Human Body Chapter 27

27.1 Structure & Function Anatomy= study of the structure Physiology = the study of the function Knowing the structure allows understanding of function

Levels of Body Structure Cell= single unit Tissue= many similar cells working together to perform a similar function Organ= several tissues that together perform a task Organ System= multiple organs performing a vital function Organism

http://68. 90. 81. 6/ScienceTAKS/Integration/Major%20Organ%20Systems http://68.90.81.6/ScienceTAKS/Integration/Major%20Organ%20Systems.htm

27.2 Tissues Cells make up various types of tissues based on function

Epithelial Sheets of tightly packed cells Line the surface of body and internal organs Protect organs and tissues they cover Many types Ciliated – catch mucus Smooth Thin/Flat

Connective Tissue Holds tissues together Provides support Cushions, insulates and connects organs Most common type = loose Ex: Bone, cartilage, blood & fat

Nervous Communication system for the organisms Neuron = basic unit (nerve cell) Transmits signals over long distances

Muscle Enables movement Aids in digestion and circulation Composed of: Connective, nervous, and muscle tissues 3 Types: Skeletal- under your control Attached to bones Involuntary- not under your control Cardiac Smooth = involuntary in most other organs Ex: Move food in intestine

HWK System Major structures Functions Circulatory Digestive Nervous

http://www.stemcure.com/images/pic_sc_stemcell.gif http://www.mhhe.com/biosci/esp/2001_saladin/folder_structure/le/m1/s7/