- 1.Covers all surfaces except joint surfaces.
- 2. is Avascular
- 3. single or multiple layers closely attached
- 4. lies on connective tissue floor call basal lamina (part of the basement membrance
- 5. free surface cells contact air, body fluids, digestive chemicals.
- 6. may have cilia or microvilli
- 7. grows and regenerates
- 8. derived embryologically from ecto, meso, or endo-derm
capability of epithelial cells-abnormal growing mass of tissue-growth not restricted by normal growth inhibitirs.
- Tumor spreads-is malignant tumor call carcinoma-treatment is surgery or radiation-can cause scarring or damage of skeletal muscle, bone and neurovascualr structure.
- **therapy to increase function by increasing joint or tissue mobility or by increasing muscle strength.
General functions of surface epithelium
- 1. protects
- 2. lubricates
- 3. absorbs, secretes, digests, and transports subst.
**each type names by shape and number of cells
Simple squamous (1 layer)
- 1. flat, plate-like (scale-like). oval nucleus in center
- 2. (a.)lining of blood vessels(endothelium), (b.)alveoli of lungs,(c.) lining outside of the lungs as visceral pleura, (d)lining of outside heart as serous visceral pericardium, (e)lining outside of intestines as visceral peritoneum, (f)line of thoracic cavity of parietal pleura, (g)ling of abdominal cavity as parietal peritoneum
- 3.a. regulate gas, metabolite and fluid exchange
- c. protection
Simple cuboidal (1 layer)
- 1. cuboidal in shape, round central nucleus, free surface microvilli
- 2. (a)ducts of glands,(b) prox and dist convoluted renal tubules (c) collecting ducts of kidneys (d)bronchioles
- 3. (a) absorption
Simple columnar (layers 1)
- 1. columanr shape, oval nucleus near base, free surface may have microv. or cilia
- 2. (a) large ducts of glands (b)lining fo the stomach and intestines (c) lining of the bronchi of the lungs
- 3. (a)absorption
Pseudostratified columnar (1layer)
- 1. all cells on basal lamina---not all cells reach free surface. cells that do are columnar in shape.nucleus in non-tapered part at base of cell. cilia. those that DO NOT reach surface are round basal cells with round central nucleus.
- 2. (a)trachea and primary bronchi (b)epididymis and vas deferens
- 3. (a)absorption
Stratified squamous mucous(non-keratinized)
- 1. surface=flat, viable, nucleated squamous
- basal lamin=columnar to cuboidal
- 2.(a)oral cavity(b)esophagus(c)vagina(d) anal canal
- 3. (a)protection
Stratified squamous cutaneous (keratinized)
- 1. surface=flat,nonviable,anucleated
- basal=columnar to cuboidal
- middle=round or oval
- 2.epidermis of the skin
- 3. protection
- 1. surface=large dome that flatten when stretch.
- basal=cuboidal and columnar
- ALL have round central nucleus
- 2. (a)urinary bladder (b)ureter (c)urethra
- 3. (a)protection
- 1. both layers=cuboidal and round central nucleus
- 2.rare ducts of the sweat glands
- 3. (a) absorption
- 1. deep cell=small irregular cuboidal
- superficial=columnar with oval nuclei
- 2. (a)large ducts of glands (b)male urethra, (c)nasal soft palate(d)larynx
- 3. (a)absorption (b)secretion (c)protection
INTERCELLULAR ATTACHMENTS=JUNCTIONAL COMPLEX
- (1) ZONULAOCCLUDENS or TIGHT JUNCTION lies nearest the free surface of the cell.This small band or zone is formed by fusion of the adjoining plasmamembranes.
- (2) ZONULA ADHERENS lies deep to the zonula occludens. Theadjacent cell membranes at this type of contact appear to be held togetherby a clear adhesive material.
- (3) MACULA ADHERENS or DESMOSOME isdeep to the zonula adherens. Cell membranes at the macula are firmlyattached by linking filaments interconnecting the adjacent membranes. Tightadhesive junctions and desmosomes are also found alone, providing strongattachment sites between epithelial cells.
The skin consists of the EPIDERMIS constructed of stratified squamouskeratinized (cutaneous) epithelium, and the DERMIS containing a papillarylayer of loose connective tissue lying superficial to a reticular layer of denseconnective tissue. Deep to the skin is the SUBCUTANEOUS LAYER. It iscomposed of LOOSE CONNECTIVE TISSUE, elastic fibers and fat covering muscles and bone.
- 1. avascular
- 2. cells call keratinocytes
- 1.substance that is packaged in lamellar bodies within the cells of the stratum granulosum.
- 2.emptied into the intracellarspaces and provides a water barrier to prevent the loss of body fluids
The epidermis also contains
- 1) MELANOCYTES that produce melanin pigmentwhich gives the skin its color;
- 2) LANGERHANS cells that are involved in theimmune response, especially skin allergic reactions; and
- 3) MERKEL CELLSwhich are slow adapting mechanoreceptors involved in cutaneous sensation.
Layers of the Epidermis
- 1.stratum basale(germinativum)-deepest contains epithelial cells,melanocytes, Langerhan cells, and Merkel cells.
- 2.STRATUM SPINOSUM-produce KERATOHYALIN GRANULESwhich begin to fill the cells and tonofilaments which bundle together to formTONOFIBRILS.
- 3.STRATUM GRANULOSUM.-flat cells accumulate large numbers ofkeratohyalin granules
- 4.STRATUMLUCIDUM and STRATUM CORNEUM-Cells of the stratum lucidum fill with keratin, losetheir nuclei and organelles, and their plasma membrane thickens. Cells ofthe stratum corneum, which is the most superficial layer of the skin, are alsofilled with keratin, have no nuclei or organelles and have a thick cell membrane.
- 1) aPAPILLARY LAYER of loose connective tissue which lies adjacent to the epidermis
- 2) a RETICULAR LAYER of dense fibrous connective tissue which is deepto the papillary layer. ****Blood vessels, nerves, sweat glands, sensoryreceptors, hair follicles and sebaceous glands lie in the dermis.
Nerves of Dermis
- 1) end at sensory receptors in thedermis
- 2) innervate smooth muscle associated with blood vessels, hairfollicles (arrector pili muscles) and sweat glands.
- 3)Nerves ending inthe dermis terminate as either non-encapsulated free nerve endings orencapsulated MEISSNER CORPUSCLES, PACINIAN CORPUSCLES, andRUFFINI ENDINGS
- ****free nerver endings in epid unclear
The SUBCUTANEOUS LAYER
containsloosely arranged collagen and elastic fibers, fat cells, nerves and large bloodvessels. Collagen and elastic fibers are few in those areas where the skin ismobile, but are abundant in areas where the skin is firmly attached to theunderlying tissues.
Burns and Decubitus Ulcers
Burns and decubiti do heal and the epithelium that is destroyed can bereplaced. To accelerate the healing process, therapists may use electricalstimulation, hydrotherapy, topical agents, and special dressings (McCullocket al., 1995; Michlovitz, 1996). Therapists may also need to remove dead ordying tissue by a process called DEBRIDEMENT. Hydrotherapy treatmentsare commonly used to help debride wounds and accelerate healing.
begins at the stratumbasale. Proliferation of the stratum basale then leads to the formation of thestratum spinosum and so forth.
A major component of scar tissue is collagen. When excessivecollagen is used to repair a wound, the result may be a wide, stiff, elevatedscar
Types Connective Tissue
CARTILAGE, and BONE.
Connective Tissue Fibers
Collagen, Reticular, and Elastic
- 1. TYPE I COLLAGEN is found in the dermis of skin, tendon, ligament,FIBROCARTILAGE, bone and fascia. It forms 90% of the collagen in the bodyand functions to resist tension and stretching.
- 2. TYPE II COLLAGEN is found in hyaline and elastic cartilage. It functions toresist tensile strain that occurs when cartilage is compressed
- .3. TYPE III COLLAGEN is found in the connective tissue of organs, such asthe liver, spleen, lungs, and intestines, and in blood vessels. It is also foundin muscle and peripheral nerves. It functions as a structural support systemin these structures.
- 4. TYPE IV COLLAGEN is found in the basement membrane of epithelium andthe external lamina of muscle cells and the axons of neurons. It functions tosupport these structures and as a filter.
- 5. TYPE V COLLAGEN is found in the basal lamina of smooth and skeletalmuscle cells and Schwann and glia cells. It functions as a support system inthese structures.
- type III collagenfibers.
- These fibers are thin and delicate, and form lace-like networks offibers. They are found around smooth muscle cells, the sarcolemma of striated muscle, and the endoneurium of peripheral nerves.
- Contian protein called ELASTIN
- abundant in some ligaments, large arteries, the trachea and the dermis ofthe skin.
Collagen is produced:
- 1.Fibroblasts-connectic tissue proper
- 2. Chondroblasts-cartilage
- 3. Osteoblasts-bone
- 4. Skeletal Muscle cells-skeletal muscle
- 5. Smooth muscle-blood vessesls and some organs
- 1. long spindle shaped
- 2. produce GAGS and proteoglycans
- 3. produce collagen and elastic
- 4.found in fibrous connective tissue
- a. Perichondrium=cartilage
Also in connective tissues proper
- 1.MYOFIBROBLASTS are cells that have properties of fibroblasts and smoothmuscle cells. They produce collagen but contain myofilaments.
- 2.Macrophages are responsible for the digestion andremoval of foreign material and cellular debris and are important in thebody's defense system.
- 3.PLASMA CELLS-produce antibodies and are part of the immunesystem. MAST CELLS are granular cells found in loose connective tissue,especially
- 4.Mast cells detect antigens and trigger alocal inflammatory response. Mast cells contain 1) heparin which is ananticoagulant, 2) histamine which increases vascular permeability, 3)serotonin which produces smooth muscle contraction, 4) slow - reactingsubstance of anaphylaxis (SRS-A) which increases vascular permeability, 5)eosinophil chemotatic factor of Anaphylaxis (ECF-A) which stimulates themigration of eosinophils
Neurophils, Basophils, and Eosinophils
granular white blood cellsthat are also found in connective tissue. All three of these granulocytesoriginate in the bone marrow but reside in the blood.
invade areas of inflamation
eave the blood andmigrate rapidly to areas of inflammation. These cells contain heperin andhistamine and function similar to mast cells.
ncrease innumber with parasitic disorders and with some allergies, but they are notusually bacterial phagocytes.
Lymphocytes and FAT Cells
- agranular white blood cells that are also involved in theimmune system. They are found commonly in loose connective tissue butshow high concentrations in the digestive tract. F
- AT CELLS or ADIPOCYTESare found primarily in loose connective tissue.
The ground substance in connective tissue consists of water,GLYCOAMINOGLYCANS (GAGs) and PROTEOGLYCANS
Types of Connective Tissue Proper
- (1) loose connective tissue
- (2) dense irregular connective tissue
- (3) dense regular connective tissue
- (4) elasticconnective tissue.
Loose connective (areolar)
- 1. Fibers-loose collagen, reticular, elastic
- 2.(1) fibroblasts, (2) myofibroblasts, (3)macrophages, (4) plasma cells, (5) mast cells, (6) neutrophils, (7)basophils, (8) eosinophils, (9) lymphocytes, (10) fat cells
- 3.LOCATIONS: (1) superficial fascia, (2) subcutaneous layer of skin, (3)epimysium,(4) papillary layer of the dermis, (5) area around neurovascularbundles.
DENSE IRREGULAR CONNECTIVE
- 1.Fibers-collagen bundles,some elastic
- 3.LOCATIONS: (1) reticular layer of the dermis, (2) periosteum, (3)perichondrium, (4) joint capsules, (5) capsules around some organs, (6)epineurium, (7) perineurium
DENSE REGULAR CONNECTIVE TISSUE
- 1. FIBERS: many densely packed collagen bundles arranged in parallel rowsrunning in the same direction 2. CELLS: few fibroblasts
- 3.LOCATIONS: (1) tendons, (2) ligaments, (3) fascia, (4) aponeuroses
ELASTIC CONNECTIVE TISSUE
- 1.FIBERS: an abundance of elastic fibers interwoven among collagen fibers
- 2. CELLS: fibroblasts
- 3. LOCATIONS: (1) ligamentum flavum, (2) ligamentum nuchae, (3) wall oflarge (elastic) arteries, (4) vocal ligaments of larynx.
Types of Cartilage
- (1) hyaline cartilage,
- (2) elastic cartilage
- (3) fibrocartilage.
- 1. FIBERS: fine network of Type II collagen fibers
- 2. CELLS: chondrocytes
- 3. LOCATIONS: (1) costal cartilage, (2) articular cartilage of most joints, (3)epiphyseal growth plate, (4) trachea, (5) skeleton of larynx, (6) nasalseptum
- 1. FIBERS: abundance of densely packed elastic fibers interwoven among TypeII collagen fibers
- 2. CELLS: chondrocytes
- 3.LOCATIONS: (1) auricle of ear, (2) epiglottis, (3) Eustachian tube, (4) wallof external auditory canal
- 1.FIBERS: dense network of Type I collagen fibers
- 2.CELLS: chondrocytes
- 3.LOCATIONS: (1) menisci of knee, temporomandibular joint, sternoclavicularjoint, acromioclavicular joint, (2) intervertebral discs, (3) disc at pubicsymphysis, (4) articular cartilage of temporomandibular joint, (5) tendoosseousjunctions, (6) tendons at points of mechanical trauma (i.e. friction)
Osteocytes, TYPE ICOLLAGEN fibers, and a mineralized ground substance.
mature bone cells entrapped in calcified ground substance
Ground substance of bone + type 1 collagen
- 1.Makes bone matrix
- 2.matrix -65-70 inorganic=calcium phosphate and calcium carbonate
- 30 organic=95 is collagen and 5 is proteo and glyco
found in the inside of thebone. It consists of a network of delicate processes called TRABECULAE.Trabeculae are abundant at the ends or EPIPHYSES of long bones, wherethey become aligned to resist common stresses placed on individual bones.
- 1. thick along the shaft or diaphysis of long bones, but thin at the epiphyses.
- 2. consists of a series of circular layers of bone that forms an OSTEON orHAVERSIAN SYSTEM (Fig. 3-02B and C). Trabecular bone does not have osteons.
- 1. have haversion canal-contain blood vessels and fine nerve fibers
- 2. blood vessels enter through nutrient foramen and then through volkmann canal(trans and obliq to haversian)
- 3. Surrounding each canal=lamella and between rings is lacuna(have osteocytes)
- -tunnels that connect lacunae and small tunnels
- -provide nutrition to osteocytes
- 1.between osteons
- 2.old osteons
- 3.separated by cement lines
- 1. arise from Mesenchymal Cells
- 2.found in the inner cellular layer of the periosteum, the endosteum of the Haversian canal and along the trabeculae in theMetaphysis of developing bone.
- 3.differentiate into OSTEOBLASTS.
- 1. immature osterocytes
- 2.secret collagen and non-calcified osteoid
- 3. become osteocytes when surrounding matrix calcifies.
- 1.large multinucleated cells that remove calcified bone and osteoid
- 2.increased by parathyroid hormone which promotesthe slow release of calcium from bone into the blood.
Types of Muscle
- SMOOTH MUSCLE, CARDIAC MUSCLE andSKELETAL MUSCLE.
- Smooth muscle contains smooth muscle cells.
- CARDIACMUSCLE and skeletal muscle are composed of striated muscle cells. The terms muscle cell and muscles fiber are generally used interchangeably.
- 1. NUCLEUS: one nucleus lying centrally in the cell 2. STRIATIONS: None
- 3. LOCATIONS: (1) digestive tract, (2) arteries and some veins, (3) urinarybladder, (4) uterus, (5) other organs
- 1. NUCLEUS: one or two lying centrally in the cell
- 2. STRIATIONS: light and dark bands
- 3.LOCATION: heart
SKELETAL (voluntary) MUSCLE
- 1. NUCLEUS: multiple nuclei lying along the periphery of the cell
- 2. STRIATIONS: light and dark bands
- 3. LOCATIONS: (1) upper and lower limbs, (2) trunk, (3) head, (4) neck
- 1. Composed of neurons and support cells
- 2.structural and functional units of nervous system
- 1. cell body
- 2.axon-are processes thatgenerally carry signals away from the cell body.
- 3.dendrites-are processesthat generally carry signals toward the cell body.
- 1.In the central nervous system, areas containing nerve cell bodies
- 2.concentration of nerve cell bodies is a
- NUCLEUS (CNS)
- 1.areas containing bundles (tracts) of nerve fibers
- 2.concentration in PNS=ganglion
1.found in peripheral ganglia surrounding nerve cell bodies.
surround nerve fibers of the PNS and form the MYELIN sheath whichinsulates sensory and motor nerve fibers.
NODE of RANVIER
he junction at which adjacent Schwann cells meet
action potentials traveling along nerve fiber jump from one node to next.
Thick dense irregular conn. tissue that wraps peripheral nerve
divide nerve fibers into bundles
wraps individual nerve fibers located in fascicle