THE MALE REPRODUCTIVE SYSTEM Flashcards by Secret acc

PHYSIOLOGICAL ANATOMY OF THE MALE SEXUAL ORGANS

The testis has ~______ seminiferous tubules forming sperm, which travel to the ______-meter epididymis.

900, 6

How well did you know this?

Not at all

Perfectly

PHYSIOLOGICAL ANATOMY OF THE MALE SEXUAL ORGANS

The epididymis connects to the ______, which expands into the ______ near the prostate.

vas deferens, ampulla

How well did you know this?

Not at all

Perfectly

PHYSIOLOGICAL ANATOMY OF THE MALE SEXUAL ORGANS

______ empty into the ampulla.

Seminal vesicles

How well did you know this?

Not at all

Perfectly

PHYSIOLOGICAL ANATOMY OF THE MALE SEXUAL ORGANS

Contents from the ampulla and vesicles flow into the ______ passing through the prostate glands then to internal urethra.

ejaculatory duct

How well did you know this?

Not at all

Perfectly

PHYSIOLOGICAL ANATOMY OF THE MALE SEXUAL ORGANS

______ also empty into the ejaculatory duct and then into the ______.

Prostatic ducts, prostatic urethra

How well did you know this?

Not at all

Perfectly

PHYSIOLOGICAL ANATOMY OF THE MALE SEXUAL ORGANS

The ______ serves as the final passage to the exterior, lined with mucus-secreting glands, including the ______ (______).

urethra, bulbourethral glands, Cowper’s glands

How well did you know this?

Not at all

Perfectly

SPERMATOGENESIS

______ migrate to the testes and become ______ in the inner surfaces of seminiferous tubules.

Primordial germ cells, spermatogonia

How well did you know this?

Not at all

Perfectly

SPERMATOGENESIS

At puberty, spermatogonia divide and differentiate to form ______.

sperm

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS: (keywords)

seminiferous tubules
Sertoli cells
primary spermatocytes, secondary spermatocytes
spermatids, spermatozoa
23 chromosomes
74 days

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS:

Spermatogenesis occurs in ______, starting around age ______, and continues throughout life, ______ with age.

seminiferous tubules, 13, decreasing

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS:

Spermatogonia migrate toward the ______ lumen of the ______ among ______, which support their development.

central, seminiferous tubule, Sertoli cells

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS:

Spermatogonia enlarge to form ______, which undergo meiosis, producing two ______.

primary spermatocytes, secondary spermatocytes

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS:

Secondary spermatocytes divide into ______, which develop into ______ (______).

spermatids, spermatozoa, sperm

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS:

Chromosomes are halved during meiosis, giving each spermatid ______ chromosomes.

How well did you know this?

Not at all

Perfectly

STEPS OF SPERMATOGENESIS:

The full process from spermatogonia to spermatozoa takes approximately ______ days.

How well did you know this?

Not at all

Perfectly

SEX CHROMOSOMES

In each ______, one of the 23 pairs of chromosomes determines the offspring’s ______: one ______ (female) and one ______ (male).

spermatogonium, sex, X, Y

How well did you know this?

Not at all

Perfectly

SEX CHROMOSOMES

During ______, the ______ chromosome goes to one spermatid (male sperm, and the ______ goes to another (female sperm).

meiosis, Y, X

How well did you know this?

Not at all

Perfectly

SEX CHROMOSOMES

The offspring’s sex depends on whether an ______ or ______ sperm fertilizes the ______.

X, Y, ovum

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM

Spermatids initially resemble ______ but soon differentiate into ______ with a ______ and ______.

epithelioid cells, spermatozoa, head, tail

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM

The ______ of the sperm is specialized for carrying and delivering genetic material.

head

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM

______ (______): Enables sperm movement.

Tail, Flagellum

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM

The head of the sperm is composed of:

Nucleus
Acrosome

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM

The head of the sperm is composed of:

______: Contains condensed nucleus with a thin layer of cytoplasm and a cell membrane around it, compacting the genetic material for fertilization.

Nucleus

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM

The head of the sperm is composed of:

______: A thick cap covering the anterior two-thirds of the head, developed from the Golgi apparatus. Containing enzymes (e.g., hyaluronidase, proteolytic)
aiding sperm entry into the ovum.

Acrosome

How well did you know this?

Not at all

Perfectly

FORMATION OF SPERM The Tail (Flagellum) consists of:

Axoneme Membrane Covering Mitochondria

FORMATION OF SPERM The Tail (Flagellum) consists of: ______: Central structure with 11 microtubules, similar to cilia, supporting movement.

Axoneme

FORMATION OF SPERM The Tail (Flagellum) consists of: ______: Thin cell membrane covering around the axoneme, preserving structure.

Membrane Covering

FORMATION OF SPERM The Tail (Flagellum) consists of: ______: Surrounds the proximal portion of the tail, called the ______, produce ATP for energy.

Mitochondria, body of the tail

FORMATION OF SPERM The Tail (Flagellum) • ______: Microtubule sliding creates a back-and-forth motion, moving sperm at ______-______ mm/min toward the ovum.

Flagellar Movement, 1, 4

HORMONAL FACTORS THAT STIMULATE SPERMATOGENESIS:

Testosterone Luteinizing Hormone (LH) Follicle-Stimulating Hormone (FSH) Estrogens Growth Hormone

HORMONAL FACTORS THAT STIMULATE SPERMATOGENESIS: ______: Secreted by ______ in the testis interstitium, it is essential for the growth and division of testicular germinal cells, the first stage of sperm formation.

Testosterone, Leydig cells

HORMONAL FACTORS THAT STIMULATE SPERMATOGENESIS: ______: Secreted by the ______, it stimulates Leydig cells to produce testosterone.

Luteinizing Hormone (LH), anterior pituitary gland

HORMONAL FACTORS THAT STIMULATE SPERMATOGENESIS: ______: Also from the ______, it stimulates Sertoli cells; without this, spermiogenesis (conversion of spermatids to sperm) cannot occur.

Follicle-Stimulating Hormone (FSH), anterior pituitary

HORMONAL FACTORS THAT STIMULATE SPERMATOGENESIS: ______: Formed from testosterone by ______ under FSH stimulation, they are likely crucial for spermiogenesis.

Estrogens, Sertoli cells

HORMONAL FACTORS THAT STIMULATE SPERMATOGENESIS: ______: Necessary for metabolic functions in the testes, it promotes early spermatogonia division; its absence can lead to infertility due to deficient or absent spermatogenesis.

Growth Hormone

MATURATION OF SPERM IN THE EPIDIDYMIS After forming in the seminiferous tubules, sperm take several days to travel through the ______-meter ______.

6, epididymis

MATURATION OF SPERM IN THE EPIDIDYMIS Sperm from the seminiferous tubules and early epididymis are ______ and cannot ______ an ovum.

nonmotile, fertilize

MATURATION OF SPERM IN THE EPIDIDYMIS After ______ to ______ hours in the epididymis, sperm gain ______ but remain inhibited until ______.

18, 24, motility, ejaculation

STORAGE OF SPERM IN THE TESTES The human testes produce up to ______ million sperm daily, primarily stored in the ______, with some in the ______.

120, epididymis, vas deferens

STORAGE OF SPERM IN THE TESTES Sperm can remain fertile in storage for at least a ______, kept inactive by ______; with frequent ______, this duration shortens to a few ______.

month, inhibitory substances, ejaculation, days

STORAGE OF SPERM IN THE TESTES After ejaculation, sperm undergo ______, becoming ______ and capable of ______ an ovum.

maturation, motile, fertilizing

STORAGE OF SPERM IN THE TESTES ______ and ______ secrete a nutrient fluid that contains hormones (______ and ______), enzymes, and nutrients essential for sperm maturation..

Sertoli cells, epididymal epithelium, testosterone, estrogens

PHYSIOLOGY OF THE MATURE SPERM Mature, motile sperm can move at ______ to ______ mm/min in a ______ medium.

1, 4, fluid

PHYSIOLOGY OF THE MATURE SPERM Sperm activity is enhanced in a ______ to ______ environment, such as in ______, but is depressed in ______ conditions, which can lead to rapid ______.

neutral, slightly alkaline, ejaculated semen, acidic, death

PHYSIOLOGY OF THE MATURE SPERM Sperm activity and metabolism ______ with temperature, ______ their lifespan.

increase, shortening

PHYSIOLOGY OF THE MATURE SPERM While sperm can survive for ______ in the testes, ejaculated sperm typically last only ______ to ______ days in the ______ genital tract.

weeks, 1, 2, female

______ is ejaculated during the male sexual act. The sperm composed of the fluid and sperm from the ______ (______% of the total), fluid from the ______ (almost ______%), fluid from the ______ (~______%), and small amounts from the ______, especially the ______.

Semen, vas deferens, 10, seminal vesicles, 60, prostate gland, 30, mucous glands, bulbourethral glands

Semen's pH and consistency are regulated by ______ and ______, which has an average pH of ______. ______ neutralizes the mild acidity of other semen components, giving it a milky look, while ______ and ______ give it a mucoid consistency.

prostatic, seminal vesicle fluids, 7.5, Alkaline prostatic fluid, seminal vesicle, mucous gland fluids

The ______ helps retain semen near the ______ by forming a temporary ______ through a ______, which creates a weak ______ that dissolves within ______-______ minutes due to ______. Once dissolved, sperm become highly ______, with a lifespan of ______-______ hours at body temperature, though ______ can extend viability for up to a year.

prostatic fluid, cervix, coagulum, clotting enzyme, fibrin clot, 15, 30, fibrinolysin, motile, 24, 48, freezing

CAPACITATION OF SPERMATOZOA Sperm are initially ______ due to inhibitory factors from the male genital ducts and cannot ______ an ovum. Upon contact with fluids in the ______, they undergo ______; a series of activating changes over ______ to ______ hours that prepares them for ______.

inactive, fertilize, female genital tract, capacitation, 1, 10, fertilization

CAPACITATION OF SPERMATOZOA These series of changes are:

1. Inhibitory Factors Removal 2. Cholesterol Loss and Membrane Weakening 3. Increased Calcium Permeability

CAPACITATION OF SPERMATOZOA These series of changes are: ______: The fluids in the ______ wash away ______ that keep sperm ______ in the male genital ducts.

Inhibitory Factors Removal, female genital tract, inhibitory factors, inactive

CAPACITATION OF SPERMATOZOA These series of changes are: ______: In the male ducts, sperm membranes become enriched with ______, which stabilizes the ______ and prevents ______. After ejaculation, sperm gradually lose this ______, making the acrosome membrane more ______.

Cholesterol Loss and Membrane Weakening, cholesterol, acrosome membrane, enzyme release, excess cholesterol, fragile

CAPACITATION OF SPERMATOZOA These series of changes are: ______: The sperm membrane becomes more permeable to ______, enhancing sperm ______ and enabling a strong ______. ______ also triggers changes that allow the acrosome to release its ______, facilitating penetration through the egg's ______.

Increased Calcium Permeability, calcium ions, motility, whiplash motion, Calcium, enzymes, protective layers

ACROSOME ENZYME, AND REACTION In the acrosome region of the sperm, an ______ is found. ______, includes the ______ and ______, which enable sperm to dissolve ______ around the ______.

acrosome enzyme, Acrosome enzymes, hyaluronidase, proteolytic enzymes, protective layers, ovum

ACROSOME ENZYME, AND REACTION During the ______, these enzymes are released, allowing sperm to penetrate the ______ and ______. ______ breaks down hyaluronic acid, which holds ______ together, ______ digest proteins in the ______ surrounding the ______.

acrosome reaction, granulosa cells, zona pellucida, Hyaluronidase, ovarian granulosa cells, Proteolytic enzymes, tissue, ovum

ONLY ______ SPERM ENTER THE OOCYTE

ONE

WHY DOES ONLY ONE SPERM ENTER THE OOCYTE? Once the fist sperm reaches the ovum, ______ occurs, The sperm binds with ______ on the ______, triggering a rapid ______ and full ______. These enzymes create a pathway through the ______, allowing the sperm head to enter the ______, and lastly ______ and ______ fuse, their genetic material will combine to create a new ______.

fusion, receptor proteins, zona pellucida, acrosome dissolution, enzyme release, zona pellucida, ovum, sperm, oocyte membranes, genome

FACTORS AFFECTING SPERMATOGENESIS AND FERTILITY:

1. Seminiferous Tubular Damage 2. Temperature Effects 3. Cryptorchidism (Undescended Testes) 4. Sperm Count 5. Sperm Shape and Movement

FACTORS AFFECTING SPERMATOGENESIS AND FERTILITY: Seminiferous Tubular Damage: • Diseases like ______ can damage the cells needed to make sperm, sometimes causing ______. Some male infants also have ______ in these cells that can affect ______.

mumps, sterility, natural defects, fertility

FACTORS AFFECTING SPERMATOGENESIS AND FERTILITY: Temperature Effects: • The ______ keeps the testes cooler than the body, which is important for ______. If the testes get too ______, it can stop sperm from forming correctly.

scrotum, sperm production, warm

FACTORS AFFECTING SPERMATOGENESIS AND FERTILITY: Cryptorchidism (Undescended Testes): • If a testis doesn't descend into the ______, it can't make sperm due to ______ body temperature.

scrotum, higher

FACTORS AFFECTING SPERMATOGENESIS AND FERTILITY: Sperm Count: Fertility usually requires a ______ sperm count. If the sperm count drops below ______ million per milliliter, it's harder to conceive, even though only ______ sperm is needed for fertilization.

high, 20, one

FACTORS AFFECTING SPERMATOGENESIS AND FERTILITY: Sperm Shape and Movement: Even with a good sperm count, fertility may still be an issue if the sperm have ______ or don't ______ well. These factors are essential for sperm to reach and fertilize the egg.

abnormal shapes, move

MALE SEXUAL ACT NEURONAL STIMULUS FOR PERFORMANCE OF THE MALE SEXUAL ACT The ______ provides primary sensory input for male sexual arousal through ______ that transmit sensations to the ______ via the ______, with additional input from the ______, ______, and ______.

glans penis, receptors, brain, pudendal nerve, anal region, scrotum, perineum.

MALE SEXUAL ACT NEURONAL STIMULUS FOR PERFORMANCE OF THE MALE SEXUAL ACT Internal structures like the ______, ______, and ______ can generate ______, while "______" drugs or mild inflammation can enhance ______ and stimulate ______.

urethra, bladder, prostate, sexual sensations, aphrodisiacs, sensitivity, sexual desire

MALE SEXUAL ACT Psychic Element of Male Sexual Stimulation • Sexual thoughts or dreams can significantly ______ male sexual performance.

enhance

MALE SEXUAL ACT Psychic Element of Male Sexual Stimulation • Thinking about or dreaming of intercourse can initiate ______ and lead to ______.

sexual activity, ejaculation

MALE SEXUAL ACT Psychic Element of Male Sexual Stimulation • For many males, especially ______, this process may result in ______, or "______," during certain stages of sexual life.

teenagers, nocturnal emissions, wet dreams

MALE SEXUAL ACT Integration of the Male Sexual Act in the Spinal Cord • Psychic factors can ______ or ______ the male sexual act, but ______ function is not essential for its performance.

initiate, inhibit, brain

MALE SEXUAL ACT Integration of the Male Sexual Act in the Spinal Cord • ______ alone can trigger ______ in animals and some humans with ______ above the ______ region.

Genital stimulation, ejaculation, spinal cord injuries, lumbar

MALE SEXUAL ACT Integration of the Male Sexual Act in the Spinal Cord • The male sexual act relies on ______ in the ______ and ______ spinal cord, activated by ______, direct ______, or both.

reflex mechanisms, sacral, lumbar, psychic stimulation, genital stimulation

STAGES OF THE MALE SEXUAL ACT:

1. PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES 2. LUBRICATION IS A PARASYMPATHETIC FUNCTION 3. EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • ______ is the initial response to male sexual stimulation, with ______ corresponding to ______.

Penile erection, strength, stimulation level

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • Erection is caused by ______ impulses from the ______ via ______ to the ______.

parasympathetic, sacral spinal cord, pelvic nerves, penis

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • Parasympathetic fibers release ______ and/or ______ in addition to ______.

nitric oxide (NO), vasoactive intestinal peptide (VIP), acetylcholine

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • Nitric oxide activates ______, increasing ______ production.

guanylyl cyclase, cyclic guanosine monophosphate (GMP)

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • Cyclic GMP relaxes ______ and ______ in the ______, enhancing ______.

penile arteries, smooth muscle, corpora cavernosa, blood flow

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • Increased blood flow releases more ______, promoting further ______.

nitric oxide, vasodilation

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • Erectile tissue contains ______ that fill with ______ as arterial flow ______ and venous outflow is ______.

sinusoids, blood, increases, partially blocked

STAGES OF THE MALE SEXUAL ACT: PENILE ERECTION-ROLE OF THE PARASYMPATHETIC NERVES • High pressure in the ______ causes the penis to become ______ and ______ during erection.

sinusoids, hard, elongated

STAGES OF THE MALE SEXUAL ACT: LUBRICATION IS A PARASYMPATHETIC FUNCTION • During sexual stimulation, parasympathetic impulses promote ______ and ______.

erection, lubrication

STAGES OF THE MALE SEXUAL ACT: LUBRICATION IS A PARASYMPATHETIC FUNCTION • These impulses stimulate the ______ and ______ glands to secrete ______ for ______ during intercourse.

urethral, bulbourethral, mucus, lubrication

STAGES OF THE MALE SEXUAL ACT: LUBRICATION IS A PARASYMPATHETIC FUNCTION • Most lubrication during coitus comes from ______ sexual organs.

female

STAGES OF THE MALE SEXUAL ACT: LUBRICATION IS A PARASYMPATHETIC FUNCTION • Inadequate lubrication can cause ______ and ______ sexual arousal, making the male sexual act less successful.

pain, inhibit

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • ______ and ______ are the final stages of the male sexual act, triggered by intense ______.

Emission, ejaculation, sexual stimulation

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • Sympathetic impulses from the ______ (______ to ______) initiate emission through the ______ and ______.

spinal cord, T12, L2, hypogastric, pelvic sympathetic nerve plexuses

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • Emission involves contractions of the ______ and ______, expelling sperm into the ______, followed by the ______ and ______ releasing fluids to form ______.

vas deferens, ampulla, internal urethra, prostate, seminal vesicles, semen

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • The filling of the ______ with ______ sends ______ that create a feeling of fullness and trigger ______ in the genital organs.

internal urethra, semen, sensory signals, rhythmic contractions

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • These contractions increase ______, leading to ______ of semen from the ______.

pressure, ejaculation, urethra

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • Rhythmic ______ and ______ muscle contractions help propel ______ into the ______ and ______.

pelvic, trunk, semen, vagina, cervix

STAGES OF THE MALE SEXUAL ACT: EMISSION AND EJACULATION ARE FUNCTIONS OF THE SYMPATHETIC NERVES • This entire process is called the ______, after which ______ diminishes rapidly, and ______ ceases.

male orgasm, sexual excitement, erection

SECRETION OF TESTOSTERONE BY THE ______ OF ______ IN THE TESTES.

INTERSTITIAL CELLS, LEYDIG

______ - are male sex hormones secreted by the testes. These include: ______, ______, and ______.

Androgens, testosterone, dihydrotestosterone, androstenedione

______ is so much more abundant than the others that one can consider it to be the primary testicular hormone. Though much of it are later converted to the more active hormone, ______ in target issues.

Testosterone, dihydrotestosterone

Testosterone is formed by the ______, which lie in the interstices between the ______ and constitute about ______% of the mass of the adult testes.

interstitial cells of Leydig, seminiferous tubules, 20

______ - are almost nonexistent in the testes during childhood, when the testes secrete almost no testosterone.

Leydig cells

______ - They are numerous in the newborn male infant for the first few ______ of life and in the adult male after ______; at both these times the testes secrete ______ quantities of testosterone.

Leydig cells, months, puberty, large

When tumors develop from the interstitial cells of Leydig, great quantities of ______ are secreted.

testosterone

When the ______ of the testes is destroyed by x-ray treatment or excessive heat, the ______, which are less easily destroyed, often continue to produce ______.

germinal epithelium, Leydig cells, testosterone

______ - means any steroid hormone that has masculinizing effects, including testosterone; it also includes male sex hormones produced elsewhere in the body besides the testes.

Androgen

The ______ - release small amounts of androgens (atleast ______), but this amount is usually too low to cause masculine traits. This is because the Masculinizing activity of all these adrogens are less than ______% of the total in the adult male.

adrenal glands, five, 5

SECRETION OF ANDROGENS ELSEWHERE IN THE BODY In women, these hormones only affect the growth of ______ and ______ (underarm) hair. However, if there's a tumor in the ______, it can lead to a high production of ______, which may cause male-like characteristics in women-a condition known as ______.

pubic, axillary, adrenal glands, androgens, adrenogenital syndrome

SECRETION OF ANDROGENS ELSEWHERE IN THE BODY Rarely, ______ in the ovary can develop into a tumor, like ______, which leads to excess androgen production.

embryonic crest cells, arrhenoblastoma

All androgens are ______. Both in the ______ and in the ______, the androgens can be synthesized either from ______ or directly from ______.

steroid compounds, testes, adrenals, cholesterol, acetyl coenzyme A

METABOLISM OF TESTOSTERONE. After being released by the testes, about ______% of testosterone binds to ______-either loosely to ______ or tightly to ______. It circulates in the blood for ______ minutes to several hours, after which it is either absorbed by ______ or broken down for ______.

97, plasma proteins, albumin, sex hormone-binding globulin, 30, tissues, excretion

METABOLISM OF TESTOSTERONE. In many tissues, especially the ______ in adults and the ______ in male fetuses, testosterone is converted to ______, which enhances its effects in these areas. Some but not all actions of testosterone rely on this conversion.

prostate gland, external genitalia, dihydrotestosterone

DEGRADATION AND EXCRETION OF TESTOSTERONE. The ______, rapidly converts testosterone that does not become fixed to the tissues into ______ and ______, and simultaneously conjugated as either ______ or ______ (______, particularly).

Liver, androsterone, dehydroepiandrosterone, glucuronides, sulfates, glucuronides

DEGRADATION AND EXCRETION OF TESTOSTERONE. These substances are excreted either into the ______ by way of the ______ or into the ______ through the ______.

gut, liver bile, urine, kidneys

PRODUCTION OF ESTROGEN IN THE MALE In addition to testosterone, small amounts of estrogens are also formed in males-about ______ the amount found in nonpregnant females. Notably, a reasonable quantity of estrogens can even be recovered from a man's ______.

one-fifth, urine

PRODUCTION OF ESTROGEN IN THE MALE Although the exact source of estrogens in males remains unclear, the following information is known: The concentration of estrogens in the fluid of the ______ is quite high, likely playing an important role in ______. This estrogen is believed to be formed by the ______ through the conversion of ______ to ______.

seminiferous tubules, spermiogenesis, Sertoli cells, testosterone, estradiol

Although the exact source of estrogens in males remains unclear, the following information is known: Larger amounts of estrogens are produced from ______ and ______ in other tissues, especially in the ______, probably accounting for up to ______% of the total estrogen production in males.

testosterone, androstanediol, liver, 80

______ - is generally responsible for the defining characteristics of the masculine body. During fetal development, ______ from the ______ prompts the testes to produce ______, lasting through development and about ______ weeks post-birth.

Testosterone, chorionic gonadotropin, placenta, moderate testosterone, 10

FUNCTIONS OF TESTOSTERONE Thereafter, essentially ______ is produced during childhood until approximately the ages of ______ to ______ years. It then rapidly increases during ______, due to ______ hormones from the ______, continuing through most of life but declining around ______-______ years.

no testosterone, 10, 13, puberty, gonadotropic, anterior pituitary, 50, 60

FUNCTIONS OF TESTOSTERONE Studies show testosterone levels remain ______ in most healthy older men, with only ______-______% of men over ______ and ______% over ______ showing "______" levels (<______ ng/ml).

normal, 10, 20, 60, 50, 80, low, 3

FUNCTIONS OF TESTOSTERONE DURING FETAL DEVELOPMENT Testosterone begins to be produced by the male fetal testes around the ______ week of embryonic life. A key difference between male and female sex chromosomes is the presence of the ______ on the male chromosome, which encodes the ______ (______). This protein triggers a cascade of gene activations that cause ______ to differentiate into testes, which then secrete ______. In contrast, the female chromosome leads to the secretion of ______.

7th, sex-determining region Y (SRY) gene, testis determining factor, SRY protein, genital ridge cells, testosterone, estrogens

FUNCTIONS OF TESTOSTERONE DURING FETAL DEVELOPMENT Injecting large quantities of male sex hormones into pregnant animals can stimulate the development of ______ in ______ fetuses. Also early removal of the testes in male fetuses results in the development of ______.

male sexual organs, female, female sexual organs

FUNCTIONS OF TESTOSTERONE DURING FETAL DEVELOPMENT Thus, testosterone secreted by the ______ is crucial for developing male body characteristics, including the formation of a ______ and ______ instead of a clitoris and vagina. It also promotes the formation of the ______, ______, and ______ while suppressing the development of ______.

fetal testes, penis, scrotum, prostate gland, seminal vesicles, male genital ducts, female genital organs

EFFECT OF TESTOSTERONE TO CAUSE DESCENT OF THE TESTES The testes typically descend into the ______ during the last ______ to ______ months of ______, when the testes begin secreting reasonable quantities of testosterone. If a male child is born with ______, yet otherwise ______ testes, the administration of ______ can facilitate their descent, provided the ______ are large enough for the testes to pass through.

scrotum, 2, 3, gestation, undescended, normal, testosterone, inguinal canals

EFFECT OF TESTOSTERONE TO CAUSE DESCENT OF THE TESTES Additionally, administering ______ stimulates the ______ in the newborn's testes to produce testosterone, which can also promote the ______ of the testes.

gonadotropic hormones, Leydig cells, descent

EFFECT OF TESTOSTERONE ON DEVELOPMENT OF ADULT PRIMARY AND SECONDARY SEXUAL CHARACTERISTICS primary Sexual Characteristics: • Testosterone secretion after ______ causes the ______, ______, and ______ to enlarge about ______ before age ______.

puberty, penis, scrotum, testes, eightfold, 20

EFFECT OF TESTOSTERONE ON DEVELOPMENT OF ADULT PRIMARY AND SECONDARY SEXUAL CHARACTERISTICS Secondary Sexual Characteristics: • Testosterone also promotes development of male ______.

secondary sexual characteristics

EFFECT OF TESTOSTERONE ON DEVELOPMENT OF ADULT PRIMARY AND SECONDARY SEXUAL CHARACTERISTICS -begins at ______, and ending at ______.

puberty, maturity

EFFECT OF TESTOSTERONE ON DEVELOPMENT OF ADULT PRIMARY AND SECONDARY SEXUAL CHARACTERISTICS -allows to distinguish the ______ from the ______

male, female

Effect on Body Hair Distribution Testosterone causes growth of hair over the ______, along the ______ (______/______), on the ______, ______, and sometimes on the ______.

pubis, linea alba, abdomen, umbilicus, face, chest, back

Male Pattern Baldness Testosterone ______ hair growth on the top of the head; baldness is influenced by ______ and ______.

decreases, genetics, androgenic hormones

Effect on Voice Testosterone causes ______ of the ______ and enlargement of the ______, leading to a "______" voice that gradually matures into an adult masculine voice.

hypertrophy, laryngeal mucosa, larynx, cracking

TESTOSTERONE ______ THICKNESS OF THE SKIN AND CAN CONTRIBUTE TO DEVELOPMENT OF ______

INCREASES, ACNE

Testosterone ______ the thickness of the ______ over the entire body and the ruggedness of the ______.

increases, skin, subcutaneous tissues

Testosterone Increases secretion rate by ______, especially on the face, leading to ______

sebaceous glands, ache

______ is common in male adolescence when first exposed to increased testosterone.

Acne

After several years of testosterone secretion, the skin normally ______ to the testosterone in a way that allows it to overcome the ______.

adapts, acne

TESTOSTERONE ______ PROTEIN FORMATION AND MUSCLE DEVELOPMENT

INCREASES

Testosterone ______ muscle mass by about ______% over that in females and ______ protein in non muscle parts of the body.

increases, 50, increases

Changes in skin and voice partly result from testosterone's ______.

protein anabolic function

______ are used by athletes to enhance performance but have prolonged harmful effects.

Synthetic androgens

Testosterone is sometimes used in old age as a "______" with questionable results, and may ______ cardiovascular risk in elderly men.

youth hormone, increase

TESTOSTERONE ______ BONE MATRIX AND ______ CALCIUM RETENTION

INCREASES, CAUSES

Testosterone ______ bones and ______ calcium retention, increasing ______ due to its protein anabolic effects.

thickens, promotes, bone matrix

Testosterone has a specific effect on the pelvis on (1) ______ the pelvic outlet, (2) ______ it, (3) cause a ______ shape instead of the broad ovoid shape of the female pelvis, and (4) greatly increase the ______ of the entire pelvis for load bearing.

narrowing, lengthen, funnel-like, strength

Testosterone can be used to treat ______ in older men. In children with excess testosterone, rapid ______ occurs, but early ______ limits final ______, ______ to shorter adult stature than in males castrated before puberty.

osteoporosis, bone growth, epiphyseal fusion, height, leading

TESTOSTERONE ______ THE BASAL METABOLIC RATE

INCREASES

Testosterone ______ the basal metabolic rate, with large injections raising it by up to ______% and normal levels during adolescence and early adulthood increasing it by ______% to ______%, likely due to its effect on ______.

increases, 15, 5, 10, protein anabolism

TESTOSTERONE ______ RED BLOOD CELLS

INCREASES

Testosterone ______ red blood cell production, with normal injections raising red blood cells by ______% to ______% in castrated adults, and average men having about ______ more red blood cells per cubic millimeter than women; however, testosterone does not directly raise ______, and its effect may be partly indirect due to increased ______.

increases, 15, 20, 700,000, erythropoietin levels, metabolic rate

TESTOSTERONE ______ PROTEIN FORMATION AND MUSCLE DEVELOPMENT

INCREASES

Testosterone ______ sodium reabsorption in the ______, but to a lesser extent than ______. As a result, after puberty, the ______ and ______ volumes in males increase by ______% to ______% relative to body weight.

increases, kidneys, adrenal mineralocorticoids, blood, extracellular fluid, 5, 10

BASIC INTRACELLULAR MECHANISM OF ACTION OF TESTOSTERONE Testosterone primarily functions by increasing ______ in target cells. In tissues like the ______, testosterone enters cells and is converted to ______ by the enzyme ______. ______ binds with a ______, forming a complex that migrates to the cell nucleus. There, it initiates ______, leading to ______ within and an increase in ______. This rise in RNA triggers a gradual increase in ______. Over several days, ______ and the number of cells in the ______ also increase.

protein synthesis, prostate gland, dihydrotestosterone (DHT), 5a-reductase, DHT, cytoplasmic receptor protein, DNA-RNA transcription, RNA polymerase activation, RNA concentration, cellular protein, DNA content, prostate

BASIC INTRACELLULAR MECHANISM OF ACTION OF TESTOSTERONE Testosterone enhances ______ throughout the body but has specific effects in target organs, promoting the development of ______ and ______ male sexual characteristics.

protein production, primary, secondary

CONTROL OF MALE SEXUAL FUNCTIONS BY HORMONES FROM THE ______ AND ______

HYPOTHALAMUS, ANTERIOR PITUITARY GLAND

The hypothalamus secretes ______, which prompts the anterior pituitary to release ______ and ______.

gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), follicle-stimulating hormone (FSH)

CONTROL OF MALE SEXUAL FUNCTIONS BY HORMONES FROM THE ANTERIOR PITUITARY GLAND ______ - primarily stimulates testosterone secretion in the testes

Luteinizing hormone (LH)

CONTROL OF MALE SEXUAL FUNCTIONS BY HORMONES FROM THE ANTERIOR PITUITARY GLAND ______ - supports spermatogenesis.

Follicle-stimulating hormone (FSH)

______ INCREASES SECRETION OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE

GONADOTROPIN-RELEASING HORMONE

GnRH is a ______-amino acid peptide produced by neurons in the ______ of the ______. These neurons release GnRH into the ______ portal system at the ______, allowing it to reach the ______. There, GRH stimulates the release of two key gonadotropins: ______ and ______.

10, arcuate nuclei, hypothalamus, hypothalamic-hypophysial, median eminence, anterior pituitary gland, luteinizing hormone (LH), follicle-stimulating hormone (FSH)

GnRH secretion occurs in short pulses every ______-______ hours, with its effect controlled by both the ______ of these pulses and the ______ of GnRH released in each cycle. LH secretion from the anterior pituitary mirrors GnRH's ______, creating a close relationship between the two. In contrast, FSH secretion fluctuates less with each ______, changing more gradually in response to long-term shifts in GnRH levels. Due to this close link with LH release, GnRH is also commonly referred to as ______.

1, 3, frequency, amount, pulsatile release pattern, GnRH pulse, LH-releasing hormone

LH and FSH are ______ hormones produced by ______ in the ______. Their release depends on ______ from the ______; without GnRH, almost ______ LH or FSH is released.

glycoprotein, gonadotropes, anterior pituitary gland, GnRH secretion, hypothalamus, no

In the testes, LH and FSH act by activating the ______, which then triggers specific enzymes in target cells to exert their effects.

cyclic adenosine monophosphate second messenger system

GONADOTROPIC HORMONES: ______ AND ______

LUTEINIZING HORMONE, FOLLICLE-STIMULATING HORMONE

REGULATION OF TESTOSTERONE PRODUCTION BY LUTEINIZING HORMONE. Testosterone is secreted by the ______ in the testes, but only under stimulation by ______ from the ______. The amount of testosterone released is ______ to the available LH. Leydig cells are present in a child's testes briefly after ______, then reappear around ______. Injection of LH at any age, or its natural rise at puberty, transforms ______ into ______ capable of testosterone production.

interstitial cells of Leydig, LH, anterior pituitary gland, directly proportional, birth, puberty, testicular fibroblast-like cells, active Leydig cells

INHIBITION OF ANTERIOR PITUITARY SECRETION OF LUTEINIZING AND FOLLICLE-STIMULATING HORMONES BY TESTOSTERONE-NEGATIVE FEEDBACK CONTROL OF TESTOSTERONE SECRETION Testosterone produced by the testes in response to LH ______ further LH and FSH secretion from the ______. This effect is primarily due to testosterone's action on the ______, reducing ______. Lower GnRH levels lead to decreased ______ and ______ production, ultimately reducing ______ by the ______.

inhibits, anterior pituitary, hypothalamus, GnRH release, LH, FSH, testosterone output, testes

INHIBITION OF ANTERIOR PITUITARY SECRETION OF LUTEINIZING AND FOLLICLE-STIMULATING HORMONES BY TESTOSTERONE-NEGATIVE FEEDBACK CONTROL OF TESTOSTERONE SECRETION This negative feedback loop helps stabilize ______. High testosterone triggers reduced ______, ______, and ______ secretion, lowering ______ production. Conversely, ______ testosterone allows increased ______, which raises ______ and ______ levels, stimulating the testes to produce ______ testosterone. This balance maintains optimal testosterone levels in the body.

testosterone levels, GnRH, LH, FSH, testosterone, low, GnRH, LH, FSH, more

REGULATION OF SPERMATOGENESIS BY FOLLICLE-STIMULATING HORMONE AND TESTOSTERONE FSH plays a critical role in spermatogenesis by binding to receptors on ______ within the ______, leading these cells to grow and release substances necessary for sperm development. ______, produced by ______ and diffusing into the ______, also supports spermatogenesis. Both ______ and ______ are essential to initiate this process.

Sertoli cells, seminiferous tubules, Testosterone, Leydig cells, seminiferous tubules, FSH, testosterone

______, a glycoprotein hormone secreted by ______ in the ______, plays a key role in regulating FSH levels through a negative feedback mechanism. When spermatogenesis is low or sperm production halts, ______ secretion by the anterior pituitary ______. When spermatogenesis accelerates, ______ by Sertoli cells rises, directly inhibiting ______ by the pituitary and thereby slowing ______.

Inhibin, Sertoli cells, seminiferous tubules, FSH, increases, inhibin release, FSH secretion, spermatogenesis

ROLE OF INHIBIN IN NEGATIVE FEEDBACK CONTROL OF SEMINIFEROUS TUBULE ACTIVITY. Inhibin's inhibitory effect on the ______ provides crucial control over ______, working alongside the ______ to maintain balanced sperm production and hormonal levels.

anterior pituitary, spermatogenesis, testosterone feedback system

MATURAHUMAN CHORIONIC CONADOTROPIN SECRETED BY THE PLACENTA DURING PREGNANCY STIMULATES TESTOSTERONE SECRETION BY THE FETAL TESTES TION OF SPERM IN THE EPIDIDYMIS • During pregnancy, ______ is secreted by the ______ and affects the sexual organs similarly to ______.

human chorionic gonadotropin (hCG), placenta, LH

MATURAHUMAN CHORIONIC CONADOTROPIN SECRETED BY THE PLACENTA DURING PREGNANCY STIMULATES TESTOSTERONE SECRETION BY THE FETAL TESTES TION OF SPERM IN THE EPIDIDYMIS • If the fetus is male, ______ stimulates the testes to secrete ______.

hCG, testosterone

MATURAHUMAN CHORIONIC CONADOTROPIN SECRETED BY THE PLACENTA DURING PREGNANCY STIMULATES TESTOSTERONE SECRETION BY THE FETAL TESTES TION OF SPERM IN THE EPIDIDYMIS • Testosterone is essential for the formation of ______.

male sexual organs

PUBERTY AND REGULATION OF ITS ONSET • The initiation of puberty was previously a mystery but is now understood to involve the ______ not secreting significant amounts of ______ during childhood.

hypothalamus, Gonadotropin-releasing hormone (GnRH)

PUBERTY AND REGULATION OF ITS ONSET • During childhood, even slight secretion of ______ strongly inhibits hypothalamic ______.

sex steroid hormones, GnRH secretion

PUBERTY AND REGULATION OF ITS ONSET • At puberty, the secretion of hypothalamic ______ overcomes childhood inhibition, signaling the beginning of adult ______.

GnRH, sexual life

MALE ADULT SEXUAL LIFE AND MALE CLIMACTERIC • After puberty, ______ are produced by the male ______, and ______ usually continues until death.

gonadotropic hormones, pituitary gland, spermatogenesis

MALE ADULT SEXUAL LIFE AND MALE CLIMACTERIC • Many men begin to experience a gradual ______ in sexual function in their late ______ or ______, especially if they ______, are ______, or have ______ and ______ disorders (e.g., hypertension, atherosclerosis, type 2 diabetes).

decline, 50s, 60s, smoke, obese, cardiovascular, metabolic

MALE ADULT SEXUAL LIFE AND MALE CLIMACTERIC • There is considerable variation in the decline of sexual function, with some healthy men remaining virile into their ______ and ______.

80s, 90s

MALE ADULT SEXUAL LIFE AND MALE CLIMACTERIC • The decline in sexual function is partly related to decreased testosterone secretion and is referred to as the ______.

male climacteric

THE PROSTATE GLAND AND ITS ABNORMALITIES • The prostate gland grows during ______ due to testosterone, stabilizes by age ______, and may involute around age ______ with decreased testosterone; ______ can cause urinary obstruction in older men.

puberty, 20, 50, benign prostatic fibroadenomas

THE PROSTATE GLAND AND ITS ABNORMALITIES • ______, stimulated by testosterone and accounting for ______% to ______% of male deaths, can be slowed by removing both ______ and treated with ______, though treatment does not stop the cancer.

Prostate cancer, 2, 3, testes, estrogens

TESTICULAR TUMORS AND HYPERGONADISM IN THE MALE • ______ in the testes can produce excessive testosterone, leading to rapid ______ in children, early ______, and development of male ______; they are difficult to diagnose in adults due to pre-existing masculine features.

Interstitial Leydig cell tumors, growth, epiphyseal closure, sexual characteristics

TESTICULAR TUMORS AND HYPERGONADISM IN THE MALE • ______, more common than Leydig cell tumors, may contain various tissues and secrete hormones like ______ or ______, potentially causing ______.

Germinal epithelium tumors, hCG, estrogen, gynecomastia

ABNORMALITIES OF MALE SEXUAL FUNCTION ______ IN THE MALE • Nonfunctional testes during fetal development lead to ______; ______ is essential for male organ formation. Loss of testes before puberty results in ______, characterized by infantile ______ and increased ______.

HYPOGONADISM, female sexual characteristics, testosterone, eunuchism, sex organs, height

ABNORMALITIES OF MALE SEXUAL FUNCTION HYPOGONADISM IN THE MALE • ______ after puberty causes partial regression of ______, decreased ______, and rare ______. Some hypogonadism cases arise from a genetic inability of the ______ to secrete normal ______, often leading to ______ and ______ (______).

Castration, male characteristics, sexual desire, ejaculation, hypothalamus, GnRH, obesity, eunuchism, adiposogenital syndrome

ABNORMALITIES OF MALE SEXUAL FUNCTION • ______ (______) is the inability to achieve or maintain an erection sufficient for sexual intercourse, often caused by ______ issues, ______ testosterone levels, certain ______, or underlying ______, particularly in men over ______.

Erectile dysfunction, impotence, neurological, low, medications, vascular disease, 40

ABNORMALITIES OF MALE SEXUAL FUNCTION ERECTILE DYSFUNCTION IN THE MALE • Vascular disease impairs ______ and decrease ______, reducing penis ability to dilate; treatments like ______ (e.g., sildenafil, vardenafil, tadalafil) can enhance erection by increasing ______ levels in erectile tissue.

blood flow, nitric oxide release, phosphodiesterase-5 (PDE5) inhibitors, cyclic GMP

ABNORMALITIES OF MALE SEXUAL FUNCTION • The ______ regulates seasonal fertility in some animals by responding to ______; its removal disrupts normal ______, which are crucial for ______ during optimal survival seasons.

pineal gland, light patterns, reproductive cycles, birthing

ABNORMALITIES OF MALE SEXUAL FUNCTION FUNCTION OF THE PINEAL GLAND IN CONTROLLING SEASONAL FERTILITY IN SOME ANIMALS • The gland secretes ______, which decreases ______ secretion from the ______, inhibiting ______ during longer periods of ______; after several months, this inhibition can ______, ______ gonadal activity.

melatonin, gonadotropic hormone, anterior pituitary, gonadal function, darkness, lift, reactivating