HIERARCHY OF STRUCTURE IN ANIMALS

Levels of Organization

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+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

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+ 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 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

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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