Tissues Groups of cells performing similar functions Grouped by cells and matrix Structure determines function and function determines location Four types Histology - study of tissues

FOUR TYPES OF TISSUES Nervous Muscle Epithelial Connective

EPITHELIAL TISSUE More cells than matrix Covers external body surfaces - some internal organs Line body cavities Some permeable

Epithelial Tissue Some secrete and absorb Makes up sense organs Make up glands Basement membrane present Avascular

Grouped by cell shape Squamous Columnar Cuboidal

Grouped by layering Simple is one layer Stratified--more than one layer Simple columnar epithelium of the gallbladder. - SEM

Pseudostratified ciliated columnar False layering Nuclei at various depths within the cells Contain goblet cells Found in upper respiratory tract

Transitional Can be stretched - changes from cuboidal to squamous Found in urinary bladder

Epithelial Tissue Review

Intercellular connections Contain CAM (cell adhesion molecules) Tight junctions: protect Found in digestive tract Belt desmosomes: permeability Superficial skin Gap junctions: communication Cardiac muscle contractions

Endocrine glands Ductless glands Secrete inside Inside blood or tissue fluids Example: Hormones-adrenaline, sex hormones, etc.

Exocrine glands Secrete out to ducts (tubes) Examples: sweat glands, mammary glands, salivary glands

CONNECTIVE TISSUE Grouped by cell type, matrix & fibers present Most abundant Bind & support Store & transport Defense Highly vascular (Except Cartilage = Avascular)

Connective Tissue Cell types: immune, bone, cartilage, fat & blood Fiber types: elastic, reticular, & collagen Matrix types: liquid, more dense than liquid, almost solid, solid

Connective Tissue Major Cell types WBC’s Fibroblasts Mast cells (defense) Adipose

Loose Connective Large intercellular space Most abundant Around & cushions organs Ex: Areolar, Adipose

Dense Connective Fiber arrangement determines type Ex: Fibers parallel in fashion are – Tendons, ligaments

Osseous (bone) tissue Dense connective More matrix than cells Hardened calcium and flexible collagen Cells and blood vessels in special arrangement

Cartilage Type of dense connective tissue 3 types – Hyaline, Elastic, Fibrocartilage Only connective tissue that is avascular Elastic cartilage in ear

Blood (Vascular) tissue Liquid connective tissue Matrix is liquid (plasma) Cells known as formed elements Erythrocytes, leukocytes, and thrombocytes

Connective Tissue Overview

Muscle Tissue Muscle cells called muscle fibers Three Types of Muscle Tissue: Skeletal Cardiac Smooth

Neural Tissue Neurons – nerve cells Neuroglia – support cells

Membranes Mucous Membranes lines structures that open to outside Digestive and respiratory tracts Serous Membranes surrounds organs and lines body cavities with no opening to outside Pleura/ pericardium/ peritoneum (abdomen) Synovial Membrane - lines cavities of freely movable joints Cutaneous Membrane = Skin