Tissues (BIS132) - Lecture Flashcards

A comprehensive set of vocabulary flashcards covering the four major tissue types, their classifications, specific cell types, and the extracellular matrix based on Dr. Fran Henshaw's lecture notes.

Tissues

A group of similar cells and products arising from the same embryonic region, working together to perform a specific physiological or structural role.

Epithelial Tissue

A classification of tissue that serves as a protective barrier, controls permeability, and separates two environments, characterized by scarce extracellular matrix ($ECM$).

Muscle Tissue

A tissue classification focused on movement and heat generation, containing myocytes and characterized by properties of excitability, contractility, and extensibility.

Nervous Tissue

A tissue classification used for communication and coordination, carrying electrical signals (action potentials) via neurons to control bodily functions.

Connective Tissue

The most prevalent tissue type derived from the mesoderm that provides structural support and connects other tissues, characterized by a prominent extracellular matrix ($ECM$).

Haploid

A term describing gametes, which are single cells containing half the genetic material of the body and are primarily used for reproduction.

Microbiome

Trillions of gut bacteria that function like a virtual organ, essential for digestion and immunity, though not considered human tissue.

Enamel

The hardest substance in the human body, classified as a mineralized tissue that contains no living cells once it is fully formed.

Neural Crest Cells

Developmental and migratory cells that undergo epithelial-mesenchymal transition ($EMT$) to form diverse cell types.

Melanocytes

Migratory skin cells that are not fixed or 'glued' in place, using specialized arms to distribute melanin.

Adult Stem Cells

Quiescent cells located in niches, such as muscle satellite cells, that remain inactive until needed for repair or growth.

Basement Membrane

A common property of all epithelia that provides a foundation for the tightly packed continuous cell layer.

Skeletal Muscle

Voluntary muscle tissue consisting of long bundles of striated, multinucleated fibers formed by cells fused during development.

Cardiac Muscle

Involuntary, highly branched, striated muscle tissue containing $1-2$ nuclei per cell and intercalated discs with gap junctions.

Smooth Muscle

Involuntary muscle tissue composed of overlapping sheets of spindle-shaped cells with a single nucleus and no striations.

Neuroglia

Also known as glial cells, these support, protect, insulate, and provide nutrition to nervous tissue; examples include astrocytes and oligodendrocytes.

Microglia

The resident immune cells of the brain, referred to as 'Brain Scouts', that constantly survey the dense web of neurons and astrocytes.

Nervous ECM

A soft, porous, and biologically active network comprising $10-20\%$ of total brain volume, containing Hyaluronic acid ($HA$) and proteoglycans.

Perineuronal Nets

A mesh of collagen and laminin around cell bodies and dendrites that stabilizes synapses and protects neurons from oxidative stress.

Mesenchyme

The embryonic tissue derived from the mesodermal layer from which all connective tissues are derived.

Collagen Fibres

Protein fibers in connective tissue that provide tensile strength and resist pulling forces.

Elastic Fibres

Protein fibers in connective tissue that provide flexibility and recoil.

Ground Substance

The interfibrillar matrix of connective tissue that can be fluid (as in blood), gelatinous (as in cartilage), or calcified (as in bone).

Areolar Tissue

A type of loose connective tissue proper that holds organs and structures in place, located beneath epithelia and surrounding blood vessels.

Dense Regular Connective Tissue

A tissue with high tensile strength consisting of parallel collagen fibers, typically found in tendons and ligaments.

Mast Cells

Connective tissue cells found notably in the skin and gut that release histamine.

Hyaline Cartilage

A solid specialized connective tissue located at bone ends and in the rings of the trachea.

Spongy Bone

A highly vascular and porous specialized connective tissue found at the heads of long bones.

Compact Bone

The rigid part of the skeleton, making up $80\%$ of bone, consisting of lamellae units in a parallel pattern for strength.

Lymph

A specialized fluid connective tissue with a liquid matrix and white blood cells ($WBC$) that maintains fluid levels and immune response.