The Human Body Levels of Organization Cell-Tissue-Organ-Organ System- Organism

Tissues Epithelium - covers the body and lines organs Muscle - contractile and attaches to bones Connective - produces blood and provides support Nervous - transmits impulses

Skin Integumentary System Maintain homeostasis Protects tissues and organ Regulates body temperature

Skeletal System Contains 206 bones Support for tissues and organs Protects Makes blood cells Stores calcium and phosphorus

Joints place where two bones meet Immovable ex. Skull Movable ex. Shoulder ball and socket hinge joint gliding pivot

Muscular System Smooth are found in hollow organs Involuntary muscles ex. Stomach and blood vessels Skeletal attached to bones made of fiber voluntary muscles

Smile it uses 17 facial muscles A frown uses more than 40 Heart found in the heart called cardiac muscle

Digestive System Receives food and breaks it down to be absorbed by body cells Also eliminates undigested food

Endocrine System Controls all metabolic activity All glands that secrete hormones

Nervous System Includes brain, spinal cord nerves and sensory receptors cells called neurons Gap between two neurons is called synapse

Respiratory System Exchange gases between blood and air Air passes into the blood through air sacs called alveoli in the lungs Oxygen used to break down glucose to make ATP needed for metabolism 12 to 20 times/minute in Humans

Urinary System Creates metabolic waste during the breakdown of amino acids and removes them from blood Maintains the balance of water and salt in blood Stores waste from urine Transports urine out of the body

Reproductive System Makes gametes Male produces sperms maintains sperms to transfer to female Femaleproduces eggs maintains eggs receives and transport sperms cells supports the development of the fetus

Circulatory system Includes heart, blood vessels and blood Blood carries oxygen from lungs Heart pumps blood Blood carries hormones, carbon dioxide back to the lungs and waste to the excretory system

Blood pressure Systolic Pressure measures pressure when right and left ventricles contract Diastolic Pressure lowest pressure in vessels just before the two ventricles contract again Blood pressure is used to evaluate artery condition

Lymphatic System Known as immune system Transport tissue fluid back into the blood stream Filters out and destroys disease causing pathogens and other foreign substances Acquired immunity involves T cells (pass information to B cells) B cells (produces antibodies)

Cells are called lymphocytes Macrophages and neutrophils engulf foreign substances that enter the body