Types of Microscopes and Histology Units

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Questions and Answers

What type of granules are found in nerve cells that can be highlighted using Toluidine blue stain?

Nissl granules (correct)

Mitochondrial granules

Glycogen granules

Mast granules

Which cells contain exogenous and endogenous granules?

Muscle cells

Liver cells

Macrophages (correct)

Skin cells

What type of acini are associated with mucous secretion?

Skeletal acini

Mucous acini (correct)

Serous acini

Pancreatic acini

Which structures are primarily stained by the Silver stain technique?

Motor-end plate Signup and view all the answers

Which type of cells are characterized by the presence of pigment granules?

Skin cells Signup and view all the answers

What type of tissue is specifically mentioned to have different types of epithelium?

Epithelial tissue Signup and view all the answers

What type of cells is primarily involved in the formation of blood platelets?

Megakaryocytes Signup and view all the answers

Which structure is characterized by the presence of rough endoplasmic reticulum?

Pancreatic acini Signup and view all the answers

What is the relationship between centimeters and millimeters?

1 cm = 10 mm Signup and view all the answers

Which part of the Light Microscope is responsible for magnification?

Eye Pieces Signup and view all the answers

What is the purpose of cedar oil in microscopy?

To increase clarity when using the oil immersion objective Signup and view all the answers

What is the maximum magnification achievable using a Transmission Electron Microscope?

How do you calculate the total magnification of a histological section using a Light Microscope?

Eyepiece power multiplied by objective power Signup and view all the answers

What type of image does a Scanning Electron Microscope provide?

3-dimensional Signup and view all the answers

Which of the following microscopes offers the highest magnification?

Atomic Force Microscope Signup and view all the answers

What characterizes the Oil Immersion Objective in a Light Microscope?

Requires immersion in a liquid for clarity Signup and view all the answers

What is the primary objective of the histology textbook?

To provide a detailed overview for both undergraduate and postgraduate medical students. Signup and view all the answers

Which significant enhancement was notably included in the new edition of the book?

Inclusion of a number of electron micrographs. Signup and view all the answers

How does the textbook approach the relationship between structure and function?

By emphasizing its significance at both optical and ultra-structural levels. Signup and view all the answers

What aspect of genetics does the textbook focus on?

Normal and abnormal cell divisions and genomic studies. Signup and view all the answers

What has been improved in the new edition concerning illustrations?

The number and quality of illustrations have been increased. Signup and view all the answers

What is one of the new inclusions in the textbook that reflects current trends in medicine?

Genetic and genomic studies. Signup and view all the answers

Who contributed significantly to the book aside from the author?

The author's wife. Signup and view all the answers

The new edition makes efforts to provide what type of illustrations?

Coloured illustrations that aid in slide examination. Signup and view all the answers

What is the function of neurotransmitter receptors found in the postsynaptic membrane?

They bind neurotransmitters to facilitate signal transmission. Signup and view all the answers

Which type of connective tissue surrounds the entire nerve trunk?

Epineurium Signup and view all the answers

What is a unique feature of spinal ganglia?

They are comprised of pseudo-unipolar nerve cells. Signup and view all the answers

What effect does the arrival of a nerve impulse have at the synapse?

It causes the discharge of the chemical transmitter. Signup and view all the answers

Which type of ganglion is characterized by stellate-shaped nerve cells?

Sympathetic ganglia Signup and view all the answers

What happens to the myelin sheath during staining with osmic acid?

It stains black. Signup and view all the answers

What is the role of satellite cells surrounding nerve cells in ganglia?

They support and protect the nerve cells. Signup and view all the answers

What forms the central structure within each nerve fiber in a stained transverse section of a nerve trunk?

Centrally stained axon Signup and view all the answers

What type of nerve cells predominantly compose spinal ganglia?

Pseudo-unipolar nerve cells Signup and view all the answers

Which of the following statements accurately describes sympathetic ganglia?

They are rich in blood supply. Signup and view all the answers

How are the nerve cells in spinal ganglia arranged compared to those in sympathetic ganglia?

In organized rows or groups Signup and view all the answers

What separates the nerve cells in sympathetic ganglia?

Non-myelinated nerve fibers Signup and view all the answers

What role do ependymal cells play in the central nervous system?

Producing cerebrospinal fluid Signup and view all the answers

Which type of neuroglia is responsible for supporting the neuron population in the central nervous system?

Astrocytes Signup and view all the answers

What feature distinguishes the shape of nerve cells in spinal ganglia from those in sympathetic ganglia?

Nerve cells in spinal ganglia are rounded, while those in sympathetic ganglia are irregular. Signup and view all the answers

Which characteristic is true regarding the number of satellite cells in spinal ganglia compared to sympathetic ganglia?

There are more satellite cells around each nerve cell in spinal ganglia. Signup and view all the answers

Study Notes

### Types of Microscopes

Light Microscope (LIM):
- Uses daylight or electric light for illumination
- Magnifies objects up to 450 times
- Different magnifying powers available (5x, 10x, 15x)
Electron Microscope (EM):
- Utilizes a beam of electrons for illumination
- Produces highly magnified images (up to 100,000 times)
Scanning Electron Microscope:
- Creates 3D images of examined samples (e.g., red blood cells, cilia)
Atomic Force Microscope:
- Magnifies fresh tissues up to 500,000 times

Measuring Units in Histology

1 centimeter (cm) = 10 millimeters (mm)
1 millimeter (mm) = 1000 micrometers (µm) or 1000 microns (µ)
1 micrometer (µm) = 1000 nanometers (nm)
1 nanometer (nm) = 10 Angstroms (Å)

### Neuroglia

Supporting tissue of CNS, instead of connective tissue
Stainable with silver or gold chloride

Neuroglia Types

Neuroglia Proper:
- Macroglia (Astrocytes): Protoplasmic and Fibrous
- Microglia (Mesoglia): Mesodermal origin
- Oligodendroglia: Few dendrites
Other Supporting Cells:
- Ependymal Cells:
  - Simple cuboidal, ciliated cells lining the spinal cord's central canal and brain ventricles
  - Derived from spongioblast cells
  - Produce Cerebrospinal Fluid (CSF)
- Satellite Cells:
  - Small cells surrounding nerve cells in the brain and ganglia

### Synapse Structure

Pre-synaptic membrane: Neuron's axon terminal
Synaptic cleft: Space between pre and post synaptic membranes
Post-synaptic membrane: Neuron's dendrites with neurotransmitter receptors
Gemmules or Spines: Small projections from pre and post synaptic membranes

Synapse Functions

Arrival of nerve impulse releases chemical transmitter into the synaptic cleft - Transmitted information either excites or inhibits the post-synaptic membrane

### Peripheral Nerve Trunk Structure

Axons bundled together
Surrounded by connective tissue (CT)
Epineurium: Outer CT fascia
Endoneurium (Henle's sheath): CT surrounding each axon
Myelin sheaths appear black with osmic acid stain

### Nerve Ganglia

Collections of nerve cells and fibers surrounded by CT
Types: Spinal and Autonomic (Sympathetic and Parasympathetic)

Spinal Ganglia

Located at both sides of the spinal cord
Relay sensations
Contain pseudo-unipolar nerve cells
Each neuron has a convolution called a glomerulus
Surrounded by satellite cells
Covered by a thick capsule

Sympathetic Ganglia

Form a sympathetic chain or isolated ganglia throughout the body
Relay motor functions from spinal cord to body organs
Contain multipolar, stellate-shaped nerve cells

Differences Between Spinal and Sympathetic Ganglia

Spinal Ganglia:
- Located at dorsal roots of spinal cord
- Thick CT capsule
- Pseudo-unipolar cells
- Large or small cells (20-120 µm)
- Cells in groups or rows
- Groups separated by myelinated nerve fibers
- Rounded cells in cross section
- Few cells per ganglion
- Axons convoluted at beginning, forming a glomerulus
- More satellite cells
- No synapse between neurons
- Poor blood supply
Sympathetic Ganglia:
- Located at sympathetic chain
- Thin CT capsule
- Multipolar, stellate-shaped cells
- Mostly small cells (30 µm)
- Scattered cells
- Cells separated by non-myelinated nerve fibers
- Irregular cells in cross section
- Many cells per ganglion
- No intracellular glomerulus
- Fewer satellite cells
- Synapse between neurons
- Rich blood supply

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Description

This quiz covers the various types of microscopes used in biological sciences, including light, electron, scanning electron, and atomic force microscopes. It also addresses measuring units relevant to histology and the types of neuroglia in the central nervous system. Test your knowledge on these essential topics in microscopy and histology!