The Hierarchy… Alveolar cells Alveolar tissue Lung (organ) Respiratory system
From Cell to Tissue Cells are organized into tissues A tissue is a groups of similar cells that have a common function Ex: endothelial cells endothelial tissue (skin) brain cells brain tissue There are 4 types of tissue: Epithelial Tissue Connective Tissue Nerve Tissue Muscle Tissue
Epithelial Tissue Epithelial tissue: Ex: covers and protects organs Secretes, absorbs and filters substances Ex: Epithelial tissue of salivary glands contains cells that secretes saliva Epithelial cells of the digestive system contains cells that absorb nutrients
Connective Tissue Connective tissue: EX: Provides organs in the body with protection and nutrients EX: Bone tissue supports and protects the body Fatty tissue stores nutrients as fat
Nerve Tissue Nerve tissue: Allows messages to sent and received between the brain and body Nerves, spinal cord and brain are made up of nerve tissue
Muscle Tissue Muscle tissue is composed of fibers capable of contracting to allow bodily movement. There are 3 types of muscle tissue: a) Skeletal: Makes up the muscles that are attached to the bones. b) Smooth: Makes up the lining of organs that contract (stomach, bladder) c) Cardiac: Found in the heart
From Tissue to Organ An organ is a structure composed of two or more tissue types performing one or more specific functions. Ex: The stomach is an organ made up of four types of tissue.
From Organ to System An system is made up of groups of organs that work together to perform a set of related tasks Ex: mouth, esophagus, stomach, intestines = digestive system Each organ performs a specific function and all organs work together