Male Reproductive System Flashcards
(180 cards)
1
Q
What are the primary sex organs?
A
Testes and ovaries
2
Q
What is another name for primary sex organs?
A
Gonads
3
Q
What is the function of the primary sex organs?
A
Produce gametes and secrete steroid sex hormones
4
Q
What are gametes?
A
Sex cells
5
Q
What are the steroid sex hormones?
A
Androgens (male); estrogens and progesterone (female)
6
Q
What are the accessory reproductive organs?
A
Ducts, glands, and external genitalia
7
Q
Where are the testes located? What do they produce?
A
Within the scrotum; produce sperm
8
Q
How is sperm delivered to exterior?
A
Through a series of ducts: epididymis, ductus deferens, ejaculatory duct, urethra
9
Q
Where is the vas deferens located?
A
Inside the ductus deferens (like a straw)
10
Q
Hidden or undescended testes
A
Cryptorchidism
11
Q
Located outside of the body to cool sperm since it cannot be produced at body temperature
A
Scrotum
12
Q
What happens during vasectomy?
A
The ductus deferens is located and cut into, then vas deferens is cut/obstructed to prevent sperm from travelling through
13
Q
Sperm producing male gonads that lie within the scrotum
A
Testes
14
Q
What are the accessory sex glands?
A
Seminal glands, prostate, and bulbo-urethral (or Cowper’s) glands
15
Q
What are the two sets of analogous male/female tissues/structures?
A
Penis and clitoris; scrotum and labia
16
Q
Sac of skin and superficial fascia that hangs outside abdominopelvic cavity; contains paired testes
A
Scrotum
17
Q
What temperature is the scrotum kept at?
A
3 degrees Celsius lower than core body temp
18
Q
What divides scrotum into 2 compartments (one for each testis)? How many lobules/seminiferous tubules present?
A
Midline septum; divides each testis into ~250 lobules, each containing 1-4 seminiferous tubules
19
Q
What are the sets of muscles (2) that keep scrotal temperature constant?
A
Dartos muscle and cremaster muscle
20
Q
Smooth muscle that wrinkles scrotal skin and pulls scrotum closer to the body
A
Dartos muscle
21
Q
Bands of skeletal muscle that elevate testes
A
Cremaster muscle
22
Q
Which 2 tunics surround each testis?
A
Tunica vaginalis and tunica albuginea
23
Q
Outer tunic surrounding testis that is derived from peritoneum
A
Tunica vaginalis
24
Q
Inner tunic surrounding testis that forms fibrous capsule
A
Tunica albuginea
25
What is the site of sperm production?
Seminiferous tubules
26
Tubules that have thick, stratified epithelium surrounding central fluid-containing lumen; contains spheroid spermatogenic cells embedded in support cells
Seminiferous tubules
27
Sperm forming cells
Spermatogenic cells
28
Support cells
Sustenocytes
29
Cells that surround each seminiferous tubule; contains smooth muscle-like cells that may squeeze sperm and testicular fluids out of testes
Myoid cells
30
Tubules of each lobule converge to form the _____ tubule
Straight tubule
31
What is the passageway of sperm from the seminiferous tubules to storage site
Seminiferous tubule to straight tubule to rete testis to efferent ductules to epididymis to storage
32
What 3 parts make up the epididymis?
Head, body, and tail
33
Where is sperm stored until ejaculation?
In the tail of the epididymis
34
Cells located in the soft tissue surrounding the seminiferous tubules
Interstitial endocrine cells
35
What do the interstitial endocrine cells produce/secrete?
Produce androgens, such as testosterone; secretes androgens into interstitial fluids
36
What do testicular arteries arise from?
Abdominal aorta
37
What do testicular veins arise from? From where?
Pampiniform venous plexus surrounding each testicular artery
38
What does pampiniform venous plexus do?
Absorbs heat from testicular arteries to keep testes cool
39
Cord that encloses nerve fibers, blood vessels, and lymphatics that supply testes
Spermatic cord
40
Rare cancer that is most common in men ages 15-35
Testicular cancer
41
Signs of testicular cancer
Painless, solid mass found in testes
42
Risk factors for testicular cancer
Hx of mumps that lead to orchitis (inflammation of testis) and hx of cryptorchidism
43
Treatment for testicular cancer
90% cured by surgical removal of testis and often chemo/radiation
44
Male copulatory organ that consists of root and shaft, which ends in glans penis
Penis
45
What makes up the external genitalia
Penis and scrotum
46
What happens during an erection?
Erectile tissue fills with blood, causing penis to enlarge and become rigid
47
Foreskin of penis; cuff of loose skin covering glans penis
Prepuce
48
Surgical removal of foreskin
Circumcision
49
What are the benefits of circumcision?
Reduction of HIV risk; reduced risk for reproductive infections
50
How common is circumcision?
60% of males in US are circumcised, but only 15% in rest of world population
51
What makes up the penis internally?
Spongy urethra and 3 cylindrical bodies of erectile tissue, spongy network of connective tissue, and smooth muscle with vascular spaces
52
Surrounds urethra and expands to form glans penis and bulb
Corpus spongiosum
53
Paired dorsal erectile bodies
Corpora cavernosa
54
Proximal ends of corpora cavernosa surrounded by ischiocavernous muscle
Crura
55
What is the function of crura?
Anchors penis to pelvic arch
56
Diamond-shaped region between pubic symphysis, coccyx, and ischial tuberosities
Male perineum
57
What does the male perineum contain?
Root of penis and anus
58
What is the function of male perineum?
Suspends scrotum
59
What does head of epididymis contain? Where is it located?
Efferent ductules; located on superior aspect of testis
60
Where is body and tail of epididymis located?
On posterolateral area of testis
61
How long is duct of epididymis?
~6 cm in length
62
_______ (or ______) absorb testicular fluid and pass nutrients to stored sperm
Microvilli (stereocilia)
63
What happens to sperm in epididymis? How long does sperm remain there?
Nonmotile sperm enter, pass slowly through, and then become motile; passes over ~20 days, but can be stored for several months
64
What happens to sperm during ejaculation?
Epididymis contracts, expelling sperm into ductus deferens
65
How long is the vas deferens/ductus deferens? What does it pass through and expand to form?
~45 cm long; passes through inguinal canal to pelvic cavity; expands to form ampulla
66
What forms the ejaculatory duct?
Ductus deferens joins duct of seminal vesicle
67
Cutting and ligating of ductus deferens; almost 100% effective form of birth control
Vasectomy
68
What propels sperm from epididymis to urethra?
Smooth muscle is walls of ductus deferens
69
Conveys both semen and urine, but at different times
Urethra
70
What are the 3 regions of male urethra?
Prostatic urethra, intermediate part (membranous) urethra, and spongy urethra
71
Male urethra surrounded by prostate
Prostatic urethra
72
Male urethra present in urogenital diaphragm
Intermediate part (membranous urethra)
73
Male urethra that runs through penis; opens at external urethral orifice
Spongy urethra
74
Where are the seminal glands located?
On posterior bladder surface
75
What is the function of seminal glands?
They contain smooth muscle that contracts during ejaculation and produce viscous alkaline seminal fluid
76
What is contained in seminal fluid?
Fructose, citric acid, coagulating enzyme (vesiculase), and prostaglandins
77
What causes seminal fluid to fluoresce with UV light?
Yellow pigment
78
How much of semen is made up of seminal fluid?
70%
79
Organ that is the size of a peach pit and encircles urethra inferior to bladder
Prostate
80
What does the prostate consist of?
Smooth muscle that contracts during ejaculation
81
What does the prostate secrete?
Milky, slightly acidic fluid that contains citrate, enzymes, and prostate-specific antigen (PSA) that enters prostatic urethra during ejaculation
82
What does the prostate do?
Plays a role in sperm activation and makes up 1/3 of semen volume
83
Bacterial infection of the prostate that can be acute or chronic; treated with Abx
Prostatitis
84
What is most common form of prostatitis?
Chronic or pelvic pain syndrome
85
What are the 2 types of chronic prostatitis?
Inflammatory (UTI symptoms, pain in external genitalia and low back, WBCs in urine); non-inflammatory (same as inflammatory except no WBCs/bacteria in urine)
86
What is benign prostatic hyperplasia (BPH)?
Disorder that distorts urethra and may be age-related
87
Treatment of BPH
Can be treated with surgery; newer options available: microwave/drugs to shrink prostate, balloon compression, or radio-frequency radiation
88
What is the second most common cause of cancer deaths in males?
Prostate cancer
89
How is prostate cancer detected?
Digital exam screening and PSA levels; biopsy if abnormal
90
Tx of prostate cancer
Tx with surgery and sometimes radiation, castration, or drugs; in clinical trials: cryosurgery, chemo, ultrasound, and proton beam therapy
91
Pea-sized glands inferior to prostate, which produce thick, clear mucus during sexual arousal
Bulbo-urethral (or Cowper's) glands
92
What is the function of secretions from bulbo-urethral glands?
Lubricates glans penis and neutralizes traces of acidic urine in urethra
93
Milky white mixture of sperm and accessory gland secretions
Semen
94
How much semen ejaculated? How much sperm contained in 1 mL of semen?
2-5mL semen; 20-150 million sperm per mL
95
What does sperm contain?
Fructose for ATP production, protects and activates sperm, and facilitates sperm movement
96
What does the alkalinity of semen do?
Neutralizes acidity of the male urethra and female vagina; enhances sperm motility
97
What are the characteristics (what does it contain) of semen?
Prostaglandins, hormone relaxin and other enzymes to enhance sperm motility, ATP for energy, antibiotic chemicals, and clotting factors
98
What do prostaglandins in semen do?
Decrease viscosity of mucus in cervix and stimulates reverse peristalsis in uterus
99
Semen can _______ female immune response
Suppress
100
What do antibiotic chemicals present in semen do?
Destroy some bacteria
101
What do clotting factors in semen do?
Coagulate semen initially to prevent draining out, then liquefy it by fibrinolysin so sperm can finish journey
102
What happens during male sexual excitement?
Causes CNS activation of parasympathetic neurons, which releases nitric oxide (NO)
103
What does nitric oxide (NO) cause?
Causes relaxation of local vascular smooth muscle, which causes arterioles to dilate
104
Arterioles are normally ______ in absence of male sexual excitement
Constricted
105
The _________ expands and retards venous drainage leading to engorgement of erectile tissues with blood and enlargement/stiffening of penis
Corpora cavernosa
106
What initiates male sexual response?
Initiated by sexual stimuli, such as touch, mechanical stimulation, erotic sights/sounds/smells; can be induced or inhibited by emotions or higher mental activity
107
What fibers around penis prevent kinking/buckling of erect penis?
Longitudinal and circular fibers
108
What keeps urethra open during erection?
Corpus spongiosum
109
Propulsion of semen from male duct system
Ejaculation
110
What happens during the sympathetic spinal reflex?
1. bladder sphincter muscle constricts
2. ducts and accessory glands contract
3. bulbospongiosus muscles undergo rapid series of contractions
111
What is the purpose of bladder sphincter muscle contracting during ejaculation?
To prevent expulsion of urine
112
What is caused by bulbospongiosus muscles undergoing rapid series of contractions during ejaculation?
Causes expulsion of semen at ~500 cm/s (close to 11 mph)
113
What is ejaculatory event called?
Climax (or orgasm)
114
Production of sperm (spermatozoa) in seminiferous tubules
Spermatogenesis
115
Most body cells have ______ chromosomes
46 chromosomes
116
Most body cells have ___ sets of ____ chromosomes
2; 23
117
What is contained in the 2 pairs of 23 sets of chromosomes?
1 maternal set and 1 paternal set; homologous chromosomes referred to as diploid chromosomal number (2n)
118
Games only have ____ chromosomes
23
119
What is contained in the 23 chromosomes of gametes?
haploid chromosomal number (n); only 1 member of homologous pair
120
______ formation involves meiosis, which differs from mitosis
Gamete formation
121
What does meiosis involve?
Involves 2 consecutive cell divisions (meiosis 1 & 2), but only one round of DNA replication, which produces 4 daughter cells
122
What are the functions of meiosis?
1. number of chromosomes are cut in half (2n to n)
| 2. introduces genetic diversity, as all daughter cells are genetically different from original cells
123
What are the effects of testosterone?
1. masculinizes embryonic brain
| 2. continues to exert effect well into adulthood
124
Reduces number of chromosomes from 2n to n during meiosis 1
reduction division of meiosis
125
_________ has events not seen in mitosis or meiosis II
prophase I
126
What events are present in prophase I that are not seen in mitosis or meiosis II?
1. Synapsis
| 2. Crossover (chiasmata)
127
Homologous chromosomes pair up forming tetrads during ______
Synapsis
128
______ consist of 4 chromatids
Tetrads
129
_______ is the exchange of genetic material between male and female chromotids
crossover (or chiasmata)
130
What does crossover during prophase I result in?
Results in unique chromosomes that are mixtures of maternal and paternal chromosomes
131
What happens to tetrads during metaphase I?
Tetrads line up randomly at spindle of equator
132
What happens to sister chromatids during anaphase I?
Sister chromatids of one homologous chromosome are separated from sister chromatids of other
133
What does each daughter cell have at end of meiosis I?
1. 2 copies (sister chromatids) of one member of each homologous pair (either maternal or paternal) and none of the other
2. haploid chromosomal # because still-united sister chromatids are considered one chromosomes (twice amount of DNA in each chromosome)
134
______ cells give rise to sperm
Spermatogenic cells
135
Where does spermatogenesis occur?
Occurs in seminiferous tubules of testis
136
What 2 important tasks does meiosis 1 accomplish?
1. reduces chromosomal # by half
| 2. introduces genetic variability
137
How does meiosis 1 introduce genetic variability?
1. Random alignment of homologous pairs in meiosis 1 leads to variability of gametes
2. Crossover ensures variability of gametes
138
_________ results in no 2 gametes being exactly alike; all are different from original mother cells
Meiosis I
139
What is another way to describe meiosis II?
Equational division of meiosis
140
What is different about meiosis II when compared to mitosis?
Events are similar to mitosis, except there is no chromosome replication before process begins
141
What happens to sister chromatids during meiosis II?
Sister chromatids from meiosis I are separated and pulled toward opposite poles, which results in one per cell
142
What are the 3 steps of spermatogenesis?
1. Mitosis of spermatogonia (stem cell)
2. Meiosis
3. Spermiogenesis
143
What happens during mitosis of spermatogonia?
Forms 2 spermatocytes
144
What happens during meiosis during spermatogenesis?
Spermatocytes form secondary spermatocytes, which form spermatids
145
What happens to spermatids during spermiogenesis?
spermatids become sperm
146
When does spermatogenesis begin?
At puberty
147
Stem cells that are in contact with epithelial basal lamina
Spermatogonia
148
What does each mitotic division yield during spermatogenesis?
1 type A daughter cell and 1 type B daughter cell
149
What does type A daughter cell maintain?
Maintains germ cell line at basal lamina
150
What happens to type B daughter cells?
Move toward lumen and develop into primary spermatocytes
151
What happens to primary spermatocyte during meiosis I?
Primary spermatocyte (2n) undergoes meiosis I, forming 2 secondary spermatocytes (n)
152
What happens to secondary spermatocyte during meiosis II?
Each secondary spermatocyte (n) rapidly undergoes meiosis II to become 2 spermatids
153
Small, non-motile cells found close to lumen of tubule
Spermatids
154
What do spermatids contain?
Contain correct haploid chromosome number needed for fertilization (n)
155
Streamlining process where spermatids elongate, lose excess cytoplasm, and form a tail to become sperm
Spermiogenesis
156
What is another name for a sperm?
Spermatozoon
157
What are the 3 major regions of sperm?
Head, midpiece, and tail
158
Genetic region of sperm that includes a nucleus and helmet-like acrosome containing hydrolytic enzymes that enable sperm to penetrate egg
Head
159
an organelle that develops over the anterior half of the head in the spermatozoa; cap-like structure
acrosome
160
metabolic region of sperm containing mitochondria that produce ATP to move tail
midpiece
161
How long does spermatogenesis take if conditions are hospitable?
64-72 hours
162
Locomotor region of sperm that contains flagellum
Tail
163
Large supporting cells that extend through wall of tubule and surround developing cells
Sustenocytes
164
What is another name for sustenocytes?
Sertoli cells
165
What is the role of sustenocytes?
1. provide nutrients and signals to dividing cells
2. move cells along to lumen
3. secrete testicular fluid into lumen for sperm transport
4. phagocytize fault germ cells and excess cytoplasm
5. produce chemical mediators to regulate spermatogenesis
166
What do sustenocytes contain?
Contain tight junctions that divide tubule into 2 compartments
167
What are the 2 compartments that tubules are divided into?
1. basal compartment
| 2. adluminal compartment
168
Area where spermatogonia and primary spermatocytes are located
basal compartment
169
Area where meiotically active cells and tubule lumen are located
adluminal compartment
170
What forms the blood testis barrier?
Tight junctions
171
Prevents sperm antigens from escaping into blood and activation of immune system
Blood testis barrier
172
Why is blood testis barrier needed?
sperm is not formed until puberty so it is absent during immune system development; results in sperm not being recognized as "self" so must be kept separated from rest of body to prevent being attacked by immune system
173
How are sperm moved when they are non-motile and unable to swim?
Pressure of testicular fluid pushes immotile sperm into epididymis, where they gain motility and fertilizing power
174
What does testosterone deficiency lead to?
Atrophy of accessory organs; semen volume declines; erection/ejaculation are impaired
175
Treatment of testosterone deficiency
testosterone replacements
176
What is the mechanism of effects of testosterone activity?
1. testosterone, synthesized from cholesterol, is transformed at some target cells
2. converted to dihydrotestosterone, or DHT, in prostate and estradiol in some brain neurons
3. prompts spermatogenesis and targets all accessory organs
4. has multiple anabolic effects throughout body
177
Features induced in nonreproductive organs by male sex hormones (mostly testosterone)
male secondary sex characteristics
178
What are the male secondary sex characteristics?
1. appearance of pubic, axillary, and facial hair
2. enhanced growth of chest hair
3. deepening of voice
4. skin thickens and becomes oily
5. bones grow and increase in density
6. skeletal muscles increase in size and mass
7. boosts basal metabolic rate
8. is basis of sex drive (libido) in males
179
Testosterone ______ embryonic brain and continues to exert effect well into adulthood
Masculinizes
180
Although ______ glands also produce androgens in small amounts, production is insufficient to maintain normal testosterone-mediated functions
adrenal glands
