SECOND TRIMESTER Unit Two: Human Body Systems Standards A, B, C 7 th Grade

I. Skeletal System – helps body move, supports the body and protects internal organs A. Bones – periosteum – tough outside covering 2. bony tissue – hard bone 3. marrow – soft tissue in center of many bones. Red marrow in end of bones produces blood cells. Yellow marrow in the middle has fat cells. B. Bone connectors 1. cartilage – rubbery tissue between bones; acts as a cushion 2. ligament – strands of tough tissue 3. joints – point at which two bones move against each other 4. tendons – connect muscle to the bone ye%20Bones%20and%20Muscles

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II. Muscle System – tissues that help move the body A. Skeletal – voluntary muscles that one can control B. Smooth – involuntary muscles that one does not control C. Cardiac – special involuntary muscles found only in the heart

III. Respiratory System – helps the body use food and oxygen to obtain energy. Takes in oxygen and gives off carbon dioxide. Parts of the body that cooperate in the respiratory process are: nose, trachea, lungs, and diaphragm.

IV. Circulatory System – supplies the body tissues with food and oxygen and removes waste and carbon dioxide A. Parts of the Circulatory System 1. Heart includes the atrium (2 upper chambers) and the ventricle (2 lower chambers) 2. Vessels a. artery – carries blood away from heart b. vein – carries blood to heart c. capillaries – tiny blood vessels connecting veins and arteries

B. Blood (5 2 / 3 liters or 6 quarts) 1. Parts of Blood a. plasma – fluid part of blood; contains water and antibodies to fight disease b. red cells – produced in red marrow of bones, carry oxygen and hemoglobin c. white cells – fight disease d. platelets – smallest blood cell, helps clot blood

2. Blood Types – human blood falls into four types. Transfusions of blood must be to the correct type including the correct RH factor. a. O – universal donor. give to O, A, B b. A – gives to A and AB c. B – gives to B and AB d. AB – gives to AB only