Module Three
,Knowledge Acquisition
Tissues and Homeostasis
A cell is a complex collection of compartments, each of which carries out a host of
biochemical reactions that make life possible. However, a cell seldom functions as an
isolated unit in the body. Instead, cells usually work together in groups called tissues.
The structure and properties of a specific tissue are influenced by factors such as the nature
of the extracellular material that surrounds the tissue cells and the connections between
the cells that compose the tissue. Tissues may be hard, semisolid, or even liquid in their
consistency. In addition, tissues vary tremendously with respect to the kinds of cells
present, how the cells are arranged, and the type of extracellular material.
The four basic types of tissues in the human body (figure 3-1) – epithelial, connective,
muscle, and nervous tissues – contribute to homeostasis by providing diverse functions
including protection, support, communication among cells, and resistance to disease, to
name just a few.
Source: Principles of Anatomy and Physiology by Brian H. Derrickson and Gerard J. Tortora
Section 3-1: Types of Tissues
What is expected of you from this section?
At the end of this section, you are expected to:
1. Name the four basic types of tissues that make up the human body
2. Describe the characteristics of each tissue
Where do you acquire knowledge to meet expectations?
1. .
2. Course Notes 3-1
Course Notes 3-1
A tissue is a group of cells that usually have a common origin in an embryo and function Figure 3-1. Four Basic Types of Tissues. Each of the four types of tissues has dif
together to carry out specialized activities. that vary in shape, structure, function, and distribution. Source: Principles of An
Physiology by Brian H. Derrickson and Gerard J. Tortora.
,Histology (his′-TOL-oˉ-jē; histo- = tissue; -logy = study of) is the science that deals with the • Only a few cells, such as phagocytes, move freely through the body, s
study of tissues. invaders to destroy.
• However, many cells migrate extensively during the growth and developm
A pathologist (pa-THOL-oˉ -jist; patho- = disease) is a physician who examines cells and tissues before birth.
to help other physicians make accurate diagnoses.
Clinical Correlation 3-1
Body tissues are classified into four basic types according to their structure and function
(figure 3-1): Biopsy
Epithelial Tissue (figure 3-1a) A biopsy (BI--op-sē; bio- = life; -opsy = to view) is the removal of a sample of l
• Epithelial tissue covers body surfaces and lines hollow organs, body cavities, and ducts. for microscopic examination. This procedure is used to helpdiagnose many
• it also forms glands. especially cancer, and to discover the cause of unexplained infections and infla
• This tissue allows the body to interact with both its internal and external environments. Both normal and potentially diseased tissues are removed for purposes of c
Once the tissue samples are removed, either surgically or through a needle a
they may be preserved, stained to highlight special properties, or cut into thin
Connective Tissue (figure 3-1b)
microscopic observation. Sometimes a biopsy is conducted while a patient is a
• Connective tissue protects and supports the body and its organs.
during surgery to help a physician determine the most appropriate treatment. F
• Various types of connective tissues bind organs together, store energy reserves as fat, if a biopsy of thyroid tissue reveals malignant cells, the surgeon can proceed im
and help provide the body with immunity to disease-causing organisms. with the most appropriate procedure.
Muscular Tissue (figure 3-1c) Source: Principles of Anatomy and Physiology by Brian H. Derrickson and Gerard
• Muscular tissue is composed of cells specialized for contraction and generation of force.
• In the process, muscular tissue generates heat that warms the body.
Self-Assessment 3-1
Nervous Tissue (figure 3-1d) 1. Define a tissue.
• Nervous tissue detects changes in a variety of conditions inside and outside the body and 2. What are the four basic types of human tissues?
responds by generating electrical signals called nerve action potentials (nerve impulses) 3. What are some differences in function among the four tissue types?
that activate muscular contractions and glandular secretions.
Epithelial tissue and most types of connective tissue, except cartilage, bone, and blood, are
more general in nature and have a wide distribution in the body.
• These tissues are components of most body organs and have a wide range of structures
and functions.
Normally, most cells within a tissue remain anchored to other cells or structures.
, Section 3-2: Cell Junctions
What is expected of you from this section? Figure 3-2. Five main types of cell junctions. Most epithelial cells and some muscle and ne
At the end of this section, you are expected to: contain cell junctions. Source: Principles of Anatomy and Physiology by Brian H. Derrick
1. Describe the structure of the five main types of cell junctions Gerard J. Tortora.
2. Discuss the functions of the five main types of cell junctions.
Where do you acquire knowledge to meet expectations?
1. .
2. Course Notes 3-2
Course Notes 3-2
Most epithelial cells and some muscle and nerve cells are tightly joined into
functional units.
Cell junctions are contact points between the plasma membranes of tissue cells.
Five most important types of cell junctions (figure 3-2):
• Tight junctions
• Adherens junctions
• Desmosomes
• Hemidesmosomes
• Gap junctions
,Knowledge Acquisition
Tissues and Homeostasis
A cell is a complex collection of compartments, each of which carries out a host of
biochemical reactions that make life possible. However, a cell seldom functions as an
isolated unit in the body. Instead, cells usually work together in groups called tissues.
The structure and properties of a specific tissue are influenced by factors such as the nature
of the extracellular material that surrounds the tissue cells and the connections between
the cells that compose the tissue. Tissues may be hard, semisolid, or even liquid in their
consistency. In addition, tissues vary tremendously with respect to the kinds of cells
present, how the cells are arranged, and the type of extracellular material.
The four basic types of tissues in the human body (figure 3-1) – epithelial, connective,
muscle, and nervous tissues – contribute to homeostasis by providing diverse functions
including protection, support, communication among cells, and resistance to disease, to
name just a few.
Source: Principles of Anatomy and Physiology by Brian H. Derrickson and Gerard J. Tortora
Section 3-1: Types of Tissues
What is expected of you from this section?
At the end of this section, you are expected to:
1. Name the four basic types of tissues that make up the human body
2. Describe the characteristics of each tissue
Where do you acquire knowledge to meet expectations?
1. .
2. Course Notes 3-1
Course Notes 3-1
A tissue is a group of cells that usually have a common origin in an embryo and function Figure 3-1. Four Basic Types of Tissues. Each of the four types of tissues has dif
together to carry out specialized activities. that vary in shape, structure, function, and distribution. Source: Principles of An
Physiology by Brian H. Derrickson and Gerard J. Tortora.
,Histology (his′-TOL-oˉ-jē; histo- = tissue; -logy = study of) is the science that deals with the • Only a few cells, such as phagocytes, move freely through the body, s
study of tissues. invaders to destroy.
• However, many cells migrate extensively during the growth and developm
A pathologist (pa-THOL-oˉ -jist; patho- = disease) is a physician who examines cells and tissues before birth.
to help other physicians make accurate diagnoses.
Clinical Correlation 3-1
Body tissues are classified into four basic types according to their structure and function
(figure 3-1): Biopsy
Epithelial Tissue (figure 3-1a) A biopsy (BI--op-sē; bio- = life; -opsy = to view) is the removal of a sample of l
• Epithelial tissue covers body surfaces and lines hollow organs, body cavities, and ducts. for microscopic examination. This procedure is used to helpdiagnose many
• it also forms glands. especially cancer, and to discover the cause of unexplained infections and infla
• This tissue allows the body to interact with both its internal and external environments. Both normal and potentially diseased tissues are removed for purposes of c
Once the tissue samples are removed, either surgically or through a needle a
they may be preserved, stained to highlight special properties, or cut into thin
Connective Tissue (figure 3-1b)
microscopic observation. Sometimes a biopsy is conducted while a patient is a
• Connective tissue protects and supports the body and its organs.
during surgery to help a physician determine the most appropriate treatment. F
• Various types of connective tissues bind organs together, store energy reserves as fat, if a biopsy of thyroid tissue reveals malignant cells, the surgeon can proceed im
and help provide the body with immunity to disease-causing organisms. with the most appropriate procedure.
Muscular Tissue (figure 3-1c) Source: Principles of Anatomy and Physiology by Brian H. Derrickson and Gerard
• Muscular tissue is composed of cells specialized for contraction and generation of force.
• In the process, muscular tissue generates heat that warms the body.
Self-Assessment 3-1
Nervous Tissue (figure 3-1d) 1. Define a tissue.
• Nervous tissue detects changes in a variety of conditions inside and outside the body and 2. What are the four basic types of human tissues?
responds by generating electrical signals called nerve action potentials (nerve impulses) 3. What are some differences in function among the four tissue types?
that activate muscular contractions and glandular secretions.
Epithelial tissue and most types of connective tissue, except cartilage, bone, and blood, are
more general in nature and have a wide distribution in the body.
• These tissues are components of most body organs and have a wide range of structures
and functions.
Normally, most cells within a tissue remain anchored to other cells or structures.
, Section 3-2: Cell Junctions
What is expected of you from this section? Figure 3-2. Five main types of cell junctions. Most epithelial cells and some muscle and ne
At the end of this section, you are expected to: contain cell junctions. Source: Principles of Anatomy and Physiology by Brian H. Derrick
1. Describe the structure of the five main types of cell junctions Gerard J. Tortora.
2. Discuss the functions of the five main types of cell junctions.
Where do you acquire knowledge to meet expectations?
1. .
2. Course Notes 3-2
Course Notes 3-2
Most epithelial cells and some muscle and nerve cells are tightly joined into
functional units.
Cell junctions are contact points between the plasma membranes of tissue cells.
Five most important types of cell junctions (figure 3-2):
• Tight junctions
• Adherens junctions
• Desmosomes
• Hemidesmosomes
• Gap junctions
