How are they organized? 2.1 Cells & Cell Systems

Cell Organization Groups of organs that have related function Systems Groups of different tissues put together for at least one function Organs Tissues Group of cells that are similar in shape and function Cells

Cell and Tissue types

Epithelial tissue Covers the outside surfaces of your body. Covers the inside of your body. Serves as membranes lining organs. Separates organs and keeps them in place. Skin, inside of mouth, stomach, tissue surrounding the body’s organs.

Connective tissue Adds support to the body Adds structure to the body Contains fibrous strands – collagen Skin, tendons, ligaments, cartilage, bone and fat tissue. Blood is considered a connective tissue.

Muscle tissue Muscle is a specialized tissue because it can contract.

Nerve tissue Can generate and conduct electrical signals. Managed by nerve tissue in brain. Transmitted down spinal cord.

Organs

ORgans The next level of organization in the body An organ contains at least two different types of tissue functioning together for a common purpose. Liver, kidneys, heart, lungs, skin Skin – 3 layers 1) epidermis 2) dermis 3) subcutaneous layer

Respiratory system Major Role Major Organs Provide gas exchange between blood and environment. Oxygen is absorbed from atmosphere. Carbon dioxide is expelled from body. Major Organs Nose. Trachea Lungs

Circulatory system Major Role Major Organs Transport nutrients, gases (O2, CO2), hormones, waste Major Organs Heart, blood vessels, blood

Excretory system Major Role Major Organs Filter out wastes, toxins, excess water, nutrients from circulatory system. Major Organs Kidneys, urteters, bladder, urethra

Major Role Digestive system Major Organs Breakdown nutrients Absorb nutrients Major Organs Mouth Esophagus Stomach Small intestine Large intestine

Nervous system Major Role Major Organs Relay electrical signals throughout the body Directs behavior and movement Controls digestion, circulation Major Organs Brain Spinal cord Peripheral nerves

Endocrine system Major Role Major Organs Relay chemical messages through the body Works with nervous system to control nutrient absorption growth etc. Major Organs Hypothalamus Pituitary Thyroid Pancreas Adrenal glands

Major Role Reproductive system Major Organs Manufacture cells for reproduction In male – sperm In female - eggs Major Organs Male – testes, seminal vesicles and penis Female – ovaries, oviducts, uterus, vagina and mammary glands.

Muscular system Major Role Major Organs Provide movement Work in pairs Provide movement in organs, stomach, intestine, heart, circulatory system. Major Organs Skeletal muscles throughout body Smooth muscles throughout body

Lymphatic / immune system Major Role Destroy and remove invading microbes and viruses. Remove fat and excess fluids from blood. Major Organs Lymph Lymph nodes and vessels White blood cells T cells B cells

Skeletal system Major Role Major Organs Provide support for the body Protect delicate internal organs Provide attachment sites for organs Major Organs Bones Cartilage Tendons Ligaments

Questions Define; tissue, organ, organ system. Give an example of each. Organize the following structures from smallest to largest and give an example: tissue, cell, organ, molecule Make a table to compare the levels of cell organization (pg 42) with the levels in some organization that you are familiar with such as: sports team RPG The school system Government system Banking system Family tree of authority Police structure of authority Science Probe 8 - pg 42