HIERARCHY OF STRUCTURE IN ANIMALS Levels of Organization

HIERARCHY OF STRUCTURE IN ANIMALS Levels of Organization

+ CELLS TISSUE SYSTEMS ORGANISMS Least Complex Most Complex

+ LEVEL 1 CELLS ■ basic unit of life ■ serve a specific function within the organism ■ Ex: bone cells, blood cells, nerve cells GERM CELLS Bone CELLS CHEEK CELLS SPERM CELLS

+ LEVEL 2 TISSUES ■ Made up of cells that are similar in structure and function ■ Cells work together to perform a specific activity ■ TYPES Muscle Connective Epithelial Nervous

+ Type Example Description Function Epithelial Skin Lining of digestive system Thin sheets of tightly packed cells covering surfaces and lining internal organs Contain no blood vessels, receive nutrients via diffusion from other tissues Protection from dehydration Low-friction surface Secrete, absorb Connective Bone Tendons Blood Cells and fibres held together by a matrix Support Insulation

+Type Muscle Nervous Example Description Skeletal (voluntary) Anchored by tendons to bones Smooth (involuntary) Walls of the esophagus stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels Cardiac Found only in the heart Brain Nerves in sensory organs Long thin cells with branches Conduct electrical impulses Function Locomotion, maintain posture Sensory Communication within the body Coordination of body functions

+ LEVEL 3 ORGANS ■ Tissues that work together to perform a specific activity ■ Most organs work within a single organ system -Stomach is part of the digestive system ■ Some organs work within more than one system eg. Pancreas is part of the digestive and endocrine system

+ LEVEL 4 SYSTEMS ■ Groups of two or more organs that work together to perform a specific function for the organism

+ System DIGESTIVE Organs Salivary glands, esophagus, stomach, liver, gallbladder, pancreas, intestines, rectum, and anus CIRCULATORY Heart, blood, and blood vessels RESPIRATORY Pharynx, larynx, trachea, bronchi, lungs, and diaphragm NERVOUS Nerves, brain, spinal cord URINARY Kidneys, ureter, bladder, and urethra REPRODUCTIVE F - ovaries, fallopian tubes, uterus M - testes, vas deferens, seminal vesicles, prostate

+ System Organs INTEGUMENTAR Skin, hair, nails Y LYMPHATIC Consists of organs, ducts, nodes transports a watery, clear fluid called lymph Defends against diseases MUSCULAR All muscles SKELETAL Bones, cartilage, ligaments and tendons ENDOCRINE Hypothalamus, pituitary gland, thyroid, and adrenals

+ LEVEL 5 ORGANISM ■ Entire living things that carry out all basic life processes. ■ Take in materials, release energy from food, release wastes, grow, respond to the environment, and reproduce ■ Usually made up of organ systems but may be made of one cell ■ Examples ■ Bacteria, amoeba, mushroom, ■ sunflower, human

+ Homework: ■ Pg 76 # 2 -6