The The Reproductive Reproductive

SystemSystem

The BasicsThe Basics

Reproduction is the only life function Reproduction is the only life function that is NOT necessary for the individual that is NOT necessary for the individual to survive BUT it is necessary for the to survive BUT it is necessary for the survival of the SPECIESsurvival of the SPECIES

Types:Types: Asexual – one parent, offspring are identical Asexual – one parent, offspring are identical

to one anotherto one another Examples: bacteria, hydra, plantsExamples: bacteria, hydra, plants

Sexual – two parents, offspring are different Sexual – two parents, offspring are different from one anotherfrom one another

Examples: humans, pandas, turtles, plantsExamples: humans, pandas, turtles, plants

Male Reproductive SystemMale Reproductive System

The Testes and ScrotumThe Testes and Scrotum Testes – male gonadTestes – male gonad

Produce sperm Produce sperm Produce testosterone (male hormone)Produce testosterone (male hormone)

Scrotum – pouch outside of body Scrotum – pouch outside of body that holds the testesthat holds the testes Keeps testes cooler, necessary for Keeps testes cooler, necessary for

proper sperm developmentproper sperm development Epididymis – structure on top of Epididymis – structure on top of

each testis, contains 6m of tubingeach testis, contains 6m of tubing Stores sperm until they are mature Stores sperm until they are mature

(20 days)(20 days)

SpermSperm

Male gameteMale gamete Produced by meiosis in Produced by meiosis in

testestestes PartsParts

Head – contains nucleus and Head – contains nucleus and chemical that allows it to chemical that allows it to pierce the egg pierce the egg

Midpiece – mitochondriaMidpiece – mitochondria Tail – flagellum (mobility)Tail – flagellum (mobility)

Seminal fluid and SemenSeminal fluid and Semen Seminal fluid is produced by Seminal fluid is produced by

the prostate gland, the prostate gland, bulbourethral gland, and bulbourethral gland, and Seminal vesicleSeminal vesicle Provides the sperm with nutrients, Provides the sperm with nutrients,

protection and chemicals needed protection and chemicals needed to help ensure fertilizationto help ensure fertilization

Sperm + seminal fluid = semenSperm + seminal fluid = semen Males ejaculate 2-5 mL semenMales ejaculate 2-5 mL semen Each mL contains 50 to 130 million Each mL contains 50 to 130 million

spermsperm

Transport of sperm out of the Transport of sperm out of the bodybody

Sperm leave the Sperm leave the epididymis, and travel epididymis, and travel through the two vas through the two vas deferens to where they join deferens to where they join the urethrathe urethra Vasectomy – cutting of both Vasectomy – cutting of both

vas deferensvas deferens Sperm are expelled from Sperm are expelled from

the body through the the body through the urethra during ejaculationurethra during ejaculation

TestosteroneTestosterone

Male sex hormoneMale sex hormone Produced by testesProduced by testes Responsible for sperm production Responsible for sperm production

and development of secondary sex and development of secondary sex characteristics characteristics Traits that appear during pubertyTraits that appear during puberty Facial/body hair, deepening of the Facial/body hair, deepening of the

voice, increased muscle massvoice, increased muscle mass

Female Reproductive Female Reproductive SystemSystem

The Ovary and OviductThe Ovary and Oviduct

Ovary – female gonadOvary – female gonad Produces eggProduces egg Produces estrogen and Produces estrogen and

progesterone (female sex progesterone (female sex hormones)hormones)

Oviduct – tube leading Oviduct – tube leading from ovary to uterusfrom ovary to uterus Where Where FERTILIZATIONFERTILIZATION

occursoccurs

The Egg cellThe Egg cell

Female gameteFemale gamete Surrounded by a Surrounded by a

follicle which follicle which provides it with provides it with protection and protection and nourishmentnourishment

Uterus, Cervix and VaginaUterus, Cervix and Vagina

UterusUterus Muscular pear-shaped Muscular pear-shaped

organorgan Where Where IMPLANTATIONIMPLANTATION and and DEVELOPMENTDEVELOPMENT occurs occurs

Cervix – opening from Cervix – opening from vagina to uterusvagina to uterus

Vagina – birth canalVagina – birth canal

The Menstrual CycleThe Menstrual Cycle Monthly series of events that prepares Monthly series of events that prepares

the female body to go through the female body to go through fertilization and then care for the fertilization and then care for the developing fetusdeveloping fetus

Lasts about 28 days (range 23-35 days)Lasts about 28 days (range 23-35 days) Involves release of egg (ovulation) and Involves release of egg (ovulation) and

thickening of the uterine lining thickening of the uterine lining Usually only occurs when there is NO Usually only occurs when there is NO

fertilized egg present in the female fertilized egg present in the female bodybody

Menstrual CycleMenstrual Cycle Days 1-5 – MENSTRUATIONDays 1-5 – MENSTRUATION

Uterine lining and unfertilized egg Uterine lining and unfertilized egg are shed from the bodyare shed from the body

Day 6-14 – Follicular PhaseDay 6-14 – Follicular Phase Egg maturesEgg matures uterine lining thickens (with blood uterine lining thickens (with blood

vessels)vessels) Day 14 – OvulationDay 14 – Ovulation

Egg is released from ovaryEgg is released from ovary Day 15-28 – Luteal phaseDay 15-28 – Luteal phase

Follicle becomes Corpus luteum Follicle becomes Corpus luteum Uterus continues to thickenUterus continues to thicken Body prepared to accept fertilized Body prepared to accept fertilized

eggegg

Estrogen and Estrogen and ProgesteroneProgesterone

Female sex hormonesFemale sex hormones Produced by ovaryProduced by ovary Controls production and release of Controls production and release of

egg AND helps prepare uterus to egg AND helps prepare uterus to accept fertilized egg during accept fertilized egg during implantationimplantation

Controls development of secondary Controls development of secondary sex characteristicssex characteristics

Breast development, widening of hip, Breast development, widening of hip, increase in amount of fat tissueincrease in amount of fat tissue