Transcript Unit 2 Cells and Tissues Part 2 notes

Human Anatomy and Physiology: Unit 2 Part 2
• Unit 2 Part 2: Tissues
• Chapter 4
•
© 2013 Pearson Education, Inc.
Chapter 4 Learning Targets
•
4-1
• Identify the body's four basic types of tissues and describe their
roles.
•
4-2
• Describe the characteristics and functions of epithelial cells.
•
4-3
• Describe the relationship between form and function for each type
of epithelium.
•
4-4
• Compare the structures and functions of the various types of
connective tissues.
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Chapter 4 Learning Targets
•
4-5
• Explain how epithelial and connective tissues combine to form four
types of tissue membranes, and specify the functions of each.
•
4-6
• Describe the three types of muscle tissue and the special structural
features of each.
•
4-7
• Discuss the basic structure and role of neural tissue.
•
4-8
• Explain how injuries affect the tissues of the body.
•
4-9
• Describe how aging affects the tissues of the body.
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Tissues (4-1)
•
Collections of cells and cell products that perform
specific, limited functions
•
Histology
•
•
The study of tissues
Four types of tissues
1. Epithelial
2. Connective
3. Muscle
4. Neural
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Figure 4-1 An Orientation to the Tissues of the Body.
CELLS
That
secrete
and
regulate
EXTRACELLULAR
MATERIAL
AND FLUIDS
Combine to form
TISSUES
with special functions
Combine
to form
ORGANS
with multiple functions
Interact
in
ORGAN SYSTEMS
Chapters 5–20
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EPITHELIAL TISSUE
• Covers exposed
surfaces
• Lines internal
passageways and
chambers
• Produces glandular
secretions
CONNECTIVE TISSUE
• Fills internal spaces
• Provides structural
support
• Stores energy
MUSCLE TISSUE
• Contracts to produce
active movement
NEURAL TISSUE
• Conducts electrical
Impulses
• Carries information
Checkpoint (4-1)
1. Define histology.
2. List the four basic types of tissues in the body.
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Epithelial Tissue (4-2)
• Covers body surfaces
• Lines cavities
• Lines tubular structures
• Serves essential functions
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Functions of Epithelia (4-2)
• Provide physical protection
• Control permeability
• Provide sensation
• Produce specialized secretions (glandular
epithelium)
• Exocrine glands- secretions are discharged outside the
epithelium (ex. Perspiration from skin glands)
• Endocrine glands- secretions are discharged within the
tissue fluid and blood (ex. Hormones)
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Figure 4-3 The Surfaces of Epithelial Cells.
Cilia
Microvilli
Apical
surface
Golgi
apparatus
Nucleus
Mitochondria
Basement membrane
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Epithelial Renewal and Repair (4-2)
• Epithelia are replaced by mitosis
• Cell division of stem cells (germinative cells)
• Occurs near basement membrane
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Checkpoint (4-2)
3. List five important characteristics of epithelial tissue.
4. Identify four essential functions of epithelial tissue.
5. Identify the three main types of epithelial cell
junctions.
6. What physiological functions are enhanced by the
presence of microvilli or cilia on epithelial cells?
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Classification of Epithelia (4-3)
• Combines a cell shape with the number of layers
of cells
• Example:
• Simple (one layer) cuboidal (square shape)
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Cell Layers and Cell Shapes (4-3)
• Classification is based on layers
• Simple epithelium: single layer of cells
• Stratified epithelium: several layers of cells
• Classification is based on shape
• Squamous epithelia: thin and flat
• Cuboidal epithelia: square shaped
• Columnar epithelia: tall, slender rectangles
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Table 4-1 Classifying Epithelia
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Cell Layers and Cell Shapes (4-3)
• Simple squamous epithelium:
• Location: kidneys, lungs, heart, lining of ventral body cavity
• Function: absorption, secretion , reduce friction
• Simple coboidal epithelium:
• Location: glands, ducts, kidneys, and thyroid gland
• Function: some protection, secretion, and absorption
• Simple columnar epithelium
• Location: stomach, intestines, gall bladder, uterus, and kidneys
• Function: some protection, secretion, absorption
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Cell Layers and Cell Shapes (4-3)
• Stratified squamous epithelium:
• Location: skin, lining of the mouth, tongue, esophagus, and anus
• Function: line areas where mechanical stresses are severe
• Stratified cuboidal epithelium :
• Location: along the ducts of sweat glands and mammary glands *very rare*
• Function: secretion
Stratified columnar epithelium:
• Location: along portions of the pharynx, epiglottis, anus, and urethra *very rare*
• Function: protection
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Figure 4-4a Simple Epithelia.
Simple Squamous Epithelium
LOCATIONS: Epithelia lining
ventral body cavities; lining heart
and blood vessels; portions of
kidney tubules (thin sections of
nephron loops); inner lining of
cornea; alveoli (air sacs) of lungs
FUNCTIONS: Reduces friction;
controls vessel permeability;
performs absorption and secretion
Cytoplasm
Nucleus
Connective tissue
Lining of peritoneal cavity
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LM x 238
Figure 4-4b Simple Epithelia.
Simple Cuboidal Epithelium
LOCATIONS: Glands; ducts;
portions of kidney tubules; thyroid
gland
Connective
tissue
Nucleus
FUNCTIONS: Limited protection,
secretion, absorption
Kidney tubule
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Cuboidal
cells
Basement
membrane
LM x 650
Figure 4-4c Simple Epithelia.
Simple Columnar Epithelium
LOCATIONS: Lining of
stomach, intestine, gallbladder,
uterine tubes, and collecting
ducts of kidneys
Microvilli
Cytoplasm
FUNCTIONS: Protection,
secretion, absorption
Nucleus
Intestinal lining
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Basement
membrane
Connective
tissue
LM x 350
Figure 4-5a Stratified Epithelia.
Stratified Squamous Epithelium
LOCATIONS: Surface of
skin; lining of mouth, throat,
esophagus, rectum, anus,
and vagina
FUNCTIONS: Provides physical
protection against abrasion,
pathogens, and chemical attack
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Squamous
superficial cells
Stem cells
Basement
membrane
Connective
Surface of tongue tissue
LM x 310
Figure 4-5b Stratified Epithelia.
Pseudostratified Ciliated Columnar Epithelium
LOCATIONS: Lining of
nasal cavity, trachea, and
bronchi; portions of male
reproductive tract
Cilia
Cytoplasm
Nuclei
FUNCTIONS: Protection,
secretion, move mucus
with cilia
Trachea
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Basement
membrane
Connective
tissue
LM x 350
Figure 4-5c Stratified Epithelia.
Transitional Epithelium
LOCATIONS: Urinary
bladder; renal pelvis;
ureters
Epithelium
(relaxed)
FUNCTIONS: Permits
expansion and recoil
after stretching
Basement membrane
Connective tissue and
Empty bladder smooth muscle layers
LM x 400
Epithelium
(stretched)
Basement membrane
Connective tissue and
smooth muscle layers
LM x 400
Full bladder
Urinary bladder
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Connective Tissue (4-4)
•
Provides a protective structural framework for
other tissue types
•
Three basic components
1. Specialized cells
2. Solid extracellular protein fibers
3. Fluid extracellular ground substance
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Characteristics of Connective Tissue (4-4)
• The extracellular components of connective
tissues (fibers and ground substance) make up the
matrix
• Majority of tissue volume
• Determines specialized function
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Functions of Connective Tissue (4-4)
• Support and protection
• Transportation of materials
• Storage of energy reserves
• Defense of the body
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Figure 4-7 Major Types of Connective Tissue.
CONNECTIVE TISSUES
CONNECTIVE TISSUE PROPER
FLUID CONNECTIVE TISSUES
SUPPORTING CONNECTIVE TISSUES
LOOSE
DENSE
BLOOD
LYMPH
CARTILAGE
BONE
Fibers create
loose, open
framework
Fibers densely
packed
Flows within
cardiovascular
system
Flows within
lymphatic
system
Solid, rubbery
matrix
Solid, crystalline
matrix
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Three Major Types of Connective Tissue (4-4)
1. Connective tissue proper
2. Fluid connective tissues
3. Supporting connective tissues
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• Connective tissue proper
• Consists of:
• Many cell types
• Matrix + ground substance
• Examples:
• Skin, fatty tissue, tendons, and ligaments
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• Fluid connective tissue
• Consists of:
• Distinct cells in a matrix of water ground substance
containing proteins
• Examples:
• Blood and lymph
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• Supporting connective tissue
• Consists of:
• Less diverse cell population
• matrix of dense ground substance and closely packed
fibers
• Examples:
• Cartilage and bone
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Ground Substance (4-4)
• Clear, colorless, and viscous
• Fills spaces between cells and slows pathogen
movement
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Types of Connective Tissue Proper (4-4)
• Loose connective tissue
• "Packing materials" of the body
• More ground substance, fewer fibers
• Example: fat (adipose tissue)
• Dense connective tissue
• Tough, strong, and durable
• More fibers, less ground substance
• Example: tendons
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Figure 4-8 Cells and Fibers of Connective Tissue Proper.
Reticular
fibers
Fixed
macrophage
Antibody
producing cell
Blood in
vessel
Mast cell
Elastic
fibers
Free
macrophage
Collagen
fibers
Fibroblast
Stem cell
Adipocytes
(fat cells)
Ground
substance
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White blood
cell
Figure 4-9a Loose Connective Tissues.
Areolar Tissue
LOCATIONS: Beneath dermis of
skin, digestive tract, respiratory
and urinary tracts; between
muscles; around blood vessels,
nerves, and around joints
FUNCTIONS: Cushions
organs; provides support
but permits independent
movement; phagocytic
cells provide defense
against pathogens
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Collagen
fibers
Fat cell
Mast cell
Fibroblasts
Elastic fibers
Macrophage
Areolar tissue
LM x 400
Figure 4-9b Loose Connective Tissues.
Adipose Tissue
LOCATIONS: Deep to the skin,
especially at sides, buttocks,
breasts; padding around eyes
and kidneys
Adipocytes
FUNCTIONS: Provides
padding and cushions
shocks; insulates
(reduces heat loss);
stores energy
Adipose tissue
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LM x 300
Figure 4-9c Loose Connective Tissues.
Reticular Tissue
LOCATIONS: Liver, kidney, spleen,
lymph nodes, and bone marrow
FUNCTIONS: Provides supporting
framework
Reticular tissue
from liver
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Reticular
fibers
Reticular tissue
LM x 375
Figure 4-10a Dense Connective Tissues.
Dense Regular Connective Tissue
LOCATIONS: Between skeletal
muscles and skeleton (tendons
and aponeuroses); between
bones or stabilizing positions
of internal organs (ligaments);
covering skeletal muscles;
deep fasciae
FUNCTIONS: Provides
firm attachment; conducts
pull of muscles; reduces
friction between muscles;
stabilizes relative positions
of bones
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Collagen
fibers
Fibroblast
nuclei
Tendon
LM x 440
Figure 4-10b Dense Connective Tissues.
Dense Irregular Connective Tissue
LOCATIONS: Capsules of
visceral organs; periostea
and perichondria; nerve
and muscle sheaths; deep
dermis of the skin
FUNCTIONS: Provides
strength to resist forces
applied from many
directions; helps
prevent overexpansion
of organs such as
the urinary bladder
Collagen
fiber
bundles
Deep dermis
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LM x 111
Fluid Connective Tissues (4-4)
• Blood and lymph
• Watery matrix of dissolved proteins
• Carry specific cell types (formed elements)
• Formed elements of blood
• Red blood cells
• White blood cells
• Platelets
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Supporting Connective Tissues (4-4)
• Cartilage
• Gel-type ground substance
• For shock absorption and protection
• Bone
• Calcified (made rigid by calcium salts, minerals)
• For weight support
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Table 4-3 A Comparison of Cartilage and Bone
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Checkpoint (4-4)
12. Identify several functions of connective tissues.
13. List the three types of connective tissues.
14. Which type of connective tissue contains
primarily triglycerides?
15. Lack of vitamin C in the diet interferes with the
ability of fibroblasts to produce collagen. What
effect might this interference have on connective
tissue?
16. Which two types of connective tissue have a fluid
matrix?
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Checkpoint (4-4)
17. Identify the two types of supporting connective
tissue.
18. Why does cartilage heal slower than bone?
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Tissue Membranes (4-5)
• Membranes
• Are physical barriers
• Line or cover portions of the body
• Consist of:
• An epithelium
• Supported by connective tissues
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Four Types of Tissue Membranes (4-5)
1. Mucous membranes
2. Serous membranes
3. Cutaneous membrane
4. Synovial membranes
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Figure 4-13 Tissue Membranes.
Mucous membranes
are coated with the
secretions of mucous
glands. These
membranes line the
digestive, respiratory,
urinary, and
reproductive tracts.
Mucous secretion
Serous membranes
line the ventral body
cavities (the peritoneal, pleural, and
pericardial cavities).
Serous fluid
The cutaneous
membrane, or skin,
covers the outer
surface of the body.
Epithelium
Lamina propria
(areolar tissue)
Epithelium
Areolar tissue
Epithelium
Areolar tissue
Dense irregular
connective tissue
Synovial membranes
line joint cavities and
produce the fluid
within the joint.
Articular (hyaline)
cartilage
Synovial fluid
Capsule
Capillary
Adipocytes
Areolar
tissue
Epithelium
Bone
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Synovial
membrane
Mucous Membranes (4-5)
• Also known as mucosae
• Line passageways that have external connections
• In digestive, respiratory, urinary, and reproductive tracts
• Epithelial surfaces must be moist
• To reduce friction
• To facilitate absorption and excretion
• Lamina propria
• Made of areolar tissue
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Figure 4-13a Tissue Membranes.
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Mucous membranes
are coated with the
secretions of mucous
glands. These
membranes line the
digestive, respiratory,
urinary, and
reproductive tracts.
Mucous secretion
Epithelium
Lamina propria
(areolar tissue)
Serous Membranes (4-5)
• Line cavities not open to the outside
• Are thin but strong
• Have fluid transudate to reduce friction
• Have a parietal portion covering the cavity
• Have a visceral portion (serosa) covering the
organs
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Three Serous Membranes (4-5)
1. Pleura
•
Lines pleural cavities
•
Covers lungs
2. Peritoneum
•
Lines peritoneal cavity
•
Covers abdominal organs
3. Pericardium
•
Lines pericardial cavity
•
Covers heart
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Figure 4-13b Tissue Membranes.
Serous membranes
line the ventral body
cavities (the peritoneal, pleural, and
pericardial cavities).
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Serous fluid
Epithelium
Areolar tissue
The Cutaneous Membrane (4-5)
• Is skin
• Covers the surface of the body
• Thick, waterproof, and dry
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Figure 4-13c Tissue Membranes.
The cutaneous
membrane, or skin,
covers the outer
surface of the body.
Epithelium
Areolar tissue
Dense irregular
connective tissue
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Synovial Membranes (4-5)
• Line moving, articulating joint cavities
• Produce synovial fluid (lubricant)
• Protect the ends of bones
• Lack a true epithelium
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Figure 4-13d Tissue Membranes.
Synovial membranes
line joint cavities and
produce the fluid
within the joint.
Articular (hyaline)
cartilage
Synovial fluid
Capsule
Capillary
Adipocytes
Areolar
tissue
Synovial
Epithelium membrane
Bone
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Checkpoint (4-5)
19. Identify the four types of tissue membranes
found in the body.
20. How does a plasma (cell) membrane differ from
a tissue membrane?
21. What is the function of fluids produced by serous
membranes?
22. The lining of the nasal cavity is normally moist,
contains numerous mucous cells, and rests on a
layer of areolar tissue. Which type of membrane
is this?
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Three Types of Muscle Tissue (4-6)
1. Skeletal muscle tissue
•
Large body muscles responsible for movement
2. Cardiac muscle tissue
•
Found only in the heart
3. Smooth muscle tissue
•
Found in walls of blood vessels
•
Found around hollow organs such as the urinary bladder
•
Around the respiratory, digestive, and reproductive tracts
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Functions of Muscle Tissue (4-6)
• Specialized for contraction
• Produces all body movement
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Figure 4-14a Muscle Tissue.
Skeletal Muscle Tissue
Cells are long, cylindrical, striated,
and multinucleate.
LOCATIONS: Combined with
connective tissues and neural
tissue in skeletal muscles
FUNCTIONS: Moves or stabilizes
the position of the skeleton; guards
entrances and exits to the digestive,
respiratory, and urinary tracts;
generates heat; protects internal
organs
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Nuclei
Muscle
fiber
Striations
Skeletal muscle
LM x 180
Figure 4-14b Muscle Tissue.
Cardiac Muscle Tissue
Nucleus
Cells are short, branched, and striated,
usually with a single nucleus; cells are
interconnected by intercalated discs.
Cardiac
muscle
cells
LOCATION: Heart
FUNCTIONS: Circulates blood;
maintains blood (hydrostatic) pressure
Intercalated
discs
Striations
Cardiac muscle
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LM x 450
Figure 4-14c Muscle Tissue.
Smooth Muscle Tissue
Cells are short, spindle-shaped, and
nonstriated, with a single, central
nucleus.
LOCATIONS: Found in the walls of
blood vessels and in digestive,
respiratory, urinary, and reproductive
organs
FUNCTIONS: Moves food, urine, and
reproductive tract secretions; controls
diameter of respiratory passageways;
regulates diameter of blood vessels
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Nucleus
Smooth
muscle
cell
Smooth muscle
LM x 235
Checkpoint (4-6)
23. Identify the three types of muscle tissue in the
body.
24. Voluntary control is restricted to which type of
muscle tissue?
25. Which type of muscle tissue has small, tapering
cells with single nuclei and no obvious striations?
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Neural Tissue (4-7)
• Also called nervous or nerve tissue
• Specialized for conducting electrical impulses
• Rapidly senses internal or external environment
• Processes information and controls responses
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Neural Tissue (4-7)
• Concentrated in the central nervous system
• Brain
• Spinal cord
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Two Kinds of Neural Cells (4-7)
1. Neurons
•
Nerve cells
•
Perform electrical communication
2. Neuroglia
•
Supporting cells
•
Repair and supply nutrients to neurons
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Cell Parts of a Neuron (4-7)
• Cell body
• Contains the nucleus and nucleolus
• Dendrites
• Short branches extending from the cell body
• Receive incoming signals
• Axon (nerve fiber)
• Long, thin extension of the cell body
• Carries outgoing electrical signals to their destination
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Figure 4-15 Neural Tissue.
Brain
Axon
terminals
Spinal
cord
Nuclei of
neuroglia
Cell
body
Cell body
Nucleus
of neuron
Axon
Dendrites
Axon
LM x 600
Neuron
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Photomicrograph
of neuron cell
body
Checkpoint (4-7)
26. A tissue contains irregularly shaped cells with
many projections, including some several
centimeters long. These are probably which type
of cell?
27. Why are both skeletal muscle cells and axons
also called fibers?
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Tissue Injuries and Repair (4-8)
•
Tissues respond to injuries to maintain
homeostasis
•
Cells restore homeostasis with two processes
1. Inflammation
2. Regeneration
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Inflammation (4-8)
• Inflammatory response
• The tissue's first response to injury
• Signs and symptoms include:
• Swelling
• Heat
• Redness
• Pain
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Inflammatory Response (4-8)
• Can be triggered by:
• Trauma (physical injury)
• Infection (the presence of harmful pathogens)
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Checkpoint (4-8)
28. Identify the two phases in the response to tissue
injury.
29. What signs and symptoms are associated with
inflammation?
30. What is fibrosis?
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Aging Tissue (4-9)
• With age:
• Rate of tissue repair declines
• Cancer rates increase
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Aging and Tissue Structure (4-9)
• Speed and efficiency of tissue repair decrease
with age due to:
• Slower rate of energy consumption (metabolism)
• Hormonal alterations
• Reduced physical activity
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Aging and Cancer Incidence (4-9)
• Cancer rates increase with age
• 1 in 4 people in the United States develops cancer
• Cancer is the #2 cause of death in the United States
• Environmental chemicals and cigarette smoke cause cancer
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Checkpoint (4-9)
31. Identify some age-related factors that affect
tissue repair and structure.
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