Tissues and Membranes
BIOL 2010 ANATOMY AND PHYSIOLOGY I
Chapter 4: TISSUES AND MEMBRANES
Outline of Notes
I. Introduction.
A. General:
Cells are highly specialized and interdependent on one another.
Groups of similar cells performing similar functions are called Tissues
The study of tissues is called Histology.
Organs are made of tissues. A detailed understanding of tissues will greatly help your understanding of organs and organ systems later in this course.
Tissues are classified into 4 main types: Epithelial, Connective, Muscular and Nervous.
B. Cell Junctions (fig 4-2, p.109)
There are three specialized junctions between cells. These are important in all tissues, but are most common in epithelial tissues. 1. Tight Junctions: no leakage between cells 2. Gap (Communication) Junctions: Channels connect cytoplasm 3. Adhering Junctions: proteins connect cytoskeleton to external structures -Desmosomes: Cells to Cells -Hemidesmosomes: Cells to extra-cellular fibers
II. Epithelial Tissues (Linings and Coverings; Glands)
A. General Characteristics of Epithelia:
Function in protection, absorption and secretion.
Consist of closely packed cells with specialized contacts
Have an Apical (free) Surface and a Basal lamina Innervated but avascular: nutrients must come from underlying tissues. Capable of Regeneration (high rate of mitosis)
B. Specializations of Epithelia: -Cilia: Aid in movement of extracellular material -Microvilli: Increased surface area to increase absorption/secretion
C. Classification: Classified by shape/arrangement.
Types: Function: Common Locations: Simple Squamous Exchange Lungs, Capillaries Simple Cuboidal Secretion/Absorption Kidneys
Simple Columnar Absorption/Secretion Digestive Tract
Pseudo-Stratified Columnar Protection (mucus) Respiratory Tract Stratified Squamous Protection (layers) Skin, Esophagus
Stratified Cuboidal Secretion (glandular)
Chapter 4: TISSUES AND MEMBRANES
Outline of Notes
I. Introduction.
A. General:
Cells are highly specialized and interdependent on one another.
Groups of similar cells performing similar functions are called Tissues
The study of tissues is called Histology.
Organs are made of tissues. A detailed understanding of tissues will greatly help your understanding of organs and organ systems later in this course.
Tissues are classified into 4 main types: Epithelial, Connective, Muscular and Nervous.
B. Cell Junctions (fig 4-2, p.109)
There are three specialized junctions between cells. These are important in all tissues, but are most common in epithelial tissues. 1. Tight Junctions: no leakage between cells 2. Gap (Communication) Junctions: Channels connect cytoplasm 3. Adhering Junctions: proteins connect cytoskeleton to external structures -Desmosomes: Cells to Cells -Hemidesmosomes: Cells to extra-cellular fibers
II. Epithelial Tissues (Linings and Coverings; Glands)
A. General Characteristics of Epithelia:
Function in protection, absorption and secretion.
Consist of closely packed cells with specialized contacts
Have an Apical (free) Surface and a Basal lamina Innervated but avascular: nutrients must come from underlying tissues. Capable of Regeneration (high rate of mitosis)
B. Specializations of Epithelia: -Cilia: Aid in movement of extracellular material -Microvilli: Increased surface area to increase absorption/secretion
C. Classification: Classified by shape/arrangement.
Types: Function: Common Locations: Simple Squamous Exchange Lungs, Capillaries Simple Cuboidal Secretion/Absorption Kidneys
Simple Columnar Absorption/Secretion Digestive Tract
Pseudo-Stratified Columnar Protection (mucus) Respiratory Tract Stratified Squamous Protection (layers) Skin, Esophagus
Stratified Cuboidal Secretion (glandular)