Questions and Answers
Which type of tissue primarily covers body surfaces and lines cavities?
Which tissue type is specifically responsible for movement in the body?
What is the main characteristic that differentiates connective tissue from other tissue types?
Which step is NOT part of the preparation process for tissue study?
Signup and view all the answers
What is the function of nerve tissue?
Signup and view all the answers
What is the primary function of cell differentiation during fetal development?
Signup and view all the answers
Which of the following statements about cells is accurate?
Signup and view all the answers
What is protoplasm primarily composed of?
Signup and view all the answers
Which tissue type is NOT one of the four basic tissue types mentioned?
Signup and view all the answers
How many nuclei do most cells typically have?
Signup and view all the answers
What is the primary function of fixatives in tissue processing?
Signup and view all the answers
Which fixative is commonly used for electron microscopy?
Signup and view all the answers
During the dehydration process, how is water extracted from the tissue?
Signup and view all the answers
What happens during the clearing stage of tissue processing?
Signup and view all the answers
What is the typical thickness for tissue sectioning in a microtome used for light microscopy?
Signup and view all the answers
Study Notes
The Cell: Fundamentals
- Cells are the basic structural and functional units of all living organisms.
- Approximately 40 trillion cells exist in the human body, which may be eukaryotic or prokaryotic.
- Most cells possess one nucleus; however, some can be multinucleated.
- Protoplasm, the living part of a cell, consists of the nucleus and cytoplasm, surrounded by a plasma membrane.
- Internal cell structure is often modified to reflect specific functions.
Cell Differentiation
- Differentiation begins with the zygote, which undergoes divisions leading to blastomeres and embryonic stem cells.
- Cell differentiation occurs in the fetus and is influenced by gene expression.
- Specific gene sets mediate cytoplasmic activities, positioning cells into specialized tissues.
Basic Tissue Types
- Four fundamental tissue types exist:
- Epithelial Tissue: Covers surfaces, lines cavities, and forms glands.
- Connective Tissue: Provides structural and functional support to other tissues, distinguished by its extracellular matrix.
- Muscle Tissue: Composed of contractile cells, enabling movement.
- Nervous Tissue: Responsible for receiving, transmitting, and integrating information, controlling body activities.
Visualization of Tissues
- Light microscopy is commonly utilized for visualizing tissue samples.
- Resolving power defines a microscope's ability to distinguish two close points.
- Specimens absorb visible light, which is focused and magnified by glass lenses.
Preparation of Tissues for Study
- Tissue preparation involves creating thin slices or sections for visual examination via transmitted light.
- Key steps in tissue preparation:
- Fixation: Preserves structure and prevents degradation; commonly involves buffered formaldehyde or glutaraldehyde for electron microscopy.
- Dehydration: Gradual extraction of water through increasing ethanol solutions.
- Clearing: Replacement of ethanol with an organic solvent that mixes with both alcohol and embedding media.
- Infiltration: Cleared tissue is immersed in melted paraffin at 52°-60°C, evaporating the clearing solvent.
- Embedding: Tissue is allowed to harden in paraffin at room temperature.
- Trimming: The hardened block is trimmed for microtome sectioning, typically at thicknesses of 3-10 micrometers for light microscopy.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the fundamentals of histology, focusing on the basic components of cells and the types of tissues. Get ready to delve into cell structure, tissue preparation, and the overall significance of cells in the human body. Perfect for beginners in the field of histology!
