Ch 4

Describe the features employed to classify the range of connective tissues and the major classifications, both mature and embryonic.

Embryonic connective tissue- refers to connective tissue present in an embryo or a fetus. - Mesenchyme - Mucous connective tissue Mature connective tissue- refers to connective tissue that is present at birth and persists throughout life. - Loose connective tissue - Dense connective tissue - Cartilage - Bone - Blood

Describe the two basic elements of connective tissue

Sparse cells Extracellular matrix

Illustrate the structures of pseudostratified epithelial tissues in addition to showing histological representations and examples of organs that contain them.

nonciliated (Lines epididymis, larger ducts of many glands, and parts of male urethra) ciliated (airways of most of upper respiratory tract)

3 types of dense connective tissue

-Dense regular connective tissue -Dense irregular connective tissue -Elastic connective tissue

Illustrate the structure of the different simple epithelial tissues in addition to showing histological representations and examples of organs that contain them.

A.Simple squamous epithelium- heart, blood vessels, lymphatic vessels B.Simple cuboidal epithelium- ovary, kidney, eyes, thyroid glands, ducts, and pancreas. C.Simple columnar epithelium- nonciliated (intestine) and ciliated (uterine) D.Pseudostratified columnar epithelium- nonciliated (Lines epididymis, larger ducts of many glands, and parts of male urethra) ciliated (airways of most of upper respiratory tract)

Describe an epithelial membrane general structure.

Epithelial membranes = epithelium + connective tissue - Mucous membranes: "interior" body surfaces open to the outside (tight junctions between cells, secrete mucus to hydrate, lubricate, and trap particles): Digestive tract, Respiratory tract, Reproductive tract - Serous membranes: line some internal surfaces: Parietal layer next to body wall, Serous fluid between layers, Visceral layer next to organ - Cutaneous membranes: Skin as a cutaneous membrane

Classify the tissues of the body into four major types.

Epithelial tissue Connective tissue Muscular tissue Nervous tissue

Contrast the three types of muscle tissue with regard to external appearance and internal structure, organs of location, modes of control, nature of contraction, and function.

Muscle tissue consists of fibers that provide motion, maintain posture, and produce heat 3 types of muscle tissue: - Skeletal muscle - Cardiac muscle - Smooth muscle

List the structure, function, and location of Elastic connective tissue

S: contains predominantly elastic fibers with fibroblasts between them; unstained tissue is yellowish. L: Lung tissue, walls of elastic arteries, trachea, bronchial tubes, true vocal cords, suspensory ligaments of penis, some ligaments between vertebrae. F: Allows stretching of various organs; is strong and can recoil to original shape after being stretched. Elasticity is important to normal functioning of lung tissue (recoils in exhaling) and elastic arteries (recoil between heartbeats to help maintain blood flow).

Describe the five most important kinds of cell junctions.

Tight Junctions-leak-proof seal between cells (epithelial tissue of the stomach, intestines, and bladder) Adherens Junctions- make an adhesion belt. Keeps tissues from separating as they stretch and contract. Desmosomes- act as "spot welds". They also use cadherin glycoprotein. Hemidesmosomes- are half-welds that join cells to the basement membrane. Gap Junctions- are pores (connexons) that allow small substances like ions to pass between cells.

Describe the general structural features and functions of the two types of cells in nervous tissues.

Two kinds of cells: -Neurons -Neuroglia Most neurons have a cell body, dendrites, and axon. Neurons can carry sensory or motor information and they can perform integrative functions. Neuroglia protect and support neurons

Compare the different processes that occur between repair of minor versus serious tissue damage.

When tissue damage is extensive, return to homeostasis depends on active repair of both parenchymal cells - if active in the repair, tissue regeneration is possible or near perfect)(satellite cells) stroma - if active then impaired scar tissue will make the repair (fibroblasts contributing to fibrosis)

Pseudostratified epithelium-

appears to have multiple layers of cells because the cell nuclei lie at different levels and not all cells reach the apical surface; it is actually a simple epithelium because all its cells rest on the basement membrane. Cells that do extend to the apical surface may contain cilia; others (goblet cells) secrete mucus.

Exocrine glands- Indicate how structural classification is based on numbers of associated cells and describe the single type of unicellular gland.

are classified as unicellular or multicellular. As the name implies, unicellular glands are single-celled glands. Goblet cells are important unicellular exocrine glands that secrete mucus directly onto the apical surface of a lining epithelium. Most exocrine glands are multicellular glands, composed of many cells that form a distinctive microscopic structure or macroscopic organ.

Stratified epithelium-

consists of two or more layers of cells that protect underlying tissues in locations where there is considerable wear and tear.

Epithelial tissue

covers body surfaces and lines hollow organs, body cavities, and ducts; it also forms glands. This tissue allows the body to interact with both its internal and external environments.

Nervous tissue

detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve action potentials (nerve impulses) that activate muscular contractions and glandular secretions.

Describe the type of tissues derived from the three embryonic germ layers.

ectoderm, mesoderm and endoderm

Connective tissue

protects and supports the body and its organs. Various types of ____ bind organs together, store energy reserves as fat, and help provide the body with immunity to disease-causing organisms.

exocrine glands

secrete their products into ducts that empty onto the surface of a covering and lining epithelium such as the skin surface or the lumen of a hollow organ. The secretions of ____ have limited effects and some of them would be harmful if they entered the bloodstream.

Simple epithelium

single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption.

Relate the terms for the variety of cell shapes with their appearance and general character.

squamous-flattened and thin cuboidal- boxy, as wide as it is tall columnar-rectangular, taller than it is wide

Epithelial tissue may be divided into two types.

surface epithelium, forms the outer covering of the skin and some internal organs. It also forms the inner lining of blood vessels, ducts, body cavities, and the interior of the respiratory, digestive, urinary, and reproductive systems. Glandular epithelium makes up the secreting portion of glands such as the thyroid gland, adrenal glands, sweat glands, and digestive glands.

Covering and Lining Epithelium

various surfaces of ________ epithelial cells often differ in structure and have specialized functions. apical surface- epithelial cell faces the body surface, a body cavity, the lumen (interior space) of an internal organ, or a tubular duct that receives cell secretions, may contain cilia or microvilli. lateral surfaces- epithelial cell, which face the adjacent cells on either side, may contain tight junctions, adherens junctions, desmosomes, and/or gap junctions. basal surface- of an epithelial cell is opposite the apical surface. The basal surfaces of the deepest layer of epithelial cells adhere to extracellular materials such as the basement membrane.

exocrine vs endocrine glands

Exocrine glands secrete their products into ducts that carry these products to other organs or outside the body Endocrine glands secrete their products directly into the bloodstream

List the structure, function, and location of cartilage connective tissue.

Hyaline cartilage is the most abundant type of cartilage; it covers the ends of long bones and parts of the ribs, nose, trachea, bronchi, and larynx. It provides a smooth surface for joint movement (weak). Fibrocartilage, with its thick bundles of collagen fibers, is a very strong, tough cartilage. Fibrocartilage discs in the intervertebral spaces and the knee joints support the huge loads up and down the long axis of the body. Elastic cartilage consists of chondrocytes located in a threadlike network of elastic fibers. It makes up the malleable part of the external ear and the epiglottis.

Discuss the factors of nutrition, blood circulation, and age in the tissue repair processes.

Nutrition is vital because the healing process places a great demand on the body's store of nutrients. Adequate protein in the diet is important because most of the structural components of a tissue are proteins. Several vitamins also play a direct role in wound healing and tissue repair. For example, vitamin C directly affects the normal production and maintenance of matrix materials, especially collagen, and strengthens and promotes the formation of new blood vessels. In a person with vitamin C deficiency, even superficial wounds fail to heal, and the walls of the blood vessels become fragile and are easily ruptured. Proper blood circulation is essential to transport oxygen, nutrients, antibodies, and many defensive cells to the injured site. The blood also plays an important role in the removal of tissue fluid, bacteria, foreign bodies, and debris, elements that would otherwise interfere with healing.

List the structure, function, and location of Dense irregular connective tissue

S: made up of collagen fibers; usually irregularly arranged with a few fibroblasts. L: occurs in sheets, such as fasciae (tissue beneath skin and around muscles and other organs), reticular (deeper) region of dermis of skin, fibrous pericardium of heart, periosteum of bone, perichondrium of cartilage, joint capsules, membrane capsules around various organs (kidneys, liver, testes, lymph nodes);heart valves. F: Provides tensile (pulling) strength in many directions.

List the structure, function, and location of Dense regular connective tissue

S: mainly collagen fibers regularly arranged in bundles with fibroblasts in rows between them. Collagen fibers (protein structures secreted by fibroblasts) are not living, so damaged tendons and ligaments heal slowly. L: tendons, ligaments, and aponeuroses (sheetlike tendons that attach muscle to muscle or muscle to bone). F: strong attachment between various structures. Tissue structure withstands pulling (tension) along long axis of fibers.

Define the terminology that indicates the types of cell layering.

Simple epithelium- single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption. Pseudostratified epithelium- appears to have multiple layers of cells because the cell nuclei lie at different levels and not all cells reach the apical surface; it is actually a simple epithelium because all its cells rest on the basement membrane. Cells that do extend to the apical surface may contain cilia; others (goblet cells) secrete mucus. Stratified epithelium-consists of two or more layers of cells that protect underlying tissues in locations where there is considerable wear and tear.

Exocrine glands-Show how functional classification is related to the mode used by the cells to deliver their secretory products.

based on how their secretions are released. Each of these secretory processes begins with the endoplasmic reticulum and Golgi complex working together to form intracellular secretory vesicles that contain the secretory product.

endocrine glands

called hormones, enter the interstitial fluid and then diffuse into the bloodstream without flowing through a duct. ______ secretions have far-reaching effects because they are distributed throughout the body by the bloodstream.

Discuss the three features of mature connective tissue.

connective tissue proper- which is flexible and contains a viscous ground substance with abundant fibers. supporting connective tissue- which protects and supports soft tissues of the body. liquid connective tissue- which means that the extracellular matrix is liquid.

List the structure, function, and location of bone connective tissue.

connective tissue with a calcified intracellular matrix. Bones work with skeletal muscles to provide movement, and protection, they store triglycerides, red bone marrow, and calcium.

Define gland

consists of epithelium that secretes substances into ducts (tubes), onto a surface, or eventually into the blood in the absence of ducts. All _____ of the body are classified as either endocrine or exocrine.

Describe the two factors of a connective tissue matrix that bestow specific properties on the tissue..

consists of protein fibers and ground substance (the ground substance may be fluid, semifluid, gelatinous, or calcified.) Gives the tissue it's characteristics (i.e. bone=hard inflexible)

Describe the general functions of epithelial tissues.

1. Selective barriers that limit or assist in the transfer of substances 2. Line surfaces and form protective barriers. 3. Secreting things like mucous, hormones, and other substances.

List the location and function of synovial membranes.

A layer of connective tissue that lines the cavities of joints, tendon sheaths, and bursae (fluid-filled sacs between tendons and bones). The synovial membrane makes synovial fluid, which has a lubricating function.

Illustrate the structures of the different stratified and transition epithelial tissues in addition to showing histological representations and examples of organs that contain them.

A.Stratified squamous epithelium (lining of mouth, esophagus, part of epiglottis, part of pharynx, and vagina) B.Stratified cuboidal epithelium (adult sweat glands, esophageal glands, male urethra) C.Stratified columnar epithelium (excretory ducts, esophageal glands, anal, mucous membrane, eyes) D.Transitional epithelium or urothelium (urinary bladder, ureters and urethra)

Considering the layers and cell shapes in combination, outline the classification of covering and lining epithelium.

I.Simple epithelium A.Simple squamous epithelium B.Simple cuboidal epithelium C.Simple columnar epithelium D.Pseudostratified columnar epithelium II.Stratified epithelium A.Stratified squamous epithelium B.Stratified cuboidal epithelium C.Stratified columnar epithelium D.Transitional epithelium or urothelium

Distinguish between an epithelial and a synovial membrane.

Synovial membranes enclose certain joints and are made of connective tissue only (lack epithelium).

List the structure, function, and location of loose connective tissue.

areolar connective tissue- consists of fibers (collagen, elastic, reticular). L: subcutaneous layer deep to skin; dermis of skin; lamina propria of mucous membranes; around blood vessels, nerves, and body organs. F: Strength, elasticity, support. adipose tissue- derived from fibroblasts (called adipocytes). L: Wherever areolar connective tissue is located: subcutaneous layer deep to skin, around heart and kidneys, yellow bone marrow, padding around joints and behind eyeball in eye socket. F: Reduces heat loss through skin; serves as an energy reserve; supports and protects organs. In newborns, BAT generates heat to maintain proper body temperature. Adipose tissue is also an excellent source of stem cells, which are used in rejuvenation medicine to repair or replace damaged tissue. reticular connective tissue- is a fine interlacing network of reticular fibers (thin form of collagen fiber) and reticular cells. L: Stroma (supporting framework) of liver, spleen, lymph nodes; red bone marrow; reticular lamina of basement membrane; around blood vessels and muscles. F: Forms stroma of organs; binds smooth muscle tissue cells; filters and removes worn-out blood cells in spleen and microbes in lymph nodes.

Name the chemical components of ground substance and how each is responsible for differing physical consistencies of connective tissues. Discuss the role of ground substances have in joint disease.

consists of protein fibers (embedded in the extracellular matrix between the cells: collagen fibers, elastic fibers, and reticular fibers). They function to strengthen and support connective tissues) and ground substance (the ground substance may be fluid, semifluid, gelatinous, or calcified.) Gives the tissue it's characteristics (i.e. bone=hard inflexible)

Discuss the cells that compose connective tissue in terms of origin, function, and mobility

fibroblasts, mast cells, plasma cells, macrophages, adipocytes, and leukocytes.

Muscular tissue

is composed of cells specialized for contraction and generation of force. In the process, muscular tissue generates heat that warms the body.

Describe the general features of epithelial tissue and describe their functions

- Cells are arranged in sheets and are densely packed - Many cell junctions are present - Epithelial cells attach to a basement membrane - Epithelial tissue is avascular but does have a nerve supply - Mitosis occurs frequently

Discuss cartilage growth and repair..

- cartilage is a relatively inactive tissue that grows slowly. When injured or inflamed, cartilage repair proceeds slowly, in large part because cartilage is avascular. Substances needed for repair and blood cells that participate in tissue repair must diffuse or migrate into the cartilage. The growth of cartilage follows two basic patterns: interstitial growth and appositional growth. interstitial growth there is growth from within the tissue. When cartilage grows by interstitial growth, the cartilage increases rapidly in size due to the division of existing chondrocytes and the continuous deposition of increasing amounts of extracellular matrix by the chondrocytes. As the chondrocytes synthesize new matrix, they are pushed away from each other. These events cause the cartilage to expand from within like bread rising, which is the reason for the term interstitial. This growth pattern occurs while the cartilage is young and pliable, during childhood and adolescence. appositional growth there is growth at the outer surface of the tissue. When cartilage grows by appositional growth, cells in the inner cellular layer of the perichondrium differentiate into chondroblasts. As differentiation continues, the chondroblasts surround themselves with extracellular matrix and become chondrocytes. As a result, matrix accumulates beneath the perichondrium on the outer surface of the cartilage, causing it to grow in width. Appositional growth starts later than interstitial growth and continues through adolescence.

List the structure, function, and location of areolar connective tissue

- consists of fibers (collagen, elastic, reticular). L: subcutaneous layer deep to skin; dermis of skin; lamina propria of mucous membranes; around blood vessels, nerves, and body organs. F: Strength, elasticity, support.

List the structure, function, and location of adipose tissue

- derived from fibroblasts (called adipocytes). L: Wherever areolar connective tissue is located: subcutaneous layer deep to skin, around heart and kidneys, yellow bone marrow, padding around joints and behind eyeball in eye socket. F: Reduces heat loss through skin; serves as an energy reserve; supports and protects organs. In newborns, BAT generates heat to maintain proper body temperature. Adipose tissue is also an excellent source of stem cells, which are used in rejuvenation medicine to repair or replace damaged tissue

List the structure, function, and location of reticular connective tissue

- is a fine interlacing network of reticular fibers (thin form of collagen fiber) and reticular cells. L: Stroma (supporting framework) of liver, spleen, lymph nodes; red bone marrow; reticular lamina of basement membrane; around blood vessels and muscles. F: Forms stroma of organs; binds smooth muscle tissue cells; filters and removes worn-out blood cells in spleen and microbes in lymph nodes.

Describe the important and prominent characteristics of connective tissue.

-is the most abundant and widely distributed of the primary tissues. - has three main components: cells, fibers, and ground substance. Together the ground substance and fibers make up the extracellular matrix.

Describe the three functions of cell junctions.

-keep liquid from escaping between cells - allowing a layer of cells (for instance, those lining an organ) to act as an impermeable barrier - keeps tissues from separating as they stretch and contract.

Identify the different constituents of collagen, elastic, and reticular fibers, as well as the alternate structures and mechanical properties of each used in specific organs.

Collagen fibers- resist pulling or stretching, but they are not stiff, which allows tissue flexibility. Often occur in parallel bundles (dense regular connective tissue). The bundle arrangement adds great tensile strength to the tissue. Chemically, collagen fibers consist of the protein collagen, which is the most abundant protein in your body, representing about 25% of the total. Most types of connective tissues, especially bone, cartilage, tendons (which attach muscle to bone), and ligaments (which attach bone to bone). Elastic fibers- consists of molecules of the protein elastin surrounded by a glycoprotein named fibrillin, which adds strength and stability. Because of their unique molecular structure, elastic fibers are strong but can be stretched up to 150% of their relaxed length without breaking. Equally important, elastic fibers have the ability to return to their original shape after being stretched, a property called elasticity. Elastic fibers are plentiful in skin, blood vessel walls, and lung tissue. Reticular fibers- consists if collagen arranged in fine bundles with a coating of glycoprotein, provide support in the walls of blood vessels and form a network around the cells in some tissues, such as areolar connective tissue, adipose tissue, nerve fibers, and smooth muscle tissue. Reticular fibers also provide support and strength, which forms the stroma (supporting framework) of many soft organs, such as the spleen and lymph nodes

Examine the cellular requirements of tissue repair and distinguish between tissues which are and are not capable of regeneration.

New cells originate by cell division from the stroma, the supporting connective tissue, or from the parenchyma, cells that constitute the functioning part of the tissue or organ. In adults, each of the four basic tissue types (epithelial, connective, muscular, and nervous) has a different capacity for replenishing parenchymal cells lost by damage, disease, or other processes.Epithelial cells, which endure considerable wear and tear (and even injury) in some locations, have a continuous capacity for renewal. In some cases, immature, undifferentiated cells called stem cells divide to replace lost or damaged cells. - Muscular tissue has a relatively poor capacity for renewal of lost cells. Even though skeletal muscle tissue contains stem cells called satellite cells, they do not divide rapidly enough to replace extensively damaged muscle fibers. - Cardiac muscle tissue lacks satellite cells, and existing cardiac muscle fibers do not undergo mitosis to form new cells. Recent evidence suggests that stem cells do migrate into the heart from the blood. There, they can differentiate and replace a limited number of cardiac muscle fibers and endothelial cells in heart blood vessels. - Smooth muscle fibers can proliferate to some extent, but they do so much more slowly than the cells of epithelial or connective tissues. - Nervous tissue has the poorest capacity for renewal. Although experiments have revealed the presence of some stem cells in the brain, they normally do not undergo mitosis to replace damaged neurons.