1

The Human

Reproductive System

Puberty• Sexual maturity begins

• Age: 9-15 years old.

Glands Involved• Hypothalamus

- GnRH (releasing hormone)

• Pituitary

- FSH (Follicle stimulating hormone)

- LH (Luteinizing hormone)

Gonads Functions

• Testes

• Ovaries

• Produces hormone (testosterone)

• Makes & stores sperm

• Gives male secondary sex

characteristics (hair growth, bone

& muscle growth, deep voice)

• Produces hormones

(estrogen, progesterone)

• Regulates menstrual cycle

• Gives secondary sex characteristics:

(hair growth, breasts, widen pelvis, fat

distribution (spread))

Key Reproductive

Hormones

• Testosterone

- made in testes

- stimulates sperm production & male sex

characteristics

• Progesterone

- made in ovaries

- prepares uterus for pregnancy

• Estrogen

- made in ovaries

- stimulates female sex characteristics

• FSH (follicle stimulating hormone)

- produced by the pituitary gland

- stimulates follicle development

- follicle is a pouch containing the egg; located in

ovary

• LH (luteinizing hormone)

- produced by the pituitary gland

- stimulates release of mature egg (ovulation)

- stimulates the development of the corpus

luteum

2

Hypothalamus

Pituitary Gland

FSH LH

Testes

Testosterone

Produces sperm

in testes

Male

Produces a

hormone

This is an

example of

Feedback

Mechanism

Hypothalamus

Pituitary Gland

LH

FSH

Estrogen

Progesterone

Pregnancy

hormoneOvary

Female

This is an

example of

Feedback

Mechanism

Produces

hormones

Male Reproductive System

1. Testes makes testosterone for

sperm development

3. Scrotum saclike pouch, holds testes

away from body so

temperature is 1-2 degrees

below body temp

2. Seminiferous tubules

4. Epididymis

tubes inside testes,

carries/stores/produces

sperm (by meiosis)

storage for sperm, sperm

matures

Male Reproductive System

5. Vas Deferens

a duct (tube) covered by

smooth muscle, transports

sperm from epididymis to

urethra

7. Penis releases the semen into

female reproductive system

6. Urethra a tube that carries sperm

& urine (not a the same

time) through the penis &

out of bodyPenis

Rectum

Epididymis

Testes

Scrotum

Vas

Deferens

Urethra

Bladder

Prostate gland

Seminal

vesicle

Bulbourethral

gland

3

Epididymis

Vas

deferens

Seminiferous

tubules

Vas deferens

Spermatogenesis

SPERMATOGENESIS

• The process of sperm

cell development.

• Begins with puberty, last

well into old age

• Meiosis: 4 haploid

gametes (23 chromosomes)

• Begins in testes, finishes

in epididymis (mature)

• 400,000,000 per day!!

3 Glands

- add fluid to sperm

1. Seminal vesicles

2. Prostate (below the bladder)

3. Bulbourethral glands(2 glands located on either side

of urethra)

• keeps sperm moist

• an alkaline fluid that

neutralizes acid in

female vagina

• feeds sperm (fructose)

Semen – 5 % sperm & 95% fluid from above glands.

Bladder Seminal vesicle

(behind bladder)

Urethra

Scrotum

Glans penisTestes

Epididymis

Vas deferens

Bulbourethral

gland

Prostate gland

TestesPathway

of

Sperm

Urethra

Epididymis

Vas deferens

Penis

4

Sperm Anatomy

Flagellum

Mitochondria

Flagellum

Haploid

nucleus

Acrosome

The Body of a Sperm• Acrosome – has enzymes needed to enter the egg for fertilization.

• Head- contains nucleus (23 chromosomes)

• Mitochondria- ATP for energy; sperm movement.

• Flagella- the tail that moves sperm up the female tract.