Download The endocrine system helps regulate body conditions

Endocrine and Reproductive Study Guide.
The endocrine system helps regulate body conditions.
1. Hormones are the body’s chemical messengers.
Hormones are chemicals made in one organ to trigger response in
another organ. The endocrine system uses hormones to control conditions
in the body.
2. Glands produce and release hormones.
 The pituitary gland directs the endocrine system. Its hormones
control growth, sexual development, and water absorption.
 The hypothalamus is the part of the brain that controls the pituitary
gland.
 The pineal gland regulates sleep, body temperature, reproduction,
and aging.
 The thyroid gland produces hormones for growth and metabolism.
 The thymus helps the body fight disease.
 The adrenal; glands produce about 30 hormones that regulate food
metabolism, water and salt levels, immunity, and response to stress.
 The pancreas produces insulin, which regulates glucose levels in the
blood.
3. Control of the endocrine system includes feedback mechanisms.
 Negative feedback mechanisms help maintain homeostasis.
 Positive feedback mechanisms, like blood clotting, result in extreme
responses.
 Some hormone actions are regulated by a hormone that produces
an opposite action.
 Hormone imbalance can cause serious disease.
The reproductive system allows the reproduction of offspring.
1. The reproductive system produces specialized cells.
The female produces eggs; the male produces sperm. These
specialized cells contain genetic material. The female reproductive
system has two functions: to produce eggs and to protect and nourish
the offspring until birth.
 The pituitary gland stimulates eggs in the ovary growth.
2. The reproduction of offspring includes fertilization, pregnancy, and
birth.
 Fertilization is the joining of one egg cell and one sperm cell.
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Once fertilized, the egg divides, producing an embryo. Cells
in the embryo continue dividing.
During the nine months of pregnancy, the embryo grows and
develops, fed through the placenta.
3. The human body develops and grows.
There are a few stages of development in a human.
Zygote- 1st day until 4th day. (fertilized egg)
Embryo- 4th day until 8th week
Fetus- 9th week until birth
Birth- 9th month
Infancy- birth until 2 years old
Childhood- age 2-13
Adolescence- age 13-18/20
Puberty- age 9-15
Adulthood- age 20 until death
SUBHEADING EVENTS
1. Heart beats regularly. Eyes and ears begin to form- 4-week embryo
2. Heart develops right and left chambers- 8-week embryo
3. Bones are visible. Heartbeat can be heard with a stethoscope. –
4-6 mo. embryo
4. Fingerprints form- 6-month embryo
5. Eyelids can open and weight can be up to 6.6 lbs (3kg)-6-9 months
embryo
6. A baby can hold its head up and reach for objects.- 3 months old
7. Infant begins to crawl- 7 months old
8. Ovulation in females and sperm production in males’ begins.- age 9-15
9. Skin starts to become wrinkled- age 30
10. Aging begins- age 30
11. Aging becomes more noticeable and progresses rapidly- age 45-60