Epithelium & Connective Tissue

HA Block 1 Histology

histology

the study of the microscopic anatomy of tissues & organs

epithelium, connective tissue, muscle, & nervous tissue

What are the 4 basic tissues that comprise all organs?

stratified

name associated with multiple layers of epithelial cells

simple

name associated with single layer of epithelial cells

pseudostratified

name associated with single layer of epithelial cells with nuclei in many areas creating the appearance of multiple cell layers but all are attached to basement membrane

columnar

shape of epithelial cell - height is larger than width

cuboidal

shape of epithelial cell - height is similar to width

squamous

shape of epithelial cell - width is larger than height

microvilli

specialization/modification - less visible in histology

cilia

specialization/modification - more visible in histology

keratin

specialization/modification - results from cornification

transitional epithelia/urothelium

identical to non-keratinized stratified squamous epithelia but found in the inside surface of the urinary bladder and renal pelvis

endothelium

simple squamous epithelium found in blood vessels

mesothelium

simple squamous epithelium that lines the outside of organs

cilia

specialization/modification - fxn: motility

microvilli

specialization/modification - fxn: increases apical surface area available for absorption

keratin

specialization/modification - fxn: protection & dehydration

desmosomes

cell modification responsible for cell-to-cell adhesion

hemidesmosomes

cell modification responsible for adhesion of cell to extracellular matrix

keratin

structural protein & intermediate filament that provides a tough protective quality to some epithelial cell types

glandular epithelium

invagination or aggregation of epithelium that forms a solid tissue structure

3 types of secretion in glandular epithelia

apocrine, merocrine, holocrine

List areas in which non-glandular epithelia are found

skin, urinary bladder, oral mucosa, esophagus, vasculature

exocrine glands

glandular epithelia that secrete into a lumen or space

endocrine glands

glandular epithelia that secrete into extracellular space which enters the blood stream

merocrine

mechanism of secretion - exocytosis of secretory vesicles to the lumen of the gland

holocrine

mechanism of secretion - death of an entire cell within a gland releases content into the lumen of the gland

apocrine

mechanism of secretion - release of budding vesicles off the epithelial cells into the lumen of the gland

apocrine

mechanism of secretion utilized by sweat glands

holocrine

mechanism of secretion utilized by sebaceous glands

What are two organs in which microvilli are commonly found?

small intestine & kidney

extracellular matrix

primary structural component in connective tissue

fiber component

Which component of connective tissue provides strength?

griund substance

Which component of connective tissue is the space filler?

cellular component

Which component of connective tissue produces and defends connective tissue

collagen

What is the predominant fiber component found in connective tissue?

type 1

Which type of collagen is most abundant?

type 2

Which type of collagen forms hyaline and elastic cartilage

type 3

which type of collagen forms reticulin

reticulin

a subtype of collagen that are delicate and unorganized - can be identified by silver staining - acts like a meshwork to hold cells together

elastin

hold water

What is the main fxn of the ground substance in connective tissue?

fibroblasts

What is the most common cellular component in connective tissue?

purple (like nuclei)

What color do fibroblasts stain?

elastin

What fiber component of connective tissue can be identified by dark pink squiggles?

macrophages

cellular component of connective tissue - fxn: phagocytose debris/surveillance system for immune system

adipocytes

cellular component of connective tissue that stores lipids

energy and insulation

2 fxns of adipose tissue

loose irregular, dense irregular, dense regular, reticular

dense regular

What kind of connective tissue do tendons and ligaments have?

chondrocytes

What is the main cellular component of cartilage?

hyaline, elastic, fibrocartilage

What are the 3 types of cartilage?

elastic cartilage

common cartilage seen in the ear and nose

hyaline cartilage

type of cartilage commonly seen in joint surfaces

fibrocartilage

type of cartilage seen in symphyses between bones and intervertebral disks

fibrocartilage

Which type of cartilage has a higher content of collagen and fewer chondrocytes

hyaline & elastic

Which 2 types of cartilage or histologically very similar?

embyronic

Which type of connective tissue is found between developing organs of a fetus?