Histology Lab

Histology is the study of tissues, which are groups of cells that work together to perform specific functions. Tissues are the building blocks of organs, and the understanding of their structure is essential to the study of human anatomy.  We will be exploring the 4 classes of tissues; epithelial, connective, nervous, and muscular tissues.

We will be using microscopes to observe tissues at the cellular level. We will also be using our devices (cellphone, tablet, etc.) to capture micrographs of the tissues we observe. This will enable us to document our observations and refer back to them as needed. We will also be drawing the tissues we observe to further enhance our understanding of their structure.

During the laboratory session, we will be identifying and describing different types of tissues. We will examine and describe the properties of epithelial, connective, muscle, and nervous tissues. We will learn to differentiate between these tissue types based on their cellular structure and function.

To help us identify and describe the tissues we observe, we will be using histology slides. These slides are prepared using special techniques that preserve the tissues and allow us to observe them under a microscope. We will learn to use staining techniques to enhance the contrast and visibility of the tissues.

This laboratory is an essential part of our study of anatomy. Through our exploration of histology, we will gain a deeper understanding of the structure and function of tissues, which will be invaluable as we continue our study of human anatomy. 

Objectives

·         Identify and describe the four classes of tissues: epithelial, connective, nervous, and muscular tissues.

·         Observe tissues at the cellular level using microscopes and document observations through micrographs captured with devices.

·         Develop skills in drawing tissues to enhance understanding of their structure.

·         Differentiate between different types of tissues based on their cellular structure and function.

·         Learn to use staining techniques to enhance the contrast and visibility of tissues on histology slides.

·         Gain a deeper understanding of the structure and function of tissues, which will contribute to the study of human anatomy.

·         Practice effective communication of histological observations and descriptions.

Table 1: Histological Tissues Classified

Materials


·         Light Microscope

·         Full set of human histology slides

·         Device (cellphone, tablet, microscope camera, etc.)


Micrograph Procedure

1.   Clean the microscope lens with a lens cleaning solution and cloth.

2.   Place the specimen slide onto the microscope stage and focus the microscope on the specimen using the appropriate magnification.

3.   Position the cellphone or tablet camera lens directly above the microscope eyepiece.

4.   Hold the cellphone or tablet steady and adjust the focus until the specimen is in clear view on the device screen.

5.   Take the photo by pressing the camera button on the device or tapping the screen.

6.   Review the image on the device to ensure it is in focus and of sufficient quality. If necessary, adjust the focus and retake the photo.

7.   If desired, use photo editing software to enhance the image.

8.   Save the image for future reference or analysis.

9.   Clean the microscope lens with a lens cleaning solution and cloth after use.

Note: It is important to use caution when using a cellphone or tablet to take micrographs, as the quality of the image may be lower than that obtained with a dedicated microscope camera. Additionally, ensure that the camera lens is clean and free of debris before taking the photo to avoid distortion or other artifacts in the image.

Epithelial Tissue Descriptions and Structures

Look at a slide of Simple Squamous Epithelium.  This tissue may be alone, as in the lung, or coupled with other types of tissues, as will hollow organs.


Provide a description of Simple Squamous Epithelium structure (including features, surroundings, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 

 


Look at a slide of Simple Cuboid Epithelium.  This tissue is mostly found around glands and forming ducts.


Provide a description of Simple Cuboid Epithelium structure (including features, surroundings, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Simple Columnar Epithelium.  This tissue may have cilia or not based on location and function.


Provide a description of Simple Columnar Epithelium structure (including features, surroundings, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Transitional Epithelium.  This tissue changes shape due to pressures and stress.  Relaxed, this tissue looks bubbled and rounded.  Stretched, this tissue looks squamous.


Provide a description of Transitional Epithelium structure (including features, surroundings, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Pseudostratified Columnar Epithelium.  This tissue appears to have two lines of nuclei, but each cell reaches fully across the tissue.


Provide a description of Pseudostratified Columnar Epithelium structure (including surroundings, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Stratified Squamous, Non-Keratinized Epithelium.  This tissue has visible nuclei and found at moist openings to the body.


Provide a description of Stratified Squamous, Non-Keratinized Epithelium structure (including features, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Stratified Squamous, Keratinized Epithelium.  This tissue has many layers of dead cells and have no nuclei in the outer layers.


Provide a description of Stratified Squamous, Keratinized Epithelium structure (including features, function, growth, and repair).
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Stratified Cuboidal Epithelium.  This tissue is used in major glands providing thicker walls to the ducts.


Provide a description of Stratified Cuboidal Epithelium structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Stratified Columnar Epithelium.  This tissue is rare, but found mostly in the male urethrae.


Provide a description of Stratified Columnar Epithelium structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 



 

Connective Tissue Descriptions and Structures

Look at a slide of Areolar Proper Loose Connective Tissue.  This tissue is very common.  It looks like various fibers randomly crossing.


Provide a description of Areolar Proper Loose Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Reticular Proper Loose Connective Tissue.  This tissue is recognized by the thick protein branches stretching through the tissue.


Provide a description of Reticular Proper Loose Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Adipose Proper Loose Connective Tissue.  This tissue is very faint in microscopic observation, only membranes and nuclei are visible.


Provide a description of Adipose Proper Loose Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Dense Regular Proper Connective Tissue.  This tissue has a regular pattern that makes it recognizable, but at times confused with smooth muscle.


Provide a description of Dense Regular Proper Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Dense Irregular Proper Connective Tissue.  This tissue is found in the dermis and has random fibers mixing in all directions.


Provide a description of Dense Irregular Proper Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Elastic Proper Dense Connective Tissue.  This tissue found through the body, but largely in the walls of arteries, allowing stretch.


Provide a description of Elastic Proper Dense Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Hyaline Cartilage Connective Tissue.  This tissue is a hardened structure with chondrocytes often pairing together.


Provide a description of Hyaline Cartilage Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Fibrocartilage Connective Tissue.  This tissue is similar to hyaline cartilage but adds wavy fibrin between the chondrocytes.


Provide a description of Fibrocartilage Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Elastic Cartilage Connective Tissue.  This tissue is found in places like the ear were the structure is harder, but flexible due to elastin.


Provide a description of Elastic Cartilage Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Compact Bone Connective Tissue.  This tissue is found in the cortex layers of all bones, and thickened layers in the shaft of long bones.


Provide a description of Compact Bone Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Spongy Bone Connective Tissue.  This tissue is encased by compact bone due to its fragile construction.


Provide a description of Spongy Bone Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Blood Connective Tissue.  This tissue is the only fluid connective tissue, but still has a ground substance, cells, and proteins.


Provide a description of Blood Connective Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Muscle Tissue Descriptions and Structures

Look at a slide of Skeletal Muscle Tissue.  This tissue the most striations of any muscle, creating a regular repeating pattern.


Provide a description of Skeletal Muscle Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Cardiac Muscle Tissue.  This tissue is less uniformed than skeletal, but still has visible striations.


Provide a description of Cardiac Muscle Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Look at a slide of Smooth Muscle Tissue.  This tissue looks similar to dense regular, but the nuclei in smooth muscle are much rounder.


Provide a description of Smooth Muscle Tissue structure (including features and surroundings) function, growth, and repair.
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 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 


Nervous Tissue Descriptions and Structures

Look at a slide of Nervous Tissue.  This tissue may look very messy depending on how it was prepared.  Motor neurons typically provide a nice image with near triangular shaped cells and large axons.


Provide a description of Nervous Tissue structure (including features and surroundings) function, growth, and repair.
 _____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
 Take a micrograph with your device then draw the tissue, detailing cell shape and surroundings

 



 


Review Questions

1.       What is the smallest unit of organization in the human body?
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2.       How does the structure of smooth muscle differ from skeletal muscle?
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3.       How does the structure of the respiratory epithelium facilitate gas exchange in the lungs?
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4.       How does the structure of the kidney nephron allow for the filtration and reabsorption of blood?
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5.       What are the different types of cells found in the nervous system, and how do they function together to transmit information?
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6.       How do the various layers of skin work together to protect the body from external threats?
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7.       What is the name of the process by which bone is formed?
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8.       How does the structure of bone contribute to its strength and resilience?
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9.       How does the structure of the digestive tract allow for the efficient absorption of nutrients?
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10.    How does the structure of the heart contribute to its ability to pump blood efficiently?
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