Tissues Biology 2 CP A Stem cells form

Tissues Biology 2 CP

A. Stem cells form when a ________ first begins to divide. 1. Stem cells can divide _______ without __________. 2. They can be coaxed into forming many cell types.

B. The most pliable of stem cells comes from human ________, which may be able to repair damaged _________ tissue. 1. Ethical issues have been raised because of the source of the embryonic tissue: 2. _________ stem cells may be useful as an alternative to some cell development.

C. The cells of the body are organized into levels. 1. A __________ is a group of cells that performs a common task. 2. Each __________ consists of different tissues working together for a common goal. 3. ____________consist of two or more organs interacting for a common task.

4 Tissue Types Epithelial primarily used for protection Connective primarily used for support Nerve primarily used for control Muscle primarily used for movement

Epithelial Tissue (ET) • ________ packed cells of mostly uniform shape that reproduce rapidly • Form a complex protective layer: – Covers the body: _____________________ – Lines all body cavities: ______________________

• In this ET, one surface is ________ and the other _________ to a basement membrane that separates the ET from the connective tissue (CT) • ___________ contains NO blood vessels

• Simple epithelium is ________ thick and may have ___________, ______________, or _______________ cells. • Stratified epithelium has ___________—as in human skin.

Squamous E. T. • ______, __________ cells with irregular shape • _______ prominent nucleus • Permeable cells: Function in _______________ during breathing. *Adapted for _________ and ________ • Also make up the ______ of the eye

Cuboidal E. T. • ______ like • Spherical nuclei in ___________ of cell • Line ducts of glands:

Columnar E. T. • ________ like: tall and thin • Nucleus near ________________ • FXNS: Concerned primarily with ________ of digestive fluids and with ___________ of food materials • Some may possess __________: increases the surface area of the cell for secretion and absorption

Pseudostratified E. T. • Appears _________ because of the different cell shapes and sizes • Not all cells reach from membrane to surface (but some do) • Possess _______ that create a wave like motion to aid in movement of materials • Possess ___________ that secrete mucus

Transitional E. T. • Surface cells are large and ________; not flat. • Some cells have _______ nuclei • Stretchy and _________; respond to changes in ________ • Peculiar cells that slide over one another

Cell Junctions

• In epithelium, cells are linked tightly together with specialized junctions, providing both _________ and __________ links between individual cells

• Adhering junctions are like “spot welds” that _____ cells together, so they can function as a unit • Tight junctions provide seals to prevent _______ across the free epithelial surface. In digestive tract, prevents attack of the wall by acids and enzymes. • Gap junctions are channels that allow _____ and ________ to flow between the cytoplasm of abutting cells

Glandular E. T. • Glands are _________ organs derived from epithelium. • Exocrine glands often secrete through ducts or tubes to free surfaces; they secrete _____________________________________ • Endocrine glands secrete _________ directly into intercellular fluid for distribution by the blood.

C. T.

C. T. 1° Fxn: Most connective tissue contains cells & fibers (_________ &/or ________) secreted by __________, all scattered in a “ground substance” that accumulates between cells & fibers.

• 2° Fxns: § Framework for internal organs § Packages & protects organs from injury § Supports body organs § Fat & E storage § Defense – Immune System

Fibers • Collagen • Reticular • Elastic

Collagenous Fibers • Contain collagen – thick fibrous protein • Made by fibrocytes • Major constituent of ligaments, tendons, cartilage and bone

Collagen Derived from Greek word meaning “to glue together” Constitutes about 25% of the weight of most mammals Present in all human organs Has high tensile strength: 4. 5 pound load needed to break collagen fiber 1 mm thick

Collagen Diseases Overproduction of Collagen Fibers lung fibrosis (cystic fibrosis) liver fibrosis (alcoholism may induce both fibrosis and cirrhosis) Contributes to atherosclerotic heart disease Insufficient Collagen Ehlers-Danlos syndrome (rubber man - contortionist disease) Osteogenesis imperfecta (brittle bones) Scurvey (Vitmain C-deficiency- too few hydrogen bonds formed) * inferior tissue formation in bones, blood vessels, skin, and teeth

Collagen Fibers

Elastic Fibers • • Contain protein called elastin Yellow fibers Highly elastic - spring-like Can be compressed or distended

Reticular Fibers • • • Short and very thin Form cobweb network called reticulum Non-elastic Form internal framework of glands Fill “space” between other tissues & organs

Soft Connective Tissues 1. _______________ supports epithelia & organs, & surrounds blood vessels & nerves; contains fibroblast cells & fibers plus macrophages.

Macrophages • Move through the CT & ingest foreign matls

Plasma Cells • Form antibodies important in body’s defense (Immune System)

Mast Cells • Located near blood vessels (BVs) • Involved in prodn of heparin – an anticoagulant • Important in prodn of histamine in allergic rxns BV

Blood Cells • White blood cells (WBCs) • Destroy bacteria

Fat Cells Store fats and oils Resemble a signet ring

2. _______________ has thicker fibers & more of them, but fewer cells. This tissue is part of the ______. It supports ________________ & it forms protective capsules around the _______ & other organs that do not stretch.

3. _______________ has its fibers in parallel with orderly rows of fibroblasts; keeps tissues from being torn apart during times of stress. This is the arrangement found in _________ (muscle to bone) and ________ (bone to bone).

Dense Irregular Tissue (Dermis of Skin & Muscle Fascia)

Dense Regular Tissue (Tendons & Ligaments) Horse Tendon x 100 arrow: orientation of collagen fibers

Reticular Tissue

Specialized Connective Tissues 1. _____________ contains a dense array of fibers in a jellylike ground substance. a. It _________ and __________ the shape of body parts; it resists compression and is resilient.

b. Locations _______________________________________ c. _____________: no BVs and therefore slow to heal.

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 Fibrous cartilage - less rigid 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 Parts that move: epiglottis

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

Elastic Cartilage (note numerous chondrocytes and elastic fibers)

2. _______________ stores mineral salts, produces blood cells, and provides spaces for its own living osteocytes. a. Organized as flat plates and cylinders, bones _______ and ___________ body tissues and organs; some have sites for ______________ production. b. Bones work with _________ to perform movement.

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 contains lymph channels functions in mineral storage and blood cell production bone remodeling - deposition and resorption of bone neg feedback Decr. blood [Ca++] - Inc. PTH – Inc. osteoclast activity Incr. blood [Ca++] – Inc. calcitonin - Inc. osteoblast activity red marrow: contains hematopoietic tissue - produces blood cells

Epiphyseal Plates Bone Histology Haversian System (osteon) Compact (Cortical) Bone Haversian Canal (contain blood vessels) Marrow Endosteum Lamellae (concentric rings of hard bone) Osteocytes in Lacunae Periosteum Volkmans Canaliculi (connecting tunnels) Trabecular (Cancellous) Bone

Cross Section of Cortical Bone Osteons

Growth Plate (epiphyseal plate) in Long Bone zone of resting cartilage Epihysis (bone end) Chondrocytes zone of proliferation zone of hypertrophy calcification Chondrocytes divide and stack on top of one another Chondrocytes die upon calcification - blood vessels from diaphysis grow into the area ossified bone Diaphysis (shaft)

Bone Diseases & Treatments Osteoporosis – d bone density…injury predisposition Inc. bone resorption in the presence of normal bone metabolism d both cortical (thick) and trabecular (porous) bone density 50% chance that a 50 yr old women will suffer osteoperotic fracture treatment Calcium supplementation Vitamin D supplementation Estrogen replacement (for postmenopausal women) Fosamax - a drug that inhibits osteoclast activity

Bone Diseases & Treatments Osteomyelitis - bone inflammation & destruction caused by bacteria and fungi symptoms: fever, localized warmth & swelling, localized pain treated with antibiotics Osteoarthritis - degenerative changes in cartilage & bone loss of articular cartilage & reduction in bone compliance (stiffness) roughening, pitting, in hyaline cartilage (progressing to destruction) formation of osetophytes (bone spurs)

Bone Diseases & Treatments Osteoarthritis (cont. ) cause changes in the microenvironment of the chondrocytes genetic defects, infection, endocrine disorders, fracture, overuse treatment exercise - helps maintain ROM & healthy cartilage Immobilization can worsen the course of the disease NSAIDS and COX 2 inhibitors for pain injections of hyaluronic acid (in the knee) or new artificial material corticosteroid injections may be useful when inflammation is present joint replacement (when conservative therapy fails)

3. __________ cells are specialized for the storage of ______, which can be used as an _________ reserve and as ________ to pad organs.

4. __________is classified as C. T. because its cellular components form from ___________ in bone. It transports (in plasma) __________ (red blood cells), _____________, and _________; it also contains clotting fac tors (_______) to protect against bleeding and components to protect against disease causing agents (_______________).

Blood & Body Fluids 62. 5% of total body fluid is intracellular (ICF) 37. 5% is extracellular (ECF) (blood & interstitial fluid)

Blood Blood: Average blood volume: 5 L (3 L plasma 2 L RBC’s) Hematocrit (Hct): packed RBC volume. 45 -men. 40 female Anemia: Hct <. 40 men Hct <. 35 (Hb < 14 g/d. L - 12 g/d. L)

Blood functions related to injury / healing hemostasis immune function inflammation transport (nutrient, waste, metabolites) Blood components formed elements (cells and platelets) red blood cells white blood cells platelets plasma

Blood Red blood cells (erythrocytes) - formed in bone marrow production and homeostasis regulated by tissue oxygenation d tissue O 2 r u erythropoietin from kidneys & liver r u RBC’s

Blood White blood cells (Leukocytes) primary effector against infection & tissue damage WBCs engulf foreign substances & lysozomal enzymes digest them inadequate circulatory or lymphatic function results in abcess

White Blood Cell Types GRANULOCYTES - granulated WBC’s neutrophils - 62% of WBC’s - 1 st to arrive at injury phagocytotic eosinophils - 2% of WBC’s - destroy parasites involved in allergies basophils - < 1% of WBC - release histamine & heparin AGRANULOCYTES - nongranulated WBC’S monocytes - 5. 3% of WBC’s - become lysosome filled macrophages - monocytes that have left the circulation macrophages release compliment proteins (inflam. mediators) lymphocytes - Tcells & Bcells - 30% of WBC’s function in immunity

Macrophage: box Pedicle for locomotion: arrow Monocytes

Basophil: large arrow Neutrophil: small arrow Eisonophil: arrow

Blood Platelets - Thrombocytes sticky cells that function in all aspects of hemostasis Plasma water (90% of plasma volume) proteins Albumin -(60%) maintains oncotic pressure & transports FFA’s Fibrinogen (4%) functions in the clotting process Globulins (36%) - function in lipid & vitamin transport enzymes, antibacterial proteins, and protein hormones metabolic by products: lactic acid, urea, creatinine, etc. nutrients: glucose, FFA’s, lipids, cholesterol, vitamins electrolytes: sodium, potassium, magnesium, bicarbonate, etc. gasses: oxygen, nitrogen, carbon dioxide, etc.

Muscle Tissue

Skeletal Muscle Tissue 1. Skeletal muscle tissue attaches to _________ for voluntary movement; it contains _________, ___________, long cells. 2. Each unit, called a __________, is contractile; muscle makes up ____ % of the weight of average humans.

Cardiac Muscle Tissue 1. __________ (heart) muscle is composed of ________, ___________ branching cells that can function in units. 2. Contraction signals pass quickly at gap junctions, and the tissue is packed with _____________ to supply ATP for the continual beating; no oxygen equals heart attack.

Smooth Muscle Tissue 1. Smooth muscle tissue contains _______shaped cells. 2. Location_____________________ 3. Its operation is ______________: like cardiac. 4. This tissue is ______________, hence the name, and its contractions are slower than skeletal but can be prolonged.

Nervous Tissue

Nervous tissue exerts the greatest control over the body's responsiveness to changing conditions. 1. ____________ are excitable cells, organized as lines of ________________ throughout the body.

2. ____________ are diverse cells that protect and metabolically support the neurons. Various neurons detect stimuli; others coordinate the body’s responses; still others relay sig nals to muscles and glands for response.

Vertebrate Skin—Example of an Organ System • The outer covering of animal bodies is called the ____________. 1. In vertebrates, the integument consists of skin and the structures derived from epidermal cells, such as _______________________________________ in an outer epidermis and underlying dermis.

• The skin ____________ and ____________ the body from ___________________; it helps control ___________________a nd helps make ____________; its sensory receptors help the brain detect environmental ____________.

The dermis lies beneath the _________, resting on the _____________, which is not part of the skin but contains loose connective tissue and fat. a. The dense C. T. of the dermis cushions the body against ___________________. b. ________________ are embedded in the tissue.

• ____________ glands produce a fluid that is released in response to stress (overheating and fright, for example). • Oil glands (_____________) lubricate and soften the skin, plus they produce secretions that reduce _____________ on the skin. • Each hair is a flexible structure rooted in the skin and projecting above it.

1. Epidermis is a ___________ epithelium, with an outermost layer (_________________) consisting of flattened, __________ cells filled with keratin.

a. Keratinocytes produce __________, a tough, water insoluble protein that accumulates in the cells. b. Melanocyte cells produce ______________ that darkens the skin and protects against the sun’s rays; ________ and ___________ also contribute to skin color. c. _________________ (phagocytes) engulf viruses and bacteria that they encounter in the skin.

The Vitamin Connection 1. _____________ helps skin cells make vitamin D, which is necessary for _______ absorption from foods. 2. The B vitamin _____________ is necessary for normal embryonic development and is broken down by UV exposure. 3. Variations in skin color among human populations are adaptations to differences in sunlight exposure.