Grade 8 Science Unit 4:“Cells, Tissues, Organs & Systems” Chapter 11: “Human body cells are organized as tissues, organs and systems.”

Systems... • All systems have the following characteristics: Made up of individual parts that work together as a whole Often connected to one or more systems If one part of a system is missing or damaged, the system will not function well or may not function at all.

Levels of Organization

•Groups of similar cells •Found in all multicellular organisms Tissues •Groups of similar cells •Found in all multicellular organisms •Ex. Muscle tissue, nerve tissue, epithelial tissue, etc.

Organs •Groups of tissues. Made up of two or more types of tissues. Ex: •They are distinct structures that perform specific functions. •Ex. Lungs, kidneys, heart, etc.

Questions in Textbook Page 425 #s 1, 3, 4, 7, 8

Organ Systems pg. 428-430 •A group of organs that perform activities that help the body as a whole. •6 examples of organ systems are... Digestive System Circulatory System Nervous System Respiratory System Excretory System Muscular System

Digestive System Consists of: •Mouth •Gall Bladder •Small Intestine •Liver •Stomach •Large Intestine •Oesophagus •Pancreas

Function: •To take in and break down food, absorb nutrients, and eliminate solid waste.

Circulatory System Consists of: •Heart •Veins •Arteries •Capillaries Function: •To transport blood, nutrients (chemicals needed for survival), gases and wastes.

Nervous System Consists of: •Brain •Sense organs (eyes, ears, nose, tongue, skin) •Spinal cord •Nerves Function: •To detect changes in the environment and to signal these changes to the body which then carries out a response.

Respiratory System Consists of: •Nasal cavity •Trachea •Lungs Function: •To control breathing, and exchange gases in lungs and tissues.

Excretory System Consists of: •Lungs •Kidneys •Urinary bladder Function: •To remove liquid and gas wastes from the body

Muscular System Consists of: •Muscle tissue connected to bones throughout the body. Function: •To work with the bones to move body parts

Questions in Textbook Page 431 #s 1-6 Page 432 #s 2, 6

p. 425 1. The parts of a system must work together and be able to interact with other systems. If part of the system operates incorrectly, the system may operate incorrectly or fail. 3. A (c) (muscle tissue) B (b) (nerve tissue) 4. Tissues are composed of cells that have the same structure and function. Organs are made up of different types of tissues working together.

p. 425 7. – muscle tissue: elastic bands or other stretchy material that is able to expand and contract – epithelial tissue: some smooth fabric or material that could be used to line a cavity. The smooth surface faces out into the cavity. – connective tissue: some hard, solid material that holds its shape, such as clay or Plasticine. – nerve tissue: a webbed material or cotton that is pulled apart. The tissue should be able to hold the shape of a web or a net. 8. B, D, C, E, A. The heart cell (B) is organized into cardiac tissue (D), then into an organ (the heart) (C), then into an organ system (the circulatory system) (E), then finally into a human (A).

p. 431 1. digestive system; circulatory system; nervous system; respiratory system; excretory system; muscular system; skeletal system; immune system; endocrine system; integumentary system; and reproductive system. 2. (a) circulatory system (b) digestive system (c) excretory system (d) respiratory system (e) respiratory system/digestive system 3. The digestive system provides the body with all the matter and energy it needs to live. 4. From left to right: circulatory system; muscular system; nervous system. 5. The excretory system filters wastes from the blood and flushes it from the body. The circulatory system carries gaseous wastes from the cells and takes them to the lungs where they are exchanged for nutrients and oxygen.

p. 431 6. (a) the digestive system (b) No, the respiratory system also connects the internal and external environment. It is responsible for exchanging gases and wastes from cells inside the body with oxygen from outside the body. (c) The digestive system fits inside the body because the intestines (particularly the small intestine) are tightly folded many times into a small area.

p. 432 Organism Tissues 2. 6. The cell needs to move materials, into and out of the cell, just as an organism needs to move materials into and out of the body. Body systems such as the digestive system and the circulatory system act to carry waste away from cells and to bring nutrients and oxygen to the cells. Cells Organs Organs Systems