Sexual reproduction entails the union of two gonads to form a zygote.

False

Males produce sperm and females produce eggs.

True

The presence of the Y chromosome guarantees the development of male secondary sex organs.

False

The mechanism that keeps the testes cooler than the body's core temperature is called descent of the testes.

False

The scrotum contains the testes and spermatic cords.

True

Sperm travels to the ampulla of the ductus deferens before reaching the spermatic cord.

False

Nurse cells secrete inhibin, which regulates the rate of sperm production.

True

Testosterone stimulates development of the secondary sex characteristics, spermatogenesis, and libido.

True

Erectile dysfunction prevents ejaculation in most cases.

False

At early puberty, follicle stimulating hormone (FSH) and luteinizing hormone (LH) stimulate enlargement of the testes.

True

Spermiogenesis is the last stage of meiosis.

False

Sperm make up just 10% of semen volume.

True

Only germ cells undergo meiosis, which produces four haploid (n) cells with 23 chromosomes each.

True

Sympathetic nerve fibers trigger the secretion of nitric oxide, which dialtes the deep arteries allowing

False

The first haploid (n) stage of spermatogenesis is prophase II.

True

Myotonia of skeletal muscles is characteristics of the excitement phase and refractory period.

False

Which of the following is generally accepted as a secondary sex characteristic?

The enlargement of the breasts

Which of the following are female primary sex characteristics?

Ovaries

Which of the following is a female secondary sex organ?

Vagina

Gonads begin to develop _________ weeks after fertilization.

5 to 6

Whether an orgasm will be genetically male or female is determines by

the sperm

The gene that codes for the testis-determining factor (TDF) is found in or on the

Y chromosome

The penis is homologous to the

clitoris

The _________ is the gonad and the _________ is the gamete.

testis; sperm

Descent of the testes is stimulated by the

presence of testosterone

The _________ is an example of the female external genitalia.

clitoris

The __________ is the small, bilateral organ found lateral to the membranous urethra.

bulbourethral land

The golf-ball sized structure found inferior to the urinary bladder, and surrounding the most proximal portion of the urethra, is called the

prostate

The __________ is the site of sperm maturation and storage.

epididymis

The deep region of the penis, surrounding the urethra, that engorges with blood during an erection is known as the

corpus spongiosum

Which of the following is the correct pathway of sperm cells from their formation to ejaculation?

Seminiferous tubule, rete testis, epididymis, ejaculatory duct, urethra, ductus deferens

When it is cold, the _________ contracts and draws the testes closer to the closer to the body to keep them warm.

cremaster

The countercurrent heat exchanger that prevents arterial blood from overheating the testes is the

pampiniform plexus of veins

Which of the following is true regarding the blood-testis barrier?

It prevents antibodies in the blood from getting to the germ cells.

By volume, most of the semen is produced in the

seminal vesicles

Which of the are not found in or around the seminiferous tubules?

Corpus cavernosum cells

The penile urethra is enclosed by the

corpus spongiosum

Men have only one

prostate

Why would an enlarged prostate interfere with urination?

It compresses the urethra

The penis is innervated by the _________ nerve.

internal pudendal

Which of the following does not play a role in thermoregulation of the testes?

The bulbosponiosus muscle

When do the testes start secreting testosterone?

In the first trimester of fetal development

Which of the following hormones directly stimulates the development of male secondary sex characteristics?

Testosterone

Which of the following is an androgen?

Testosterone

__________ stimulates the interstitial cells of the testes to secrete __________.

Luteinizing hormone (LH); testosterone

Which hormone suppresses spermatogenesis without affecting testosterone secretion?

Inhibin

The _________ has/have no androgen receptors and do/does not respond to it.

germ cells

Which of the following is inhibited by testosterone?

Gonadotropin-releasing hormone (GnRH) secretion

Changes called male climacteric are a consequence of a(n)

decreased secretions of testosterone

The haploid (n) result meiosis I is called a

secondary spermatocyte

In the process of spermiogenesis, __________ become ___________ .

spermatids; spermatozoa

In meiosis, each parent cell produces

four haploid (n) cells

The process of spermatogenesis begins with a __________ and ends with four __________.

germ cell; gametes

At the end of meiosis I there are _________, whereas at the end of meiosis II there is/are __________.

two haploid (n) cells; four haploid (n) cells

Which of the following is the most important role of meiosis in sexual reproduction?

It prevents the chromosome number from doubling in each generation.

At what stage does a developing sperm cell begin to grow a tail?

Spermatid

Sperm cells get energy to power their movement from _________, which is contributed by the __________.

fructose; seminal vesicles

Male infertility (sterility) refers to

the inability to fertilize an egg

The acrosome contains enzymes used to

penetrate barriers surrounding the ovum

_________ have 46 chromosomes, whereas __________ have 23.

Primary spermatocytes; spermatids

A sperm count any lower than _________ million sperm per mL of semen is usually associated with infertility (sterility).

20 to 25

Dilation of the _________ causes the lacunae to fill with blood and the penis to become erect.

deep arteries

The orgasm-emission phase of the male sexual response is stimulated by

efferent sympathetic signals from the lumbar region of the spinal cord

Which of the following explains the neural mechanism of an erection?

It is an autonomic reflex mediated predominantly by parasympathetic nerve fibers

Heart rate, blood pressure, and respiratory rate peak during the

climax (orgasm)

Sildenafil (Viagra) prolongs erection by

inhibiting degradation of cGMP

Which of the following are changes in the male body that results from puberty?

Deepening of the voice, gain in muscle mass, growth of the scrotum and penis, acne

Which of the following is not a function of the nurse cells?

They secrete testosterone

Genetic males are XY and genetic females are XX.

True

In the female fetus, the absence of testosterone results in the development of the external genitalia into clitoris, labia minora, and labia majora.

True

The uterus is a thick muscular chamber inferior to the urinary bladder.

False

The vagina has no glands but it is moistened by mucus from glands in the cervical canal.

True

Although two breast cancer genes are known, most cases are nonhereditary.

True

Inhibin modulates the secretion of LH.

False

The number of ovarian follicles declines with age, leading to a reduction of estrogen levels.

True

The ovarian cycle typically lasts about 28 days, with day 1 considered to be the first day ovulation.

False

Most primary oocytes undergo atresia during climacteric.

False

The proliferative phase of the uterus is driven by estrogen from the ovaries.

True

In the excitement phase, the uterus rises from its forward-tilted (anteverted) position.

True

Unlike men, women lack a refractory period and may experience successive orgasms.

True

Human chorionic gonadotroping (HCG) stimulates the corpus luteum to grow and secrete estrogen and progesterone.

True

Progesterone stimulates uterine contractions.

False

Prolactin is secreted during pregnancy to stimulate milk synthesis so that milk will be available by the time the infant is born.

False

Oxytocin stimulates contraction of myoepithelial cell of the mammary acini.

True

Which of the following is a part of the internal female genitalia?

Vagina

In which structure does fertilization usually occur?

Uterine tube

Which of the following structures is composed of a theca folliculi, granulosa cells, a zona pellucida, and a secondary oocyte?

Secondary follicle

What structure leads from each ovary to the uterus?

Uterine tube

Which uterine layer is composed of a simple columnar epithelium containing tubular glands?

Endometrium

Which of the following is not a component of the vulva?

Cervix

In the prementrual phase of the menstrual cycle, which arteries rhythmically constrict and dilate causing endometrial ischemia?

Spiral

After puberty, which epithelium lines the vagina?

Stratified squamous epithelium

Where does an embryo usually attach to its mother?

To the endometrium

What provides most of the natural lubrication during female sexual excitement?

Greater vestibular glands

The nonpregnant uterine wall consists mostly of

myometrium

Which of these is not found in the vestibule?

Mons pubis

__________ are found in both male and female external genitalia, but the __________ is/are only found in the female.

Corpora cavernosa; vestibular bulbs

When do mammary glands primarily develop within the breasts?

During pregnancy

What determines breast size?

The amount of adipose tissue

Where are follicles located?

Cortex of the ovary

What is the earliest sign of puberty in girls?

The onset of breast development

Which of the following is considered a "feminizing hormone"?

Estrogen

Which hormone acts primarily on the uterus?

Progesterone

The appearance of pubic and axillary hair is characteristic of which stage of puberty?

Pubarche

What is the midlife change in estrogen and progesterone levels referred to as?

Climacteric

What is the cessation of menstruation referred to as?

Menopause

During climacteric, what can cause hot flashes?

Vasodilation of cutaneous arteries

What does the term "menstrual cycle" specifically refer to?

The cyclic changes in the uterus determined by shifting hormonal changes

What is an ovulated egg more technically referred to as?

A secondary oocyte

Which stage of meiosis is an ovulated egg in?

Metaphase II

When does an ovum finish meiosis?

During fertilization

Most ovulation home test kits measure a surge of which hormone?

LH

In ovulation, after expelling the oocyte the follicle becomes a _________ and secretes __________.

corpus luteum; estrogen and progesterone

What is a follicle composed of?

An oocyte enclosed in follicular or granulosa cells

Which follicle stage is characterized by the development of a corona radiata?

Tertiary

When does oogenesis begin?

During embryonic development

In the adult ovary, more than 90% of the follicles are found as

Primordial follicles

During the follicular phase, granulosa cells secrete _________, which stimulates secretion of _________.

estradiol; LH

Which of these blood hormone levels reaches its maximum during the luteal phase?

Progesterone

What hormone(s) inhibit(s) the secretion of FSH and LH during the female sexual cycle?

Estradiol and progesterone

What do lutein cells develop from?

The theca interna

Which phase of the mentrual cycle is the one associated with menstrual cramps?

Premenstrual

Which of the following occurs during the proliferative phase of the menstrual cycle?

Several follicles are developing an antrum

The ________ sometimes expels copious fluid similar to prostatic fluid, which constitutes the female ejaculate.

paraurethral glands

During the plateau phase of the sexual response, the glans and clitoris swell as the deep arteries dilate and the ________ engorge with blood.

corpora cavernosa

In early pregnancy, what hormone stimulates growth of the corpus luteum?

Human chorionic gonadotropin

During ________, the uterus is tented (erected) and the cervix is withdrawn from the vagina. Typically, the clitoris is engorged and the labia are bright red to violet due to hyperemia.

excitement

Pregnancy kits test for the presence of what hormone?

Human chorionic gonadotropin

Between weeks 3 and 8 of development, a developing individual is considered a(n)

embryo

Contraceptive pills mimic the ________ feedback effect of ________.

negative; estrogens and progesterone

Which form of estrogen is the most potent in pregnancy?

Estradiol

Which of the following provides fetal nutrition and secretes hormones that regulate pregnancy and fetal development?

The placenta

What is the longest stage of labor?

The dilation stage

Milk ejection occurs as a result of stimulation of nerve endings in the ________, which leads to the release of ________from the pituitary.

nipple and areola; oxytocin

Why is breast milk superior to cow's milk for an infant?

Cow's milk has too much protein and minerals in it.

What is the infant's only source of nutrition during the first 2-3 days postpartum?

Colostrum

The medial pole of the ovary is attached to the uterus by which ligament?

Ovarian ligament

The anterior margin of the ovary is anchored by a peritoneal fold called the

mesovarium

The ovary receives blood from which artery/arteries?

Ovarian and uterine

During climacteric, women secrete

less estrogen and progesterone

Which of the following is true of the female sexual response?

Women do not have a refractory period and may quickly experience additional orgasms.

Why do pregnant women often have heartburn?

As the uterus enlarges it pushes upward on the stomach, causing gastric reflux.

Women with morning sickness tend to prefer spicy and pungent foods.

False

"False labor" is result of what type of contractions?

Braxton Hicks

When an infant suckles at its mother's breast, milk moves through the breast structures in what order?

Acinus > lactiferous duct > lactiferous sinus > nipple

How is colostrum different than breast milk?

It has one-third less fat.

Which of the following is not a benefit of breast feeding?

It prevents colonization of the neonatal intestine with beneficial bacteria.

Sperm must travel to the distal end of the uterine tube to encounter the egg before it dies.

True

The slow block referes to the mechanism that prevents fertilization of another egg when one is already pregnant.

False

The fertilization membrane is the endometrial tissue that receives the conceptus.

False

Cleavage results in daughter cells containing half the number of chromosomes of the parent cell.

False

During implantation, the embryoblast undergoes gastrulation.

True

The embryonic stage extends from 16 days through the end of week 8.

True

The chorion forms the fetal part of the placenta.

True

The placenta begins to form after week 8.

False

Trophoblastic nutrition refers to the nutrition of the conceptus before it implants.

False

Neonatal immunity depends on IgG and IgA acquired through the placenta and colostrum, respectively.

True

To some extent, the heat loss of the neonate is compensated for by the thermal insulation provided by brown fat.

False

Inadequate liver function is the most common reason that premature infants suffer from multiple dysfunctions.

True

Teratogens usually do not cause congenital anomalies.

False

Senescence begins different ages and progresses at different rates in different organ systems.

True

Life expectancy has steadily increased in the last century, whereas life span has not.

True

A person in his or her 90's can increase muscle strength by two or three times with 40 minutes of isometric exercise per week.

True

Which of the following lists the stages or structures of prenatal development in the correct order?

Zygote, cleavage, morula, blastocyst, embryo, fetus

The process that makes it possible for sperm to penetrate the eggs is called

capacitation

In the slow block to polyspermy, sperm penetration release an inflow of _________, which in turn stimulates the __________.

Ca²⁺; cortical reaction

In the fast block to polyspermy, binding of sperm opens up __________ channels, which depolarizes the egg membrane and __________.

Na⁺; prevents the entrance of any more sperm

Regarding fertilization, which of the following events happens first?

The acrosomal reaction

The optimal "window of opportunity" to conceive a child is

a few days before ovulation to less than a day after

The spheroidal stage of early prenatal development with about 16 to 64 cells is called a(n)

morula

Twins produced when a single egg is fertilized are called __________ twins. Twins produced from two eggs ovulated at the same time are called _________ twins.

monozygotic; dizygotic

In the blastocyst, the trophoblast will become________, whereas the embryoblast will become __________.

part of the placenta; the embryo

Primary germ layers are formed during

gastrulation

Mesenchyme gives rise to _________.

muscle, bone, and blood

During implantation, the trophoblast divides into a deep layer called the ________, which is composed of individual cells.

cytotrophoblast

By the time the conceptus arrives in the uterus, it consists of at least ________ or more cells.

16

During implantation, the trophoblast divides into a superficial layer called the ________, which is composed of a multinucleate mass of cytoplasm.

syncytriotrophoblast

Out of the 300 million ejaculated sperm, only about ________ reach the vicinity of the egg.

200 to 300

Prior to ejaculation, __________ in the plasma membrane of the sperm prevents premature release of __________.

cholesterol; acrosomal enzymes

Which of the following is not a derivative of ectoderm?

The dermis

The first body cavity is called the

coelom

By the end of 8 weeks, the individual is considered a fetus because

all of the organ systems are present

The __________ completely encloses the embryo and provides it with a stable environment.

amnion

The _________ encloses all the rest of the membranes and the embryo.

chorion

The _________ is an embryonic membrane that serves as the origin of the first blood and germ cells.

yolk sac

As it implants, the concepts is nourished by means of

trophoblastic nutrition

The ________ begins to develop about 11 days after conception, and is the sole source of fetal nutrition from the end of week 12 until birth.

placenta

In fetal circulation, the ________ bypasses the liver and the _________ bypasses the lungs.

ductus venosus; ductus arteriosus

In fetal circulation, blood bypasses the lung by flowing through the

foramen ovale and ductus arteriosus

Which of the following major events of prenatal development happens first?

The central nervous system begins to form

Oxygenated blood reaches the fetus through the

umbilical vein

Which of the following is not considered an embryonic membrane?

Placenta

________ pass(es) from the maternal blood to the fetal blood. Fetal ________ pass(es) the other way.

Oxygen and nutrients; wastes

The digital rays of a fetus give rise to

fingers and toes

The first 6 weeks of postpartum life constitute the _______ period.

neonatal

The fossa ovalis is a remnant of the ________ of the fetus.

foramen ovale

During birth, an infant is normally stimulated to breathe by

CO² accumulating in the baby's blood

Which of the following organ systems shows the greatest anatomical change in the transitional period after birth?

Circulatory system

Infant respiratory distress syndrome (IRDS) is caused by

deficiency of pulmonary surfactant

Which of the following organ systems faces the greatness physiological challenge in the transitional period after birth?

Respiratory system

A teratogen is most likely to cause

a deformity of the limbs

Which of the following does not have potentially teratogenic effects?

Sunlight

Down syndrome (trisomy-21) results from

nondisjunction

The most likely outcome of nondisjunction is the production of a gamete receiving

22 chromosomes

Only autosomal trisomes involving chromosomes 13, 18, and 21 are survivable. Why would this be?

These are relatively gene-poor chromosomes

Urine retention is a greater problem for elderly men than for elderly women because men

can develop benign prostatic hyperplasia

Which of the following is not a reason muscular weakness tends to develop in old age?

The myocytes of aged muscle no longer synthesize myosin.

Older people may require lower drug doses than younger people because

they have lower rates of renal clearance

Which of the following statements is true regarding telomeres?

Telomeres are DNA segments at each end of a chromosome.

The observation that there is a limit to how many times a cell can divide is the basis for the ________ theory of senescence.

replicative

Which of the following systems shows the least overall senescence?

Endocrine system

Senescence of the immune system makes older people more susceptible to cancer and infectious disease because of a decline in

antigen-presenting cells and helper T cells

Which of the following is not a known benefit of regular exercise?

Prolonged life expectancy

Which of the following is not a known cause of congenital anomalies?

Smoking during lactation

The fetus deposits fat in its subcutaneous tissue in the 7th month of gestation.

True