Biomed I: Tissue flashcards

tissues

groups of cells with similar structure and function

four primary types of tissues

epithelial tissue, connective tissue, muscle tissue, nervous tissue

location of epithelial tissue

body coverings, body linings, and glandular tissue

functions of epithelial tissue

protection, absorption, filtration, and secretion

first hallmark of epithelial tissue

cover and line body surfaces

second hallmark of epithelial tissue

often form sheets with one free surface and an anchored surface (the basement membrane)

third hallmark of epithelial tissue

Avascular (no blood supply)

fourth hallmark of epithelial tissue

Regenerate easily if well nourished

classification of epithelia

number of cell layers and shape of cells

squamous

flattened, like fish scales

cuboidal

cube-shaped, like dice

columnar

saped like columns

basal surface

lower surface (the underside)

apical surface

the top surface

function of simple squamous epithelial tissue

Diffusion and filtration, secretion in serous membranes

function of stratified squamous epithelial tissue

protection

function of simple cuboidal epithelial tissue

Secretion and absorption; ciliated types propel mucus or reproductive cells

function of simple columnar epithelial tissue

Secretion and absorption; ciliated types propel mucus or reproductive cells (same as cuboidal)

function of stratified cuboidal epithelial tissue

Protection; these tissue types are rare in humans

function of stratified columnar epithelial tissue

Protection; these tissue types are rare in humans (same as cuboidal)

function of simple transitional epithelial tissue

this type of tissue does not exist

function of stratified transitional epithelial tissue

Protection; stretching to accommodate distension of urinary structures

simple epithelia

Very thin (so not suited for protection) and functions in absorption, secretion, and filtration

simple squamous epithelium

single layer of flat cells that functions in diffusion, filtration, and secretion in membranes

locations of simple squamous epithelia

usually in membranes-- lines air sacs of the lungs, forms walls of capillaries, forms serous membranes that line and cover organs in ventral cavity

simple cuboidal epithelium

a single layer of cubelike cells that functions in secretion and absorption; ciliated types propel mucus or reproductive cells

locations of simple cuboidal epithelia

glands and their ducts, forms walls of kidney tubules, covers the surface of ovaries

simple columnar epithelium

a single layer of tall cells that functions in secretion and absorption; ciliated types propel mucus or reproductive cells

locations of simple columnar epithelia

Lining of the digestive tract from stomach to anus and mucous membranes (mucosae) line body cavities opening to the exterior

pseudostratified columanr epithelium

a single layer but appears stratified because some cells are shorter than others, all cells rest on the basement membrane, and functions in absorption and secretion

locations of pseudostratified columnar epithelia

respiratory tract (ciliated and known as ciliated pseudostratified columna epithelium)

stratified epithelia

consists of two or more layer and mainly functions in protection

stratified squamous epithelium

named for cells present at the apical surface, which are squamous and is the most common stratified epithelium (functions as a protective covering where friction is common)

Locations of stratified squamous epithelia

outer skin, mouth, esophagus

stratified cuboidal epithelium

two layers of cuboidal cells, functions in protection

stratified columnar epithelium

surface cells are columnar, and cells underneath vary in size and shape; functions in protection

stratified cuboidal and columnar

rare in the human body and found mainly in ducts of large glands

transitional epithelium

composed of modified stratified squamous epithelium, cell shape depends on amount of stretching, functions in stretching and the ability to return to normal shape

location of transitional epithelium

lining of urinary system organs

endocrine glands

ductless, secrete hormones and diffuse into blood vessels

exocrine glands

secretions empty through ducts to the epithelial surface

examples of exocrine glands

sweat and oil glands, liver, and pancreas (internal and external)

connective tissue

includes the most abundant and widely distributed tissues

locations of connective tissue

found everywhere in the body to connect body parts

functions of connective tissue

protection, support, and binding

characterstics of connective tissue

variations in blood supply (some are vascularized and some are avascular), extracellular matrix (nonliving material that surrounds living cells)

two main elements of the extracellular matrix

ground substance and fibers

ground substance

mostly water, along with adhesion proteins and polysaccharide molecules

fibers

collagen (white) fibes, elastic (yellow) fibers and reticular fibers (a type of collagen)

types of connective tissue (most to least rigid)

bone, cartilage, dense connective tissue, loose connective tissue, and blood

bone (osseous tissue)

composed of osteocytes (bone cells) sitting in lacunae (cavities), hard matric of calcium salts, large numbers of collagen fibers

functions of bones

to protect and support the body

cartilage

less hard and more flexible than bone, found in only a few places in the body

chondrocyte

cartilage cell, major cell type

types of cartilage

hyaline cartilage, fibrocartilage, and elastic cartilage

hyalin cartilage

most widespread type of cartilage, abundant collagen fibers hidden by a glassy, rubbery matrix

locations of hyalin cartilage

trachea, attaches ribs to the breastbone, covers ends of long bones, entire fetal skeleton prior to birth, epiphyseal (growth) plates in long bones

elastic cartilage

provides elasticity

locations of elastic cartilage

supports the external ear

fibrocartilage

highly compressible

locations of fibrocattilage

forms cushionlike discs between vertebrae of the spinal column

dense connective tissue (dense fibrous tissue)

main matrix element is collagen fiber, fibroblasts are cells that make fibers

locations of dense connective/fibrous tissue

tendons, ligaments, and dermis

tendons

attach skeletal muscle to bone

ligaments

attach bone to bone at joints and are more elastic than tendons

dermis

lower layers of the skin

loose connective tissue

softer, have more cells and fewer fibers than other connective tissues (except blood)

types of loose connective tissue

areolar, adipose, reticular

areolar connective tissue

most widely distributed connective tissue, soft pliable tissue like cobwebs, all fiber types form a loose network

functions of areolar connective tissue

universal packing tissue and “glue” to hold organs in place and soak up excess fluid (cases edema)

lamina propria

layer of areolar tissue that underlies all membranes

adipose connective tissue

an areolar tissue in which fat cells dominate

functiond of adipose connective tissue

insulates the body, protects some organs, and serves as a site of fuel storage

locations of adipose connective tissue

subcutaneous tissue beneath the skin, protects organs, such as the kidneys, fat “depots” include hips, breasts, and belly

reticular connective tissue

delicate network of interwoven fibers with reticular cells (like fibroblasts), forms stroma (internal framework) of organs

locations of reticular connective tissue

lymph nodes, spleen, and bone marrow

vascular tissue (blood)

soluble fibers are visible only during clotting

blood plasma

blood cells surrounded by fluid matrix

functions of vascular tissue

a transport vehicle for the cardiovasculr system, carrying nutrients, wastes, and respiratory gases

functions of muscle tissue

to contract, shorten, and produce movement

three types of muscle tissue

skeletal, cariac, and smooth

skeletal muscle tissue

packaged by connective tissue sheets into skeletal muscles, which are attached to the skeleton and pull on bones and skin, voluntary control, and proiduces gross body movements or facial expressions

characteristics of skeletal muscle cells

striations, multinucleate, and long, cylindrical shape

cardiac muscle tissue

involuntary controlled, found only in the heart, and pumps blood through blood vessels

characteristics of cardiac muscle cells

striations, one nucleus per cell, short branching cells, and intercalated discs containing gap junctions to connect cells together

smooth muscle tissue

involuntary controlled, also known as visceral tissue

locations of smooth muscle tissue

the walls of hollow organs such as the stomach, uterus, and blood vessels

peristalsis

a wavelike activity, is a typical activity

characteristics of smooth muscle cells

no visible striations, one nucleus per cell, and spindle-shaped cells

function of nevous tissue

to receive and conduct electrochemial impulses to and from body parts (irritability and conductivity)

nervous tissue

composed of neurons and nerve support cells

neuroglia

nerve support cells that insulate, protect, and support neurons