2011 Cycle 3 Science Snippets Wks 1-12

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Science Snippet

Four types of tissue are connective, epithelial, muscle, and nerve.

Tissues are groups of cells that work together to perform the same function.

Connective tissues bind parts of the body together and provide support. They also store fats.

Epithelial tissues cover and protect the body.

Muscle tissues are designed to contract and allow the body to move.

Nerve tissues send and receive signals to and from the brain allowing the body to feel and move.

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3week 1



Science Snippet

The bones that make up the axial skeleton are cranium, vertebrae, ribs, and sternum.

The axial, or core, skeleton consists of the skull, which is made of the cranium and facial bones; the vertebral column, or the vertebrae; the ribs; and the sternum, or breastbone.

The rest of the skeleton is called the appendicular skeleton, because it contains the bones of the appendages: the shoulder girdle, arms, hands, pelvic girdle, legs, and feet.

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3week 2



Science Snippet

The three kinds of muscle are skeletal, smooth, and cardiac.

Skeletal muscle moves bone. Tendons attach the long, slim muscles to bones. At the direction of brain signals (voluntary control), muscles work in pairs to move the bones in opposite yet complementary directions.

Smooth muscle moves slowly AND steadily. It is involuntary. Smooth muscle lines the blood vessels, the stomach, and the digestive tract, among other organs.

Cardiac muscle, the toughest of all muscle, makes the heart beat. It is involuntary. Cardiac muscle is only found in the heart.

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3week 3



Science Snippet

Three parts of the nervous system are the brain, spinal cord, and nerves.

The central nervous system consists of the brain and the spinal cord. The brain controls all of the body systems and organs, and allows us to think, feel, remember, and imagine. The spinal cord is a long thin bundle of nerve tissue, which connects the brain to the peripheral nerves and transmits messages to and from the brain.

The peripheral nervous system is made up of nerves, or neurons, which emerge from the spinal cord and reach into all the muscles and organs sending messages to and from the brain. These messages enable the brain to control movement and sensation and regulate breathing, heart rate, and other automatic responses.

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3week 4



Science Snippet

The five main senses are sight, hearing, taste, smell, and touch.

The eye focuses images from deflected waves of light, and the optic nerve carries the information to the brain, producing sight.

Sound waves enter the ear canal. Organs in the inner ear translate them to vibrations, which the auditory nerve carries to the brain to produce hearing.

Taste is determined by receptor cells called taste buds that cover the tongue and send chemical messages to the brain.

Smell occurs when molecules in the air trigger the smell receptors in the nasal passage. The olfactory nerves carry signals from the receptors to the brain.

Touch comes from messages from the hair and receptors on the skin.

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3week 5



Science Snippet

Some parts of the digestive system are the mouth, esophagus, stomach, liver, small intestine, and large intestine.

In the mouth, food is broken down into small pieces and mixed with saliva to smooth and speed the rest of its journey.

The food travels down the esophagus into the stomach, where muscular contractions and stomach acids break the food down into a form that the body can use. The liver stores nutrients from digestion.

From the stomach, food passes into the small intestine, where nutrients are absorbed into the bloodstream, and waste is sent on to the large intestine so it can be removed from the body.

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3week 6



Science Snippet

Four parts of the excretory system are the urinary tract, lungs, skin, and intestines.

The excretory system is responsible for capturing poisonous wastes and filtering them out of the body. It also helps to maintain a balance of salt and water in the bloodstream and keeps fresh oxygen cycling through the body.

The urinary tract removes liquid wastes and excess salt from the system in the form of urine.

The lungs exhale used carbon dioxide from the body.

The skin removes excess salt in the form of sweat.

The intestines compress and move solid waste out of the body.

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3week 7



Science Snippet

Six parts of the circulatory system are the heart, arteries, veins, capillaries, red and white blood cells, and platelets.

The circulatory system carries nutrients, water, and hormones to and from the cells. It removes wastes and oversees the exchange of oxygen and carbon dioxide. The circulatory system also regulates body temperature.

The heart pumps blood to the arteries. The arteries transport oxygenated (fresh) blood from the heart to the rest of the body. Capillaries transfer blood from the arteries to the veins. The veins carry de-oxygenated (old) blood back to the heart to be recycled.

Blood is made of red blood cells, white blood cells, and platelets. Red blood cells carry oxygen and carbon dioxide to the body. White blood cells defend the body against infection. Platelets react to damaged blood vessels by binding together to form a clot.

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3week 8



Science Snippet

Four parts of the lymph system are lymph vessels, lymph nodes, spleen, and thymus.

The lymph system plays an important role in the body’s defense and distribution system. It filters out harmful microorganisms and produces white blood cells. It also moves fluid and nutrients through the body.

Lymph is a thin fluid that circulates throughout the body. It is trans-ported in the lymph vessels. Lymph nodes, which act as traps for micro-organisms and infections, are small glands along the lymph vessels.

The spleen filters harmful substances out of the body, produces white blood cells, and removes old cells from the blood.

The thymus is responsible for developing specialized white blood cells called T-cells that can adapt to new viruses in order to fight them.

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3week 9



Science Snippet

Some parts of the respiratory system are the nose, pharynx, larynx, trachea, bronchi, bronchioles, alveoli, and lungs.

When you inhale, air flows in through the nose and mouth, through the pharynx, larynx, and trachea, and into the lungs.

When the trachea reaches the lungs, it divides into two bronchi. One bronchus leads to the left lung; the other, to the right. The bronchi narrow and branch out into the bronchioles.

At the end of the smallest branches are the alveoli, or air sacs, where tiny blood vessels oversee the exchange of oxygen and carbon dioxide.

The oxygen in the air is traded for carbon dioxide from the blood, and the air then traces the same path backwards to be exhaled.

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3week 10



Science Snippet

The endocrine system consists of glands and organs that use hormones to send messages through the bloodstream to the rest of the body.

The endocrine system regulates growth, mood, and metabolism, among other things. It operates by using hormones (chemical messengers) produced by the glands.

The hypothalamus, in the brain, is the starting point for the endocrine system. The hypothalamus receives signals from the nervous system and passes them on to the pituitary gland. The pituitary gland produces hormones that signal other parts of the endocrine system.

Other significant glands include the thyroid gland, which regulates growth; the adrenal glands, which regulate stress; the pineal gland, which regulates sleep cycles; and the pancreas, which regulates blood sugar.

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3week 11



Science Snippet

The major purposes of blood are transportation, protection, communication, and temperature regulation.

The blood transports nutrients and waste products throughout the body. It regulates the pH level (level of acid) and the temperature of the body. It also removes toxins and excess salts from the body.

Blood communicates messages to and from parts of the body through hormones (chemical messengers).

As a form of protection, new blood cells constantly replace old or damaged cells. Red and white blood cells are produced in the bone marrow. Some white blood cells also come from the lymph nodes, the thymus, and the spleen.

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3week 12

2011 Cycle 3 Science Snippets Wks 1-12

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Transcript of 2011 Cycle 3 Science Snippets Wks 1-12