Anatomy & PhysiologyTissue Review
October 2012
General Characteristics of Epithelial Tissue
General Characteristics of Epithelial Tissue
Cells tightly packed together; very little intercellular space
Therefore, avascular Free surface Basement membrane anchors to connective
tissue below Regenerates readily, if close to nutrient
source (if avascular, how does it get nourished?)
Terms to understand
Simple Stratified Cell shapes Microvilli Cilia Goblet cells
Epithelium: identify by location
Lines air sacs of lungs: Lines respiratory passages: Lines bladder & urinary passages: Lines mouth, throat, anal canal, vagina: Forms outer layer of skin: Lines digestive tract: Forms most glands:
Epithelium: identify by function
Protection Modified for excellent absorption Secretion Can distend, then return to original
shape/layers Fabulous for diffusion
Glandular epithelium
EXOCRINE Has ducts to secrete
product to free surface Sweat, oil, milk
ENDOCRINE Ductless Empties product
directly into bloodstream
hormones
Connective tissue (in general)
Cells far apart from each other Intercellular space filled with FIBERS &
MATRIX Vascular, with exceptions (dense regular &
cartilage) Protects, connects, binds, supports
Possible fibers in matrix
1. COLLAGEN: thick, white, tough, very strong
2. ELASTIC: thin, yellow, stretchy
3. RETICULAR: thin, delicate strands of collage; from delicate framework/web-like support
Which connective tissue?
Universal glue; contains all 3 fibers; watery-gel matrix
Hard matrix made of calcium salts Parallel bundles of collagen; tendons &
ligaments Rubbery matrix; glassy appearance;
connects ribs to breastplate Fluid matrix
More connective tissues
Thick, cushion; shock absorber; intervertebral disks
Delicate framework supporting lymph nodes and bone marrow
Strong; interwoven collagen fibers; vascular; dermis of skin
Fat cells are dominant in this specialized areolar tissue
Compare dense regular & dense irregular fibrous conn.
REGULAR Parallel bundles of
collagen, tightly packed Avascular Forms tendons &
ligaments
• IRREGULAR• Interwoven mesh of
collagen fibers; lots more space
• Vascular• Forms dermis of the
skin
More terms to understand
Tendon Ligament Adipocyte Chondrocyte Osteocyte Fibroblast Neuron
Muscle tissue: skeletal, cardiac, or smooth?
Striated/banded Non-striated/banded Intercalated disks Spindle-shaped Multinucleate Uninucleate Heart Walls of hollow organs Moves the body
Muscle and nervous tissue functions
Muscle: contract to produce movement
Nervous (1) irritability—can be stimulated
(2) conductivity—can conduct an electrochemical impulse
Inflammation—the 4 Cardinal Signs
Edema---tissue swelling due to increased flow of tissue fluid to injury—why?
Rubor—
Calor—
Dolor--
Tissue healing
Which tissue regenerates the easiest?
Which tissue will never regenerate?
Which tissues are slow to regenerate?
Which tissues will be replaced with scar tissue?
Describe the general characteristics of connective tissue.
How does connective tissue differ from other tissues as to relative amount of cells and intercellular substance?
Describe the three types of fibers which might be found in connective tissue.
Identify the connective tissue
Composes tendons and ligaments Composes skeleton “glues” epithelium with basement membrane
to other structures Fluid matrix Rubbery, smooth glassy matrix Composes the dermis of the skin
Identify the connective tissue
Areolar with large deposits of adipocytes Forms stroma of the liver, bone marrow Which cartilage:
Framework of the ear Intervertebral disks Meniscus of knee Covers ends of long bones
Loose (areolar) tissue, bone, cartilage, and blood are different types of connective tissue. Explain why their physical characteristics differ so much.
What is the function of fibroblasts? Name the major types of cartilage. Describe
their differences and similarities.
Joints such as the elbow, shoulder, and knee contain considerable amounts of cartilage and fibrous connective tissue. How does this relate to the fact that joint injuries are often very slow to heal?
A group of disorders called collagenous diseases are characterized by deterioration of connective tissues. Why would you expect such diseases to produce widely varying symptoms.