Male Reproductive Anatomy Flashcards
Male Puberty begins at __-__ y/o and is Caused by ↑___ production
9-14 testosterone
hat changes occur in men during puberty?
Enlargement of external & internal genitalia Voice changes Androgenic hair growth Mental changes Changes in body conformation and skin Sebaceous gland secretions thicken ↑acne is more common
What hormones are involved in the male reproductive system
FSH LH Testosterone
____ Stimulates development of male 2° sex characteristics & spermatogenesis.
Testosterone
___ stimulates spermatogenesis
FSH
__stimulates production of testosterone
LH (aka ICSH)
testosterone spikes at __-__ y.o. And slowly decreases over time
20-30
testosterone is produced by ___ of the testes
Leydig cells
In testes, prostate, seminal vesicles, and skin, testosterone acts only when converted to ___ by____
5α-DHT by 5α-reductase
____ steroids (androgenic but not testosterone) are resistant to this conversion
Anabolic
Who may be candidates for Testosterone Replacement:
Men w/ primary hypogonadism or hormonal decline
____ are Synthetic testosterone derivatives & Mimic the effect of testosterone in muscle, bone, liver, other peripheral tissues (stimulates growth of muscle tissue and bones; speeds muscle recovery following exercise or injury)
Anabolic Steroids
Effect of ↑ peripheral androgens (5)
- ↑ muscle mass/bone growth - ↑ liver toxicity/cholesterol - ↑ risk of CV dz - ↑ mood effects (‘roid rage) - Paranoia and delusions
Effect of ↓ 5α-DHT
- ↓ sperm counts - ↓ size of reproductive organs - ↓ libido - Infertility - Depression
Effect of ↓ 5α-DHT
- ↓ sperm counts - ↓ size of reproductive organs - ↓ libido - Infertility - Depression
What makes up external male genitalia?
Testes Scrotum Penis
Each testis is an oval structure ~___ cm long and __ cm in diameter
5 3
the testis is covered by a cortex structure called the ____ ______ located in the scrotum
tunica albuginea
There are ~__ lobules in each testis, each contains __-___ seminiferous tubules that converge to form single straight tubule, which leads into the ___
250 1-4 rete testis
____ produce male sex hormones, located b/w the seminiferous tubules w/in a lobule
Interstitial cells (cells of Leydig)
Each human male has >__ meters of seminiferous tubules in his testes (length is best measurement for SA)
600
____ is an undescended by birth
Cryptorchidism
the Scrotum Consists of ___ and ___
skin subcutaneous tissue
the ___ is made of smooth muscle fibers in subcutaneous tissue, which contract to give scrotum its wrinkled appearance→ when relaxed, scrotum is smooth
dartos muscle
____, controls position of scrotum and testes→ when cold or sexually aroused, it contracts to pull testes closer to body for warmth
Cremaster muscle
the ____ is a Cylindrical organ located anterior to scrotum, functions to transfer sperm to vagina.
Penis→
Consists of ___ columns of erectile tissue wrapped in connective tissue and covered with skin. There are 2 ___ columns called the ____ And a single, ___ column surrounding the urethra called the ____
3 dorsal, corpora cavernosa. ventral, corpus spongiosum.
what are the 3 parts fo the penis?
Root Body (shaft) Glans penis The root of penis attaches it to the pubic arch the body is the visible, pendant portion. The corpus spongiosum expands at the distal end to form the glans penis.
The urethra, which extends throughout the length of the ___, opens through the external urethral orifice at the tip of the glans penis.
corpus spongiosum
A loose fold of skin, called the _____, covers the glans penis.
prepuce, or foreskin
What makes up the internal male genitalia
Epididymitis Spermatic cord Ductus Deferens (vastus deferens) Ejaculatory duct Seminal vesicles Urethra Accessory glands Prostate Bulbourethral glands Seminal fluid/semen
The ___ is a comma shaped organ that is a long tube (~6 meters) located along the superior and posterior margins of the testes
Epididymitis
what is the function of the epididymitis?
Aid in the Complete maturation of sperm Mature sperm are stored in the lower portion/tail of the epididymis
The Spermatic Cord contains:
Proximal ductus deferens Testicular A&V Lymph vessels Testicular nerve Cremaster muscle Connective tissue covering
_____ is a Fibromuscular tube continuous w/ the epididymis that enters the abdominopelvic cavity through the inguinal canal and passes along the lateral pelvic wall, behind bladder, toward the prostate gland
Ductus Deferens [Vas Deferens]
Just before it reaches the prostate gland, each ductus deferens enlarges to form an ___ Sperm are stored in the (proximal/distal) portion of the ductus deferens, near the epididymis
ampulla PROXIMAL
Each ductus deferens, at the ampulla, joins the duct from its corresponding seminal vesicle (one of the accessory glands) to form a ____
Ejaculatory Duct
Each ejaculatory duct passes through the ___ and empties into the____
prostate gland urethra
what would happen is the ejactulatory duct were obstructed
Won’t be able to ejaculate
_____ are Glands posterior to the urinary bladder Each have a short duct that joins w/ the ductus deferens at the ampulla to form an ejaculatory duct, which empties into the urethra
Seminal Vesicles
Describe the fluids in the seminal vesicles and what it contains
Fluid is viscous, contains fructose, prostaglandins, and proteins
The ___ Extends from the urinary bladder to the external urethral orifice at the tip of the penis. It is a passageway for sperm and fluids from the reproductive system and urine from the urinary system.
Urethra
what are the 3 regions the urethra is divided into
The prostatic urethra membranous urethra penile urethra (also called spongy urethra or cavernous urethra)
What are the Accessory Glands and what do they do?
Seminal vesicles Prostate gland Bulbourethral glands They secrete fluids that enter the urethra.
The __ is a Firm, dense structure ~size of a walnut located just inferior to the urinary bladder. Encircles the urethra as it leaves the urinary bladder
prostate
Numerous short ducts from the prostate gland empty into the ____.
prostatic urethra
Waht are the secretions of the prostate like? what is the function of this fluid?
Thin, milky colored, and alkaline. function to enhance sperm motility
What is the consequence of an Enlarged Prostate
Inhibited Urination
____ small (about the size of a pea) and located near the base of the penis. A short duct from each enters the proximal end of the penile urethra.
Bulbourethral Glands
In response to sexual stimulation, the bulbourethral glands secrete an ____ fluid
alkaline mucus-like
_____ is a slightly alkaline mixture of sperm cells and secretions from the accessory glands.
Seminal Fluid/semen→
Semem is made up of __% from seminal vesicles, almost __% from prostate, tiny amount bulbourethral glands
60% 40
Volume in a single ejaculation varies from ___-____ ml. There are between ___-___ million sperm per milliliter of semen.
1.5 to 6.0 50 to 150
Sperm counts < 10 to 20 million/ml can present ____ problems
fertility problems.
What does an Erection involve?
↑ in length, width & firmness Changes in blood supply: arterioles dilate, veins constrict/ are compressed→ The spongy erectile tissue fills w/ blood
____ is the uncoordination or inability of erection
Erectile Dysfunction
What are the steps of spermatogenesis?
Spermatogonium –> Primary spermatocyte –> secondary spermatocyte –> spermatid –> sperm –> into the seminiferous tubule
where are sperm produced?
seminiferous tubules.
W/in the seminiferous tubules are large cells called ____, that support/nourish other cells.
sustentacular cells (Sertoli’s cells)
In early puberty, PGCs locate themselves around the periphery of the seminiferous tubules in the testes At puberty, hormones stimulate these cells to begin dividing by mitosis. Some remain at the periphery as ____. Others become ____. Because they are produced by mitosis, spermatogonia and primary spermatocytes have the same chromosomal composition as the individual’s somatic cells– ___
spermatogonia primary spermatocytes 46, XY
Genetic material is replicated , then each primary spermatocyte goes through ___ to produce , each w/ ___ chromosomes (haploid). Just prior to this division, the genetic material is replicated
meiosis 2 secondary spermatocytes 23
During ___, each secondary spermatocyte divides to produce _____, no replication of genetic material in this division, but a single-stranded sister chromatid goes to each daughter cell.
meiosis II two spermatids
As a result of the two meiotic divisions, each primary spermatocyte produces____, each with ___ chromosomes (haploid)– one from each pair in the original primary spermatocyte.
four spermatids 23
mature sperm cell has a ___, __ and ____
head midpiece tail
What does the head contain?
the 23 chromosomes surrounded by a nuclear membrane.
The tip of the head is covered by an ___, which contains enzymes that help sperm penetrate the female gamete
acrosome
The midpiece os sperm (metabolic region) contains ____ that provide ___.
mitochondria ATP
The tail, locomotor region, uses a ____ for locomotion.
flagellum
What is the path of a sperm cell?
testes (seminiferous tubules–> epididymis –> vas deferens –> ejaculatory duct –> urethra
How long does spermatogeneis take?
beginning with a primary spermatocyte, takes about 74 days
After ejaculation, the sperm can live for about__ hours in the female reproductive tract.
48+
How long after the time of a vasectomy does a man become officially “infertile”?
~ 3 months
What organs does Testosterone affect?
