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

Lining of digestive system 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

Anchored by tendons to bones Type Example Description Function Muscle Skeletal (voluntary) Smooth (involuntary) Cardiac Anchored by tendons to bones Walls of the esophagus stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels Found only in the heart Locomotion, maintain posture Nervous Brain Nerves in sensory organs Long thin cells with branches Conduct electrical impulses 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 Organs DIGESTIVE 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 INTEGUMENTARY Skin, hair, nails 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