Histology, Ch 4 Flashcards
Allows substances to diffuse across quickly. Lines air sacs, outer boundary of serous membranes, kidney tubules, blood vessels
Simple squamous epithelium
Large, central nucleus. Relatively thin so that substances can diffuse across quickly. Certain kidney tubules and respiratory passages, ducts of many glands, thyroid gland
Simple cuboidal epithelium
Things can diffuse across but it’s generally too thick to be efficient. Found in upper respiratory passages and the nasal cavity, where it’s ciliated.
Pseudo stratified columnar epithelium
Apical layers that lack nuclei, with cells that are no longer living. Filled with keratin and resistant to friction. Outer layer of skin.
Keratinized stratified squamous epithelium
Found in organs that require protection from mechanical abrasion but need to retain moist surfaces. Mouth, throat, lungs, esophagus, anus, vagina
Nonkeratinized stratified squamous epithelium
Increase membrane surface area for absorption. Much smaller than?
Microvilli, which are smaller than cilia
Typical function is excretion. Kidney tubules, sweat glands.
Simple cuboidal epithelium
Has goblet cells, microvilli, nucleus near basement membrane. Stomach and intestine lining.
Simple columnar epithelium
Stratified. Cells change shape as bladder fills.
Transitional epithelium
Voluntary movements, cells/fibers striated, multinucleate, nuclei are peripheral. Attached to bones of skeleton and the skin
Skeletal muscle
Non-striated because myofilaments are not arranged into bundles. Walls of most viscera (organs) such as stomach, intestines, urinary bladder
Smooth muscle
Wall of heart. Striated, multinucleate, intercalated discs, tight junctions between adjacent cells, fibers/cells can branch
Cardiac muscle
Cells that generate and conduct nerve impulses. Consists of soma, densities, axons
Neurons
Cells that nourish, support, and protect neurons. Over 90% of cells in the brain.
Neuroglia. Glial cells.
Contains large amount of tissue fluid. Collagenous and elastic fibers, cell types include macrophages and fibroblasts. Around blood vessels, superficial fascia
Loose connective (areolar)
Adipocytes with large triglyceride vacuoles. Superficial fascia, around organs. Connective.
Adipose
Forms dermis of skin, perichondrium, periosteum. Similar to areolar but more tightly packed with more collagen. Main cell type is fibroblast
Dense irregular connective
Mostly collagenous fibers, main cell is fibroblast. Collagen fibers packed in tight parallel bundles, with fibroblasts squeezed between. Tendons, ligaments, fascia, and aponeuroses
Dense regular connective
Chondroblasts produce a firm ground substance called chondrine. Chondrocytes in lacunae. A vascular and surrounded by perichondrium.
Cartilage
Collagenous fibers closely packed, individual fibers cannot be seen. Matrix is glassy. Embryonic skeleton, costal cartilage, and caps on long bones.
Hyaline cartilage
Similar to hyaline but contains elastic fibers in the matrix making it very flexible. Outer ear, epiglottis
Elastic cartilage
Collagenous fibers visible with light microscope. Compressible, acts as shock absorber. Intervertebral discs, symphysis in pubis
Fibrocartilage (fibrous cartilage)
Matrix of calcium salts and collagenous fibers. Osteoblasts in lacunae. Haversian canal surrounded by rings of matrix called lamellar. Canaliculi connect lacunae. Vascular. Blood vessels travel though the canals.
Bone
Fluid matrix called plasma consisting mainly of water and proteins. Erythrocytes, leucocytes, thrombocytes
Blood
Long, straight polysaccharide chains. Negative charges of sugars attract positive ions in the ECF, creating a concentration gradient within the ECF that draws water out of cells and blood vessels by osmosis and traps it within the ECM.
Glycosaminoglycans
GAGS
GAGS bound to a protein core. Thousands of these can bind to a very long GAG, forming what? The size of this helps make the ECM firmer, acts as a barrier to diffusion which protects the underlying tissues from invasion
Proteoglycans
Proteoglycan aggregates
Glycoproteins of different types. Responsible for adhering cells to each other and into their places within the ECM. Bind to surface proteins as well as protein fibers and proteoglycans.
Cell-adhesion molecules
CAMs
Make up 20-25% of all protein within the body. Very resistant to tension and pressure.
Collagen fibers
May be stretched one and a half times their resting length without breaking, a property called what? When stretching force is removed they return to their original length, a property called what?
Elastic fibers.
Extensibility, elasticity.
Elastin allows the fiber to stretch, whereas the glycoproteins support and organize the elastin.
Results from abnormal collagen fibers. Recurrent joint dislocations, hyperextensibility of the skin, fragility of the blood vessels, easy bruising, etc.
Ehlers-Danlos syndrome
