferous tubules to become spermatozoa

68

what are spermatozoa?

nonmobile sperm incapable of fertilization

69

how do spermatozoa move?

they are immobile therefore they move passively along the seminiferous tubule lumen by flow of the fluid secreted by the sertoli cells and by contractions of the myoid cells (of tunica propria)

70

What are the stratight tubules (tubuli recti) in the testes?

intratesticular ducts located at the ends of seminiferous tubules where they meet the mesiastium testis

71

what type of epithelium line the straight tubules (tubuli recti) of the testes?

simple cuboidal epithelium

72

What are the rete testis?

intratesticular duct system of interconnecting epithelial-lined channels within the CT mediastinum testis

73

what type of epithelium lines the rete testis?

simple cuboidal

74

what is the function of the straight tubules and the retes testis?

to transport spermatozoa from the seminferous tubules to the epididymal duct via movements of the testicular fluid (with sperm) through the duct

75

What forms the efferent ductules of the testes?

fusion of the retes testes

76

are efferent ductules intratesticular or extratesticular ducts?

EXTRAtesticular

77

what acts as the bridge between the testes and the epididymis?

efferent ductule

78

what is formed by the efferent ductules merging?

the head of the epididymis

79

what type of epithelium is found in the efferent ductule?

pseudostratified columnar made of alternating tall ciliated columnar and non-ciliated cuboidal ;

incomplete layer of basal cells

80

where is most of the testicular fluid secreted by the sertoli cells reabsorbed?

in the efferent ductules by the non-ciliated cuboidal cells

81

how does sperm move through the efferent ductule?

facilitated by the action of the ciliated epithelial cells and the contraction of SMC layer that surrounds the ductule

82

What is the epididymal duct?

a single high coiled tube that extends 5-6 m long!

83

Describe the epithelium found in the epididymal duct

Pseudostratified columnar with principal cells and basal cells (+some narrow cells, clear cells, and halo cells)

84

Describe the morphology of the principal cells of the epididymal duct

apical surface has non-motile branched stereocilia (elongated microvilli)

85

what are the functions of the principal cells of the epididymal duct?

1. absorption of testicular fluid that wasnt absorbed by efferent ductules (mainly at epididimis head)
2. phagocytosis of abnormal spermatozoa and residual body
3. Secretion of glycerylphosphorylcholine (GPC), glycoproteins and other molecules for maturation of spermatozoa (for motility and fertility)

86

what allows for sperm to be motile and fertile?

Secretion of glycerylphosphorylcholine (GPC), glycoproteins and other molecules from the prinicpal cells of the epididimis

87

what cells secrete glycerylphosphorylcholine (GPC)

principal cells of the epididymal duct

88

where are mature sperm stored?

in the epididymal tail

89

What is the function of basal cells of the epididymal duct?

1. precursors for principal cells
2.regulat electolyte and water transport by the principal cells

90

What surrounds the epididymal duct? Does it's morphology change?

surrounded by SMC that gets progressively thicker, such that the tail has 3 layers of SMC

91

What is the ductus dereferns a continuation of? what does it expend to?

continues directly from the tail of the epidimis and is a component of the spermatic cord

92

Describe the mucosa layer of the ductus deferens

epithelium = PSC similar to epididymal duct + STEREOCILIA until the ampula

LP = contains elastic fibers

93

Describe the muscularis layer of ductus deferens

inner longitudinal, middle circular, and outer longitudinal layers;

94

How is sperm propelled during ejaculation?

due to the peristaltic activity of the muscular wall of the ductus deferens

95

Describe the adventitia layer of the ductus deferens

loose elastic CT that blends with the CT of structures in spermatic cord

96

what is the ampulla of the ductus deferens?

dilated region of the ductus deferens adjacent to the prostate and the seminal vesicle

97

describe the epithelium of the ampulla of the ductus deferens

becomes folded and resembles that of a seminal vesicle; epithelium may have secretory function

98

What is the function of the accessory glands of the male reproductive system?

they are secretory glands that provide fluid and nutrients to support and nourish the spermatozoa (fluids form the bulk of semen)

99

what do all accessory glands depend on? for what?

testosterone for mophological development and physiological activity

100

what are the seminal vesicles?

paired, elongate, and highly folded tubular glands that secrete tons of fluid for semen (largest contributor to semen volume)

101

Describe the epithelium of the seminal vesicles (morphology)

PSC but can vary with aging or with amount of testosterone present

102

Describe the morphology of the mucosa of the seminal vesicles and how it contributes to its function

extensively branched and folded, creating a large surface area for secretion

103

What does the epithelium of the seminal vesicles secrete?

FRUCTOSE (+ other sugars), bicarbonate, prostaglandins, proteins, amino acids

104

describe the lamina propria of the epithelial cells of the seminal vesicles

loose CT, vasculatized, elastic fibers

105

Describe the muscularis layer of the seminal vesicles

inner circular + outer longitudinal SMC

106

Describe the adventitia of the seminal vesicles

collagenous CT with many elastic fibers

107

What does the seminal vesicle connect to? how? what does this form?

combines with the ampulla of the ductus deferns as they enter the prostate gland via a short excretory duct; forms the ejaculatory duct

108

Where is the prostate gland located?

surrounds the prostatic segment of the urethra

109

How is the prostate gland organized? Describe the organizations

into zones of tubulo-alveolar glands around the urethra:
1. Main prostatic gland = peripheral zone
2. Submucosal gland = central zone
3. mucosal glands = transitional zone

110

what do the ducts of each zone of the prostate converge to form?

an excretory duct that opens into the prostatic urethra

111

Describe the epithelium of the prostate

varies between simple columnar and PSC, depending on adequate levels of testosterone

112

what is the effect of inadequate testosterone on the epithelium of the prostate?

results in a change in the epithelial shape and loss or reduction in secretory activity

113

what do the epithelial cells of the prostate secrete?

prostate specific acid phosphatase, citric acid, fibrinolysin (liquifies semen), prostatic specific antigen (protease), and amylase

114

What is found in the lumen of the prostatic glands?how does it stain?

calcified bodies called prostatic concretions; stains eosinophilically

115

what is found in the stroma of the prostate gland?

fibromuscular stroma = SMC + Fibroblasts + elastic + collagen fibers

116

What causes benign prostatic hyperplasia?

As men age, mucosal and submucosal glands and the prostatic stroma begin to hypertrophy which occurs by the conversion of testosterone to DHT via 5-reductase (which causes a growth factor production leading to hyperplasia)

117

What is the effect of DHT on the prostate?

acts as an autocrine factor of the stromal cells and a paracrine factor on the epithelium to produce growth factors

118

What does benign prostatic hyperplasia cause?

since it is causing hyperplasia of both stroma and epithelium, and the prostate is located adjacent to the prostatic urethra, the enlarged tissue gradually decreases the lumen of the urethra resulting in difficulties urinating

119

Where do most tumors develop in in prostatic cancer?

in the main (outer) glands)

120

How is prostatic cancer usually detected?

by the prostate impinging on the urethra;

also blood levels of PSA and prostatic specific acid phostatas

121

what does a prostatic carcinoma cause?

an increase in blood levels of PSA and prostatic specific acid phostatase --- both used to detect and monitor progress of disease.

122

Where are the ducts of the bulbourethral glands located? where do they open into?

located in the UG diaphragm; open into the penile urethra

123

what type of glands are all of the bulbourethral glands? what are they all lined by?

ALL MUCUS GLANDS; all lined by tall epithelium

124

what surrounds the corpus cavernosum and corpus spongiosum?

tunica albuginea (dense collagenous sheath)

125

what does the skin covering the penis contain?

a thin subcutaneous layer of SMC

126

How is the male urethra organized?

into 1. prostatic 2. membranous 3. penile segments

127

where is the penile portion of the male urethra located?

in the copus spongiosum

128

what type of epithelium is found in the male urethra?

stratified or pseudo strat. columnar

129

what are the glands of Litre?

MUCUS glands common as outpouching of the urethra

130

What is the morphology of erectile tissue of the penis?

interconnecting vascular spaces (lacunae) lined with endothelium and composed of trabeculae (dense CT + SMC)

131

What molecules effect an erection?

Nitrous oxide (NO) and a specific phosphodiesterase

132

How is an erection produced?

ACh (released by the PS nerves in the penis/clitoris) act on the endothelium of erectile tissue to produce NO; NO spreads into the SMC of trabeculae and helicine arteries causing and enzyme, gunylate cyclase, to produce cGMP, which relaxes SMC; this causes an increase in blood flow, filling the lacunae with blood and producing an erection

133

What is the effect of phosphodiesterase on an erection?

it breaks down cGMP to constrict SMC

134

How is eretile dysfunction treated?

with an phosphodiesterase inhibitor (SILDENAFIL CITRATE) suppressing destruction of cGMP so that the erection can take place