Chapter 27 Flashcards
1
Q
Sexual reproduction is biparental, meaning offspring receives genes from__
A
two parents
2
Q
is offspring genetically identical too either parent?
A
no
3
Q
what are sex cells called
A
gametes
4
Q
gametes are produced by each parent and contain
A
their genetic information
5
Q
what are the male and female gametes
A
sperm (spermatozoon) and egg (ovum)
6
Q
gametes combine to form a
A
zygote
7
Q
what is another name for a fertilized egg
A
zygote
8
Q
Our cells contain ___ pairs of chromosomes
A
23
9
Q
__ pairs of autosomes
A
22
10
Q
_ pairs of sex chromosomes
A
1
11
Q
the chromosomes are __ for male and __ for female
A
XY, XX
12
Q
Males produce 1/2 __ carrying sperm and 1/2 __ carrying sperm
A
Y, X
13
Q
all eggs cary the __ chromosome
A
X
14
Q
the sex of the child is determined but he type of __
A
sperm that fertilizes the egg
15
Q
what are autosomes
A
chromosomes that are not your sex chromosomes
16
Q
what are the functions of the male reproductive system
A
produce sperm and introduce sperm into the female body
17
Q
what are the functions of the female reproductive system,
A
- produces eggs
- receives sperm
- provides for gametes’ union
- harbors fetus
- nourishes offspring
18
Q
what is another name for the primary sex organs
A
gonads
19
Q
what do the primary sex organs do
A
produce gamete
20
Q
what are the primary sex organs of the male and females
A
testes and ovaries
21
Q
what are secondary sex organs
A
organs other than gonads that are necessary for reproduction
22
Q
what are the secondary sex organs for males
A
system of ducts, glands and penis
23
Q
what are the secondary sex organs for females
A
uterine tubes, uterus, and vagina receive sperm and harbor developing fetus
24
Q
what are some intersex conditions
A
Discrepancy between a person’s genotype and their external genitalia
Genotypic sex vs Phenotypic sex
25
what is the difference between genotypic and phenotypic sex
genotypic-chromosomes given during birth
| phenotypic- the appearance of one
26
what are the male external genitalia
penis and scrotum
27
what are the female external genitalia
1. mons pubis
2. labia majora
3. labia minora
4. clitoris
5. vaginal office
6. vestibular bulbs
7. vestibular glands
8. paraurethral glands
28
what are the male internal genitalia
1. testes
2. epididymides
3. ductus deferentes
4. seminal vesicles
5. prostate
6. bulbourethral glands
29
what are the female internal genitalia
1. ovaries
2. uterine tubes
3. uterus
4. vagina
30
what are the telltale signs of androgen-insensitivity syndrom
a girl will show all the signs of puberty but fails to menstruate
31
what causes androgen-insensitivity syndromn
1. presence of testes in the abdomen
2. Karyotype of XY chromosomes
3. Testes produce normal male levels of testosterone
4. Target cells lack receptors for it
5. No ovaries, uterus, vagina, or menstruation
32
what are secondary sex characteristics
features that appear as sexual maturity is approached and play a role in mate attraction
33
what are secondary sex characteristics of both sexes
Pubic and axillary hair and their associated scent glands, and the pitch of the voice
34
what is are the secondary sex characteristics of males
Facial hair, coarse and visible hair on the torso and limbs, relatively muscular physique
35
what are the secondary sex characteristics of females
Distribution of body fat, breast enlargement, and relatively hairless appearance of the skin
36
true or false: there is overlap between sexes in the secondary sex characteristics
true
37
true or false: Initially, a fetus is sexually undifferentiated
true
38
when do gonads begin to develop
5-6 weeks as gonadal ridges
39
there are __ sets of ducts adjacent to gonadal ridges
two
40
In males, __ ducts develop into reproductive tract; __ ducts degenerate
mesonephric, paramesonephric
41
In females, ___ducts develop into reproductive tract; ___ ducts degenerate
paramesonephric, mesonephric
42
the __ gene is only in males
SRY
43
what does SRY gene stand for
sex determining region of the Y chromosome
44
SRY codes for what protein
testes-determining factor
45
what does testes determining factor do
initiates development of testes
46
Testes begin to secrete testosterone at __ weeks stimulating the __ducts to develop into male tracts
8 to 9, mesonephric
47
at 8-9 weeks the testes secrete __ causing degeneration of the paramesonephric ducts
müllerian-inhibiting factor
48
true or false: estrogen levels lower in pregnancy
false, estrogen levels are always high win pregnancy
49
If estrogen was the hormone that directed female development, all fetuses would be
female
50
Female development of a fetus occurs whenever there is an absence of
androgen hormones
51
__ becomes the head (glans) of the penis or glans clitoris
Genital tubercle
52
Pair of __ encloses male urethra helping to form the penis or forms the labia minora
urogenital folds
53
Pair of __ becomes either scrotum or labia majora
labioscrotal folds
54
By week __, either male or female genitalia are distinctly formed
12
55
Male and female organs that develop from the same embryonic structure are __
homologous
56
Penis is homologous to the
clitoris
57
Scrotum is homologous to the
labia majora
58
Urogenital makes __ or body of penis
shaft
59
what does homologous mean
one structure is from the same embryonic structure
60
Gonads initially develop high in the__ and then migrate into the __ (ovaries) or scrotum (testes)
abdominal cavity, pelvic cavity
61
Descent of the testes begins as early as __ weeks
6
62
In seventh month, testes pass through the __ canal into the __ guided by the __
inguinal, scrotum, gubernaculum
63
Testes accompanied by __
1. elongating testicular arteries 2. veins
3. lymphatic vessels
4. nerves
5. spermatic ducts
6. extensions of internal abdominal oblique muscle
64
what is the term for undescended testes
Cryptorchidism
65
Cryptorchidism occurs in about __% of male births
3
66
in most cases of Cryptorchidism the testes descend within the first __ of infancy
year
67
what can aid in making the testes descend
testosterone injections or simple surgery
68
what can uncorrected cases cryptorchidism lead to
sterility or testicular cancer
69
the ovaries lodges on the __ of the lesser pelvis during descent
inferior brim
70
__ becomes a pair of ligaments that supports the ovary and the uterus
Gubernaculum
71
what is the perineum and what occupies it
diamond shaped area between the thighs, scrotum and penis
72
what is the scrotum
sac of skin, connective tissue and muscle that contains the testes
73
why do the human testes reside in the scrotum
because of its cooler environment
74
the __ testis is usually lower so they are not compressed
left
75
what is the spermatic cord
bundle of connective tissue, muscle, blood and lymphatic vessels, and nerves
76
Right testicular vein drains to
inferior vena cava
77
Left testicular vein drains into
left renal vein
78
what is the cremaster muscle and its functions
1. extension of internal abdominal oblique muscle
2. In cold temperatures, contracts and draws testes upward toward body
3. In warm temperatures, relaxes suspending testes further from body
79
what is the darts muscle made of and its functions
1. subcutaneous smooth muscle
2. Contracts when cold, wrinkling the scrotum, holding testes against warm body
3. Reduces surface area of the scrotum and heat loss
80
what is the pampiniform plexus and its functions
1. network of veins
| 2. Removes heat from the descending arterial blood
81
what would happen without the pampiniform plexus
warm arterial blood would inhibit sperm production
82
what is the countercurrent heat exchanger and where does it occur
1. Removes heat from the descending arterial blood
| 2. Pampiniform plexus
83
The testes are combined endocrine and exocrine glands that produce__, respectively
sex hormones and sperm
84
each testis is covered anteriorly and laterally by
tunica vaginalis
85
what is the tunica albuginea
white fibrous capsule on testes
86
Connective tissue septa divides testes into __ wedge-shaped lobules
250 to 300
87
Seminiferous leads into the
rete testes
88
__cells are the ones that become sperm
Germ
89
what do nurse cells do
protect germ cells
90
what cells produce testosterone
interstitial cells (of leydig)
91
what are the seminiferous tubules
ducts where the sperm are produced
92
how many seminiferous tubules are in each lobule
1-3
93
Each seminiferous tubule is lined with a thick germinal epithelium of __ cells
germ
94
where are nurse cells
in between germ cells
95
what do nurse cells do
protect the germ cells and promote their development
96
where are the interstitial endocrine cells
in between tubules
97
what cells produce testosterone
interstitial endocrine cells
98
what is the rete testis
a network on the posterior side of the testis that collects sperm from seminiferous tubules
99
what is the blood testis barrier
1. formed by tight junctions between nurse cells
2. Separates sperm from immune system
3. Prevents antibodies and other large molecules in the blood from getting to germ cells
4. Germ cells are immunologically different from body cells and would be attacked by the immune system
100
what are the efferent ductules
About 12 small ciliated ducts collecting sperm from rete testes and transporting it to epididymis
101
what is the site of sperm maturation and storage
Duct of the epididymis
102
how long are sperm fertile for
40-60 days
103
if sperm are not ejaculated what happens to them
they disintegrate and the epidemic reabsorbs them
104
what is the ductus deferens
Muscular tube, 45 cm long, passing up from scrotum through inguinal canal to posterior surface of bladder
105
Duct ends by uniting with duct of the
seminal vesicle
106
what is the ejaculatory duct formed by
the ductus deferent and seminal vesicle
107
what are the seminal vesicles and their functions
1. Pair of glands posterior to bladder
2. Empties into ejaculatory duct
3. Forms 60% of semen
108
what is the prostate and its functions
1. Surrounds urethra and ejaculatory duct
2. Empty through pores in the prostatic urethra
3. Forms 30% of semen
109
what part of the body produces the majority of semen
the seminal vesicles
110
what are the bulbourethral glands, where are they located, and their functions
1. Near bulb of penis
2. During sexual arousal, they produce a clear slippery fluid that lubricates the head of the penis in preparation for intercourse
3. Protects the sperm by neutralizing the acidity of residual urine in the urethra
111
what does BPH stand for
benign prostatic hyperplasia
112
what is benign prostatic hyperplasia and what does it do
1. noncancerous enlargement of the prostate
2. Compresses urethra and obstructs flow of urine
3. Promotes bladder and kidney infections
113
what is prostate cancer and what does it do
1. Second most common cancer in men after lung cancer
2. Tumors tend to be near the periphery of the gland where they do not obstruct urine flow
3. Go unnoticed until they cause pain
4. Metastasize to nearby lymph nodes and then to lungs and other organs
5. Digital rectal exam (DRE): palpated through rectal wall to check for tumors
6. Diagnosed from elevated levels of serine protease (Prostate-specific antigen PSA) and acid phosphatase in the blood
114
what is the role of the penis
to deposit semen into the vagina
115
what is the normal size of the penis
4 inches when flaccid and 5-7 inches when erect
116
what is another name for the foreskin
the prepuce
117
what are the three cylindrical bodies of erectile tissue that fill with blood and account for erection
corpus spongiosum and two corpora cavernosa
118
what corpus spongiosum is located where and does what
1. along ventral side of penis
2. encloses urethra
3. distal end enlarges and forms the glans penis
119
each divergences of the two corpora cavernosa does what and is called
attaches penis to pubic arch, rus
120
the reproductive system remains dormant for how long in males and females
10 to 12 years in most boys; 8 to 10 years in most girls
121
A surge of ___awakens the reproductive system
pituitary gonadotropins
122
what its the definition of adolescence
period from onset of gonadotropin secretion and reproductive development to when a person attains full adult height
123
what is the definition of puberty
first few years of adolescence, until the first menstrual period in girls or the first ejaculation of viable sperm in boys
124
when does puberty hit for males and females
Typically around age 12 in girls and age 14 in boys
125
Testes secrete testosterone in __ of fetal development then testes becomes dormant until puberty
first trimester
126
From puberty, reproductive function is regulated by the
hypothalamus, pituitary gland, and gonads
127
As hypothalamus matures it produces
gonadotropin-releasing hormone
128
GnRH stimulates anterior pituitary cells to secrete
1. follicle stimulating hormone, which stimulates nurse cells to secrete androgen binding protein the binds to testosterone
2. Luteinizing hormone which stimulates interstitial endocrine cells to produce testosterone
129
Nurse cells can inhibit follicle stimulating hormone without inhibiting ___ which means it can continue to produce testosterone
luteinizing hormone
130
Both androgens stimulate growth of sex organs such as
Penis, testes, scrotum, ducts, glands
131
Testosterone stimulates generalized body growth such as
1. Limbs elongate, muscle mass increases, and larynx enlarges
2. Erythropoiesis, basal metabolic rate, and increase in appetite
3. Stimulates sperm production and libido (sex drive)
132
Dihydrotestosterone (DHT) stimulates
1. Pubic hair, axillary hair, facial hair and associated apocrine swear/scent glands;
2. Darker, thicker skin with more sebum contributing to acne
133
during adulthood, testosterones functions include
sustains the male reproductive tract, sperm production, and libido
134
during adulthood inhibin's functions include
from nurse cells suppresses FSH output from the pituitary, reducing sperm production without reducing LH and testosterone secretion
135
Peak secretion of testosterone at age __; declines to __of that by age 80
20, one-fifth
136
what is andropause
the male version of menopause; A period of declining reproductive function that may be first seen in early 50s
137
Age-related drop in testosterone and inhibin triggers a rise in what hormones
FSH and LH
138
what are some symptoms of andropause
Although most men do not notice this, some experience mood changes, hot flashes, “illusions of suffocation”
139
what is the percentage of men effected by ED
20% of men in 60s to 50% of those in 80s
140
define mitosis
a somatic (body) cell doubles its DNA and then divides to produce two genetically identical daughter cells that are diploid
141
what is the Basis for division of single-cell fertilized egg, growth of an embryo, all postnatal growth, and tissue repair
mitosis
142
define meiosis
* production of four genetically different gametes, each with half the number of chromosomes (haploid cells) of diploid body cells
* Combining male and female gametes with half the genetic material produces an embryo with the same number of chromosomes as each of the parents
143
what is spermatogenesis
process of sperm production in seminiferous tubules
144
what are the three principle events of spermatogenesis
1. Division of large germ cells into small, mobile sperm cells with flagella
2. Reduction of chromosome number by one-half
3. Shuffling of genes so each chromosome contains new gene combinations that did not exist in parent
145
what does meiosis do
recombines genes and reduces chromosome number, while producing four daughter cells that will differentiate into sperm
146
is mitosis or meiosis used in the spermatogenesis
meiosis
147
what are the stages of meiosis 1
prophase I, metaphase I, anaphase I, and telophase I
148
what happens before meiosis 1
DNA is doubled
149
what happens in prophase 1 of meiosis1
Prophase I: each pair of homologous chromosomes lines up side by side and forms a tetrad
Crossing-over creates new combinations of genes (recombination)
150
what happens in metaphase1
Independent assortment further increases genetic variation as homologous chromosome pairs randomly align on separate poles of the equatorial plate
151
After meiosis I, each cell is reduced to __ chromosomes, but each chromosome is
23, double-stranded
152
what are the stages of meiosis 2
prophase II, metaphase II, anaphase II, and telophase II
153
which meiosis is more like mitosis
meiosis 2
154
what happens in meiosis 2
Each of double-stranded chromosomes divides into two chromatids, and these separate
At the end, each cell contains 23 single-stranded chromosomes
155
__ brings on spermatogenesis
Puberty
156
__ form in yolk sac of embryo
Primordial germ cells
157
Primordial germ cells colonize __ and become __which divide by mitosis into type A and type B spermatogonia
gonadal ridges, spermatogonia
158
When a primary spermatocyte undergoes meiosis, it becomes genetically different and needs to be protected from the
immune system
159
Tight junctions between __ dismantle ahead of the spermatocyte and reform behind it- forming a new BTB
nurse cells
160
what is spermiogenesis
four spermatids undergo transformations in which they differentiate into a spermatozoa
161
during spermiogenesis, spermatocytes lose their cytoplasm and get
a tail
162
describe the structure of the spermatozoon
1. Head is pear-shaped with three structures
2. Nucleus contains haploid set of chromosomes
3. Acrosome—enzyme cap over the apical half of the nucleus that contains enzymes that penetrate the egg
4. Basal body—indentation in the basal end of the nucleus where flagellum attaches
163
the tail of the spermatozoon is divided into what three regions
1. Midpiece contains mitochondria around axoneme of the flagella, produces ATP for flagellar movement
2. Principal piece is axoneme surrounded by sheath of supporting fibers
3. Constitutes most of tail
Endpiece is very narrow tip of flagella
164
how much semen is expelled during ejaculation
2-5 mL
165
what is the contents of semen
1. 60% seminal vesicle fluid,
2. 30% prostatic fluid, and
3. 10% sperm and spermatic duct secretions
4. Only trace amounts of bulbourethral fluid
166
what is normal sperm count
50 to 120 million/mL
167
what sperm count infers infertility
20 to 25 million/mL
168
what organs contribute to the production of semen
prostates, seminal vesicles
169
what is the name of the antibiotic that combat sUTIs in males
Seminalplasmin
170
the prostate produces what
1. Prostate produces a thin, milky white fluid
2. Contains calcium, citrate, and phosphate ions (buffers)
3. Clotting enzyme
4. Seminalplasmin (antibiotic that combats UTIs in males)
5. Protein-hydrolyzing enzyme called serine protease (prostate-specific antigen)
171
the seminal vesicles produce what
1. vesicles contribute viscous yellowish fluid
2. Contains fructose and other carbohydrates (nourish sperm)
3. Citrate (ATP production & nutrient for sperm)
4. Prostaglandins (sperm motility & smooth muscle contraction of uterus)
5. Proseminogelin
172
what is Proseminogelin
1. Clotting enzyme from prostate activates proseminogelin and converts it to a sticky fibrin-like protein called seminogelin
2. Entangles the sperm, sticks to the inner wall of the vagina and cervix, and ensures semen does not drain back into vagina
3. 20 to 30 minutes after ejaculation, serine protease from prostatic fluid breaks down seminogelin, and liquifies the semen
173
semen needs the __ for ATP production
fructose
174
what are the two requirements for sperm motility
elevated pH and an energy source
175
what does prostatic fluid do
buffers vaginal acidity from pH 3.5 to 7.5
176
what does seminal fluid do
provides fructose and other sugars to the mitochondria of sperm for ATP production
177
__ in semen may thin the mucus of the cervical canal and may stimulate waves of contractions in uterus and uterine tubes to spread the semen
Prostaglandins
178
intercourse into four recognizable phases for males and females
Excitement
Plateau
Orgasm
Resolution
179
Sexual intercourse is also known as
coitus, coition, or copulation
180
Each internal iliac artery gives rise to an __(penile) artery enters root of the penis and divides in two.
internal pudendal
181
dorsal artery does what
Supplies blood to skin, fascia, and corpus spongiosum
| When penis is flaccid, most blood comes from dorsal artery
182
what does the deep artery do
Gives off smaller helicine arteries that enter lacunae
| Dilation of deep artery fills lacunae causing an erection
183
Many __ unite deep and dorsal arteries
anastomoses
184
__ vein drains blood from penis
Deep dorsal
185
The glans and prepuce have an abundance of __receptors
tactile, pressure, and temperature
186
___nerves lead to sacral spinal cord
Dorsal nerves of penis and internal pudendal
187
__ fibers carry impulses from spinal integrating center to penis
Both autonomic and somatic motor
188
__ help induce erection in response to input from special senses and sexual thoughts
Sympathetics
189
__ induce an erection in response to direct stimulation of the penis
Parasympathetics
190
what are some drugs used to treat ED
Viagra®, Levitra®, and Cialis®
191
what are ED drugs and how do they work
1. Phosphodiesterase inhibitors
| 2. These drugs slow breakdown of cGMP by phosphodiesterase type 5 (PDE5) and prolong duration of erection
192
what're some bacterial STDs and their symptoms
1. Gonorrhea: pain and pus discharge; uterine bleeding
2. Chlamydia: may cause urethral discharge, testicular pain, pelvic pain
3. Pelvic Inflammatory Disease: caused by Chlamydia or 4. Gonorrhea
5. Syphilis: hard lesions (chancres) at site of infection
Disappearance of chancres ends first stage
Second stage is widespread pink rash
Neurosyphilis is third stage with cardiovascular damage and brain lesions
193
what are some viral STDs and their symptoms
1. Genital herpes: Blisters and pain
2. Genital warts: warts on perineal region, cervix, anus
Caused by human papillomavirus (HPV)*
Cause of nearly all cervical cancer and 70% of throat cancer
Vaccine available
3. Hepatitis B and C: inflammatory liver disease
Leading cause of cancer
Leading reason for liver transplants in the United States
