The Endocrine System & Reproduction

Ch. 16

Questions?Completely Anonymous

The Endocrine System Hormones and the

Endocrine System The endocrine system

produces chemicals that control many of the body’s daily activities.

Endocrine glands release chemicals directly into the bloodstream

Hormones Turn on, turn off, speed

up, slow down activities of different organs and tissues

Hormone Production Nerve impulses from the

brain Brain interprets signals,

and sends a response in the form of a hormone

Adrenaline! Hormone Action

Adrenaline lasts until blood returns to a normal level

Target Cells Muscle cells for adrenaline

The Endocrine System Functions of

Endocrine Glands Hypothalamus

Center of your head Controls hunger,

sleep and other body processes

Major role in homeostasis

Pituitary Gland Size of a pea Regulates growth,

blood pressure, & water balance

The Endocrine System

Negative Feedback Example: thermostat When the amount of

a particular hormone in the blood reaches a certain level, the endocrine system sends signals that stop the release of that hormone

The Male & Female Reproductive Systems

Sexual Reproduction

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Sperm is the male sex cell

23 chromosomes

Egg is the female sex cell

23 chromosomes

Fertilization, 46 chromosomes

Zygote

Male Reproductive System

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The Testes

Clusters of tiny coiled tubes, called seminiferous tubules. Immature sperm form on the walls of these tubes until it matures, gains a flagellum and then carried to the epididymis.

Located in the scrotum, stays slightly below body temperature.

The Path of Sperm Cells

As the sperm move the mix with fluids and become semen. This fluid allows for the sperm to swim. It also contains nutrients that the sperm use for energy.

Semen travels through the urethra and exits out the penis. Bladder muscles contract as to keep urine from mixing with the semen. Ejaculation, sperm exiting the penis at over 50 million sperm. 5-10 million per drop!

Female Reproductive System

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The Ovaries

Produce & store eggs

Hormones

Ovaries also have endocrine glands that produce estrogen. This hormone causes hips to widen and breasts to develop.

The Path of the Egg Cell

The fallopian tubes, oviducts, are passage ways for the eggs at they travel to the uterus. The uterus, a muscular organ the size of a pear, is where a fertilized egg will attach and pregnancy begins.

If the egg is not fertilized, it starts to break down and exit through the cervix and then finally the vagina or birth canal.

The Menstrual Cycle

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400,000 undeveloped eggs are in the ovaries. However, only 500 of those eggs will leave the ovaries and reach the uterus. An egg is released once a month, called the menstrual cycle.

Stages

The maturing egg with its own grouping of cells is called a follicle. At the same time the uterus begins to thicken. Halfway through the cycle the follicle ruptures and the mature egg is released into the fallopian tube, called ovulation. It can now be fertilized for the next few days. If not, it fails to implant and starts to break down. The extra blood and tissue, lining of the uterus, is sloughed off and passed out through the vagina called menstruation.

The Menstrual Cycle

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Endocrine Control

Hormones trigger a girl’s first menstruation. Many girls begin between the ages of 10-14, some earlier, some later. Women continue to menstruate until about age 50. Then the production of sex hormones drops and the ovaries stop releasing mature eggs.

Pregnancy, Development & Birth

Development Before Birth From Zygote to Embryo

Zygote moves down fallopian tube toward the uterus

Takes about 4 days From one to two to four

and so on… Blastula

Differentiation of the Embryo Process by which cells

change and become specialized

Development of the Fetus From ninth week to birth,

the developed human is called a fetus 3 months

Internal organs 6 months

heartbeat

Fetal DevelopmentMonth By Month

Cameron Randall Judd

RoxanneMarieJudd

Pregnancy, Development & Birth Protection & Nourishment

Membranes and other structures that form during development protect and nourish the developing embryo

Amniotic Sac Cushions and protects

embryo Placenta & Umbilical Cord

Embryos’ blood vessels and is linked to the mother via the umbilical cord

Keeping the Fetus Healthy This barrier helps

keep the embryo healthy, but some viruses can pass. HIV, alcohol,

chemicals in tobacco and other drugs.

Pregnancy, Development & Birth

Birth After 40 weeks…

Labor Strong muscular contractions

cause the cervix to dilate or open

Can last from 2-20 hours! Delivery

Pushed through the uterus, through the vagina and out the mother’s body

Umbilical cord is clamped and then cut

Afterbirth The placenta & other

membranes

Birth & the Baby Birth creates a strain on the

baby Pressure decreases baby’s

supply of oxygen Heart rate increases Within seconds, the baby

begins breathing with a cry or cough

Multiple Births Twins! 1 out of 30 in the U.S. Identical and Fraternal

Single egg splits = Id. Two sperm, two eggs = Fr

Pregnancy, Development & Birth Growth &

Development Infancy

Weight can double Walking at 10-14

months Simple directions,

play

Childhood Starts at 2 Bones and muscles

increase in size Skills improve, learn to

read and solve problems

Pregnancy, Development & Birth

Adolescence Start to think like

adults Bodies undergo

physical changes 9-15 years, puberty

Pregnancy, Development & Birth

Adulthood After 30, aging

begins Eyes can lose ability

to focus, hair loss and or coloring

Great wisdom!

Pregnancy, Development & Birth