BIOL 1260: male reproduction Flashcards
1
Q
function of the testes
A
producing sperm and certain hormones
2
Q
function of the ducts system
A
to transport and store sperm
3
Q
4 ducts
A
epididymis, ductus deferens, ejaculatory ducts, and urethra
4
Q
3 accessory sex glands
A
seminal vesicles, prostate gland, and bulbourethral gland
5
Q
function of accessory sex glands
A
to create secretions and connect to the ducts
6
Q
supporting structures
A
scrotum and penis
7
Q
scrotum anatomy
A
consists of loose skin and an underlying subcutaneous tissue; is separated into lateral portions by the raphe and the scrotal septum
8
Q
function of the scrotum
A
to protect the testes
9
Q
scrotal spetum
A
separates the testes as each sac holds one of the two testes
10
Q
dartos muscle
A
found in the scrotal septum
11
Q
cremaster muscle
A
small bands of skeletal muscle that are extensions of the internal obliques; is contained within the spermatic cord
12
Q
spermatic cord
A
contains vessels, nerves, muscles, and the vas deferens and is an extension of the peritoneum
13
Q
sperm production temperature
A
should be 2 degrees lower than body temperature, therefore testis are held outside of the body
14
Q
scrotum and temperature regulation
A
when it is cold, the cremaster muscle and the dartos muscle contract, pulling the testes closer to the body and vise versa when it is warm
15
Q
muscles of the testis
A
cremaster muscle and dartos muscle
16
Q
embryonic development of the testis
A
develop near the kidneys and descend into the scrotum through the inguinal canals near the 7th or 8th month of pregnancy
17
Q
outside layer of the testis
A
the tunica vaginalis
18
Q
the tunica vaginalis
A
is a serous membrane derived from the peritoneum and has two layers (visceral and parietal layers)
19
Q
tunica albuginea
A
is a white fibrous capsule that consists of dense irregular CT and projects inwards to divide the internal parts of the tests into lobules; is deep to the tunica vaginalis
20
Q
what are deep to the tunica albuginea?
A
the seminiferous tubules
21
Q
where is sperm produced?
A
the seminiferous tubules
22
Q
two cells that make up the seminiferous tubules
A
the spermatogenic cells and sustentacular cells
23
Q
another name for sustentacular cells
A
sertoli cells
24
Q
spermatogenic cells deeper in the testis
A
are in more developed stages
25
stem cells for sperm
spermatogonia
26
where do spermatogonia come from?
the primordial germ cells from the yolk sac
27
order of development for spermatogenesis
PGCs, spermatogonia, primary spermatocytes, secondary spermatocytes, spermatid and sperm cells
28
sustentacular cells location
fill in the spaces between the sperm cells and connect to one another via tight junctions; are found in the seminiferous tubules
29
blood-testis barrier
is created by the sustentacular cells and isolate sperm from the blood
30
why does sperm need to be isolated from the blood?
because the body recognizes sperm as foreign thus the immune system will attack
31
sustentacular cell functions (7)
establish the blood-testis barrier, nourish the spermatocytes, phagocyte excess spermatid cytoplasm during development, control the release of sperm into the tubules, produce a fluid for sperm transport, secrete inhibin, and regulate the effects of testosterone and FSH
32
interstitial cells other name
leydig cells
33
interstitial cells location
found in the spaces between adjacent seminiferous tubules and are often found in clusters
34
function of interstitial cells
produce testerone
35
function of testerone
is responsible for the male sex drive and male sex characteristics
36
where and what does spermatogenesis begin with?
in the yolk sac by the primordial germ cells that migrate to the testis
37
spermatogonia
male gametes and these are sperm stem cells and are diploid
38
seminal vesicles location
close to the ampulla of the vas deferens and sit on top of the prostate, at the base of the bladder, and anterior to the rectum
39
seminal vesicles secretions
fructose, prostaglandins, clotting proteins, and alkaline secretions
40
function of fructose from seminal vesicle secretion
is used for ATP production
41
function of prostaglandins from seminal vesicle secretions
contribute to sperm motility and smooth muscle in the female reproductive tract (to move the sperm up)
42
function of clotting proteins in seminal vesicle secretion
is not fully understood but they clot within 5 minutes of ejaculation and these are different than normal blood clotting proteins
43
function of alkaline secretions in semen
protects from the acidic urethra and female tract, and functions to neutralize these areas
44
how much of semen do seminal vesicles make up?
60%
45
prostate location
surrounds the prostatic urethra and is inferior to the bladder
46
prostate secretions
citric acid, proteolytic enzymes, acid phosphatase, and seminalplasmin
47
function of citric acid in prostate secretions
is an energy source for sperm ATP
48
proteolytic enzymes function in prostate secretions
includes pepsingone, lysozyme, amylase, hyaluronidase, and prostate specific antigen, and these all function to break down the clotting factors from the seminal vesicles but have a delayed effect
49
seminalplasmin function in prostate secretions
is an antibiotics that destroys bacteria and vaginal flora
50
where do prostatic secretions drain into?
the prostatic urethra
51
how much of semen do prostate secretions make?
about 25%
52
bulbourethral glands other name
cowper's glands
53
bulbourethral glands location
on either side of the membranous urethra and below the prostate
54
where do the bulbourethral glands drain into?
the membranous urethra
55
bulbourethral glands secretions
alkaline fluid and mucus
56
function of mucus from bulbourethral glands secretions
lubricates the urethral lumen and the end of the penis during intercourse
57
how many sperm per mL of semen?
50-150 million
58
what is the cutoff rate for male infertility?
less than 20 million sperm/mL
59
characteristics of semen
alkaline, sticky (due to fructose), and milky (due to prostatic secretions)
60
how much semen per ejaculation?
2-5 mL
61
capacitation
is a process that occurs in the uterus or uterine tubes in which sperm are affected by these secretions
62
purpose of seminal fluid
to provide a transport medium for sperm, to provide nutrients for sperm to survive outside of the body, and to provide chemical protection from the urethra and acidic female tract
63
how are sperm ejected from the seminiferous tubules?
by pressure created by the sustentacular cells
64
where is sperm made?
in the lumen of the seminiferous tubules
65
what do the seminiferous tubules feed into?
the straight tubules?
66
what do the straight tubules feed into?
the rete testis
67
what do the rete testis feed into?
the efferent duct
68
what do the efferent ducts feed into?
the ductus epididymis
69
order of ducts starting at the seminiferous tubules
seminiferous tubules > straight tubules > rete testis > efferent ducts > ductus epididymis
70
epididymis location
is a comma shaped organ that lies along the posterior border of each testis and is about 6 cm long
71
3 regions of the epididymis
the head, the body, and the tail
72
anatomy of the ductus epididymis
is pseudostratified columnar epithelium; apical surfaces are lined with stereocilia; it is encircled by layers of smooth muscle, and has CT surrounding this layer that contains vessels and nerves
73
sterocilli
are microvilli not cilia and are actin based structures; these increase the surface area for reabsorption and degeneration of sperm
74
functions of the ductus epididymis (4)
site of sperm maturation, helps to propel to sperm into ductus deferens during arousal due to smooth muscle peristalsis, keeps sperm alive, and reabsorbs non-ejaculated stored sperm
75
ductus deferens location
lies on the posterior border of the epididymis and passes through the spermatic cord, loops over the ureter and passes through the posterior surface of the bladder
76
length of ductus deferens
45 cm
77
ampulla of ductus deferens
is the terminal and thicker end
78
anatomy of the ductus deferens
pseudostratified columnar epithelium, surrounded by a lamina propria, 3 layers of smooth muscle (inner long, middle circular, outer long), and an adventitia
79
functions of the ductus deferens (3)
convery sperm during sexual arousal from the epididymis to the urethra via peristalsis, stores sperm, and absorbed unused sperm
80
where does the spermatic cord pass through?
the inguinal canal
81
the inguinal canal
is an oblique passageway in the anterior part of the abdominal all that is superior and parallel to the inguinal ligament
82
where does the inguinal canal originate?
at the deep inguinal ring
83
ejaculatory duct
is the merging point between the seminal vesicle and the ampulla of the vas deferens that is located superior to the base of the prostate; this then delivers to the urethra
84
male urethra
is a passageway for sperm and urine and passes through the deep muscles of the perineum and the penis
85
3 parts of the male urethra
prostatic, intermediate, and spongy
86
prostatic urethra
is 2-3 long and passes through the prostate
87
intermediate urethra
is 1 cm long and passes through the deep muscles of the perineum
88
spongy urethra
is 15-20 cm long and passes through the corpus spongiosum of the penis and terminates at the external urethral orifice
89
head of the sperm
contains the acrosome and the nucleus
90
acrosome
is the head of the sperm and contains enzymes that help the sperm penetrate an oocyte during fertilization
91
enzymes found in the acrosome
hyaluronidase and protease
92
tail of the sperm four parts
neck, middle piece, principal piece, and end piece
93
neck of the sperm tail
contains the structures needed to start building the flagella
94
middle piece of the sperm tail
is where the mitochondria and found and this ATP helps to make the flagella 'swim'
95
principal piece of the sperm tail
the longest part and is the flagella and its surrounding membrane
96
end piece of the sperm tail
the terminal part where the tail tappers off
97
how many sperm does a man produce a day
300 million
98
how long can sperm live for outside of the body?
48 hours
99
when is GnRH secreted?
beginning at puberty
100
effect of GnRH
released from the hypothalamus and goes to the anterior pituitary to release FSH and LH
101
FSH function
activates the sustentacular cells, which work with testosterone to make androgen binding hormone
102
LH function
stimulates the interstitial cells to produce testosterone due to the accumulation of cholesterol in the testes
103
negative feedback loop of testerone
when there are high levels of testerone, this will inhibit LH production and GnRH production (decreased LH will decrease testosterone production from the interstitial cells); inhibin is also released from the sustentacular cells and inhibits FSH release
104
where is inhibin released from?
the sustentacular cells
105
similar hormone to testosterone
dihydrotestosterone; there is an enzyme that will convert between these two and these both bind to the same cytoplasmic receptors
106
function of testosterone or dihydrotesterone inside the cell
these causes transcription of the genes of the cells
107
testerone before birth
will stimulate the male reproductive ducts and the descent of the testis
108
dihydrotesterone before birth
will stimulate the development of the external genitals
109
testosterone and estrogen
testerone will be converted into estrogen in the brain and this functions for development of certain brain regions
110
testosterone at puberty
will contribute to the enlargement of male sex organs and secondary sex characteristics, as well as sex drive
111
male secondary sex characteristics
broader shoulders (due to the stimulation of anabolism and protein synthesis), thicker skin, increased sebaceous gland activity, more hair, and deeper voice
112
female androgens
are produced in the adrenal cortex
113
spermatogenesis
is the whole process of creating sperm
114
spermiogenesis
is a small subset of changes that happens at the end when the spermatids develop into sperm cells
115
spermination
is the subset of spermatogenesis in which the newly formed sperm cells detach from one another and are free
116
what do spermatogonia produce?
2 diploid spermatogonia in which one stays nears the basement membrane and remains undifferentiated and one that breaks off to make it near the tubule, and this will form a primary spermatocyte
117
primary spermatocyte
is formed from mitosis of a spermatogonia and is diploid; this will undergo meiosis I to form a secondary spermatocyte
118
secondary spermatocyte
are haploid and formed by meiosis I of primary spermatocytes; these will then undergo meiosis II
119
result of meiosis II
4 haploid cells called spermatids that are connected by bridges called cytoplasmic bridges
120
cytoplasmic bridges
connect sperm in various stages of development and function to allow the sperm production to be synchronized as only half of the cells have the X chromosome
121
hydrocele
is the serous fluid in the tunica vaginalis layer that develops between the two layers of this structure; this can accumulate during injuries
122
lobules
are formed by inward extensions of the tunica albuginea and each lobule houses a system of seminiferous tubules
123
how do interstitial cells produce testosterone?
via an accumulation of cholesterol in the testes
124
function of androgen binding hormone
binds to testosterone to keep these levels as high as possible; these high levels allow spermatogenesis to finish
125
where does androgen binding hormone accumulate?
in the seminiferous tubules
126
what does inhibin mainly act of?
FSH release from the anterior pituitary
127
