Chapter 4
Tissues
I. Epithelia and Glands (pp. 69–81)
A. Epithelial sheets of tissue cover body surfaces and organs, and line body cavities; all functions reflect their role
as interface tissues and boundary layers.
B. Functions include: protection, sensory reception, secretion, absorption, ion transport, filtration, and formation
of slippery surfaces for substance movement.
C. Special characteristics of epithelium differentiate it from the other basic tissue types (p. 69, Fig. 4.1).
1. Cellularity
2. Specialized contacts
3. Polarity
4. Support by connective tissue
5. Avascular but innervated
6. Regeneration
D. Classification of Epithelia (pp. 69–76, Figs. 4.2–4.4, Table 4.1)
1. In classification, each epithelial tissue is identified by two names. The epithelial tissue’s first name indicates
the number of cell layers; its second name categorizes by cell shape.
2. In categorizing epithelial cells by shape, cells are recognized in three categories; squamous, cuboidal, and
columnar.
3. In classification by cell layers, simple epithelia have a single layer of cells and stratified epithelia have more
than one layer of cells.
a. Simple epithelia
i.
Simple squamous epithelium
ii. Simple cuboidal epithelium
iii. Simple columnar epithelium
iv. Pseudostratified columnar epithelium
b. Stratified epithelia
i.
Stratified squamous epithelium
ii. Stratified cuboidal epithelium
iii. Stratified columnar epithelium
iv. Transitional epithelium
E. Glands (pp. 76–77, Figs. 4.5–4.6)
1. Certain specialized epithelial cells make and secrete a product and are called glands.
2. Glands are classified as exocrine (with ducts), or endocrine (without ducts), as well as unicellular or
multicellular.
3. The only example of a one-celled exocrine gland is the goblet cell; its product is mucin, which combines
with water to form mucus.
4. Endocrine glands secrete hormones.
F. Epithelial tissues have specialized functional features associated with their lateral, basal, and apical surfaces.
(pp. 77–81, Figs. 4.7–4.8)
1. Cell junctions are lateral surface features that primarily bind adjacent cells to each other. The main types are
the tight junction, adherent junction (desmosome), and gap junction.
2. Features of the basal surface permit filtration and regeneration. The basal lamina separates the epithelium
and underlying connective tissues.
3. Apical surface features of epithelia are microvilli and cilia.
a. Microvilli increase surface area for absorption in the small intestines and other organs.
b. Cilia beat in coordinated waves to propel mucus and other substances across the epithelial surface.
II. Connective Tissue (pp. 83–93, Figs. 4.9–4.12)
A. Connective tissue is the most diverse and abundant type of tissue.
B. There are four main classes and many subclasses.
1. Connective tissue proper (loose and dense)
2. Cartilage
3. Bone tissue
4. Blood
C. Connective tissue has special characteristics.
1. It has relatively few cells with a large amount of extracellular matrix.
2. Matrix is composed of ground substance and fibers.
3. Common embryonic origin is mesenchyme.
D. Areolar connective tissue shares characteristics with many other connective tissue types. Thus, areolar
connective tissue is used as a connective tissue “model” to describe general functional and structural elements
of other connective tissues. (p. 83, Figs. 4.1–4.11)
1. General functional features of areolar connective tissue:
a. Supporting and binding
b. Holding tissue fluid
c. Defending against infection
d. Storing fat
E. Connective tissue proper has two primary subdivisions: loose connective tissue and dense connective tissue.
(pp. 83–88, Fig. 4.12, Table 4.2)
1. Loose connective tissues:
a. Areolar connective tissue (underlies almost all epithelial tissues)
b. Adipose connective tissue (contains fat)
c. Reticular connective tissue (found in bone marrow, the spleen, and lymph nodes)
2. Dense connective tissues:
a. Dense regular connective tissue (found in tendons, ligaments, and aponeuroses)
b. Dense irregular connective tissue (found in the dermis of skin and joint capsules)
F. Other connective tissues. (pp. 88–93, Fig. 4.12, Table 4.2)
1. Cartilage
2. Bone
3. Blood
III. Covering and Lining Membranes (pp. 93–94, Fig. 4.13)
A. Covering and lining membranes combine connective and epithelial tissues.
B. The three types of covering and lining membranes include cutaneous, serous, and mucous.
1. The cutaneous membrane is the skin, which is discussed further in Chapter 5.
2. Mucous membranes (mucosae) line the inside of every hollow internal organ system that opens to the
exterior of the body.
3. Serosae secrete watery fluid and line the closed pleural, pericardial, and peritoneal cavities.
IV. Muscle Tissue (pp. 94–96, Fig. 4.14)
A. There are three basic types of muscle tissue: skeletal, cardiac, and smooth muscle tissues.
V. Nervous Tissue (p. 96, Fig. 4.15)
A. Nervous tissue is the main component of the brain, spinal cord, and nerves. The characteristic cells are neurons
and supporting cells.
VI. Tissue Response to Injury (pp. 96–98, Fig. 4.16)
A. Once the epithelia and connective tissues are penetrated, the body reacts with inflammatory and immune
responses.
B. Tissue repair occurs in two major ways: regeneration and fibrosis.
VII. The Tissues Throughout Life (pp. 98–101, Fig. 4.17)
A. Most epithelium and nervous tissue are derived from embryonic epithelia, the ectoderm, and endoderm.
B. Mesodermal mesenchyme is the origin of endothelium, mesothelium, connective tissue, and muscle tissue.
C. Poor nutrition and circulatory deficits contribute to declining tissue function with aging.
SUPPLEMENTAL STUDENT MATERIALS to Human Anatomy,
Fifth Edition
Chapter 4: Tissues
To the Student
By focusing on the relationship between cellular organization and tissue function, learning the major characteristics of
each tissue type is easily accomplished. Since most organs contain all four basic tissue types, understanding tissue
interactions permits you to better understand the organization and specific functions of organs and systems in the
human body.
Step 1: Distinguish between the four main types of tissue in the human body.
- Define tissue.
- List four main types of tissue and examples of each.
Step 2: Distinguish between the different types of epithelia of the body.
- Devise an epithelial classification scheme based on the shape of a cell and the number of
cell layers.
- List and describe the characteristics unique to epithelial tissue.
- Relate cell shape and number of layers to functions of epithelial tissue.
- Incorporate specific examples of cell locations into your classification scheme.
- List and describe three specific epithelial surface features, including detailed examples of each.
- Define gland.
- Explain why glands are included with epithelium.
- Explain the difference between endocrine and exocrine glands, including examples.
- Devise a simple classification scheme for glands based on cellularity, including duct structure and secretory units
structure. Refer to Figure 4.6.
- Describe the goblet cell and its important glandular role.
Step 3: Distinguish between the types of connective tissues.
- Name and describe basic components of connective tissue.
- List functions of connective tissue.
- Devise a summary outline for the four major types of connective tissues, including subtypes.
- For each type of connective tissue in your summary outline, list specific associated cells.
- For each type of connective tissue in your summary outline, list specific fibers and describe mechanical properties.
- Also, for each type of connective tissue, discuss properties of the extracellular matrix and the nature of the ground
substance.
- Explain important functions of tissue fluid.
Step 4: Distinguish between covering and lining membranes.
- Define and illustrate cutaneous membrane.
- Define and give examples of mucous membranes.
- Explain how mucus is moved along the membrane surface.
- Review the goblet cell and mucus production using Figure 4.5.
- Review Chapter 2 and summarize the roles of the rough ER, Golgi apparatus and secretory vesicles in goblet cells.
- Define and give examples of serous membrane.
- Explain the difference between visceral and parietal serosa.
- Explain how cutaneous, serous, and mucous membranes are compositions of epithelium and connective tissues.
Step 5: Distinguish between three types of muscle tissue.
- Devise a chart to compare skeletal, smooth, and cardiac muscle tissues in terms of the following characteristics:
•
Cell shape
•
Number of nuclei
•
Cell arrangement
•
Striations present/absent
•
Intercalated discs present/absent
•
Locations in body
•
Functions
•
Type of nervous control
Step 6: Describe the nature of nervous tissue.
- Define neuron.
- Define supporting cells.
- Explain the function of nervous tissue.
Step 7: Understand tissue response to injury.
- Explain inflammation.
- Describe tissue repair.
Step 8: Distinguish the embryonic origins of the four basic tissue types.
- Name tissues derived from mesenchyme, mostly of the mesoderm germ layer.
- Name tissues derived from endoderm.
- Name tissues derived from ectoderm.
- Discuss the significance of stem cells.