Histology Lecture

Histology Microscopy and its definition

- study of microscopic anatomy of normal • Polarizing Microscopy
tissues and cells. - normal light passes through a polarizing
filter
Microtome • Scanning Electron Microscope
- used for sectioning parrafin-embedded - the surface of the specimen is first dried
tissues for light microscopy and dried spray-coated with a very thin
layer of heavy metal through which
electrons do not pass readily.
Chromatin
• Transmission Electron Microscopy
- the combination of DNA and its associated
proteins - very thin tissue sections can be observed
with details at magnifications up to about
120,000 times.
Mitosis
• Phase-contrast Microscopy
- a cell division that produces two diploid cells - uses a lens system that produces visible
images from transparent objects, canbe
Osmosis used with living and cultures cells.
- the diffusion of water across selectively • Fluorescence Microscopy
permeable membrane - tissue sections are usually irradiated with
ultraviolet (UV) light and the emission is in
the visible portion of the spectrum.
Cancer
- the common term for all malignant tumor
Tissue Processing
• Infiltration
Simple diffusion
- tissue is placed in the melted paraffin
- exchange of oxygen and carbon dioxide
between blood and body tissues • Fixation
- use of formalin to preserve all cells and
tissues.
Phagocytosis
• Embedding
- cell eating
- tissue is placed in a mold with the paraffin
and allowed to be harden
Parts of the microscope and its function
• Staining
• Mechanical Stage - use of stains before viewing the
- permit movements of the stage while microscope
holding the slide in the phase of focuse
• Dehydration
• Base - use of series increasing alcohol
- provides support for the microscope
• Arm The cell organelles and its functions
- supports and holds the magnifying and
• Nucleus
adjustment system
- contains genetic material of cell
• Stage
- flat platform where the slide is placed • Mitochondrion
- site of aerobic respiration and the major
• Substage site of ATP synthesis
- located directly under the stage and holds
• Lysosomes
the condenser and diaphragm
- contains enzymes that digest materials
taken into the cell

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• Golgi Apparatus Connective Tissue

- modifies protein structure and packages Hyaline
proteins in secretory vesicles - provides a low friction surface
• Centrioles - holds open passages so we can breath
- facilatate the movement of chromosomes Elastic
during cell divisions. - allows structures to stretch and return to
original shape
The 22 pairs of autosome, as well as the X - forms the external ear
and Y chromosomes have the same size, Fibrocartilage
morphology, and location of the centromere.
- absorbs compressive forces in the spine
- FALSE
- found in the intervertebral discs

Tissue membrane with its function Epithelial Tissue

Synovial Membrane Simple squamous
- composed of only connective tissue and - lining of blood vessels and alveoli of lungs
lines the inside of joint cavities. - one layer of flat, or scale-like celss that rest
Cutaneous Membrane on a basement membrane.
- keratinized squamous epithelium and an - type of epithelium that is best suited for
underlying layer of connective tissue allowing diffusion of substances as would be
Serous Membrane found lining the air sacs (alveoli) of the
lungs.
- composed of simple squamous epithelium
and underlying layer of loose connective Simple cuboidal
tissue - kidney tubules, secretory cells of glands
Mucous Membrane - one layer of cells that are as wide as they
- composed of various types of epithelium are tall and rest on basement membrane.
and an underlying thick layer of loose Simple columnar
connective tissue - absorption in the small and large intestines
- one layer of cells in which the cells are taller
Tissue membrane with the location than they are wide and almost all cells are
Skin touch the basement membrane and extend
to the free surface.
- keratinized squamous epithelium and an
underlying layer of connective tissue Stratified squamous
Knee - protection against abrasion, barrier against
infection
- composed of only connective tissue and
secretes synovial fluid - many layers of cells with cube-shaped cells
near the basement membrane and flat cells
Pleural Cavity (cavity that contains a lung) at the free surface
- composed of simple squamous epithelium Stratified cuboidal
and underlying layer of loose connective
tissue - sweat gland ducts, ovarian follicular cells
Respiratory Tract - many layers of cells where most cells are as
wide as they are tall
- composed of various types of epithelium
and an underlying thick layer of loose Stratified columnar
connective tissue - mammary gland ducts, larynx, parts of the
male urethra
Pseudostratified columnar
- lining of the nasal cavity, pharynx, and

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trachea The various types of epithelium

- special type of simple epithelium that - classified by the shape of cells and number
appears to be stratified but is not of cell layers
- epithelium of a single layer with both tall
columnar cells reaching the free surface Secretions of endocrine glands are
and shorter basal cells, called released directly
pseudostratified columnar epithelium.
- into the bloodstream
Holocrine
Transitional
- type of gland accumulates its secretion in
- lining of the urinary bladder and ureters the cytoplasm of the cells with the cell then
rupturing and becoming part of the section.
Connective tissue and its function/location
• Areolar connective tissue Marfan syndrome
- basement membrane of epithelia sits - is a genetic disorder that results in abnormal
• Fibrocartilage collagen production.
- intervertebral disks, pubic symphysis - most likely assciated with connective
tissue.
• Elastic cartilage
- external ear, epiglottis and auditory tubes
Basement membrane
• Adipose tissue
- a thin layer of specialized extracellular
- energy storage material beneath the deepest cells of an
• Dense regular collagenous connective epithelium, serving to bind the epithelium to
tissue underlying tissue.
- tendons and ligaments
• Dense irregular elastic connective tissue A student is completing her first anatomy
- capable of strength with stretching and practical and is struggling with the last
recoil in several directions histology slide. She cannot determine if the
slide is of an epithelial tissue or connective
• Dense irregular collagenous connective tissue. Which of the following is an accurate
tissue
and helpful clue to determine the tissue type?
- tensile strength capable of withstanding - If the tissue has an obvious free surface,
stretch in all direction
it is most likely epithelial tissue.
• Blood
- transports oxygen, carbon dioxide and
Fibroblasts
other substances.
- The major cells of connective tissue proper,
are elongated, irregularly shaped cells with
Tissue oval nuclei that synthesize and secrete most
- collection of similar cells and surrounding components of the ECM.
substances
Adipocytes
Epithelial tissue - A very large cells specialized for storage of
- characterized by tightly packed cells triglycerides, they predominate in a
- an epithelial tissue is exposed to constratnt specialized form of connective tissue.
abrasion and is often stretched during
normal activities. This type of tissue is most At the tissue level, age-related changes affect
likely to be stratified squamous with many cells and the extracellular materials they
desmosomes to connect adjacent cells. produce.
- TRUE
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 Histology Lecture

As an individual ages, collagen fibers become Satellite cells derived from embryonic neural
more irregular in structure and decrease in crest.
number. - TRUE
- FALSE
Endomysium is the external sheath of dense
With age, elastic fibers fragment, bind to connective tissue surrounds the entire muscle.
calcium ions, and become less elastic. - FALSE
- TRUE
Defense and immune-related activities are the
Many cell losses and functional declines of function of astrocyte.
aging can be slowed by physical and mental - FALSE
exercise.
- TRUE
When a muscle contracts, it shortens because
the interaction of the actin and myosin
Exocrine glands are classified as compound if molecules causes the thin and thick filaments
they have a single unbranched duct. to slide past each other, resulting in the
- FALSE shortening of the sarcomeres.
- TRUE
Bone tissue is entirely inorganic (formed of
mineralized matrix). Pia mater is the external layer in CNS.
- FALSE - FALSE

Redness, limitation of movement from edema, Thick and thin filaments in smooth muscle
and tissue destruction all contribute to fibers do not form sarcomeres, and no
disturbed function. striations are present.
- TRUE - TRUE

Integumentary is a primary tissue type in the Muscle tissue

body? (Structures, location or function)
- FALSE
Smooth Muscle
Skeletal primary tissue type in the body? - single small, closely packed fusiform cells
- FALSE - hollow organs and blood vessels
- striations is absent
Nervous tissue
- found in the brain, spinal cord, and nerves. Cardiac Muscle
- can counduct electrical signals called action - pumps blood
potentials - intercalated disc joining cell
- primary tissue type in the body. - uninucleated striated branched cells

In skeletal muscle fibers the dark bands are A Skeletal Muscle

bands and the light bands are I bands. - moves the body
- TRUE - single multinucleated cell
- voluntary movements
- tongue, diaphragm, eyes
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Striated involuntary
- A tissue that has the ability to contract, is
not consciously controlled, and has a
banded appearance is

Glia cells
- Support cells of the brain and spinal cord
are called __________.

Ependymal cells
- to aid production and movement of CSF.

Schwann cells
- seen in the Peripheral nerves.

Perimysium
- A thin connective tissue layer that
immediately surrounds each bundles of
muscle fibers.

Cell body
- The neuronal region that contains the
nucleus and surrounding cytoplasm,
exclusive of the cell processes.

Astrocyte/s
- the most abudant neuroglia cell.

Sarcoplasm
- the cytoplasm of muscle cells is called

Parkinson's disease
- A slowly progressing disorder affecting
muscular activity leads to shaking, stiffness,
and difficulty with walking, balance.