ANAPHY CHAPTER 4

Tissues

groups of specialized cells and the extra cellular substance surrounding them

Histology

the microscopic study of tissue structure

Epithelium

forms the layers that cover the surfaces and line the hollow organs of our body; protects against foreign materials entering the body

Free surface or apical surface

the exposed surface of epithelial tissue that interacts with the environment, such as air or body fluids.

Lateral surface

the side surfaces of epithelial cells that connect to neighboring cells, playing a crucial role in cell adhesion and communication.

Simple epithelium

consists single layer of cells, with each cell extending from the basement membrane to the free surface

Stratified epithelium

consists of more than one layer of cells, but only the deepest layers of cells attach to the basement membrane

Pseudostratified columnar epithelium

appears to be stratified but is not, consists of one layer of cells but at different levels

Squamous cells

flat or scale-like cells

Cuboidal cells

cells that are cube-shaped — about as wide as they are tall

Simple squamos epithelium

single layer of thin flat cells

Simple cuboidal epithelium

single layer of cubelike cells

Simple columnar epithelium

single layer of tall, thin cells

Stratified squamos epithelium

consists of several layers of cells, the newly formed cells are pushed to the surface appearing flat

Transitional epithelium

type of stratified epithelium that can stretch

Endothelium

the tissue forma a single layer, type of simple squamos epithelium

Desmosomes

Mechanically bind epithelial cells together

Hemidesmosomes

bind cells to the basement membrane

Tight junctions

cell connection structure that form barrier and anchor cells to each other

Adhesion Belts

found just below the tight junctions and help the tight junctions anchor the epithelial cells to each other

Gap junctions

consists of groups of channels that small molecules and ions pass from one epithelial cell to an adjacent one

Glands

composed of epithelium supported by a network of connective tissue

Endocrine glands

produce chemicals called hormones, ductless

Exocrine glands

secretions that enter ducts, which are continuous with the epithelial tissue surface

Unicellular

exocrine glands that are composed of only a single cell

Simple glands

multicellular glands that have a single, branched duct

tubular

a straight, narrow tube the same width as the duct

acinar

a saclike structure whose width is greater than the width of the duct

Collagen fibers

resemble microscopic ropes, very flexible but resist stretching

Reticular fibers

very fine, short collagen fibers that branch to form supporting network

Elastic fibers

ability to return to their original shape after being stretched or compressed, giving tissue an elastic quality

Cartilage

composed of chondrocytes located in spaces called lacunae

Hyaline

most abundant type of cartilage, rings the respiratory tract, the nasal, and the costal cartilages attaches the ribs to the sternum

Fibrocartilage

has more collagen, can withstand both compression and pulling or tearing forces

Elastic cartilage

contains elastic fibers, and is able to recoil to its original shape when bent

Bone

a hard connective tissue that consists of living cells and a mineralized matrix

Spongy bone

has spaces between trabeculae, resembling a sponge

Compact bone

more solid, no spaces between many thin layers if mineralized matrix

Blood

the matrix is liquid, carries the nutrients, waste products and other materials

Muscle tissue

Its function is to contract, or shorten making movement

Skeletal muscle

described as voluntary because a person can purposefully cause skeletal muscle contraction to achieve a specific body movement (striated)

Cardiac muscle

muscle of the heart, involuntary, striated, and is often branched and connected to one another by intercalated disks

Intercalated disks

contain specialized gap junctions, are important in coordinating the contractions of the cardiac muscle cells

Smooth muscle

Involuntarily, tapered at each end, have a single nucleus, and are not striated

Nervous tissue

forms the brain, spinal cord, and nerves, and is responsible for coordinating and controlling many body activities

Neuron

responsible for conducting electrical signals

Cell body

contains the nucleus and is the site of general cell functions

Dendrites

usually receive stimuli that lead to electrical changes

Axons

conduct electrical signal which usually originates at the base of an axon where it joins the cell body and travel to the end of the axon

Glial cells

support cells of the nervous system, and nourish, protect, and insulate the neurons

Tissue membrane

thin sheet or layer of tissue that covers a structure or lines a cavity

Mucous membrane

line cavities that open to the outside of the body

Serous membrane

line cavities that do not open to the exterior of the body

Synovial membrane

line cavities of freely movable joints

Inflammation

occurs when tissues are damaged

Tissue repair

The substitution of viable cells for dead cells can occur by regeneration or replacement

Replacement

new type of tissue develops

Regeneration

same type of tissue usually restored