Male Reproductive System

What does the male reproductive system consist of?

Scrotum
Testes
Epididymis
Vas Deferens
Seminal Vesicles
Prostate gland
Bulbourethral glands
Urethra
Penis

Scrotum: What is the scrotum?

a saclike structure that contains the testes.

Scrotum: The scrotum is divided into _ internal compartments.

2

Scrotum: The scrotum is marked in the midline by an irregular ridge known as the...

raphe

Scrotum: In colder temperatures these two muscles contract pulling the scrotum up towards the body, and in warmer temperatures the relax.

Dartos and Cremaster

Scrotum: This response is important because sperm cells do not develop normally if its too cool or warm. You could say sperm cells are...

temperature-sensitive

Testes: They are small, ovoid organs, each about ___ cm long, within the scrotum.

4-5

Testes: They function as what kind of glands?

Exocrine and Endocrine

Testes: Their major exocrine secretion is...

sperm cells

Testes: Their major endocrine secretions is the hormone...

testosterone

Testes: What is inside the testes where sperm is first developed?

Seminiferous tubules

Testes: The combined length of the tubules in both testes is about how long?

nearly half a mile in length

Descent of Testes: Testes develop in utero at approximately _ weeks with all other organs.

8

Descent of Testes: The testes are originally located in the...

retroperitoneal cavity

Descent of Testes: Between ______________ months of development, the testes move through the inguinal canals into the scrotum.

7 and 9

Descent of Testes: Prior to the 28 weeks the testes have descended into the scrotum in about __% of males.

79

Descent of Testes: After the 28 weeks the testes have descended into the scrotum in about __% of males.

98

Sperm Cell Development: The testes remain relatively simple and unchanged from the time of their initial development before...

puberty

Sperm Cell Development: When does sperm production begin?

12-14 years of age

Sperm Cell Development: How long does it take for sperm to develop?

74 days

Sperm Cell Development: Out of the 74 days of development __ of those days the sperm cells spend in the seminiferous tubules.

50

Sperm Cell Development: Sperm cell development or _________________ occurs in the seminiferous tubules.

spermatogenesis

The Ducts: After being released into the seminiferous tubules, the sperm cells leave the testis and enter the...

epididymis

The Ducts: The sperm cells then leave the epididymis and pass through the...? (3)

vas deferens, ejaculatory duct, and urethra

The Epididymis: The Ducts from each testis become extremely convoluted and form a comma-shaped structure on the posterior side of the testis called the...

epididymis

The Epididymis: How long does it take for sperm to finish its final maturation and travel through the epididymis to appear in the ejaculate.

12-16 days

The Epididymis: Are sperm cells from the head of the epididymis able to fertilize secondary oocytes?

no

The Epididymis: Are sperm cells from the head of the epididymis motile?

no

The Epididymis: If sperm cells are taken from the tail are they are both fertile and motile (True/False)

True

Vas Deferens & Ejaculatory Duct: What is the spermatic cord?

Where the vas deferens emerge from the tail of the epididymis and associates with the blood vessels and nerves that supply the testis.

Vas Deferens & Ejaculatory Duct: What makes up the spermatic cord? (4)

Vas Deferens
Testicular artery
Lymphatic Vessels
Nerves

Vas Deferens & Ejaculatory Duct: The spermatic cord structures ascend and pass through the ___________ ___________ to enter the pelvic cavity.

inguinal canal

Vas Deferens & Ejaculatory Duct: The vas deferens crosses the lateral and posterior walls of the __________ cavity, travels over the _________, and loops over the posterior surface of the urinary ____________ to approach the _____________ gland to form the _________ of the vas deferens

Pelvic, Ureter, Bladder, Prostate, Ampulla

Vas Deferens & Ejaculatory Duct: Adjacent to the vas deferens is a sac-shaped gland called the...

seminal vesicle

Vas Deferens & Ejaculatory Duct: A short duct from the seminal vesicle joins the vas deferens to form the...

ejaculatory duct

Vas Deferens & Ejaculatory Duct: These ducts project into the prostate gland and end by opening into the...

urethra

Urethra: How long is the male urethra?

20 cm

Urethra: What is the urethra the passageway for?

Urine and Male Reproductive fluids

Urethra: The three parts

Prostatic part
Membranous part
Spongy part

Penis: The male organ of __________, through which sperm cells are transferred from the male to the female.

copulation

Penis: It contains how many columns of erectile tissue.

3 (three)

Penis: What is an erection?

Engorgement of this erectile tissue with blood causes the penis to enlarge and become firm.

Penis: A cap over the distal end of the penis is known as?

Glans Penis

Penis: Skin is loosely attached to the connective tissue that surrounds the erectile columns, and a ______ layer of skin tightly covers the glans penis.

thinner

Penis: What are the two names for the loose skin fold that covers the glans penis?

Prepuce or Foreskin

Accessory Glands: Seminal Vesicles - Sac-shaped glands located next to the ampulla of the...

Vas Deferens

Accessory Glands: Seminal Vesicles - The end of the seminal vesicles join with the ampulla of the vas deferens to from the...

ejaculatory duct

Accessory Glands: Prostate Gland - The prostate gland resembles a ____________ in shape and size.

walnut

Accessory Glands: Prostate Gland - Where is the prostate gland located?

It is dorsal to symphysis pubis at the base of the urinary bladder, where it surrounds the prostatic urethra and the two ejaculatory ducts.

Accessory Glands: Prostate Gland - How many small prostatic ducts carry these secretions into the prostatic urethra?

15-30

Accessory Glands: Bulbourethral Gland - Located near the ____________________ part of the urethra.

membranous

Accessory Glands: Bulbourethral Gland - How big is it in young males?

the size of a pea

Accessory Glands: Bulbourethral Gland - The small ducts of each gland unite to form a single duct, which then enters the ___________ urethra at the base of the penis.

spongy

Semen Contents: What is semen?

The sperm cells and secretion from the male reproductive glands

Semen Contents: Seminal Vesicles

60%

Semen Contents: Prostate Gland

30%

Semen Contents: Testes

5%

Semen Contents: Bulbourethral Glands

5%

Semen Contents: What is the discharge of all these secretions from the vas deferens into the urethra?

Emission

Semen Contents: What is the forceful expulsion of semen from the urethra caused by contraction of the urethra, the skeletal muscles in the pelvic floor, and the muscles at the base of the penis.

Ejaculation

Purpose of Semen Contents: Bulbourethral gland Secretions

Produce a substance that neutralizes the contents of the normally acidic spongy urethra.

Purpose of Semen Contents: Testicular Secretions

sperm cells

Purpose of Semen Contents: Seminal Vesicle Secretions

large amounts of fructose, citric acid, and other nutrients that nourishes sperm cells.

Purpose of Semen Contents: Prostate Gland Secretion

Thin milky secretions with a basic pH that help protect the semen from the acidic female reproductive tract.

Semen: The normal sperm cell count in the semen ranges from __________ million sperm cells per ML.

75 - 400

Semen: A normal ejaculation usually consists of about __________ ML of semen.

2 - 5

Semen: The semen with the highest sperm count if expelled from the penis _______ because it contains the greater percentage of sperm-containing fluids from the epididymis.

first

Semen: When do sperm cells become motile?

after ejaculation

Regulation of Sex Hormones: Hormonal mechanisms that influence the male reproductive system involve which three things?

Hypothalamus
Pituitary Gland
Testes

Regulation of Sex Hormones: The hypothalamus releases...

Gonadotropin-releasing hormone (GnRH)

Regulation of Sex Hormones: In response the pituitary gland secretes __________ which influences the gonads in both males and females.

gonadotropins

Regulation of Sex Hormones: LH

increase the rate of testosterone synthesis and secretion

Regulation of Sex Hormones: FSH

promotes sperm cell development

Testosterone: It is?

The major male hormone secreted by the testes

Testosterone: It is classified as a...

androgen

Testosterone: The testes secrete small amounts of...

estrogen and progesterone

Puberty in Males: What is secreted by the placenta that stimulates the synthesis and secretion of testosterone by the fetal testes.

Human chorionic gonadotropin (hCG)

Puberty in Males: The testes of the newborn baby atrophy slightly and secrete only small amounts of testosterone until...

puberty

Puberty in Males: What is puberty?

The age at which individuals become capable of sexual reproduction

Puberty in Males: At puberty what three things increase?

GnRh, LH, FSH

Effects of Testosterone: __________________ and differentiation of the male genitals and reproductive duct system and is necessary for sperm cell ________________.

Enlargement, Formation

Effects of Testosterone: Stimulates ______________________ in the pubic area and extending up the linea alba, as well as on the legs, chest, axillary region, face, and back

hair growth

Effects of Testosterone: Texture of skin becomes...

rougher and coarser

Effects of Testosterone: ______________ of the larynx

Hypertrophy

Effects of Testosterone: ____________ metabolism

stimulates

Effects of Testosterone: Red blood cell ______________.

Production

Effects of Testosterone: Promotes protein production ->

increased skeletal muscle mass