systemic histology week 1 terms

week 1 lecture terms to know for 1st test

Histology definition:

science of the

microscopic structure of cells,

tissues, and organs. Helps

understand the relationship

between structure and function

Levels of organization in histology are…

subatomic particles, atoms and molecules

define cell

smallest independently functioning unit of

living organism

define tissue

group of many similar cells that work

together to perform a specific function

define organ

anatomically distinct structure of the

body. Composed of 2 or more tissue types

define system

group of organs that work together to

perform major functions or meet physiological

needs of the body

define organism

highest level of organization in

anatomy/physiology. Can independently

perform all physiologic functions necessary for

life

A ______ is the smallest functional unit of an organism

cell

Cells are categorized into various

types, all of which perform different______

functions

Cells of the human body are____

eukaryotic

cells are organized into two parts which are…

nucleus and cytoplasm

the _____ contains specialized subunits called ____ which work like ‘little organs’

cytoplasm; organelles

membranous organelles:

mitochondria,

Golgi apparatus, endoplasmic

reticulum

non membranous organelles

ribosomes,

nucleolus, centrioles

nucleus:

brain of cell; Houses information about each

structure and process of the

cell and organism, in the form

of DNA (deoxyribonucleic

acid)

DNA is condensed and coiled up into ___

chromosomes

Cells are enveloped by a semipermeable two-layered ____

membrane

the semi-permeable two layered membrane is the medium for the cell to ____ with the external environment. also controls everything that comes in and out of the cell

interact

key differences between eukaryotic and

prokaryotic cells is…

eukaryotic cells are more complex and

have a nucleus and membrane-bound

organelles whereas prokaryotic cells do not, making them simpler in size

eukaryotes include:

plants, animals and fungi

prokaryotes include:

bacteria and archaea

Cells come together with extracellular matrix to form the 4 main

types of tissues found in the human body which are:

Epithelial

Connective

Muscle

Nervous

Epithelial tissue locations:

External surfaces - skin

Lining hollow organs - intestines

Forms glands

epithelial tissue is composed of densely packed…

epithelial cells with little extracellular

matrix (ECM)

epithielial tissue is classified by both its ____, and the number of cell___

cellular morphology; layers

epithelial tissue is based on ____, and _____

morphology; number of layers

epithelial tissue morphology includes:

Squamous (flat)

Cuboid (cube)

Columnar (rectangular)

epithelial tissue single and multi layer is known as ___ and ____

simple; stratified

Additional sub-classifications of epithelial tissue are possible,

based on the ____

cell specializations

connective tissue:

Connects, separates, and supports the body

organs

connective tissue consists of…

a few cells and an abundance of

extracellular matrix (ECM)

the ECM contains…

different protein fibers

(collagen, reticular, elastic) embedded in ground

substance

Depending on the type of cells present

(fibroblasts, osteocytes, erythrocytes) and the

ECM arrangement, connective tissue can be classified as ____ or _____

connective tissue proper; specialized

connective tissue

connective tissue proper is subdivided into ______ and ______

Loose/areolar connective tissue; dense connective tissue

Loose/areolar connective tissue function:

surrounds

blood vessels and provides support to internal

organs

examples of dense connective tissue include ___ and ____

regular (tendons & ligaments); irregular (dermis of the skin, organ capsules)

Specialized connective tissue includes:

blood, reticular, cartilage, bone, lymph, and adipose tissue

Third type of connective tissue is:

embryonic tissue, which is a primitive tissue present in the embryo and

umbilical cord

nervous tissue is made of:

cells (neurons, glial cells) and extracellular

matrix (ECM)

neurons are…

specialized cells that contain a body

(soma) and one or more processes (dendrites,

axons). Classified into multipolar, bipolar and

unipolar based on the number of processes they

have

Glial cells…

provide support, nourishment,

myelination, and protection to neurons

muscle tissue allows movement and is categorized as:

skeletal, cardiac, smooth

muscle tissue is categorized based on what two functions?

voluntary (skeletal) and involuntary (cardiac, smooth)

Gives muscles the ability to contract and perform

functions, such as movement of the extremities (skeletal

muscle), peristalsis of the gastrointestinal tract (smooth

muscle), and beating of the heart (cardiac muscle)

muscle tissue

skeletal muscle fibers are…

striated, tubular and multi nucleated; usually attached to skeleton

smooth muscle fibers are…

non-striated, spindle shaped and uninucleated; usually covering wall of internal organs

cardiac muscle fibers are…

striated, branched and uninucleated; only covering walls of heart

tools for histology include:

optic (light) microscopy,

electron microscopy,

histochemistry,

immunocytochemistry,

hybridization techniques,

tissue culture, and many others

The first step in tissue preparation for optic microscopy is:

fixation

The tissue is immersed in a fixative solution to…

preserve it into the same

state that it had when it was in the body, and keep it from degrading

the second step of tissue preparation is:

the tissue is embedded with paraffin wax, which firms the tissue to

permit thin slices.

The tissue is sectioned thinly enough so that…

light can pass through it

the thin sliced tissue sections are then…

mounted on a glass slide, using a mounting

medium as an adhesive

after tissue preparation, the tissue is ___

stained

tissues are normally ___

colorless

the most common staining techniques for tissue preparation is:

hematoxylin and eosin (H&E)

histological specimens:

are very thin slices

of tissue, mounted on a glass microscope

slide and colored with stains

most fresh tissue specimens are…

colorless,

so they do not provide much useful

information

For scientific or diagnostic purposes,

____ must undergo

substantial alteration in preparation for

viewing under a ____

tissue specimens; microscope

4 steps of tissue preparation:

fixation - stabilizes and preserves the tissue

embedding - converts the tissue into a solid orm which can be sectioned

sectioning - slicing. Provides very thin specimens needed for microscopy

staining - provides visual contrast, facilitates identification of specific tissue components

The most ___ mode of

routine tissue preparation

involves ____ with buffered

formaldehyde, embedding in

paraffin, ____ into thin

slices, and staining with ____

common; fixation; sectioning; hematoxylin and eosin (H&E)

____ preserves tissue samples for

future examination. The resulting

____ is described as “fixed”

fixation; specimen

Boiling an egg and pickling a cucumber

represent examples of ____, in which

heat or chemistry stabilizes the organic

materials

fixation

histological sections are…

Thin, flat slices of fixed and stained tissues or

organs mounted on glass slides.

tissues and organs are composed of what 3 structures?

cellular, fibrous, tabular

cellular structure of histological section:

variety of shapes and sizes, may be layered

fibrous structure of histological section:

fibers. Solid structures found in

connective, nervous, and muscle tissues

tubular structure of histological section:

hollow. Represent blood vessels, ducts,

or glands

H&E staining:

Ions of the opposite charge are attracted to each other through

electrostatic interaction

when H&E staining…

one charge is from the tissue the other is from the dye

Hematoxylin:

basic dye. Reacts with basophilic components of

tissue, such as the nuclei, staining it blue

Eosin:

acidic dye negatively charged. Reacts with acidophilic

cell components of the tissue, such as the amino group in the

protein in the cytoplasm, staining it pink

Periodic-Acid Schiff:

staining technique is used to demonstrate the

presence of carbohydrates and carbohydrate compounds such as

polysaccharides, mucin, glycogen, and

fungal cell wall components

Periodic-Acid Schiff is used to…

detect glycogen (stored form of

glucose) in tissues such as the skeletal

muscle, the liver, the cardiac muscle

Feulgen reaction:

a staining process that identifies DNA in cells.

Immunohistochemistry (IHC):

technique that uses binding between an antibody and antigen to detect

and localize specific antigens in cells and tissue

the two Immunohistochemistry (IHC) methods are:

Direct - labeling primary antibody with a

fluorescent label.

Indirect - using a fluorescently labeled secondary

antibody that reacts with the primary antibody

In Situ Hybridization cleaning method:

allows to localize DNA or RNA sequences. Detects the expression pattern of a

particular gene sequence in cells or tissues using a complimentary

sequence known as a probe

what is F.I.S.H.?

Fluorescence In Situ Hybridization

it detects and localizes specific DNA sequences using fluorescently labeled complimentary DNA probes

Polymerase chain reaction (PCR):

technique used to amplify/copy small segments of DNA.

Reverse transcription-polymerase chain reaction (RT- PCR):

amplifies specific regions of DNA for diagnosis

and analysis in medical research. Uses

RNA as the starting template, instead

of DNA.

Autoradiograph records the…

distribution of radioactive materials in

botanical and histological specimens

autoradiograph creates image using…

photographic film or emulsion that captures the

radiation emitted by a radioactive

isotope absorbed by tissue.

Each step of tissue preparation introduces

artifacts by altering or

distorting the natural appearance of cells

____ by its very nature, kills cells and

stabilizes dynamic cell processes

fixation

Some ___ are intentional, most notably the colors added by ____

artifacts; staining

other artifacts are ____

accidental

Other artifacts are accidental, but common cells may:

shrink or swell or during fixation

Extracellular spaces may be distorted by ___ or ___

compression or stretching

Lipid is usually extracted from adipocytes, leaving nothing to maintain the ____ of the spaces where

each lipid droplet once resided

shape

____ and ___ can be introduced during slicing and handling of section

ripples and wrinkles

Unintended artifacts can be minimized by ____ preparation procedures.

optimizing

Microscopy:

the technical field of using microscopes to view objects that are too

small to see with the naked eye.

look up final slide of week 1 2nd lecture to compare conventional light microscope to electronic microscope