Anatomy & Physiology Tissue Review October 2012. General Characteristics of Epithelial Tissue

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.