BIO- The Tissue Level and Histology

Working Distance

Space between lens and table 

Fine adjustment

only used on high power

Course adjustment

used on scanning and low power

Parfocal lens

a lens that stays in focus when magnification or focal length is changed

DOF (depth of field) 

the amount of depth (layers of specimen) seen with a specific objective lens

FOV (field of view)

The amount of area seen with a specific objective lens. (Decreases with increasing magnification)

Identify parts of microscope

Epithelial Tissue

Lines body cavities, cover organs.

Connective Tissue

Connects tissues to each other, connects skin to muscle.

Muscular Tissue (Cardiac) 

Pumps blood

Smooth muscle tissue

lines digestive system, helps things move.

Skeletal muscle

Connects to skelton, muscle pulls on bones and helps movement, contracts and relaxes.

Nervous tissue

Consists of neurons and sends signals. Found in nervous system organs such as the brain and spinal cord as well as nerves. 

Apical surface

top

Basement membrane

bottom

Regeneration

easily undergoes mitosis for replacement and repair

High mitotic rate

cell division

Endocrine glands

produce hormones

Exocrine glands

non-hormonal

Tight junctions

prevent substances from passing between cells

Desmosomes

(Strong) Hold cells together with the assistance of intermediate filaments

Gap junctions

Allow substances to move through cells

Simple

One layer. (Easy for substances to move through)

Stratified

Many cell layers. (Difficult for substances to move through, designed for protection.)

Squamous

flat cells

Cuboidal

cube shaped cells

Columnar

tall, thin cells

Simple Squamous

Lines blood vessels, found in kidneys and lungs. Cover organs, lines cavities (serous membranes). Allows diffusion. Produces serous fluid. Promotes gas exchange.

Simple Cuboidal

Found in glands, ducts and kidney tubules. Involved in secretion and absorption of nutrients and ions. Allows movement of chemicals across wall.

Simple Columnar

Lines GI tract (stomach to large intestine). Involved in secretion of digestive enzymes and absorption of nutrients.

Pseudostratified ciliated columnar

Lines respiratory tract (lungs, nasal cavity, trachea). Allows production of mucus and movement of mucus by cilia.

Stratisfied Squamous

Skin, lining of oral cavity, throat, and esophagus (rectum, anus, and vagina). Provides protection and withstands abrasion.

Transitional

Urinary bladder, ureters. Allows organ distention. When stretched appears small and compressed, when empty appears expanded.

Connective Tissue

cells spread out, much extracellular space, different types of cells.

Collagen

sturdy, won’t tear

Reticular

smaller & branching

Elastic

stretch & recoil

Dense regular connective tissue

Skin. Collagen fibers arrange in one direction with fibroblasts. Found in tendons and ligaments.

Dense irregular connective tissue

Tendons. Dermis of skin, collagen fibers, shaped irregular. 

Areolar loose connective tissue

Fills space in body, wraps organs. Holds and conveys fluid for damaged areas. Protects and cushions.

Adipose loose connective tissue

Under layers of skin, around organs. Cushions, insulates, stores lipids.

Hyaline Cartilage

Between articulating bones. Provides flexible support and reduces friction.

Elastic cartilage

External ear, epiglottis. Supports with tremendous flexibility.

Mucous membrane

produce mucous. underneath is areolar connective tissue.

Serous membrane

lines body cavities that are not open to the exterior of the body. produces serous fluid. lubricates organs.

pleural

lungs

pericardial

heart

peritoneum

abdomen

visceral

directly to organ

parietal

along wall

cutaneous

dry membrane. synovial membrane articulating joints of the limbs.

Stratum corneum

outer layer of skin. (dead skin)

stratum granulosum

layer of skin. keratin and kertohyalin, cells dehydrate.

stratum spinosum

spiny layer of skin, some cell division

stratum basale

germinative layer of skin, mitosis occurs, new cells created

stratum lucidum

only in thick skin. translucent layer.

Simple Squamous Epithelium

Simple Cuboidal Epithelium

Simple Columnar Epithelium

Pseudostratisfied Ciliated Epithelium

Stratified Squamous Epithelium

Transitional Epithelium

Areolar Connective Tissue

Adipose Connective Tissue

Dense Regular Connective Tissue

Dense Irregular Connective Tissue 

Hyaline Cartilage

Elastic Cartilage

Fibrocartilage

Bone