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The Endocrine System

Body’s Control System

Functions of the Endocrine

System:

Prepare the body for fight or flight (in emergency situations)

Control & Regulate Hormones

Hormones –

Chemicals that are made in tissues called glands found throughout the body; which control many other systems of the body.

Hormones are released from glands directly into your blood

stream.

Endocrine glands are ductless which

means they do not release there

products through small tubes called

ducts.

Instead hormones are released

directly into the blood & affect

specific tissues called target tissues.

The body reacts more quickly to the

nervous system than to the

endocrine system.

Major Endocrine Glands:

9 major Glands-each with specific jobs

Pineal Gland-located deep in the brain; Produces melatonin, which regulates your sleep/wake patterns-internal clock.

Pituitary Gland-peasize structure attached to the hypothalamus in your brain

Produces hormones that affect body activities that range from growth to reproduction.

◘ Thymus - located in the upper chest; behind the sternum

Produce hormones that stimulate production of infection fighting cells

Thyroid Gland

Located below the larynx, in your throat

Produces hormones that regulate metabolic rate, control the uptake of calcium by bones, & promote normal nervous system development.

Parathyroid Gland

Attached to back surface of the thyroid

Helps regulate calcium levels in the body

Adrenal Gland

Located on top of the kidneys

Produce a variety of hormones that play a critical role in helping your body adapt to physical and emotional stress and help stabilize blood sugar levels

Pancreas

Scattered through the Pancreas are tiny clusters of endocrine tissue called islet of langerhans

Produce hormone-insulin that control sugar levels

Testes

Male reproductive organs

Produce testosterone that controls development and maintenance of male sexual traits and controls production of sperm

Ovaries

Female reproductive organs

Produce estrogen and progesterone that regulate the female reproductive cycle and responsible for production and maintaining female sex characteristics

Negative-Feedback System

To control the amount of hormones in your body, the endocrine system sends messages back and forth within itself.

Works much like a thermostat-if it too hot, it kicks the air conditioner on until it reaches a certain temperature and then signals for it to turn off.

EX: Pancreas controls level of glucose

in your bloodstream

You eat a food containing sugar (glucose)

Intestines take in glucose during digestion

Glucose level in bloodstream increases

Pancreas responds to high glucose level by producing the hormone insulin

Insulin is released into the blood stream causing the liver and other tissues to take up more glucose

Blood glucose level returns to normal level

Lymphatic System

Immune System-Keeps us healthy & well

Objectives:

What are the functions of the lymphatic system?

What is the function of the lymph fluid?

Where does lymph come from?

How do lymph organs help fight infection?

Function of Lymphatic System

Defends body from foreign and harmful organisms and toxins

keep your body free of disease.

Disease-anything that stops all or parts of your body from working

Causes of Diseases

Microscopic organisms

Diet

Old age

Poisonous chemicals

Faulty genes

Lack of exercise

Parts of your lymphatic system not considered organs

Lymph-fluid of the lymphatic system

Lymph vessels-vessels in which lymph moves through, movement is caused by the contraction of smooth muscles in these vessels, they are similar to veins, have valves that keep lymph fluid from flowing backward

Lymphocytes- a type of white blood cell, helps your body defend itself against disease causing organisms.

Lymphatic Organs-

Lymph nodes- filter out microorganisms and foreign particles, when fighting off infection the lymph nodes become red, warm, reddened and tender to the touch. Once the invaders are destroyed, the redness, warmth and tenderness go away.

Tonsils- found in the back of the throat, protect body from harmful microorganisms that might enter through the nose and mouth.

Thymus- soft mass of tissue located behind the sternum, makes lymphocytes that travel to other lymph organs.

Spleen- largest lymph organ located behind the upper-left part of the stomach and filters blood by removing worn out and damaged red blood cells. Cells in the spleen take up and destroy bacteria and other substance that invade your body.

Disease of the Lymphatic System

HIV (Human immunodeficiency virus) –attacks and destroys a type of lymphocyte called helper T-cells.

Helper T-cells make antibodies to fight infection, so a person with HIV cannot fight off certain diseases. Usually the person dies from other infections not from the HIV

infection

Tonsils

Thymus

Spleen

Lymph Nodes