Chapter 4: Tissues

Stratified columnar epithelium

Basal layers in ________________________________ usually consist of shortened, irregularly shaped cells; only apical layer has columnar cells; uncommon. Function: protection and secretion Location: Lines part of urethra; large excretory ducts of some glands, such as esophageal glands; small areas in anal mucous membrane; part of conjunctiva of eye.

osseous tissue (bone)

Bones are organs composed of several different connective tissues, including ____________________ the periosteum, red and yellow bone marrow, and the endosteum (a membrane that lines a space within bone that stores yellow bone marrow)

calcium and phosphorus

Bones store...

Dendrites

Branchlike parts of a neuron that are specialized to receive information.

parallel bundles

Collagen fibers often occur in ________________________. The bundle arrangement adds great tensile strength to the tissue.

sprain

Despite their strength, ligaments may be stressed beyond their normal capacity. This results in sprain, a stretched or torn ligament

satellite cells

Even though skeletal muscle tissue contains stem cells called ____________________, they do not divide rapidly enough to replace extensively damaged muscle fibers; not present in cardiac muscle tissue

proteoglycans

Except for hyaluronic acid, the GAGs are associated with proteins called ______________; form a core protein and the GAGs project from the protein like the bristles of a brush

CT exceptions for vascularity

Exceptions include cartilage (avascular), and tendons, with a scanty blood supply. Except for cartilage, connective tissue, like epithelial tissue, is supplied with nerves.

diffusion

Exchange of substances between an epithelial tissue and connective tissue occurs by...

Simple multicellular exocrine glands have a nonbranched duct; compound multicellular exocrine glands have a branched duct.

How do simple multicellular exocrine glands differ from compound ones?

A high rate of cell division allows constant renewal and repair of itself by sloughing off dead or injured cells and replacing them with new ones

How does epithelial tissue stand against its constant exposure to physical stress and injury?

tissue regeneration

If parenchymal cells accomplish the repair, ______________________ is possible, and a near-perfect reconstruction of the injured tissue may occur; if fibroblasts of the stroma are active in the repair, the replacement tissue will be a new connective tissue

compound gland

If the duct branches, it is a ______________________

simple gland

If the duct of the gland does not branch, it is a ___________________

interstitial growth

In _________________________ , there is growth from within the tissue; 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; occurs while the cartilage is young and pliable, during childhood and adolescence.

connexons

In a gap junction, a protein channel linking adjacent cells

basal layer

In discussing epithelia with multiple layers, the term ______ _____ refers to the deepest layer of cells

apical layer

In discussing epithelia with multiple layers, the term ______ _____ refers to the most superficial layer of cells

adhesion belts

In epithelial cells, adherens junctions often form extensive zones called ________ ______ because they encircle the cell similar to the way a belt encircles your waist (1)

-cyte

In some connective tissues, once the extracellular matrix is produced, the immature cells differentiate into mature cells with names ending in...

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.

striations

are alternating light and dark bands within fibers that are visible under a light microscope

Cuboidal cells

are as tall as they are wide and are shaped like cubes or hexagons. They may have microvilli at their apical surface and function in either secretion or absorption.

lamellae

are con- centric rings of extracellular matrix that consist of mineral salts (mostly calcium and phosphates), which give bone its hardness and compressive strength, and collagen fibers, which give bone its tensile strength; responsible for the compact nature of this type of bone tissue.

Cell junctions

are contact points between the plasma membranes of tissue cells

Adipocytes

are fat cells or adipose cells, connective tissue cells that store triglycerides (fats). They are found deep to the skin and around organs such as the heart and kidneys.

Membranes

are flat sheets of pliable tissue that cover or line a part of the body

Plasma cells (plasmocytes)

are found in many places in the body, but most plasma cells reside in connective tissue, especially in the gastrointestinal and respiratory tracts

Leukocytes (white blood cells)

are not found in significant numbers in normal connective tissue. However, in response to certain conditions they migrate from blood into connective tissue. For example, neutrophils gather at sites of infection, and eosinophils migrate to sites of parasitic invasions and allergic responses

Macrophages

are phagocytes that develop from monocytes, a type of white blood cell.

Neurons

are sensitive to various stimuli. They convert stimuli into electrical signals called nerve action potentials and conduct these action potentials to other neurons, to muscle tissue, or to glands

Squamous cells

are thin, which allows for the rapid passage of substances through them.

Collagen fibers

are very strong and resist pulling or stretching, but they are not still, which allows tissue flexibility; found in most types of connective tissues, especially bone, cartilage, tendons (which attach muscle to bone), and ligaments (which attach bone to bone).

nonciliated pseudostratified columnar epithelium

Single layer of cells of varying heights. All cells connected to basement membrane but not all cells reach apical surface so looks like multiple layers; contains cells without cilia and also lacks goblet cells location: lines epididymis, larger ducts of many glands, and parts of male urethra function: absorption and secretion

voluntary

Skeletal muscle is considered _________________ because it can be made to contract or relax by conscious control.

formed elements

Suspended in the blood plasma are ___________________—red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes)

synoviocytes

Synovial membranes are composed of a discontinuous layer of cells called ___________________, which are closer to the synovial cavity (space between the bones), and a layer of connective tissue (areolar and adipose) deep to the synoviocytes

Hypertrophy

Increase in the size of a tissue because its cells enlarge without undergoing cell division.

dermis

Inner layer of skin; consists of dense irregular connective tissue and areolar connective tissue

embryo; fetus

Mesenchyme is present primarily in the __________, the developing human from fertilization through the first two months of pregnancy, and in the ___________, the developing human from the third month of pregnancy

white adipose tissue

Most adipose tissue in adults is...

multicellular glands

Most exocrine glands are ________________________, composed of many cells that form a distinctive microscopic structure or macroscopic organ Examples include sudoriferous (sweat), sebaceous (oil), and salivary glands.

stroma

New cells originate by cell division from the ___________ the supporting connective tissue, or from the parenchyma

connective tissue proper

One category of mature connective tissue is ___________________________, which is flexible and contains a viscous ground substance with abundant fibers

trap water

One of the most important properties of GAGs is that they______________, making the ground substance more jellylike.

Papanicolaou test

Pap smear; an exfoliative biopsy for the detection of conditions that can be early indicators of cervical cancer

Holocrine glands

The cells of _______________________________accumulate a secretory product in their cytosol; As the secretory cell matures, it ruptures and becomes the secretory product. secretion contains large amounts of lipids from the plasma membrane and intracellular membranes. The sloughed off cell is replaced by a new cell. example: sebaceous gland of the skin.

chondrocytes

The cells of mature cartilage, called __________________, occur singly or in groups within spaces called lacunae in the extracellular matrix

extracellular matrix

The chemical substances located between connective tissue cells

lamina propria

The connective tissue layer of a mucous membrane is areolar connective tissue and is called the _______________________, so named because it belongs to (is owned by) the mucous membrane

protein fibers and ground substance

The extracellular matrix consists of _________________________________, the material between the cells and the fibers.

loose connective tissue

The fibers of __________________________________ are loosely arranged between cells. The types are areolar connective tissue, adipose tissue, and reticular connective tissue

fibrosis

The fibroblasts synthesize collagen and other extracellular matrix materials that aggregate to form scar tissue, a process known as...

glandular epithelium

The function of _________ __________ is secretion, which is accomplished by glandular cells that o en lie in clusters deep to the cover- ing and lining epithelium

lateral surfaces

The lateral surfaces of an epithelial cell, which face the adjacent cells on either side, may contain tight junctions, adherens junctions, desmosomes, and/or gap junctions

parietal layer

The layer attached to and lining the cavity wall is called the...

fibronectin

The main adhesion protein of connective tissues is __________________, which binds to both collagen fibers and ground substance, linking them together; also attaches cells to the ground substance

epithelial membranes

The majority of membranes consist of an epithelial layer and an underlying connective tissue layer and are called _________________________________ the principal ones of the body are mucous membranes, serous membranes, and the cutaneous membrane, or skin

connexins

The membrane proteins that make up gap junctions and form tiny fluid-filled tunnels called connexons

serous fluid

The mesothelium of a serous membrane secretes_______________, a watery lubricant that allows organs to glide easily over one another or to slide against the walls of cavities.

Xenotransplantation

The replacement of a diseased or injured tissue or organ with cells or tissues from an animal. Porcine (from pigs) and bovine (from cows) heart valves are used for some heart-valve replacement surgeries.

Tissue transplantation

The replacement of a diseased or injured tissue or organ. The most successful transplants involve use of a person's own tissues or those from an identical twin.

cadherins

Transmembrane glycoproteins called __________ join the cells of adherens junctions (3)

Simple branched tubular

Tubular secretory part is branched and attaches to a single unbranched duct Ex: gastric glands.

Simple coiled tubular

Tubular secretory part is coiled and attaches to a single unbranched duct Example: sweat glands.

Simple tubular

Tubular secretory part is straight and attaches to a single unbranched duct. Ex: glands in the large intestine.

canaliculi

Projecting from the lacunae are _______________, networks of minute canals containing the processes of osteocytes; provide routes for nutrients to reach osteocytes and for wastes to leave them.

adhesions

Scar tissue can form ____________, abnormal joining of tissues

merocrine glands

Secretions of __________________________ are synthesized on ribosomes attached to rough ER; processed, sorted, and packaged by the Golgi complex; and released from the cell in secretory vesicles via exocytosis; most exocrine glands of the body Ex: salivary glands and pancreas

Compound tubuloacinar

Secretory portion is both tubular and rounded and attaches to a branched duct Example: acinar glands of the pancreas.

Compound acinar

Secretory portion is rounded and attaches to a branched duct Example: mammary glands.

Simple acinar

Secretory portion is rounded, attaches to single unbranched duct Example: glands of penile urethra.

Compound tubular

Secretory portion is tubular and attaches to a branched duct Example: bulbourethral (Cowper's) glands.

Mesothelium (simple squamous)

Serous membranes consist of areolar connective tissue covered by...

basal surface

The _____ _______ of an epithelial cell is opposite the apical surface; in the deepest layer of epithelial cells, it adheres to extracellular materials such as the basement membrane

ciliated pseudostratified columnar epithelium

Single layer of cells of varying heights. All cells connected to basement membrane but not all cells reach apical surface so looks like multiple layers; Contains cells that extend to surface and secrete mucus (globlet cells) or bear cilia location: Lines airways of most of upper respiratory tract function: Secretes mucus that traps foreign particles, and cilia sweep away mucus for elimination from body.

apical (free) surface

The ______ _______ of an 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

hyaluronidase

White blood cells, sperm cells, and some bacteria produce__________, an enzyme that breaks apart hyaluronic acid, thus causing the ground substance of connective tissue to become more liquid

Since epithelial tissue lacks blood vessels and forms surfaces, it is always found immediately adjacent to blood vessel-rich connective tissue

Why do epithelial and connective tissues make a great bond?

Because the cells are closely packed and are held tightly together by many cell junctions

Why is there little intercellular space between adjacent plasma membranes in epithelium?

plaque (adherens junctions)

a dense layer of proteins on the inside of the plasma membrane that attaches both to membrane proteins and to microfilaments of the cytoskeleton (4)

Dense connective tissue

a second type of connective tissue proper that contains more fibers, which are thicker and more densely packed, but have considerably fewer cells than loose connective tissue

Simple epithelium

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

anti-

against

White blood cells

are involved in phagocytosis, immunity, and allergic reactions

Mast cells (mastocytes)

are involved in the inflammatory response, the body's reaction to injury or infection and can also bind to, ingest, and kill bacteria.

Fibroblasts

are large, flat cells with branching processes. They are present in all the general connective tissues, and usually are the most numerous

Goblet cells

are modified columnar epithelial cells that secrete mucus, a slightly sticky fluid, at their apical surfaces. Before release, mucus accumulates in upper portion of cell, causing it to bulge and making the whole cell resemble a goblet or wine glass.

Columnar cells

are much taller than they are wide like columns, and protect underlying tissues. Their apical surfaces may have cilia or microvilli, and they often are specialized for secretion and absorption.

granulation tissue

all processes that occur when tissue damage is extensive create an actively growing connective tissue called ______________________; forms across a wound to provide a framework (stroma) that supports the epithelial cells that migrate into the open area and fill it; also secretes a fluid that kills bacteria

desmosomes in cardiac muscle

strengthen tissue and hold fibers together during vigorous contractions

osteon (haversian system)

structural unit of compact bone

Histology

study of tissues

trabeculae

supporting bundles of bony fibers in cancellous (spongy) bone; contain lamellae, osteocytes, lacunae, and canaliculi

electrical excitability

the ability to respond to a stimulus and convert it into an action potential

ground substance

the component of a connective tissue between the cells and fibers; may be fluid, semifluid, gelatinous, or calcified; It supports cells, binds them together, stores water, and provides a medium for exchange of substances between the blood and cells; plays an active role in how tissues develop, migrate, proliferate, and change shape, and in how they carry out their metabolic functions

axon

the extension of a neuron, ending in branching terminal fibers, through which messages pass to other neurons or to muscles or glands

visceral layer

the layer that covers and adheres to the organs within the cavity is the...

biopsy

the removal of living tissue from the body for diagnostic examination

lamina

thin layer

acinar glands (alveolar glands)

those with rounded secretory portions are ___________________

Platelets

participate in blood clotting

collagen fibers, elastic fibers, and reticular fibers function

to strengthen and support connective tissues

wound dehiscence

patients can develop a complication of surgery called _______________________, the partial or complete separation of the outer layers of a sutured incision.

Embryonic connective tissue

refers to connective tissue present in an embryo or a fetus.

Mature connective tissue

refers to connective tissue that is present at birth and persists throughout life

Fixed macrophages

reside in a particular tissue; examples include alveolar macrophages in the lungs or splenic macrophages in the spleen

Synoviocytes

secrete some of the components of synovial fluid

more

collagen fibers in cartilage are surrounded by more water molecules than those in bone, which gives cartilage a ____ cushioning effect

3 types of fibers are embedded in the extracellular matrix between the cells

collagen fibers, elastic fibers, and reticular fibers

protects, secretes (mucus, hormones, and enzymes), absorbs (nutrients in the gastrointestinal tract), and excretes (various substances in the urinary tract).

function of epithelial tissue

colla

glue

3 types of cartilage

hyaline cartilage, fibrocartilage, and elastic cartilage

-blast

immature class of cells; to bud or sprout; retain the capacity for cell division and secrete the extracellular matrix that is characteristic of the tissue

appositional growth

in ____________________________ there is growth at the outer surface of the tissue; cells in the inner cellular layer of the perichondrium differentiate into chondroblasts; starts later than interstitial growth and continues through adolescence.

does not

in contrast to epithelial tissue, connective tissue ________________ usually occur on body surfaces

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; location: Sweat, oil, and earwax glands of skin; digestive glands such as salivary glands (secrete into mouth cavity) and pancreas (secretes into small intestine). function: Produce substances such as sweat to help lower body temperature, oil, earwax, saliva, or digestive enzymes.

Muscular tissue

is composed of cells specialized for contraction and generation of force. In the process, _______________________ generates heat that warms the body; consists of elongated cells called muscle fibers or myocytes that can use ATP to generate force; produces body movements, maintains posture, and provides protection

Brown adipose tissue

is darker due to very rich blood supply and numerous pigmented mitochondria that participate in aerobic cellular respiration; is widespread in the fetus and infant; adults have only small amounts; generates heat to maintain proper body temperature

serous membrane (serosa)

lines a body cavity that does not open directly to the exterior (thoracic or abdominal cavities), and it covers the organs that are within the cavity

mucous membrane (mucosa)

lines a body cavity that opens directly to the exterior; line the entire digestive, respiratory, and reproductive tracts, and much of the urinary tract. They consist of a lining layer of epithelium and an underlying layer of connective tissue

endothelium

lines heart, blood vessels, and lymphatic vessels

action potentials

long distance signals of axons; can propagate (travel) along the plasma membrane of a neuron or muscle fiber due to the presence of specific voltage- gated ion channels

Synovial fluid

lubricates and nourishes the cartilage covering the bones at movable joints and contains macrophages that remove microbes and debris from the joint cavity.

pleura

serous membrane lining the thoracic cavity and covering the lungs is the...

Simple cuboidal epithelium

single layer of cube shaped cells; round, centrally located nucleus. secretion and absorption Location: Covers surface of ovary; lines anterior surface of capsule of lens of the eye; forms pigmented epithelium at posterior surface of retina of the eye; lines kidney tubules and smaller ducts of many glands; makes up secreting portion of some glands such as thyroid gland and ducts of some glands such as pancreas. Function: Secretion and absorption.

blood

one of the liquid connective tissues has a liquid extracellular matrix called blood plasma and formed elements location: Within blood vessels (arteries, arterioles, capillaries, venules, veins), within chambers of heart.

-propria

one's own

epidermis

outermost layer of skin; superficial; consists of keratinized stratified squamous epithelium, which protects underlying tissues

pseudo

false

gland

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

perichondrium

A covering of dense irregular connective tissue called the __________________________ surrounds the surface of most cartilage and contains blood vessels and nerves and is the source of new cartilage cells

Atrophy

A decrease in the size of cells, with a subsequent decrease in the size of the affected tissue or organ.

tissue

A group of similar cells that perform the same function

supporting connective tissue

A second category of mature connective tissue is _______________________________________, which protects and supports so tissues of the body

integrins

A transmembrane protein that interconnects the extracellular matrix and the cytoskeleton (3)

adhesion proteins

Also present in the ground substance are ______________________________, which are responsible for linking components of the ground substance to one another and to the surfaces of cells

elastin

An elastic fiber consists of molecules of the protein ____________

fibrillin

An elastic fiber consists of molecules of the protein elastin surrounded by a glycoprotein named ____________, which adds strength and stability

Tissue rejection

An immune response of the body directed at foreign proteins in a transplanted tissue or organ; immunosuppressive drugs, such as cyclosporine, have largely overcome tissue rejection in heart-, kidney-, and liver-transplant patients.

involuntary

Cardiac muscle tissue is under _______________ control

basement membrane

Cells at the base of an epithelial layer are attached to this; thin extracellular layer

collagen

Chemically, collagen fibers consist of the protein ______________, which is the most abundant protein in your body, representing about 25% of the total

mesenchymal cells

Embryonic cells called ________________________ give rise to the cells of connective tissue

avascular

Epithelial tissue has its own nerve supply but, as mentioned previously, is _________, relying on the blood vessels of the adjacent connective tissue to bring nutrients and remove wastes

tubular glands

Glands with tubular secretory parts are ______________________

glycosaminoglycans (GAGs)

Ground substance contains water and an assortment of large organic molecules, many of which are complex combinations of polysaccharides and proteins; The polysaccharides include hyaluronic acid, chondroitin sulfate, dermatan sulfate, and keratan sulfate. Collectively, they are referred to as __________________________

compact bone

Hard, dense bone tissue that is beneath the outer membrane of a bone

What are the benefits of having the ability to produce hyaluronidase?

Helps white blood cells move more easily through connective tissue to reach sites of infection and aids penetration of an oocyte by a sperm cell during fertilization. It also accounts for the rapid spread of bacteria through connective tissue.

cell body

Largest part of a typical neuron; contains the nucleus and much of the cytoplasm

Epithelial: -many cells are tightly packed together with little of no extracellular matrix -no blood vessels -almost always forms surface layers and is not covered by another tissue (exception: epithelial lining of BVs) Connective: -a large amount of extracellular material separates cells that are usually widely scattered -significant network of blood vessels

Major differences between epithelial and connective tissues

Sebaceous (oil) glands are holocrine glands, and salivary glands are merocrine glands.

Q To what class of glands do sebaceous (oil) glands belong? Salivary glands?

provides physical support for the epithelial tissue and plays a part in growth and wound healing, restriction of molecular movement between tissues, and blood filtration in the kidneys.

Q What are the functions of the basement membrane?

Epithelial tissue covers the body, lines various structures, and forms glands. Connective tissue protects, supports, binds organs together, stores energy, and helps provide immunity. Muscular tissue contracts and generates force and heat. Nervous tissue detects changes in the environment and generates nerve impulses that activate muscular contraction and glandular secretion.

Q: What are some key differences in function among the four tissue types?

Simple branched acinar

Rounded secretory part is branched and attaches to a single unbranched duct Example: sebaceous glands.

endocrine glands

The secretions of _________________________, called hormones, enter the interstitial fluid and then diffuse into the bloodstream without flowing through a duct; location: Examples include pituitary gland at base of brain, pineal gland in brain, thyroid and parathyroid glands near larynx (voice box), adrenal glands superior to kidneys, pancreas near stomach, ovaries in pelvic cavity, testes in scrotum, thymus in thoracic cavity. function: Hormones regulate many metabolic and physiological activities to maintain homeostasis.

peritoneum

The serous membrane lining the abdominal cavity and covering the abdominal organs is the...

pericardium

The serous membrane lining the heart cavity and covering the heart is the...

Dermatan sulfate

The skin, tendons, blood vessels, and heart valves contain ________________________

resilience

The strength of cartilage is due to its collagen fibers, and its ________________ (ability to assume its original shape after deformation) is due to chondroitin sulfate

liquid connective tissue

The third category of mature connective tissue is __________________________, which means that the extracellular matrix is liquid.

Supporting Connective Tissue

This type of mature connective tissue includes cartilage and bone.

intermediate filaments

Threadlike proteins in the cell's cytoskeleton that are roughly twice as thick as microfilaments

Adipose tissue

Tissue that stores fat. location: 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. function: Reduces heat loss through skin; serves as an energy reserve; supports and protects organs. An excellent source of stem cells, which are used in rejuvenation medicine to repair or replace damaged tissue.

the arrangement of cells into layers and the shapes of the cells

Types of covering and lining epithelial tissue are classified according to two characteristics:

1. Ducts - Branched or Unbranched 2. Shape of the secretory portions of the gland

What are the 2 criterias of multicellular glands?

1. covering and lining various surfaces and 2. forming the secreting portions of glands

What are the 2 general patterns of epithelium arrangement in the body

the basal lamina and reticular lamina

What are the 2 layers of the basement membrane?

endothelium and mesothelium

What are the 2 types of a simple squamous epithelium

Covering and lining epithelium (surface epithelium) and Glandular epithelium

What are the 2 types of epithelial tissue?

a cell body, dendrites, and axons

What are the 3 basic parts of a neuron?

skeletal, cardiac, and smooth

What are the 3 classifications of muscular tissue?

nutrition, blood circulation, and age

What are the 3 factors that affect tissue repair?

dense regular connective tissue, dense irregular connective tissue, and elastic connective tissue

What are the 3 types of dense connective tissue?

epithelial, connective, muscular, and nervous

What are the 4 basic types of tissues?

lamellae, lacunae, canaliculi, central canal

What are the 4 parts of an osteon?

neurotransmitters

When an action potential forms in a neuron, the neuron releases chemicals called ___________________________, which allow neurons to communicate with other neurons, muscle fibers, or glands. When an action potential occurs in a muscle fiber, the muscle fiber contracts, resulting in activities such as movement of the limbs, propulsion of food through the small intestine, and movement of blood out of the heart and into the blood vessels of the body

cardiac muscle tissue and nervous tissue (worst)

Which tissues have a poor capacity for renewal?

Apocrine glands

accumulate their secretory product at the apical surface of the secreting cell. Then, that portion of the cell pinches o by exocytosis from the rest of the cell to release the secretion. The cell repairs itself and repeats the process. Ex. Secretion of milk fats in the mammary glands

-viscer

body organ

keratan sulfate

bone, cartilage, and the cornea of the eye contain ___________________________

yellow bone marrow

bones contain... (storage site for triglycerides)

red bone marrow

bones house... (which produces blood cells)

antiangiogenesis factor

cartilage does not have a blood supply because it secretes an ________________________________, a substance that pre-vents blood vessel growth

parenchyma

cells that constitute the functioning part of the tissue or organ

neuroglia

cells that support and protect neurons; do not generate or conduct nerve impulses, these cells do have many important supportive functions

Transitional cells

change shape, from squamous to cuboidal and back, as organs such as the urinary bladder stretch (distend) to a larger size and then collapse to a smaller size

Systemic lupus erythematosus (SLE) (lupus)

chronic autoimmune inflammatory disease of collagen in skin, joints, and internal organs

highly vascular

connective tissue usually is...

gap junctions

connexons connect neighbouring cells; plasma membranes are not fused but are separated by a very narrow intracellular space; ions and small molecules can diffuse from the cytosol of one cell to another; assist in the transfer of nutrients, and perhaps wastes in avascular tissues (ex. lens and cornea of eye); in a developing embryo, some of the chemical and electrical signals that regulate growth and cell differentation travel via this junction; enable nerve or muscle impulses to spread rapidly among cells, a process that is crucial for the normal operation of some parts of the nervous system and for the contraction of muscle in the heart, gastrointestinal tract, and uterus

Tight junctions

consist of weblike strands of transmembrane proteins that fuse together the outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells; lines the stomach, intestines, and urinary bladder; inhibit substances between cells and prevent the contents of these organs from leaking into the blood or surrounding tissues

Reticular fibers

consisting of 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; These fibers also help form the basement membrane.

Cartilage

consists of a dense network of collagen fibers and elastic fibers firmly embedded in chondroitin sulfate, a gel-like component of the ground substance. Cartilage can endure considerably more stress than loose and dense connective tissues

Cardiac muscle tissue

consists of branched, striated fibers with usually only one centrally located nucleus (occasionally two). Attach end to end by transverse thickenings of plasma membrane called intercalated discs. location: heart wall function: pumps blood to all parts of body

epithelial tissue (epithelium)

consists of cells arranged in continuous sheets, in either single or multiple layers

Skeletal muscle tissue

consists of long, cylindrical, striated fibers; vary greatly in length;. A muscle fiber is a roughly cylindrical, multinucleated cell with nuclei at the periphery. location: attached to bones by tendons function: motion, posture, heat production, protection

Smooth muscle tissue

consists of nonstriated fibers (lack striations, hence the term smooth). Smooth muscle fiber is a small spindle-shaped cell thickest in middle, tapering at each end, and containing a single, centrally located nucleus. Gap junctions connect many individual fibers in some (for example, in wall of intestines). Usually involuntary; can produce powerful contractions as many muscle fibers contract in unison. Where gap junctions are absent, such as iris of eye; contract individually, like skeletal muscle fibers. location: Iris of eyes; walls of hollow internal structures such as blood vessels, airways to lungs, stomach, intestines, gallbladder, urinary bladder, and uterus. Function: Motion (constriction of blood vessels and airways, propulsion of foods through gastrointestinal tract, contraction of urinary bladder and gallbladder).

Compact bone tissue

consists of osteons (haversian systems) that contain lamellae, lacunae, osteocytes, canaliculi, and central (haversian) canals location: make up the various parts of bones of the body function: Support, protection, storage; houses blood-forming tissue; serves as levers that act with muscle tissue to enable movement.

spongy bone tissue

consists of thin columns called trabeculae; spaces between trabeculae are filled with red bone marrow. location: make up the various parts of bones of the body. function: Support, protection, storage; houses blood-forming tissue; serves as levers that act with muscle tissue to enable movement.

Stratified epithelium

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

desmosomes

contain plaque and have transmembrane glycoproteins (cadherins) that extend into the intercellular space between adjacent cell membranes and attach cells to one another. However, the plaque of desmosomes does not attach to microfilaments. Instead, a desmosome plaque attaches to elements of the cytoskeleton known as intermediate filaments, which consist of the protein keratin; common among the cells that make up the epidermis (the outermost layer of the skin) and among cardiac muscle cells in the heart; prevent epidermal cells from separating under tension and cardiac muscle cells from pulling apart during contraction.

Adherens junctions

contain plaque; help epithelial surfaces resist separation during various contractile activities, as when food moves through the intestines.

Hyaline cartilage

contains a resilient gel as ground substance and appears in the body as a bluish-white, shiny substance (can stain pink or purple when prepared for microscopic examination; fine collagen fibers are not visible with ordinary staining techniques); prominent chondrocytes are found in lacunae surrounded by perichondrium (exceptions: articular cartilage in joints and cartilage of epiphyseal plates, where bones lengthen during growth). location: Most abundant cartilage in body; at ends of long bones, anterior ends of ribs, nose, parts of larynx, trachea, bronchi, bronchial tubes, embryonic and fetal skeleton. function: Provides smooth surfaces for movement at joints, flexibility, and support; weakest type of cartilage and can be fractured.

central canal (haversian canal)

contains blood vessels and nerves

Elastic connective tissue

contains predominantly elastic fibers with fibroblasts between them; unstained tissue is yellowish. location: Lung tissue, walls of elastic arteries, trachea, bronchial tubes, true vocal cords, suspensory ligaments of penis, some ligaments between vertebrae. function: 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).

secretory portion

contains the cells that do the secreting (1)

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; has one free surface

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 location: nervous system function: Exhibits sensitivity to various types of stimuli; converts stimuli into nerve impulses (action potentials); conducts nerve impulses to other neurons, muscle fibers, or glands.

keratinized stratified squamous epithelium

develops tough layer of keratin in apical layer of cells and several layers deep to it; Relative amount of keratin increases in cells as they move away from nutritive blood supply and organelles die. location: forms superficial layer of skin

autoimmune diseases

diseases in which antibodies produced by the immune system fail to distinguish what is foreign from what is self and attack the body's own tissues

Hemidesmosomes

do not link adjacent cells but link the basement membrane; the transmembrane glycoproteins in are integrins rather than cadherins; on the inside of the plasma membrane the integrins attach to intermediate filaments made of the protein keratin; on the outside of the plasma membrane the integrins attach to the protein laminin which is present in the basement membrane

nonkeratinized stratified squamous epithelium

does not contain large amounts of keratin in apical layer and several layers deep and is constantly moistened by mucus from salivary and mucous glands; organelles are not replaced. location: lines wet surfaces (lining of mouth, esophagus, part of epiglottis, part of pharynx, and vagina) and covers tongue.

elasticity

elastic fibers have the ability to return to their original shape after being stretched, a property called ________________

nerve action potentials (nerve impulses)

electrical signals that conduct action potentials to other neurons, to muscle tissue, or to glands.

nervous tissue

epithelial tissue combines with ____________________ to form special organs for smell, hearing, vision, and touch

Lymph

extracellular fluid that flows in lymphatic vessels; It is a liquid connective tissue that consists of several types of cells in a clear liquid extracellular matrix that is similar to blood plasma but with much less protein

adipocytes

fat cells that make up most of the subcutaneous layer

microvilli

fingerlike cytoplasmic projections, increase surface area of plasma membrane, thus increasing cell's rate of absorption

squamous

flat

Mesothelium

forms epithelial layer of serous membranes (peritoneum, pleura, pericardium)

Dense regular connective tissue

forms shiny white extracellular matrix; 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. Location: Forms tendons (attach muscle to bone), most ligaments (attach bone to bone), and aponeuroses (sheetlike tendons that attach muscle to muscle or muscle to bone). Function: Provides strong attachment between various structures. Tissue structure withstands pulling (tension) along long axis of fibers.

Covering and lining epithelium (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

Transitional epithelium (urothelium)

has a variable appearance. In relaxed or unstretched state, looks like stratified cuboidal epithelium, except apical layer cells tend to be large and rounded. As tissue is stretched, cells become flatter, giving the appearance of stratified squamous epithelium. Multiple layers and elasticity make it ideal for lining hollow structures (urinary bladder) subject to expansion from within. location: Lines urinary bladder and portions of ureters and urethra. function: Allows urinary organs to stretch and maintain protective lining while holding variable amounts of fluid without rupturing.

Fibrocartilage

has chondrocytes among clearly visible thick bundles of collagen fibers within extracellular matrix; lacks perichondrium. location: Pubic symphysis (where hip bones join anteriorly), intervertebral discs, menisci (cartilage pads) of knee, portions of tendons that insert into cartilage. function: Support and joining structures together. Strength and rigidity make it the strongest type of cartilage.

Elastic cartilage

has chondrocytes in threadlike network of elastic fibers within extracellular matrix; perichondrium present. location: Lid on top of larynx (epiglottis), part of external ear (auricle), auditory (eustachian) tubes. Function: Provides strength and elasticity; maintains shape of certain structures.

Mesenchyme

has irregularly shaped mesenchymal cells embedded in semifluid ground substance that contains delicate reticular fibers. location: Almost exclusively under skin and along developing bones of embryo; some in adult connective tissue, especially along blood vessels. function: Forms almost all other types of connective tissue.

Stratified squamous epithelium

has two or more layers of cells; cells in apical layer and several layers deep to it are squamous; cells in deeper layers vary from cuboidal to columnar. As basal cells divide, daughter cells arising from cell divisions push upward toward apical layer. As they move toward surface and away from blood supply in underlying connective tissue, they become dehydrated and less metabolically active. Tough proteins predominate as cytoplasm is reduced, and cells become tough, hard structures that eventually die. At apical layer, after dead cells lose cell junctions they are sloughed off, but they are replaced continuously as new cells emerge from basal cells. Nonkeratinized and keratinized Function: Protection against abrasion, water loss, ultraviolet radiation, and foreign invasion. Both types form first line of defence against microbes.

Stratified cuboidal epithelium

has two or more layers of cells; cells in apical layer are cube-shaped; fairly rare type. Function: protection; limited secretion and absorption Location: ducts of adult sweat glands and esophageal glands, part of male urethra

Mucous (mucoid) connective tissue

has widely scattered fibroblasts embedded in viscous, jellylike ground substance that contains location: umbilical cord of fetus function: support

Tubuloacinar glands

have both tubular and more rounded secretory parts

excitable cells

have the ability to generate changes in their membrane potentials.

Wandering macrophages

have the ability to move throughout the tissue and gather at sites of infection or inflammation to carry on phagocytosis.

reticular lamina

is closer to the underlying connective tissue and contains proteins such as collagen produced by connective tissue cells called fibroblasts

basal lamina

is closer to—and secreted by— the epithelial cells; contains proteins such as laminin and collagen as well as glycoproteins and proteoglycans

The growth of cartilage follows 2 basic patterns

interstitial growth and appositional growth

Reticular connective tissue

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

blood plasma

is a pale yellow fluid that consists mostly of water with a wide variety of dissolved substances— nutrients, wastes, enzymes, plasma proteins, hormones, respiratory gases, and ions

pathologist

is a physician who examines cells and tissues to help other physicians make accurate diagnoses

ciliated simple columnar epithelium

is a single layer of ciliated column like cells with oval nuclei near base of cells. Goblet cells are usually interspersed. location: lines the lower respiratory tract and uterine tubes some paranasal sinuses, central canal of spinal cord, and ventricles of brain; wavelike motion of cilia propels materials through the lumen function: Cilia beat in unison, moving mucus and foreign particles toward throat, where they can be coughed up and swallowed or spit out. Coughing and sneezing speed up movement of cilia and mucus. Cilia also help move oocytes expelled from ovaries through uterine (fallopian) tubes into uterus

Simple squamous epithelium

is a single layer of flat cells that resembles a tiled floor when viewed from apical surface; centrally located nucleus that is flattened and oval or spherical in shape; Also found in.. (other than endothelium and mesothelium) air sacs of lungs, glomerular (Bowman's) capsule of kidneys, inner surface of tympanic membrane (eardrum) Function: Present at sites of filtration (such as blood filtration in kidneys) or diffusion (such as diffusion of oxygen into blood vessels of lungs) and at site of secretion in serous membranes. Not found in body areas subject to mechanical stress (wear and tear).

Hyaluronic acid

is a viscous, slippery sub- stance that binds cells together, lubricates joints, and helps maintain the shape of the eyeballs

Dense irregular connective tissue

is made up of collagen fibers; usually irregularly arranged with a few fibroblasts. Location: Often 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); also in heart valves. Function: Provides tensile (pulling) strength in many directions.

areolar connective tissue

is one of the most widely distributed connective tissues; consists of fibers (collagen, elastic, reticular) arranged randomly and several kinds of cells (fibroblasts, macrophages, plasma cells, adipocytes, mast cells, and a few white blood cells) embedded in semifluid ground substance (hyaluronic acid, chondroitin sulfate, dermatan sulfate, and keratan sulfate). location: In and around nearly every body structure (thus, called "packing material" of the body): in subcutaneous layer deep to skin; papillary (superficial) region of dermis of skin; lamina propria of mucous membranes; around blood vessels, nerves, and body organs. function: Strength, elasticity, support.

Absorption

is the intake of fluids or other substances such as digested food from the intestinal tract

Secretion

is the production and release of substances such as mucus, sweat, or enzymes

laminin

key basement membrane glycoprotein

Spongy bone

lacks osteons. Rather, it consists of columns of bone called trabeculae

cutaneous membrane (skin)

largest membrane in the body; covers the entire surface of the body

stratum

layer

Synovial membranes

line the cavities of freely movable joints (joint cavities); line structures that do not open to the exterior (like serous membranes); lack an epithelium and are therefore not epithelial membranes

Glandular epithelium

makes up the secreting portion of glands such as the thyroid gland, adrenal glands, sweat glands, and digestive glands.

osteocytes

mature bone cells

What are the 2 types of Embryonic connective tissue?

mesenchyme and mucous connective tissue

-genesis

production

Connective tissue

protects and supports the body and its organs. Various types of connective tissues bind organs together, store energy reserves as fat, and help provide the body with immunity to disease-causing organisms; most abundant and widely distributed

gap junction in cardiac muscle

provide route for quick conduction of electrical signals (muscle action potentials) throughout heart

Chondroitin sulfate

provides sup- port and adhesiveness in cartilage, bone, skin, and blood vessels

nonciliated simple columnar epithelium

single layer of non-ciliated column-like cells with oval nuclei near base of cells; contains microvilli at apical surface and goblet cells Location: Lines GI tract, ducts of many glands, and gallbladder Function: Secretion and absorption; larger columnar cells contain more organelles and thus are capable of higher level of secretion and absorption than are cuboidal cells. Secreted mucus lubricates linings of digestive, respiratory, and reproductive tracts, and most of urinary tract; helps prevent destruction of stomach lining by acidic gastric juice secreted by stomach

unicellular glands

single-celled glands. Goblet cells are important _____________ ____________ that secrete mucus directly onto the apical surface of a lining epithelium.

lacunae

small spaces between lamellae that contain mature bone cells called osteocytes

intercalated discs

specialized connections between myocardial cells containing gap junctions and desmosomes

Red blood cells

transport oxygen to body cells and remove some carbon dioxide from them

stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

angio-

vessel

neurons (nerve cells) and neuroglia

what are the 2 principal types of cells?

tight junctions, adherens junctions, desmosomes, hemidesmosomes, and gap junctions

what are the 5 most important types of cell junctions?

Elastic fibers

which are smaller in diameter than collagen fibers, branch and join together to form a fibrous network within a connective tissue; plentiful in skin, blood vessel walls, and lung tissue.