Histology Test

Tissues

Tissues

Groups of cells with similar structure and function

Epithelium, Connective tissue, Nervous tissue, Muscle

Name the four primary types of body tissues.

Body coverings, body linings, glandular tissue

Where are epithelial tissues found?

Protections, absorption, filtration, secretion

Functions of epithelial tissues.

Epithelium

Cells fit closely together / Tissue layer always has one free surface / Lower surface is bound by a basement membrane / Avascular (no blood supply) / Regenerate easily

Simple, one layer. Stratified, more than one layer.

What are the classifications of epithelium?

Squamous, flattened. Cuboidal, cube. Columnar, column-like.

Shapes of epithelium.

Simple Squamous

Single layer of flat cells / Usually forms membranes - Lines body cavities / Lines lungs and capillaries.

Simple Cuboidal

Single layer of cube-like cells / Common in glands and their ducts . Forms walls of kidney tubules / Covers the ovaries

Simple Columnar

Single layer of tall cells / Often includes goblet cells, which produce mucus / Lines digestive tract

Pseudostratified

Single later, but some cells are shorter than others / Often looks like a double cell layer / Sometimes ciliated, such as in respiratory tract / May function in absorption or secretion

Stratified Squamous

Cells at the free edge are flattened / Found as a protective covering where FRICTION is common / Found in skin, mouth, and esophagus.

Stratified Cuboidal

Two layers of cuboidal cells

Stratified Columnar

Surface cells are columnar, cells underneath vary in size and shape.

Stratified Cuboidal and Columnar

Rare in human body / Found mainly in ducts of large glands.

Transitional Epithelium

Shape of cells depends upon the amount of stretching / Lines organs of the urinary system.

Connective Tissue

Found everywhere in the body / Includes the most abundant and widely distributed tissues / Functions: Binds body tissues together, supports the body, provides protection

Variations in blood supply and extracellular matrix

Name two dominant characteristics of Connective tissues.

Extracellular matrix

Non-living material that surrounds living cells

Ground substance and fibers

What are the two main elements in extracellular matrix?

Bone (Osseous)

____ cells in lacunae (cavities) / Composed of: hard matrix of calcium salts, large numbers of collagen fibers / Used to protect and support the body

Hyaline Cartilage

Most common cartilage / Composed of: abundant collagen fibers, rubbery matrix / Entire fetal skeleton is hyaline cartilage

Elastic Cartilage

Provides elasticity / EX: supports the external ear

Fibrocartilage

Highly compressible / EX: forms cushion-like discs between vertebrae

Dense Connective Tissue

Main matrix element is collagen fibers / Cells are fibroblasts / EX: tengon - muscle --> bone; ligaments - bone --> bone

Areolar Connective Tissue

Most widely distributed connective tissue / Soft, pliable tissue / Contains all fiber types / Can soak up excess fluid

Adipose Tissue

Matrix is an areolar tissue in which fat globules predominate / Many cells contain large lipid deposits / Functions: insulates the body, protects some organs, serves as a site of fuel storage

Reticular Connective Tissue

Delicate NETwork of interwoven fibers / Forms stroma (internal supporting network) of lymphoid organs - lymph nodes, spleen, bone marrow

Blood

Cells surrounded by fluid matrix / Fibers are visible during clotting / Functions as the transport vehicle for materials / Fight infections / ONLY fluid connective tissue

Muscle

Function is to produce movement / Three types: skeletal, cardiac, smooth

Skeletal Muscle

Can be controlled voluntarily / Cells attach to connective tissue / Cells are striated (striped) / Cells have more than one nucleus / Locomotion and body heat

Cardiac Muscle

Found only in the heart / Function is to pump blood (involuntary) / Cells attached to other cardiac muscle cells at intercalated disks (gap junctions) / Cells are striated (striped) / One nucleus per cell

Smooth Muscle

Involuntary muscle / Surround hollow organs / Attached to other smooth muscle cells / No visible striations / One nucleus per cell

Nervous Tissue

Neurons and nerve support cells / Function is to send impulses to other areas of the body

Irritability

Electrochemical messages from one tissue to another

Conductivity

Respond to natural changes in the environment (detect and send messages)

Regeneration and fibrosis

Name two types of tissue repair.

Regeneration

Replacement of destroyed tissue by the same kind of cells (skin)

Fibrosis

Repair by dense fibrous connective tissue (scar tissue)

Mass, viability

With old age there is a decrease in ____ and ____ in most tissues.

Epithelial, fibrous connective tissue and bone

What tissues regenerate easily?

Skeletal muscle

What tissue regenerates poorly?

Cardiac, nervous

What tissues are replaced largely with scar tissue?

Formation of granulation tissue

In tissue repair, when is the beginning of actual repair?

Scars

Regeneration of surface epithelium.

Where are epithelial tissues found within the body?

lines/covers body surfaces and cavities

What are the functions of the epithelial tissues?

secrete, absorb, line, cover and protect

What do you call the upper or free surface of epithelial tissues?

apical surface

What do you call the attached bottom layer of epithelium?

basal surface

What is the basement membrane?

a thin, delicate membrane of separating an epithelium from underlying tissue.

Epithelial cells are said to be avascular. What does this mean?

no blood or blood vessels

What is unique about transitional epithelium?

It is stratified with cells that are able to change shape to account for increasing volume

What type of tissue always can be found underneath epithelial?

connective tissue

Since the epithelial tissues have no blood flow, they are able to receive needed nutrients and expel wastes through the process known as _____.

diffusion

Do epithelial cells reproduce rapidly or slowly?

rapidly

Are epithelial cells tightly packed or loosely spaced?

tightly packed

You're looking at epithelial tissue in the microscope and notice the specimen has several layers with flattened cells on the apical surface. What type of epithelia?

stratified squamous

Which type of epithelial tissue usually forms membranes where filtration or exchange of substances by diffusion occurs? (simple or stratified)

simple

What type of epithelium would be found in areas subjected to considerable wear and tear? (simple or stratified)

stratified

apical surface

unattached that lines external surfaces or inner cavity of organs

basal surface

attached surface to basement membrane

simple squamous

alveoli or capillary walls. diffusion and filtration.

simple cuboidal

kidney tubules. secretion and absorption

simple columnar

digestive tract. protection, secretion, absorption.

pseudostratified columnar

respiratory tract. has cilia. secretion.

stratified squamous

mouth. protection.

stratified cuboidal and columnar

rare in body. some glands and male urethra

transitional epithelium

stretchable. urinary bladder.

glandular epithelium

exocrine (into ducts) and endocrine (into bloodstream)