Reproductive Systems

Human Reproduction and Childbirth

Today

Review male reproductive anatomy

View a video on human reproduction, fertilization, pregnancy and childbirth

Do the review sheet found in your Google Classroom

MALE REPRODUCTIVE SYSTEM

EXTERNAL MALE REPRODUCTIVE ORGANS

Penis ▶ The male organ for sexual intercourse,

reproduction, and urination. ▶ The reproductive purpose of the penis is to

deposit semen in the vagina during sexual intercourse.

▶ The head of the penis or glans contains many nerve endings.

▶ At birth, the glans is covered by a loosely fitting skin called the foreskin.

▶ When a male gets excited the penis becomes engorged with blood, causing the penis to be stiff and hard.

Scrotum

▶ A sac-like pouch located behind the penis that holds each testes and helps regulate temperature for sperm production.

▶ Needs to be 1 ½ degrees cooler than body temperature to produce sperm.

Testicles or Testes▶ The two testes are small organs

about the size of a peach pit that lie in the scrotum and produce sperm and male hormone testosterone. The testicles are the male sex gland.

▶ Each testes has about 1 mile of tubing.

▶ Produce 1 – 10 million sperm per day.

 INTERNAL MALE REPRODUCTIVE ORGANS

Testosterone▶ The male reproductive hormone made by the

testicles which causes the changes of puberty. (Counterpart to female estrogen and progesterone).

▶ This hormone causes secondary sex characteristics, production of sperm, sexual urge.

▶ Testosterone is produced in the testicles and enters the bloodstream at a fairly constant rate.

Sperm▶ The microscopic cells produced by the male’s testicles which can fertilize

the female’s ovum.

▶ They are tiny, living cells 100 times smaller than a pencil dot. Enough sperm would fit on the head of a pin to re-populate the earth if each sperm fertilized an egg.

▶ Sperm is the male reproductive cell or seed (counterpart to female ovum).

▶ Can swim 1 inch every 8 minutes.

▶ Can live inside the female for about 5 days

▶  The average ejaculation contains close to 100 million sperm.

▶ Men who have fewer than 20 million sperm per milliliter of semen may be at risk for having infertility issues

Epididymis▶ The structure that forms a mass

over the back and upper part of each testes.

▶ Sperm may be held for as long as six weeks while they ripen to maturity.

▶ Here, they gain the ability to swim.

▶ The epididymis can be felt when doing a testicular exam

Testicular Self-Exam

▶ Testicular cancer is RARE▶ Usually seen in males

between the ages of 15 and 35

▶ Easily diagnosed and treated▶ Symptoms include lump or

feeling of heaviness in the scrotum, dull ache in abdomen or groin

Seminal Vesicles▶ Two small glands

that secrete a sugary fluid that nourishes and enables the sperm to move.

Cowper’s Gland▶ Two small pea-sized

glands located beneath the prostate gland on both sides of the base of the penis.

▶ They secrete a clear, sticky fluid that adds lubrication.

Prostate Gland▶ Surrounds the urethra beneath the

bladder.

▶ The gland secretes an alkaline (milky) fluid that neutralizes the acid found in the male urethra and the female reproductive tract.

▶ Protects the sperm from the hostile female environment.

▶ Common site of cancer in males over the age of 50

▶ Prostate exam is a rectal exam by a healthcare professional

Vas Deferens▶ Two long, thin tubes that serve as

a passageway for sperm.

▶ About 18 inches long.

▶ Receive sperm from the epididymis and carry to the urethra

▶ A VASECTOMY is a minor surgical sterilization procedure. A small portion of the vas deferens is snipped to interrupt the flow of sperm from the epididymis.

▶ The male is still able to discharge semen when ejaculating, as all the other male reproductive glands contribute fluid to the ejaculate

Urethra▶ Dual purpose tube that

both semen and urine pass through to leave the body.

▶ Semen and urine never mix.

▶ Special muscles or sphincters surround the urethra.

▶ When a male has an erection, he can not urinate.

Circumcision▶ Process that surgically

removes the flap of skin that covers the glans of the penis.

▶ May reduce the risk of infection and spread of STIs

▶ Intact men must retract the foreskin to keep area beneath the foreskin clean

▶ Smegma collects under the foreskin if not kept clean

▶ Ejaculation/Orgasm: the passage of sperm from the penis, a result of a series of muscular contractions. Pleasurable.

▶ Semen: a combination of fluid that is produced in the seminal vesicles, prostate gland, and Cowper’s gland. This fluid nourishes and helps sperm move through the urethra.

▶ Nocturnal Emission (wet dream): a normal, involuntary ejaculation of semen while a male is asleep. Only a teaspoon of sticky fluid.

▶ Sterility: The failure of sperm to fertilize an egg. Has many causes.

▶ Erectile dysfunction: Inability to get or maintain an erection. Also called impotence.

Functions of the Male Reproductive System

Video: Human Reproduction and Childbirth

The video will

● Review male and female anatomy● Discuss fertilization, pregnancy, fetal development, and

childbirth.● Here’s the video (21 minutes)

Complete your worksheet for the video

Look in your Google Classroom

“Day 2: Human Reproduction and Childbirth”