histo exam 1

Who is Alphonse Laveran and what did he study

French physician and professor of military medicine who studied sick patients. Discovered malaria. Found commonality of black granules in red blood cells which turned out to be hemozoin

What is hemozoin

digestion product of hemoglobin breakdown

Did Laveran study unstained or stained slides?

Unstained, which made studies harder. 1880 found filiform bodies in blood.

What is filiform

String-like bodies that normally happen in female mosquito guts

In 1878, who showed that mosquitos can be affected with a human disease

Sir Patrick Manson (Father of Tropical Medicine): studied filariasis (filamentous nematodes)

Who found malaria in the actual mosquito guts in 1897

Sir Ronald Ross

When is World Mosquito Day

August 20th

What is pathology

The study of suffering

Signs

Measurements of an observer

Symptoms

Patient’s Complaints

Etiology (Acquired or Genetic)

What causes a disease

Pathogenesis

Step-by-step series of chemical and mechanical events of disease progression

Differential Diagnosis

Set of possible diagnosis

Independent Prognostic Variable

Clinical outcomes of an UNTREATED patient that can predict the likely course and outcome of a disease. (factors like age, gender, etc)

Independent Predictive Variable

Predicts responses to specific therapies

Do you need etiology to start treating a patient?

No: If you come in with a headache, dr can say to take naproxen without needing to get labs done for the underlying cause.

Clinical Manifestations

Functional consequences if changes

Who dissected monkeys because he was prohibited from dissecting humans

Galen

Who is the founder of pathology

Rudolf Virchow (1821-1902)

According to Virchow: Disease originates in _____, not tissues or organs

cells

True or False: Aristotle was the 1st to use microscopes to study pathology

False: Virchow was

Magnification

How much larger the virtual image is vs the real image

Resolution

Ability to tell two point apart

What are the two types of microscopy

Light microscopy and electron microscopy.

What are the 2 types of electron microscopy

Transmission electron microscopy (TEM) and scanning electron microscopy (SEM).

Theodore Schwann

Father of modern histology: study of body tissues and cells.

DAPI and Hoechst

used for DNA (blue)

Acridine Orange

DNA (green) / RNA (orange)

Birefringence

Changes the direction of polarized light. Will appear one color under non-polarized light then appear another color under polarized light

Flat cell view for …

diffusion and exchange

Square cell view for …

protectionWhy is EM performed in a vacuum?

Why is EM performed in a vacuum?

To prevent scattering of electrons by air molecules, ensuring clearer images.

Can we get color images on EM?

No, EM images are in grayscale.

Can we use antibodies with EM?

Yes, antibodies can be used with EM for specific labeling of targets.

What is a kEV and how does it relate to EM? Why aren’t higher kEV always better?

A kEV, or kilo-electron volt, is a unit of energy used to measure the accelerating potential of electrons in an electron microscope. Higher kEV can provide greater resolution but can also damage samples and introduce unwanted artifacts.

Why cant we use heavy metals when staining?

Blocks transmission of electrons where bound

Dark areas on an EM

Electron-dense

light areas on EM

Electron-lucent

Low mag EM

too zoomed out

High mad EM

too zoomed in

What is Ki-67 and what information does it provide?

Ki-67 is a protein that is associated with cell proliferation. It is used as a marker to determine the growth fraction of a given cell population, indicating how many cells are actively dividing.

What is mitotic index and how is it determined, and what information does it provide?

Mitotic index is a measure of the proportion of cells undergoing mitosis in a given cell population. It is determined by counting the number of cells in mitosis relative to the total number of cells, and it provides information about the rate of cell division and tissue growth.

Why don’t we typically use H&E on blood smears?

H&E staining can obscure important cellular details in blood smears, making it difficult to differentiate between specific cell types.

What is a mordant and what is the mordant in the H&E stain?

A mordant is a substance that helps fix a dye to a tissue, enhancing the staining process. In the H&E stain, the mordant is typically aluminum sulfate, which assists in the binding of the hematoxylin dye to nucleic acids.

What is the relationship between hematoxylin and hematein?

Hematoxylin is a natural dye derived from the logwood tree, while hematein is the oxidized form of hematoxylin. In histology, hematoxylin is used for staining, and it is converted to hematein during the staining process, allowing it to bind to nucleic acids in cells.

What is the difference between a progressive and regressive stain

A progressive stain allows tissues to be stained gradually, leading to consistent coloration, while a regressive stain over-stains the tissue initially and then is differentiated to achieve the desired level of staining.

microscopic autoradiography and in situ hybridization.

Microscopic autoradiography is a technique used to visualize the distribution of radioactively labeled substances in tissue sections, while in situ hybridization is a method for detecting specific nucleic acid sequences within fixed tissues or cells using labeled probes.

the various cell types that arise from the 3 embryonic layers

are referred to as germ layers. These include ectoderm, mesoderm, and endoderm, which give rise to different tissues and organs during development.

four main types of tissues in the body

epithelial, connective, muscle, and nervous tissue.

What is the most widely distributed tissue in the body, and what is the most widely distributed example of that tissue in the body?

Connective tissue; areolar tissue.

Understand the difference between the various epithelial cells we discussed. How does cell height affect function? How do layers affect function?

Epithelial cells vary in shape and arrangement, influencing their functions such as absorption, secretion, and protection. The height of the cells can affect their ability to transport materials, while the number of layers determines the level of protection and permeability.

Know generally where in the body the various tissues are found.

Epithelial tissues are found lining organs and surfaces, connective tissues support and bind other tissues, muscle tissues facilitate movement, and nervous tissues are located in the brain, spinal cord, and nerves.