Chapter 4: Tissues
Tissues are groups of
I. Epithelial
 Epithelial and Glands

formed of closely joined cells

Regenerate well

always underlain with

avascular:

Functions:
1. Provide physical protection
2. Control permeability
3. Provide Sensation
4. Produce specialized secretions
Microvilli and cilia (fig 4-1)
Intercellular Connections:
cell adhesion molecules (CAM)
intercellular cement: glycosaminoglycans – hyaluronan
Cell Junctions
tight junctions
desmosomes (CAMS)
gap junctions
Connective tissue attaches by Basement Membrane:

basal lamina:
1. Lamina lucida
2. lamina densa
Classified by the number of layers and the shape of cells
A. Layers:
1. simple:
2. stratified:
B. Shape of Cells:
1. squamous:
2. cuboidal:
3. columnar:
Types of epithelial tissues:
1. Simple Squamous:
-good for
-found in the linings of
2. Stratified Squamous:
-most widespread
-functions:
-found in areas subject to friction:
3. Simple Cuboidal:
-have large spherical central
-found in glands:
4. Simple Columnar:
-oval nucleus
-may contain goblet cells:
-some have cilia
-ciliated found in
5. Pseudostratified Columnar
-single layer of cells of
-nuclei vary in shape &
-function in
-found in
Glandular Epithelium
-Most glands composed
- secretion -2 types of glands:
A. Endocrine Glands:
B. Exocrine Glands:
-Modes of secretion
1.) merocrine: exocytosis of secretions (mucin)
2.) apocrine: loss of cytoplasm with secretion
3.) Holocrine: destroys the cell – ruptures with secretion
sebaceous glands
-Types of secretions:
1.) serous glands
2.) mucous glands
3.) mixed
Unicellular vs. Multicellular
-Glands can be simple or compound in structure
II. Connective
•Functions:
1.
2.
3.
4.
5.
6.
7.
Defends the body against
Support and structure for
__ cells and tissues
Protects
Storage sites for
Forms rigid skeletal framework for body
Limits ROM
Transports
and fights
Cells associated with connective tissue
1. fibroblast:
2. macrophages: (free and fixed)
3. adipocytes:
4. mesenchymal:
5. melanocytes:
6. mast cells
7. lymphocytes
8. microphages: (neutrophils and eosinophils)
Connective tissue consists of few cells with a lot of intercellular matrix
- intercellular material: ground substance and fibers
1. Ground substance:
2. Fibers: 3 types
A. collagenous: most abundant
B. elastic:
C. reticular: short, thin:
Types of Connective Tissue:
Loose Connective Tissues - large spaces between cells; unorganized fiber arrangement
1. Areolar:
• consists mostly of collagenous fibers
• fibroblasts, WBC
• ”loose” arrangement of its fibers
• good site for injecting medications
2. Adipose Tissue: (adipocytes)

surround and protect

adipocytes dominate tissue mass
3. Reticular Connective Tissue:
•similar to loose connective tissue, but the only fibers in its matrix are reticular
•forms a strom or internal framework that can support many free blood cells
Dense connective Tissue (2)
1. Dense Regular Connective Tissue:
•tightly packed bundles of collagenous fibers
•referred to as white fibrous connective tissue
•only has fibroblasts for cells
•resists tension in
•found:
1. tendons
2. ligaments
3. fascia
4. aponeuroses
2. Dense Irregular Connective Tissue:
•contains more collagenous fibers than above
•fibers oriented randomly:
•found in:
1. dermis
2. fibrous coverings: (perichondrium), (periosteum), & (perineurium)
3. joint capsule
Fluid connective Tissue

Blood

Lymph
Supporting Connective Tissue (2)
1. Cartilage
•numerous collagen fibers in a firm matrix
•fibers/matrix formed by cells:
-chondroblast:
-chondrocytes:
-lacunae
•avascular:
3 types of cartilage
A. Hyaline: most abundant
-provides support with some pliability
-articular cartilage
-also found in:
-precursor to bone
B. Fibrocartilage (fibrous)
-collagen fibers in thick bundles
-slightly compressible
-found in regions where
-intervertebral discs, meniscal discs, and pubic symphysis
C. Elastic
-nearly identical to hyaline but
-found in
2. Bone:
• support and protects; provides cavities for fat storage and synthesis for blood cells
• mineralized matrix constructed from
• osteoblasts
• bone well supplied by
• single bone may be classified as an organ
Membranes:
1.) mucous membranes
-found in areas with opening
-secrete mucin:
-function
2.) serous membranes
-found in
-form parietal and visceral portions of pleura, pericardium, peritoneum
-cells secrete clear watery fluid:
3.) cutaneous membrane: skin
4.) synovial membranes
Fasciae (–a, singular)

Superficial fascia

Deep fascia

Subserous fascia
III. Muscular
•highly cellular, well vascularized especially adapted for movement
•3 types of muscle tissue:
1. skeletal:
2. cardiac:
3. smooth (visceral):
IV. Nervous
•brain, spinal cord, nerves
•Two types of cells: neurons & supporting cells
-neurons: generate and conduct nerve impulses
-supporting cells: nonconductive cells; support, protect, insulate the neurons
Tissue Response to Injury and Tissue Repair:
First phase - Inflammation: short term (acute) inflammation has 4 symptoms:
1.
2.
3.
4.
what causes this?
1. initial insult causes release of chemicals from neutrophils, macrophages, mast
cells
 these chemicals cause
• why is this good?
a. helps dilute toxins
b. brings
c. brings
2. stasis: "standing"
-slowdown of blood flow
Second phase - Repair: 2 major ways:
1. regeneration:
2. fibrosis: scar tissue
Aging, Tissue Structure and Cancer
Review Selected Clinical Terminology pg.138