TISSUES

TISSUES Groups of cells working together in similar function

4 MAJOR TISSUE TYPES Epithelial (protection) Connective (bind organs) Muscle (movement) Nerve (communication)

EPITHELIAL TISSUE Protective coverings Secretion Absorption Excretion Lack blood vessels Readily divide Tightly packed

9 types of Epithelial STRATIFIED SQUAMOUS TRANSITIONAL SIMPLE SQUAMOUS STRATIFIED CUBOIDAL SIMPLE CUBOIDAL SIMPLE COLUMNAR GLANDULAR STRATIFIED SQUAMOUS PSEUDOSTRATIFIED COLUMNAR TRANSITIONAL STRATIFIED COLUMNAR

SIMPLE SQUAMOUS EPITHELIUM Single layer of thin flat cells Allow substances to easily pass through PROTECTION Air sacs of lungs (alveoli) Capillary walls Blood & lymph vessels Membranes that line body cavities

SIMPLE CUBOIDAL EPITHELIUM Single layer of cube shaped cells SECRETION ABSORPTION Ovaries Kidney tubules Gland ducts (salivary, thyroid, pancreas)

SIMPLE COLUMNAR EPITHELIUM Single layer of elongated (column) shaped cells Thick SECRETE DIGESTIVE FLUIDS ABSORB NUTRIENTS Stomach Intestines (microvilli) Oviducts Uterus

STRATIFIED SQUAMOUS EPITHELIUM Many layers of flat cells Thick Deeper cell layers push older layers away (keratinization) WATERPROOF LAYER Epidermis Linings of mouth, throat, vagina, anal canal

STRATIFIED CUBOIDAL EPITHELIUM Layers of cube shaped cells PROTECTION Lining of blood vessels & intestines (lumen) Ducts of mammary glands, sweat glands, salivary glands, pancreas Lining of ovarian follicles & seminiferous tubules

STRATIFIED COLUMNAR EPITHELIUM Layers of elongated cells ABSORPTION SECRETION Urethra Vas deferens pharynx

PSEUDOSTRATIFIED COLUMNAR EPITHELIUM Appear layered but really are a single layer (nucleus at diff locations) Usually have cilia MOVE DUST & MICROBES Respiratory passages

TRANSITIONAL EPITHELIUM Can change shape in response to increased tension Allow for expansion & contraction of some organs so contents don’t diffuse back into organ Inner lining of bladder Ureter Parts of urethra

GLANDULAR EPITHELIUM Usually found within cuboidal or columnar epithelium Produce or secrete substances into ducts (EXOCRINE) or body fluids (ENDOCRINE) Mammary glands Sebaceous glands Salivary glands Sweat glands Pancreas

CONNECTIVE TISSUE Bind structures Support & protection of body organs Frameworks Fill spaces Store fat Produce blood cells Protect against infection Repair tissue damage

CONNECTIVE TISSUE Cells are farther apart Abundant intercellular material (matrix) tissue space Good blood supply (most) Some rigid (bone & cartilage) Some flexible (adipose & dense connective)

LOOSE CONNECTIVE Also called AREOLAR Delicate thin membranes Collagenous fibers (collagen)… long parallel bundles, slightly elastic but tensile strength Elastic fibers (elastin)… thin, stretch easily BIND SKIN TO UNDERLYING ORGANS FILL SPACES B/W MUSCLES SUPPLY EPITHELIUM W/BLOOD Skin beneath epithelium

DENSE CONNECTIVE Also called RETICULAR Closely packed (very little if any matrix) Collagen & elastin (strong) Low blood supply; slow repair/healing BINDS BODY PARTS TOGETHER Ligaments & tendons

ADIPOSE “fat” CUSHION JOINTS & ORGANS INSULATION STORED ENERGY Beneath skin; b/w muscles Surrounds most organs

CARTILAGE Rigid Mostly collagenous fibers PROVIDE SUPPORT FRAMEWORK ATTACHMENT PROTECT UNDERLYING TISSUE DEVELOPING BONES Skeleton, nose, ears, joints

TYPES OFCARTILAGE ELASTIC HYALINE Dense network of elastic fibers Framework of external ear Parts of larynx Most common Fine collagenous fibers Ends of bone & joints Soft part of nose Respiratory passages FIBROCARTILAGE Very tough Collagenous fibers Shock absorber Intervertebral discs Cushions bone in knee & pelvis

BONE Also called OSSEOUS osteocytes (bone cells) Most rigid connective tissue (mineral salts: CaPO4; CaCO3) Abundant collagenous fibers Good blood supply; heals rapidly Red Marrow: produce blood cells PROTECT BODY STRUCTURES & ORGANS ATTACHMENT FOR MUSCLES Skeleton, rib cage, skull

BLOOD Fluid filled matrix Red blood cells White blood cells Platelets TRANSPORT MATERIALS THROUGH BODY HELP MAINTAIN STABLE INTERNAL ENVIRONMENT In blood vessels throughout body

MUSCLE TISSUE Contractile (elongates & shortens) SKELETAL MUSCLE MOVES BODY PARTS SKELETAL MUSCLE SMOOTH MUSCLE CARDIAC MUSCLE

SKELETAL MUSCLE TISSUE STRIATED: long, thread-like cells w/ alternating light & dark bands VOLUNTARY Move head, trunk, limbs Allow us to make facial expressions, write, walk, talk, chew, swallow, breathe Muscle attached to bones

SMOOTH MUSCLE TISSUE NO STRIATIONS INVOLUNTARY Spindle-shape Control body processes (digestion; excretion; respiration) Internal organs

CARDIAC MUSCLE TISSUE Found only in HEART STRIATED INVOLUNTARY Cells join end to end Intercalated disks: allow nerve impulses to travel rapidly

NERVE TISSUE Neurons: nerve cells Long branching cells SENSE CHANGES COMMUNICATE WITH EACH OTHER, MUSCLES, & GLANDS COORDINATE, REGULATE, INTEGRATE BODY FUNCTIONS Brain Spinal cord Peripheral nerves