Histology and Tissue Types Vocabulary

A set of vocabulary flashcards defining tissues, cell junctions, embryonic germ layers, tissue membranes, glands, muscle types, connective tissue categories, cell types, and neuroglia from Chapter 4.

Histology

The microscopic study of tissue appearance, organization, and function.

Epithelial Tissue

Sheets of cells that cover exterior surfaces of the body, line internal cavities and passageways, and form certain glands.

Tight Junctions

Cell junctions between adjacent epithelial cell membranes that block the movement of substances through the extracellular space, creating a selective barrier.

Anchoring Junctions

Cell junctions that stabilize epithelial tissue and influence the shape and folding of epithelial tissue.

Gap Junctions

Cell junctions that form intracellular passageways between membranes of adjacent cells, facilitating movement of small molecules and ions and allowing electrical and metabolic coupling.

Ectoderm

The outer germ layer formed during embryonic development from which tissue and nervous tissue derive.

Mesoderm

The middle germ layer formed during embryonic development from which muscle tissue and connective tissue originate.

Endoderm

The inner germ layer formed during embryonic development.

Synovial Membrane

A connective tissue membrane that encapsulates organs and lines moveable joints.

Mucous Membranes

Epithelial membranes that line cavities and passageways that lead to the exterior of the body.

Serous Membranes

Epithelial membranes that line cavities that do not open to the external environment and cover organs within those cavities.

Cutaneous Membrane

The skin; an epithelial membrane composed of stratified squamous epithelium resting on top of connective tissue.

Simple Squamous Epithelium

Epithelium located where there is rapid passage of chemical compounds, such as in the alveoli of the lungs, parts of the kidney tubules, and the lining of capillaries.

Simple Cuboidal Epithelium

Epithelium active in secretion and absorption of molecules, found in the lining of kidney tubules and ducts of glands.

Simple Columnar Epithelium

Epithelium active in absorption and secretion of molecules, forming the lining of parts of the digestive system and female reproductive system.

Pseudostratified Columnar Epithelium

Epithelium found in the respiratory tract composed of irregularly shaped cells that give the appearance of more than one layer.

Goblet Cells

Unicellular glands found in mucous membranes that secrete mucous.

Transitional Epithelium

A type of stratified epithelium found in the bladder, urethra, and ureters that changes appearance from cuboidal when empty to squamous when filled.

Endocrine Glands

Ductless glands that release secretions (hormones) directly into surrounding tissues and interstitial fluid, which then travel through the blood to target organs.

Exocrine Glands

Glands that secrete chemicals through a duct that opens directly or indirectly to the external environment.

Merocrine Secretion

A secretion method where secretions are enclosed in vesicles that move to the surface of the cell to be released via exocytosis.

Apocrine Secretion

A secretion method where secretions accumulate near the surface of the cell and are then pinched off from the cell and released.

Holocrine Secretion

A secretion method involving the rupture and destruction of the entire gland cell after accumulating secretions.

Skeletal Muscle Tissue

Voluntary, striated, multinucleated muscle tissue attached to bone that produces heat, protects organs, and enables movement.

Cardiac Muscle Tissue

Involuntary muscle tissue consisting of single cells with a central nucleus and intercalated discs, forming the contractile walls of the heart.

Smooth Muscle Tissue

Involuntary, spindle-shaped muscle tissue with no visible striations, found within internal organs like the digestive, urinary, and reproductive systems.

Adipose Tissue

A type of loose connective tissue mostly composed of fat storage cells.

Areolar Tissue

Loose connective tissue that fills space between muscle fibers, surrounds blood and lymph vessels, and supports organs in the abdominal cavity.

Reticular Tissue

Loose connective tissue that provides structural support for organs like the spleen and liver.

Dense Regular Connective Tissue

Dense connective tissue with parallel fibers that enhance tensile strength and stretch resistance in the direction of the fibers, found in ligaments and tendons.

Dense Irregular Connective Tissue

Dense connective tissue with fibers aligned in random directions, providing greater strength in all directions, found in the dermis of the skin.

Hyaline Cartilage

The most common type of cartilage, featuring short dispersed collagen fibers, found in the rib cage, nose, and covering bone surfaces at joints.

Fibrocartilage

Tough cartilage consisting of thick bundles of collagen fibers dispersed in a matrix, found in menisci and vertebral discs.

Elastic Cartilage

Cartilage made of elastic fibers, collagen, and proteoglycans that provides rigid support and elasticity, found in the external ear.

Osteocytes

Bone cells located within bone tissue.

Erythrocytes

Red blood cells that transport oxygen and carbon dioxide throughout the body.

Leukocytes

White blood cells that defend the body from pathogens.

Platelets

Cell fragments in the blood that help with blood clotting.

Mesenchyme

The first connective tissue to develop from stem cells during embryonic development.

Fibroblasts

Cells present in all forms of connective tissue proper that secrete polysaccharides, proteins, collagen fibers, elastic fibers, and reticular fibers.

Fibrocytes

The second most common cell type in connective tissue proper, representing a less active form of fibroblasts.

Adipocytes

Cells within connective tissue that store lipids as droplets filling most of the cytoplasm.

Mesenchymal Cells

Stem cells from which all connective tissue forms and which act to replace damaged connective tissues.

Macrophage Cells

Large cells that enter the connective tissue matrix from blood vessels to defend against pathogens and play an important role in the inflammatory response.

Astrocytes

Neuroglia that regulate ion concentration in intercellular space, uptake/breakdown neurotransmitters, and form the blood-brain barrier.

Oligodendrocytes

Neuroglial cells responsible for producing myelin in the Central Nervous System (CNS).

Schwann Cells

Neuroglial cells responsible for producing myelin in the Peripheral Nervous System (PNS).