Tissue Types in the Human Epithelial primarily used for protection Connective primarily used for support Nerve primarily used for control Muscle primarily used for movement

Epithelial Tissue Consists almost entirely of cells One side always exposed to “free surface”: body exterior organ cavity Cells have high regeneration potential * Cells are avascular * …. (Perfusion) Always attached to“Basement Membrane” Basement Membrane nonliving adhesive substance (Similar to Scotch® tape) composed of connective tissue (collagen and glycoproteins)

Adjectives Describing Epithelial Tissue Squamous (meaning “scale”) - flat cells Cuboidal - cells as tall as they are wide Columnar - tall and column shaped Simple - having a single layer of cells Stratified - having multiple or stacked layers Transitional - dome shaped surface cells Examples SIMPLE SQUAMOUS EPITHELIUM permeable - used for filtration and exchange examples: capillaries, alveoli, kidney glomeruli STRATEFIED SQUAMOUS EPITHELIUM used for protection - basil cells may be cuboidal examples: skin, inside of mouth

Kidney tubules, glands, lining of terminal bronchioles, etc.

Glands, bronchioles, stomach, intestines, bile ducts, etc.

Mouth, throat, esophagus, urethra, skin (keratinized)

Sweat gland ducts, salivary gland ducts, etc.

Mammary gland ducts, larynx, urethra (males)

Lines nasal cavity & sinuses, auditory tubes, trachea, bronchi

Bladder lining, ureters, and superior urethra

Connective Tissue Matrix Ground substance Fibers Cells

Connective Tissue Matrix - “non-living” component of connective tissue - Produced by cells of the connective tissue Ground substance- mainly water plus adhesion proteins and carbohydrates Fibers Collagen, Elastin, and Reticular Fibers

Connective Tissue (cont.) Cells - “living” component of connective tissue “blast” cells (create), “cyte” cells (maintain), “clast” cells (remove)

Fibrous protein in connective tissue structure Collagen Fibers Fibrous protein in connective tissue structure

Fibers (cont.) Reticular Fibers: Actually very fine collagen fibers Branch out to form a network Fill “space” between other tissues & organs Elastic Fibers: Contain protein called “elastin” Spring like properties Can be compressed or distended

Types of Connective Tissue Fibroconnective Tissue Cartilage Bone

Types of Connective Tissue Fibroconnective tissue - matrix is mostly fibers Areolar -”loose connective tissue” serves as “packing material” – Elastic & Collagen Fibers basal membrane component (attaches skin to underlying structures) separates muscles - allows for muscles to slide over each other Adipose - highly vascular: insulator, shock absorber, & energy store cells account for 90% of tissue mass (little matrix present): cells engorged with lipids Reticular - fibers forming a soft internal skeleton for other tissues

Types of Connective Tissue Fibroconnective Tissue (cont.) Dense regular - contains closely packed parallel collagen fibers found where tension is exerted in a particular direction Examples: tendons, ligaments Dense irregular - closely packed non-directional collagen forms “sheets” where tension is exerted in many directions Examples: dermis of skin, muscle fascia, organ & nerve coverings Elastic - composed of mostly elastin fibers Examples: vocal cords, ligamenta flava (vertebral connection tissue)

Areolar Tissue Fibrocyte Nucleus Collagen Fiber Elastic Fiber

(arrow: adipocyte nucleus) Adipose Tissue 200 X (bv = blood vessel) (arrow: adipocyte nucleus) bv

Reticular Tissue

Dense Regular Tissue (Tendons & Ligaments) Horse Tendon x100 arrow: orientation of collagen fibers

Dense Irregular Tissue (Dermis of Skin & Muscle Fascia)

Types of Connective Tissue Cartilage (cont.) types of cartilage: hyaline - tough & flexible - more matrix / fewer cells – serves as shock absorber covers ends of long bones (articular cartilage) forms “skeleton” of trachea and bronchi fibrocartilage - less firm than hyaline - more cells and fibers similar in structure to dense regular tissue (tendon) transitional tissue between tendon and articular hyaline cartilage forms intervertebral disks and spongy knee menisci elastic - contains more elastin fibers forms ear pinna & epiglottis

perichondrium on the left Hyalin Cartilage X 250 arrows: Perichondrial borders Hyaline Cartilage perichondrium on the left chondrocytes form in the perichondrium and move out into the tissue

Fibrocartilage

(note numerous chondrocytes and elastic fibers) Elastic Cartilage (note numerous chondrocytes and elastic fibers)

Types of Connective Tissue Bone - matrix mostly calcium and phosphate 65% of bone weight is calcium hydroxyapatite calcium phosphate, calcium hydroxide, calcium carbonate highly vascular and well innervated functions in mineral storage and blood cell production

Cross Section of Cortical Bone Osteons

Blood Blood components formed elements (cells and platelets) red blood cells white blood cells platelets Matrix- Plasma and soluble fibers

Macrophage: box Pedicle for locomotion: arrow Monocytes

Basophil: large arrow Neutrophil: small arrow Eisonophil: arrow

Nervous Tissue Branching cells with many long processes Large central nucleus Transmit impulses from one area of the body to other areas Regulate activities through neuron impulses

Nervous Tissue

Muscle Tissue

Skeletal muscle