Histology Photos

Brown fat. Found in fetus and hibernating mammals. Temperature regulation. Multilocular.

White fat. Found in adults. Used for energy storage, insulation, cushioning, some endocrine functions.

• Basement membrane: basal lamina.
• Made up of: collagen (mainly type IV), proteoglycans, multiadhesive glycoproteins (laminin, fibronectin).
• It is a thin sheet of fiber that lines the epithelium.

Dense, regular connective tissue. Abundant collagen fibers arranged in parallel. Also found in tendons, ligaments.

• Dense irregular connective tissue. Abundant collagen fibers arranged irregularly.
• Found in dermis of skin, submucosa of many organs, organ capsules.

• Loose connective tissue.
• More cells and ground substance, few fibers. Ground substance doesn't stain and appairs as white spaces.
• Found in: lamina propria of tubular organs, surrounding vessels and nerves.

• Part of elastic connective tissue.
• Provides elasticity. Found in aorta and other places.

• Macrophages. Type of histiocyte and phagocyte.
• Abundant eosinophilic cytoplasm. Round to oval euchromatic nucleus.
• Two types: fixed and migratory. Lung: alveolar macrophages.
• Fight infection.

• Shown here are fibroblasts and the collagen they produce (stain blue with Masson's trichrome stain).
• Heterochromatic nuclei.
• Found in connective tissue.

• Abundant eosinophilic cytoplasm with euchromatic nucleus.
• Both fixed and migratory.
• Phagocytes that fight infection.

• •Brain
• – Microglial or Gitter
• cells
• •Liver
• – Kupffer
• cells

• •Lung
• – Alveolar macrophages
• •Kidney
• – Mesangial cells
• •Bone
• - Osteoclasts

• Found in skin and lung tissues, and near blood vessels within loose connective tissue.
• Origin: bone marrow stem cell precursors.
• Large, round cell with abundant cytoplasm and numerous cytoplasmic granules (containing histamine, heparin, and proteases)
• Involved in inflammation and allergic reactions.

• Plasma cell.
• Antibody secreting cell, derived from stimulated B lymphocyte.
• Common in lamina propria of GI and respiratory tracts.
• Eccentric nucleus with mixture of euchromatin and heterochromatin.
• Perinuclear clearning from poorly staining Golgi.

Plasma cell.

• Neutrophil.
• Primary acute inflammatory response cell. Ingests and kills bacteria.
• Poorly staining granules.

• Eosinophil.
• Segmented heterochromatic nucleus.
• Parasitic defense and some other immune reactions.

Genetic collagen disease. Characterized by increased skin elasticity and hypermotility of joints.

Most common type (90% of vertebrate collagen). Tensile strenth of tissues.

Hyaline cartilage matrix.

Loose CT in organs. Fibrils thinner than Type I (reticular)

• Basement membrane. Binds to laminin.
• Non-fibrillar.

Descemet's membrane (cornea)

• Type 3 collagen.
• Do not bundle into thick fibers. Arranged into loose mesh-like pattern.
• Principle fiber in CT in lymph nodes, spleen, surrounding vessels and muscle cells.

• Nonsulfated, anionic GAG (glycosaminoglycans).
• Widely distributed, constant component of ECM.
• Forms in plasma membrane rather than Golgi.

• Transitional cells.
• Function: barrier, distensible property.
• Location: renal pelvis, ureters, bladder, proximal urethra.

Allow the bladder to stretch.

• Functions: exchange, lubrication, barrier.
• Locations:
• Blood vessels & lymphatics (endothelium)
• Endocardium
• Body cavities (mesothelium)
• Bowman’s capsule of renal glomerulus
• Alveoli (lung)

• Functions: barrier, conduit, absorption, secretion.
• Locations: small exocrine gland ducts, kidney tubules, thyroid follicles, surface of ovary.

• Functions: absorption, secretion.
• Locations: small intestine, colon, stomach lining and gastric glands, and gallbladder.

• functions: barrier, protection
• location: skin, oral cavity, esophagus, vagina, distal urethra.

• functions: barrier, conduit
• locations: large ducts (sweat, salivary glands)
• Junction b/n pseudostratified columnar and stratified squamous (urethra, anorectal junction).

• F: protection, conduit, secretion.
• L: large ducts of compound glands, conjunctive, transitional zones.

Single layer of cells sitting along the basement membrane. Not all the cells reach the free surface- look stratified.

• F: secretion, absorption, conduit
• L: tracheal, large bronchi, ductus deferens, efferent ductules of epididymis.

• Fingerlike cytoplasmic projections found on most epithelial cells.
• Increase surface area.
• Number correlates with
• absorptive capacity.

• Made up of microvilli.
• Gastrointestinal and renal epithelial cells.
• May contain specific enzymes.

Steriocilia. Note how they aggregate into pointed bundles. Also found in the proximal ductus deferens and sensory (hair) cells of the ear.

• Cilia. Short, fine, hair-like structures. Basal bodies anchor cilia.
• Locations:
• mucociliary clearance in air ways.
• Oviducts=move ova and fluid toward uterus.
• Sperm (flagellum)

• 9+2 structure. 9 microtubule doublets, 2 central microtubules.
• Dynein arms: microtubule-associated motor protein.
• Radial spokes.
• 

• Non-motile.
• Specialized primary cilia that can be found in sensory organs (retina and nose)
• 9+0 arrangement (lack central pair of microtubules and motor proteins)
• 
• Role in embryonic development.
• Mechanoreceptors that monitor fluid flow (kidney, pancreas, liver)

• zonula occludens
• zonula adherens (anchoring)
• desmosome (anchoring)
• communicating/gap junctions

Zonula adherens, desmosome

• Mechanical stability and structural integrity.
• Cytoskeletal linkage between cells.
• Cell to cell recognition.

• Zonula occludens (tight junction)
• band goes around entire apical perimeter
• limits movement of molecules through intercellular space
• prevent movement of essential integral proteins.
• Adhesion molecules: claudins, occludins.

95% water, Type II collagen, GAGs, and proteoglycan aggregates.

Hyaline, Elastic, Fibrous.

• Water
• Collagen, mostly type 2 (about 80%)
• Proteoglycans: hyaluronan, chondroitin sulfate, and keratin sulfate.
• Glycoproteins: fibronectin (the adhesion molecule that binds matrix proteins to chonrdocyte cell membranes) and chondronectin (facilitates proteoglycan binding to collagen fibers).

• Most abundant type in vertebrates.
• Found in sites where ability to resist compression, and tensile strength, is required.
• Remodels throughout life. Chondrocytes replace/degrade matrix and respond to environment.
• All surfaces surrounded by perichondrium, except articular surface.
• 

Hyaline cartilage.

Elastic cartilage.