zoo chap 3

microscope

• is one of the most utilized and indispensable tools man has ever held on to

• aided the advancement of science and scientific research

• paved the way for the development of various medical breakthroughs in the battle against diseases

• become a tool for studying insects, algae, and other extremely minute life forms

magnifying glass

considered the earliest ancestor of microscope

burning “glass”

magnifying glass during ancient times was used as a __

13th century

the concept of its use(magnifying glass) in magnifying objects to help the eye see came later at around the __

Roger Bacon

the glass lens was also in its beginnings during this time as discovered by __

glass lens

was then utilized to help people with impaired sight

1268 and 1289

glass lens were incorporated into spectacles or eyeglasses between __

England

microscope was first developed in __

16th century

microscope was developed at the later part of the ___

inversion of the telescope

microscope was derived from the __

six feet long and had a one inch barrel with a lens at the either end

one of the first microscopes was __

simple microscope

was described as merely a tube with a plate for the object at one end and a lens at the other end that gave a magnification ten times the actual size

Hans and Zacharias Janssen

• discovered a better arrangement for the lenses in a tube, resulting in increased magnification and visual clarity

• they arranged the lenses with one at the eyepiece and the other is placed in close proximity to the sample observed

compound microscope

the Janssens undoubtedly initiated the invention of the __

Robert Hooke (1)

• modified the Janssen’s microscope and made it smaller and lighter with significant changes

• English scientist and a mechanical genius who pioneered microscopic research, which included the discovery of plant cells

Robert Hooke (2)

• English Father of Microscopy

• one of his greatest discovery was the cell

Antonie Van Leeuwenhoek

• worked with Robert Hooke and designed a better microscope

• developed a more practical microscope than the one he and Hooke earlier invented

• He provided the first accurate description of RBC in 1674

very short focal lengths

were the key to better magnification

double convex lenses

• robert hooke and van leeuwenhoek used _ in their modified compound microscope

• this change improved their microscope’s resolution and magnification and paved the way to various discoveries

finely polished clear glass

Van Leeuwenhoek’s microscope was made from a __ instead of the usual greenish glass

pointed needle

in front of the lens is a __ where the specimen is mounted

3-4 inches

(van leeuwenhoek) the entire instrument is only _ long

270x

(van leeuwenhoek’s microscope) can magnify up to _ which is greater than the 20-30x magnification of the earlier compound microscope

prevalent theory of spontaneous generation

Van Leeuwenhoek also opposed the ___, and through the use of the microscope, demonstrated that granary weevils, fleas, and mussels were not created from wheat grains and sand but developed from tiny eggs

1. bacilli

2. cocci

3. spirilli

3 types of bacteria

objective lenses

enhanced and controlled the magnification and resolution of the observed sample

18th-19th century

all of these improvements came up around (modern microscope) __

World War 1

standardization of the parts of the microscope during__ caused by its high demand

cast-iron in black

microscope made out of __

23 mm diameter tube

eyepiece is held in a __

1. compound microscope

2. electron microscope

3. scanning tunneling microscope

4. scanning probe microscope

types of microscope

compound microscope

• makes use of two lenses, the objective lens and the ocular lens, which are are mounted at the opposite ends of a closed tube

• the objective lens is made up of several lens elements that form an enlarged, real image of the object being examined

• microscope’s body has a firm stand with a flat stage to hold the examined material

• knobs were placed at the sides to promote ease in moving the stage and the tube toward and away from the specimen for better focusing

Electron Microscope

• is very useful in high magnification microscope that is commonly used in almost all fields in science

• this uses electrons to illuminate an object

• this type of microscope has an electron gun that emits electrons in a vacuum, which then strike the specimen

electrons

have a much smaller wavelength than light, so they can resolve much smaller structures

1. Transmission electron microscope

2. Scanning electron microscope

2 types of electron microscopes

Scanning Electron Microscope

• it scans the surface of a thinly sliced sample bit by bit

• can magnify objects 100,000 times or more

Transmission Electron Microscope

looks at relatively large area of the sample all at once

Scanning Tunneling Microscope

• it is a very powerful microscope and can obtain images of conductive surfaces at an atomic level and scale of 2×10^-10 or 0.2 nanometers

• it can be used manipulated individual atoms, trigger chemical reactions, and create ions

1981

scanning tunneling microscope was invented in

Gerd Binnig and Heinrich Rohrer

scanning tunneling microscope was invented by

IBM’s Zurich Laboratory of Switzerland

Gerd Binnig and Heinrich Rohrer of __

Scanning Probe Microscope

uses a probe to scan the surface of a sample and provides a three-dimensional image of atoms or molecules on the surface of the object

the probe

• is an extremely sharp metal point that can be as narrow as a single atom at the tip

• its strength is its ability to provide detailed images o substance that can conduct electricity

Titan 80-300 Cubed electron microscope

• has revolutionized nanotechnology, bringing it to newer, more exciting frontiers\

• this microscope can identify atoms, measure their chemical states, and probe the electrons that bind them together

x-rays

• most popular and widely used medical imaging technology

• very useful to medical and dental practitioners

• are highly recommended in examining bones and teeth rather than soft tissues

Magnetic Resonance Imaging

• this technology uses a strong magnetic to produce a cross-section image of a part of the body

• a series of __ images can be placed together to create a complete view of tissues, e.g., ligament in that area

Functional MRI

• can produce images that can differentiate between active, functioning parts, and non-active ones

• example: active parts of the brain light up in the image when a person is performing a certain activity

Computerized Tomography Scan

• an imaging procedure that combines a series of x-ray images taken from different angles of the body

• it uses a computer to process and create cross-sectional images of the blood vessels, soft tissues, and bones

• this scan creates an excellent anatomical detail, compared to plain x-rays

• can help visualize nearly all parts of the body which can guide medical practitioners to diagnose disease, injuries, as well as plan radiation therapies and surgery

Positron Emission Tomography Scan

• an imaging test that allows medical practitioners to check for disease to check for diseases in the human body, such as cancer and Alzheimer’s disease

• the scan uses special dye that contains radioactive tracers

• the images created reveal how tissues and organs are functioning

radioactive tracers

• may be swallowed, injected, or inhaled, depending on the organ of interest

• concentrates on the areas of the body of higher metabolic activities

Fused PET/CT Imaging

allows for superb anatomic localization of abnormal metabolic activity, which helps in detecting cancer, the staging and monitoring of treatment, as well as diagnosing Alzheimer’s disease