1. The Human Body in Health and Illness, 4th edition
Barbara Herlihy
Chapter 6:
Tissues and Membranes

2. Lesson 6-1 Objectives List the four basic types of tissues.
Describe the functions of epithelial tissue.
Explain how epithelial tissue is classified.
Differentiate between endocrine and exocrine glands.
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3. Types of Tissues
Tissues: Groups of cells that are similar to one another in structure and function
Histology: Study of tissues
Four major types of tissues
Epithelial
Connective
Nervous
Muscular
How does cytology differ from histology?
Cytology is the study of cells and histology is the study of tissues.
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4. Epithelial Tissue Functions
Protection
Absorption
Filtration
Secretion
Transportation
Epithelial tissue helps form the skin and lines most of the inner cavities, such as the mouth, respiratory tract, and reproductive tract. Epithelial tissues also transport substances. For example, epithelial tissue in the intestines absorbs water and nutrients.
From what does epithelial skin tissue protect the body?
It protects the body from environmental influences such as sunlight, heat, and cold and from invasion by pathogens.
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5. Traits of Epithelial Tissue
Forms continuous sheets, like floor tiles
Outer surface unattached
Undersurface attached to basement membrane
Avascular
Well-nourished, regenerates quickly
The basement membrane is a thin membrane that anchors the epithelium to the underlying structure.
Epithelial tissues, unlike connective tissues, have very little intercellular matrix.
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6. Types of Epithelial Tissue
Classification according to shape
Squamous
Cuboidal
Columnar
Epithelial tissue is classified according to its shape and number of layers.
Squamous epithelium cells are thin, flat, and look like fish scales.
Cuboidal epithelium cells are cubelike and resemble dice.
Columnar epithelium cells are tall and narrow, like columns.
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7. Layers of Epithelial Tissue
Classified according to number of layers
Simple epithelium
Stratified epithelium
One layer of cells is a simple epithelium.
Two or more layers of cells form a stratified epithelium.
Transitional epithelium changes from simple layer to stratified (e.g., the urinary bladder appears as simple epithelium when stretched and stratefied epithelium when unstretched).
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8. Location of Epithelial Tissues
Simple squamous epithelium is found where substances move by rapid diffusion or filtration (e.g., walls of capillaries, alveoli).
Simple cuboidal epithelium, found in glands and the kidneys, secretes and transports various substances.
Simple columnar epithelium lines the digestive tract and helps in the absorption of the products of digestion. Pseudostratified columnar epithelium facilitates absorption and secretion.
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9. Glandular Epithelia Exocrine glands Endocrine glands
The exocrine glands have ducts that carry the exocrine secretions outside the body. These excretions include mucus, sweat, saliva, and digestive enzymes.
The endocrine glands are ductless glands and secrete hormones, such as insulin, directly into the blood.
Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved.

10. Lesson 6-2 Objectives
Describe the functions of connective, muscle, and nervous tissue.
List the types of epithelial and connective tissue membranes.
Differentiate between mucous and serous membranes.
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11. Functions of Connective Tissue
Connection
Support
Protection
Fat storage
Transportation
Of the four types of tissue, connective tissue is the most abundant in the human body.
It is widely distributed throughout the body and is found in blood, under the skin, in bone, and around many organs.
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12. Characteristics of Connective Tissue
Intercellular matrix
Abundant
Varies from liquid to hard
Most is well vascularized.
Exceptions: Tendons, ligaments, and cartilage
Presence and amount of protein fibers vary.
Collagen
Elastin
Reticular fibers (fine collagen)
Each type of cell secretes a different type of intercellular matrix, which may be liquid, gel, or solid. Composed of fibrous protein and ground substance, intercellular matrix fills the spaces between cells. Protein fibers, like collagen and elastin, are present in different amounts.
How do pregnancy and aging weaken connective tissue?
Possible answers include stretch marks on the abdomen and sagging breasts (Cooper’s droop).
Dense fibrous tissue includes tendons, ligaments, and capsules and fascia.
Cartilage contributes to the structure of the skeletal system and has a cushioning effect, as in pads in the knee joints.
Ask students to feel the rings in their windpipes, the midpart of the nose, and upper external ear. Point out that these structures are all cartilage.
Bone, blood, and lymph are described in great detail in separate chapters.
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13. Types of Connective Tissue
Loose
Areolar, adipose, reticular
Dense fibrous
Cartilage
Hyaline, fibrocartilage, elastic
Bone
Blood and lymph
Why are tendons, ligaments, capsules, and fascia composed of dense fibrous tisssue and not areolar tissues?
Dense fibrous tissue is stronger than areolar tissue. Areolar tissue is more suitable for acting as tissue glue.
Ask students to feel cartilage in the rings in their windpipes, middle part of the nose, and upper external ear.
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14. Locations of Connective Tissue
Provide examples of tissues with an intercellular mix ranging from liquid to hard (solid).
Blood and lymph are liquid, areolar tissue is gel, cartilage is semisolid, and bone is solid.
Ask students to describe personal injuries involving torn ligaments.
Points include how the injury happened, pain, and treatment.
Neuroglia are cells that support and take care of the neurons. They are also called glia.
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15. Nervous Tissue Makes up the brain, spinal cord, and nerves
Two types of cells
Neurons
Neuroglia
Neurons carry the electrical signals that allow for rapid communication throughout the body.
Neuroglia are cells that support and take care of the neurons. They are also called glia.
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16. Muscle Tissue
Composed of cells (fibers) that contract to cause movement of a body part.
Three types of muscle
Skeletal muscle
Smooth muscle
Cardiac muscle
There are three types of muscle: skeletal, smooth, and cardiac.
Smooth muscles move viscera and tubes such as blood vessels and ureters.
Cardiac muscle is only found in the heart.
What does cardiac muscle do?
It is responsible for the pumping action of the heart.
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17. Locations of Muscle Tissue
Skeletal muscle is elongated and appears striated.
Cardiac muscle is found only in the heart. It is elongated and striated; it forms lateral connections with other cardiac muscle fibers. This allows the electrical signal to spread very rapidly throughout the cardiac muscle.
Smooth muscle is non-striated. Its shape, appearance and function are distinctive from the other two types of muscle tissue.
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18. Tissue Repair Regeneration: Replacement of tissue via mitosis
Fibrosis: Replacement of injured tissue with fibrous connective tissue (scar tissue)
Keloid scarring: Excessive fibrosis
Regeneration only occurs in tissues whose cells undergo mitosis.
Skeletal muscle, cardiac muscle, and nervous tissue do not undergo mitosis and must be replaced by scar tissue.
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19. Steps in Tissue Repair Wound Clot and scab Tissue repair begins
Scar tissue forms
Epithelial cells multiply
Scab detaches
When a deep wound to the skin severs blood vessels, blood fills the wound, and then a blood clot forms, resulting in a scab.
When the epithelial cells multiply, they fill the area between the scar tissue and the scab. When the epithelium is complete, the scab detaches.
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20. Membranes Thin sheets of tissue that Classification of membranes
Cover surfaces
Line body cavities
Surround organs
Classification of membranes
Epithelial
Connective
There are two types of membranes, epithelial and connective.
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21. Cutaneous Membrane: Skin
What types of functions does the skin perform?
Responses include: protection, excretion, temperature regulation, and sensory role (touch and pain).
The skin can tell a clinical story. For example, blue or cyanotic skin suggests there is not enough oxygen in the blood. Yellow skin suggests too much bilirubin in the blood and may indicate a liver or blood disease.
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22. Connective Tissue Membranes
Synovial (lines joints)
Periosteum (lines bones)
Perichondrium (lines cartilage)
Meninges (lines central nervous system)
Fascia (found throughout the body)
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23. Mucous Membranes
Line all body cavities that open to the exterior of the body
Respiratory
Digestive
Urinary
Reproductive
The mucous membranes contain stratified squamous epithelium or simple columnar epithelium.
Mucous membranes are adapted to enable absorption, secretion, and protection.
Mucus is secreted to lubricate and moisturize.
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24. Serous Membranes
Line ventral body cavities that do not open to the exterior
Pleura
Parietal and visceral
Pericardium
Peritoneum
The parietal layer is the part of the serous membrane that lines the walls of the cavity, and the visceral layer covers the outside of the organ. The intrapleural space is between the visceral and parietal pleurae. Puncture wounds of the chest can upset the negative pressure within the intrapleural space causing the lung to collapse.
Why can a ruptured appendix result in peritonitis?
Fecal material enters the pelvic cavity; infection ensues.
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