The study of tissues Tissues1 Histology The study of tissues Tissues1

Vocabulary Adip-: fat Chondr-: cartilage -cyt: cell Epi-: upon -glia: glue Inter-: between Macr-: large Os-: bone Pseud-: false Squam-: scale Strat-: layer Phag-: to eat

Tissues Tissues: a group of similar cells specialized for a particular function

Fun Facts About Skin The body’s largest organ Most of the dust in homes is dead skin cells The average body’s skin is as large as a twin size blanket Skin is about 15% of your body weight…figure out how much your own skin weighs… Your weight x 0.15 = ? It takes about 27 days for the outer layer of skin to be replaced… That is about 1.5 lbs of skin cells we shed per year

Skin Repair skin gun

Tissue Naming Simple: single layer Stratified: multiple layers Squamous: flat Cuboidal: square Columnar: column (rectangle)

Epithelial Tissue Location: Characteristics Function: Covers all body surfaces inside and outside Main tissue of glands Characteristics Has no blood supply Cells reproduce rapidly Cells are tightly packed Function: Protection, absorption, excretion, secretion

Types of Epithelial Tissue Simple Squamous Location: air sacs, capillaries, vessels, membranes Characteristics: flat, thin, easily damaged Function: diffusion and filtration

Types of Epithelial Tissue Simple Cuboidal Location: kidneys, ducts, glands, covers ovaries Characteristics: single layer of cube-shaped cells Function: secretion and absorption

Types of Epithelial Tissue Simple Columnar Location: digestive tract, uterus Characteristics: can have microvilli, contain goblet cells that secrete mucus Function: secretion and absorption

Types of Epithelial Tissue Stratified Squamous Location: skin, mouth, vagina and anal canal Characteristics: many cell layers, deeper layers divide and push older layers up Function: protection

Types of Epithelial Tissue Pseudostratified columnar: Location: lining of air passages and reproductive system Characteristics: not layered but appear to be, cells vary in shape Function: protection, secretion, excretion of mucus

Types of Epithelial Tissue Stratified Cuboidal Location: mammary, sweat and salivary glands, pancreas Characteristics: 2-3 layers of cells Function: protection

Types of Epithelial Tissue Stratified Columnar Location: male urethra and pharynx Characteristics: several layers of cells Function: protection and secretion

Types of Epithelial Tissue Transitional Location: bladder, ureters and urethra Characteristics: stretches and contracts Function: blocks diffusion to prevent leaks

Types of Epithelial Tissue Glandular Location: salivary, sweat and endocrine glands Characteristics: release fluid, parts of cells or whole cells Function: secretion Epithelial Tissue

Connective Tissue Location: Most abundant tissue- found throughout the entire body Characteristics Cells are spread out and are within a matrix Abundant blood supply Functions Binds structures together Supports Protects Produces blood cells Fights infection Stores fat Repairs tissue damage Transports

Major Types of Connective Tissue Cells Fibroblasts: produce fibers Macrophages: phagocytosis and help in defense Mast cells: secrete heparin to aid in blood clotting

Types of Fibers Collagenous: strong and flexible Hold structures together Bones, ligaments, tendons Elastic fibers: very flexible Makes up ears and vocal cords Tissues Connective connective tissue 2

Types of Loose Connective Tissue Fat, layers under skin Dense Cartilage Bone Blood

Types of Loose Connective Tissue Adipose Tissue: Function: protects, insulates, stores energy and fat Location: under skin, kidneys, heart, eyeballs

Types of Loose Connective Tissue Areolar tissue: Function: binds organs Location: beneath skin and muscles

Types of Loose Connective Tissue Reticular tissue: Function: supports Location: walls of liver and spleen

Types of Connective Tissue Dense Connective Tissue Function: Binds organs Location: tendons, ligaments, deep layers of the skin Hyaline cartilage Function: supports, protects, provides framework Location: ends of bones, nose, respiratory passages, ribs Elastic Cartilage Function: supports, protects and provides flexible framework Location: ear and larynx

Types of Connective Tissue Fibrocartilage Function: supports, protects, absorbs shock Location: between vertebrae, pelvic girdle, knee Bone Function: supports, protects, provides framework Location: bones of the skeleton Blood Function: transports substances, maintains homeostasis Location: blood vessels and heart

Types of Connective Tissue Muscle Tissue Smooth: organs Skeletal: muscles Cardiac: heart muscle

Types of Membranes Epithelial: cover body surfaces and lines body cavities Serous: lines cavities with no openings to the outside Secretes serous fluid for lubrication Mucous: line cavities and tubes that open into the outside of the body Secretes mucus Cutaneous: skin Synovial: lines joints

Nerve Tissue Nervous Tissue: found in the brain, spinal cord and peripheral nerves Neurons: basic nerve cells that respond to and send electrical impulses Coordinate, regulate and integrate bodily functions Neuroglia: support and bind nervous tissue together