Chapter 1 The human Body

Body Organization Cell Tissue Organ Organ System Organism Homeostasis Basic unit of structure & function in living things Tissue Group of similar cells performing the same function nervous, epithelial, muscle, connective Organ Different tissues working together to perform a job Organ System Organs working together to perform a major function Organism Anything that can live on its own Homeostasis Body systems work together to keep the body in balance

Human Body Systems Skeletal Muscular Integumentary Cardiovascular/circulatory Respiratory Digestive Excretory Nervous Endocrine Lymphatic Reproductive

Skeletal System Functions Protection Storage Movement Ex. Ribs protect heart & lungs; vertebrae protect spinal cord Storage Store minerals that help the nerves & muscles function (calcium, potassium, sodium) Movement Skeletal muscle pulls on the bones to produce movement Blood Cell Formation Bones are filled with red bone marrow that makes blood cells. Yellow bone marrow is important for white blood cells. Support

Bone is strong, but not heavy when compared to other substances with comparable strength (concrete) Compact bone Smooth, outer layer Spongy bone Inner bone with open spaces (typically filled with marrow) Gives bones their strength

Muscular system Voluntary muscle Involuntary muscle Under your control (ex. Skeletal muscle) Involuntary muscle Not under your control (ex. Cardiac and smooth muscle) Muscles work in pairs because they can only pull; never push. Types of muscle Flexor – bend a body part Extensor – straightens a body part

Skeletal muscle moves your bones Cardiac muscle is found in your heart. (note how the cells overlay to improve communication) Smooth muscle is found in your digestive system and blood vessels

How can you increase your strength? Resistance training – increases the size & strength of skeletal muscles Aerobic training – strengthens the heart & increases the endurance of the skeletal muscle

Integumentary system Skin, Hair, and Nails Skin Protects – keeps moisture in and foreign particles out Sense – nerve endings in the skin help you feel what’s around you Regulates body temperature with help of sweat glands Removes waste – waste chemicals leave the bloodstream and body in sweat Epidermis – outer layers of skin Dead cells filled with the protein keratin Dermis – beneath the epidermis Connective tissue that allows skin to stretch and bend without tearing.

Hair Protects Helps block UV light, blocks dust from eyes & nose, helps regulate body temperature Nails Allows tips of digits to stay soft and sensitive to allow for the sense of touch.