reproduction - 1 men Flashcards
1
Q
what is the role of the seminiferous tubules
A
produce spern
2
Q
when does spermatogenesis begin
A
puberty
3
Q
what is the role of leydig cells
A
secrete testosterone
4
Q
what is the role of sertoli cells
A
support sperm development
5
Q
what are myoid cells
A
smooth muscles that do peristalsis to propel sperm
6
Q
what is the blood testis barrier
A
tight junctions between the luminal and basal compartment
7
Q
which cells are the epithelial cells
A
sertoli cells
8
Q
which cells are the interstitial cells
A
leydig cells
9
Q
what is the trophic role of sertoli cells
A
support sperm development
10
Q
what do sertoli cells secrete (3)
A
- luminal fluid for sperm housing
- androgen binding protein
- inhibin
11
Q
what do androgen binding proteins do (2)
A
buffer androgens and help maintain steady [androgens] in lumen
12
Q
which hormones are sertoli cells a target for
A
testosterone and FSH
13
Q
what is inhibin
A
hormone of negative feedback loop for FSH
14
Q
who secretes inhibin
A
sertoli cells
15
Q
where is old and damaged sperm phagocytized
A
sertoli cells
16
Q
where is the site of immunosupression
A
sertoli cells (blood testis barrier)
17
Q
what are 2 roles of the gonads
A
production of sperms and hormones
18
Q
what is the role of the scrotum
A
temperature regulation
19
Q
what are 2 roles of the epididymis
A
maturation of sperm
storage site for sperm
20
Q
what are 2 roles of the vas deferens
A
channel
storage site for sperm
21
Q
what is the role of the accessory sex glands
A
production of seminal fluid
22
Q
what is the precursor for steroid hormones
A
cholesterol
23
Q
is progesterone found in males or females
A
both
24
Q
are corticosteroids slow or fast acting
A
slow
25
which cells are under influence of LH
leydig cells
26
what causes the descent of the testes
high levels of testosterone
27
when do the testes descent
7 months (before birth)
28
is testosterone or adrenal androgens more potent
testosterone
29
what are 4 fates of testosterone
-stays as T
-becomes E
becomes inactive
-becomes DHT
30
what does DHT do
helps with maintaing healthy prostate gland
31
how potent is DHT
very
32
what stage in life are men able to reproduce
puberty
33
how many peaks of testosterone through a mens life & when
- 2nd trimester
- neonatal (differentiation)
- puberty (descends till death)
34
where is GnRH released from
hypothalamus
35
where does GnRH act
anterior pituitary
36
where is LH produced
anterior pituitary
37
what causes LH production
GnRH acting at the anterior pituitary
38
what causes FSH production
GnRH acting at the anterior pituitary
39
where is FSH produced
anterior pituitary
40
where does LH act
leydig cells
41
where does FSH act
sertoli cells
42
what happens when LH activates leydig cells
testosterone is released
43
what causes 2ary male sexual characteristics
testosterone release from leydig cells
44
where can testosterone negative feedback
on anterior pituitary (desensitive to GnRH) and hypothalamus
45
what was the patten of GnRH release before puberty
slow and steady release
46
what was the patten of GnRH release in puberty
major pulses with higher amplitude and frequency
47
what is an anabolic effect of androgens
promote protein synthesis in skeletal muscles
48
what do androgens do to spermatogenesis
stimulate
49
what do androgens do to 2ary characteristics
promote
50
what do androgens do to sex drive
increase
51
what do androgens do to growth hormone secretion
increase
52
what do androgens do to erythropoietin
testosterone increases it (men have more RBC than women)
53
where does spermatogenesis occur
seminiferous tubule
54
how long does it take from meiosis 1 until you have spermatozoa
64 days
55
what is the purpose of mitosis in spermatogenesis
ensures continous supply of spermatogonia
56
what are spermatogonia
the ones going through mitosis and differentiation
57
what happens to chromosome number in meiosis in spermatogenesis
chromosome number becomes half
58
what is differentiation and packaging in spermatogenesis
specialization for transport and delivery of proper genetic material
59
where does spermatogenesis start (where are spermatogonia)
in the basement membrane
60
which direction does spermatogenesis continue
towards the lumen
61
where does spermatogenesis happen (specific)
between the space between adjacent sertoli cells
62
what is spermiogenesis
how spermatid develop into a complete spermatozooa
63
what is the difference with spermatogenesis and spermiogenesis
spermiogenesis is the last step of spermatogenesis
64
how long does spermiogenesis take
24 days
65
what happens in spermiogenesis
structural changes, it sheds cytoplasm, gets tail, makes a mitochondrial spiral
66
what are the three structures in the sperm
head
midpiece
tail
67
what is in the head of the sperm
nucleus and chromosomes
| acrosome
68
what are acrosomes
enzymes that are necessary for fertilization
69
what is in the midpiece of the sperm
mitochrondia - energy source
70
what is in the tail of the sperm
what makes the wavelike(not mature) and whiplike(fully mature) movements
71
what is the name of the sperm after spermiogenesis
spermatozoa
72
what happens to the spermatozoa after they are made
they are released into the lumen of seminiferous tubules and stay immotile for 20 days
73
what causes the sperm to move to the epididymis
pressure generated by the fluid secreted from sertoli cells
74
how long do sperm stay in the epididymis
6-12 days
75
what happens to sperm in the epididymis (2)
aquire wave-like movement/motility
| -fluid is reabsorbed to concentrate sperm
76
how do sperm move into vas deferens
peristalsis
77
what does FSH do
stimulates gametogenesis
78
what does LH do
stimulates androgen secretion
79
who creates the pulse generation of GnRH
the hypothalamus
80
where does GnRH act
anterior pituitary
81
what two hormones are released from the anterior pituitary in response to GnRH
LH and FSH
82
how do sertoli cells do negative feedback
release inhibin onto the anterior pituitary
83
can inhibin act on the hypothalamus
no
84
can testosterone act on the hypothalamus
Yes
85
how do leydig cells do negative feedback
release testosterone which acts on the anterior pituitary and the hypothalamus
86
what is the frequency of pulses of GnRH in men
90 mins
87
does testosterone act on sertoli cells
yes and it causes a secretion of paracrine factors that stimulate spermatogenesis
88
what happens when testosterone and FSH act on sertoli cells
they secrete paracrine factors that stimulate spermatogenesis
89
what kind of a hormone is FSH LH and TSH
glycoproteins
90
how does the prostate gland release its secretions
it has tiny holes that gives out its secretion
91
what are the 3 functions of seminal fluid
dilution of sperm
fructose for energy
make semen clot
92
what % of semen volume is seminal fluid
60%
93
what makes the semen clot
semenogelin is a protein
94
what is the point of a semen clot
to help deposit semen into the female tract
95
sperm + seminal fluid = ?
semen
96
what do the seminal vesicles secrete
alkaline fluid witth fructose, enzymes and prostaglandins
97
what do the prostaglandins from the seminal vesicle cause
they stimulate uterine contractions
98
what does the prostate gland secrete
citrate and enzymes (PSA)
99
what is PSA
prostate specific androgen - antioxidant to help sperm survive and to dissolve the clot so sperm can swim away freeeeely
100
where is PSA released from
prostate gland
101
what does high levels of PSA mean
either prostate cancer or a benign growth
102
what do the bulbourethral glands secrete
viscous fluid with mucus
103
what nervous system does erection
parasympathetic
104
what nervous system does emission
sympathetic nervous system
105
how does the nervous system do emission
sympathetic stimulation to the smooth muscles of the ducts
106
what kind of nervous system is involved in ejaculation
somatic nervous system control
107
what happens after the parasympathetic nerve is activated (erection pathway)
increased nitric oxide
108
what happens after nitrric oxide in increased
increase cGMP
109
where does nitric oxide and cGMP act
on smooth muscle
110
what happens with increased cGMP
vasodilation, increased blood flow and erection
111
how is cGMP broken down
by phosphodiesterase
112
what does cGMP break down into
inactive product (doesnt make erection)
113
what does sildenafil do
it inhibits phosphodiesterase so then cGMP remains to keep erection
114
what causes erections to stop in men (unwanted)
cGMP is broken down by phosphodiesterase
115
what accounts for the low number of sperm to reach the site of fertilization
high acidity and not all of them have enough energy
116
what is capacitation
changes in sperm head and tail
117
why must sperm go through capacitation
sperm must go through this to be able to fertilize
118
what happens to the head in capacitation
destabilization of sperm surface membrane
119
what happens to the tail in capacitation
wavelength movement becomes a whiplike movement
120
when does the acrosome reaction happen
after capacitation
121
what happens in the acrosome reaction
the membrane opens up and releases the acrosomal enzymes
122
how many sperm are produced per day
30 000 000 sperm/day
123
which hormone works on the male internal genitalia before birth
testosterone
124
which hormone works on the male external genitalia before birth
DHT
