Tissue Introduction
Overview
- Lecture begins with a short quiz on the four mature tissues in the body.
Types of Mature Tissues
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Epithelial Tissue
- Found lining and covering body structures.
- Examples: Skin, mouth lining, nostrils, vagina, esophagus, stomach, urethra.
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Connective Tissue
- Most abundant and diverse tissue in the body.
- Functions: Connects and supports organs.
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Muscular Tissue
- Allows for contraction and movement.
- Electrically excitable.
- Types: Smooth, cardiac, skeletal.
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Nervous Tissue
- Consists of cells that send electrical signals.
- Stimulates organs and structures for specific reactions.
Germ Tissues and Differentiation
- Differentiation: The process through which the four mature tissues arise from germ tissues.
Development Process
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Zygote Formation
- Sperm fertilizes an egg to form a zygote.
- Develops through mitosis into a gastrula (approx. 2 weeks into development).
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Gastrula
- A ball of cells with three layers (germ tissues).
- Three Germ Layers (Derm):
- Endoderm (innermost, yellow): Gives rise to epithelial tissues.
- Mesoderm (middle, red): Gives rise to some epithelial tissues, most muscle, and connective tissue.
- Ectoderm (outermost, blue): Gives rise to epithelial and nervous tissues.
Germ Tissues to Mature Tissues
- Epithelia can derive from all germ tissues.
- Important for testing: Know specific germ tissue origins for specific tissues (e.g., simple squamous).
Study Tip
- Remember: "Derm" rhymes with "Germ" to recall germ layers.
These notes capture the essential elements from the tissue introduction lecture, including the types of mature tissues, the concept of differentiation, and the role of germ layers in tissue development.