Anatomy & Physiology Chapter 3 – Part 3 Tissues

Body Tissues Tissues Groups of cells with similar structure and function 4 primary types: Epithelium Connective Nervous Muscle

Epithelial Tissues Found in different areas: Functions: Body Coverings Body Linings Glandular Tissue Functions: Protection Absorption Filtration Secretion

Epithelial Tissues Epithelium Characteristics: Cells fit closely together Have no blood supply of their own

Classification of Epithelium Number of Cell Layers: Simple = one layer Stratified = more than one layer Shape of Cells: Squamous = flattened Cuboidal = cube shaped Columnar = column like

Classification of Epithelium

Connective Tissue Includes the most abundant tissues Functions: Binds body tissues together Supports the body Provides protection

Connective Tissue Extracellular Matrix: Non-living material that surrounds living cells Two main elements: Ground substance = mostly water along with proteins and polysaccharides Fibers

Muscle Tissue Function is to produce movement Three types: Skeletal Muscle Cardiac Muscle Smooth Muscle

Nervous Tissue Comprised of neurons and nerve support cells Function is to send impulses to other areas of the body

Tissue Repair Regeneration Fibrosis Replacement of destroyed tissue by the same kind of cells Fibrosis Repair by dense fibrous connective tissue (scar tissue)

Events in Tissue Repair Capillaries become very permeable Regeneration of surface epithelium

Regeneration of Tissues Tissues that regenerate easily: Epithelial Fibrous Connective Bone Tissues that regenerate poorly: Skeletal Muscle Tissues that are replace largely with scar tissue: Cardiac Muscle Nervous tissue within the brain and spinal cord

Developmental Aspects of Tissues With old age there is a decrease in mass and viability in most tissues.

Developmental Aspects of Tissues Some cells lose their ability to divide when they are fully mature. This is called AMITOTIC For example: heart muscle and nervous tissue However, if these tissues are injured, the lost cells cannot be replaced by the same type of cells but by scar tissue. If a cell multiplies wildly, the abnormal cell mass is known as NEOPLASM. May be benign or malignant (cancerous)

Simple Epithelium Simple Squamous Single layer of flat cells Lines body cavities Lines lungs and capillaries

Simple Epithelium Simple Cuboidal Single layer of cube-like cells Covers the ovaries

Simple Epithelium Simple Columnar Single layer of tall cells Includes GOBLET CELLS – produce mucus for secretion Lines the digestive tract

Simple Epithelium Pseudostratified Single layer, but some cells are shorter than others Found in the respiratory tract – has cilia Functions in absorption and secretion

Stratified Epithelium Stratified Squamous Several layers of flat cells Locations: Skin Mouth Esophagus

Stratified Epithelium Transitional Epithelium Shape of cells depends upon the amount of stretching Lines organs of the urinary system to help stretch the bladder

Glandular Epithelium Gland = one or more cells that secretes a particular product Two major gland types: Endocrine Glands Ductless Secretions hormones directly into the blood Exocrine Glands Have ducts Include sweat and oil glands

Connective Tissue Types Dense Connective Made up of collagen fibers Examples: tendons and ligaments

Connective Tissue Types Adipose Made of areolar tissue with fat globules Functions: Insulates the body Protects organs Serves as a site of fuel storage

Connective Tissue Types Areolar Most widely distributed connective tissue Soft tissue Contains all fiber types

Connective Tissue Types Hyaline Cartilage Most common cartilage Entire fetal skeleton is hyaline cartilage

Connective Tissue Types Elastic Cartilage Made of elastic fibers Provides elasticity Example: supports the external ear

Connective Tissue Types Fibrocartilage Highly compressible Example: forms cushion-like discs between vertebrae

Connective Tissue Types Bone Composed of a hard matrix of calcium salts Used to protect and support the body

Connective Tissue Types Blood Blood cells are surrounded by fluid matrix Functions as the transport vehicle for materials

Connective Tissue Types Reticular Delicate network of interwoven fibers Forms internal support for the lymph nodes, spleen, and bone marrow

Muscle Tissue Types Skeletal Muscle Can be controlled voluntarily Cells are striated Cells have more than one nucleus Attached to the bones Function: Movement

Muscle Tissue Types Smooth Muscle Involuntary muscle Surrounds hollow organs No visible striations One nucleus per cell Function: movement

Muscle Tissue Types Cardiac Muscle Found ONLY in the HEART Cells are striated One nucleus per cell Function: pump blood