One of the key differences between histology and cytology is that histology is a branch of biology that studies about tissues of animals and plants under the microscope while cytology is another branch of biology that studies cells under the microscope. Moreover, histological studies are broader, more detailed and more expensive than cytological studies.
Every living organism on earth constitutes of either a cell or a collection of cells except viruses. The cell is the smallest structural and functional unit of an organism. A tissue is a group of cells that perform a common function and has a similar origin. Different kinds of tissues work together and form an organ. An organ system is a collection of organs. Likewise, the animal or plant body comprises different levels of organizations with the increasing complexity of each level from cells to organ systems to organisms. Hence, unicellular organisms have simple structures while most multicellular organisms have very complex structures. Histology and cytology are two branches of biology that study the tissues of animals and plants and cells microscopically.
CONTENTS
1. Overview and Key Differences
2. What is Histology
3. What is Cytology
4. Similarities Between Histology and Cytology
5. Side by Side Comparison – Histology vs Cytology in Tabular Form
6. Summary
What is Histology?
Histology is the study of the structure and function of the microscopic anatomy of plants and animals. Microscopic anatomy includes the cells, tissues, organs and organ systems of an organism. These studies are mainly carried out by examining the cells and tissues under the microscope.
Figure 01: Histology
Initially, the biologist selects a particular part of an organ which should be studied. Then using an appropriate stain, he stains the tissue and mounts it on a microscopic slide. Next, using a light or electron microscope, he examines the stained tissue under the microscope and records the necessary observations. Hence, microscopes are important and are the basic tools in histological studies. Histological stains are also very important as they enhance the ability to visualize and differentiate microscopic structures.
What is Cytology?
Cytology is a branch of biology that focuses on the study of the structure and function of cells. Hence, cytology deals directly with the structural and functional organization of cells and also with other phenomena such as metabolism, ontogenetic differentiation, heredity, and phylogeny. Furthermore, cytological studies cover areas of physiological properties, signaling pathways, life cycle, chemical composition and interactions of the cell with their environment. All these cytological studies are done at the microscopic and molecular level.
Figure 02: Cytology
Cytological studies began with the English scientist Robert Hooke’s microscopic investigations. Then, cytology expanded into studies covered under the electron microscope for more and tiny details of the cells.
What are the Similarities Between Histology and Cytology?
- Histology and cytology are two branches of biology.
- Both studies about the anatomy of the organisms
- Also, both use a microscope for the observations.
What are the Differences Between Histology and Cytology?
Histology and cytology are two types of studies in biology. In histology, we mainly examine the tissue architecture of particular tissue while in cytology, we go only for the cellular level. Hence, the study of cellular structure and function is called cytology, while the study of cells and tissues in an organism is called histology. These are the key differences between histology and cytology.
Moreover, cytology mainly aims the cells. Therefore, cytological observations have excellent cellular details, unlike histological observations. On the other hand, tissue details are present only in histology while details of tissue architecture cannot be observed in cytology. These are the major differences between histology and cytology. Furthermore, the cost of doing each is also one of the notable differences between histology and cytology. That is; the cost of histological studies are higher than that of cytology.
Summary – Histology vs Cytology
Histology is the examination of tissues under the microscope while cytology is the examination of cells under the microscope. Histology provides excellent details of tissue architecture while cytology provides excellent cellular details. However, histological studies are wider than cytological studies. Hence, histological studies are more costly than cytological studies. But both types of studies are important branches of biology. Thus, this summarizes the differences between histology and cytology.
Reference:
1. “Histology.” Wikipedia, Wikimedia Foundation, 8 Feb. 2019, Available here.
2. Britannica, The Editors of Encyclopaedia. “Cytology.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 20 Nov. 2018, Available here.
Image Courtesy:
1. “Emphysema H and E” (CC BY 2.0) via Commons Wikimedia
2. “Granuloma cytology” By Nephron – Own work (CC BY-SA 3.0) via Commons Wikimedia