Ch. 4 Lab Notes Histology and Tissue Types

Flashcards covering introductory histology concepts, microscopic staining history, and classifications of nervous, muscle, epithelial, and connective tissues based on the lecture transcript.

Homeostasis

The balance of materials and energy within an organism that maintains life.

Tissues

Groups of similar cells coming together to perform a common function, derived from a word literally meaning 'woven'.

Antoni van Leeuwenhoek

An early scientist known as the 'father of microbiology' who was the first to observe microorganisms and used a saffron dye in 1673 to study biological structures.

Joseph von Gerlach

A German anatomist who developed the first true histological stain in the 1850s by diluting carmine with ammonia and gelatin to stain brain tissue.

Carmine

A red dye derived from the scales of crushed-up insects used in biological tissue staining.

Soma

The cell body of a neuron that serves as its life support, housing the nucleus, mitochondria, and DNA.

Dendrites

Bushy extensions of a neuron that collect signals from other cells and convey them back to the soma.

Axon

The long, cable-like projection of a neuron that transmits signals away to other neurons, muscles, or glands.

Glial Cells

Supportive nervous tissue cells that provide insulation, protection, and tethering to blood vessels for neurons.

Skeletal Muscle Tissue

Voluntary muscle tissue featuring long, straight, striated, and multinucleate cells that pull on bones or skin to generate movement.

Cardiac Muscle Tissue

Involuntary, striated muscle tissue found exclusively in the heart, consisting of branching uninucleate cells connected by intercalated discs.

Intercalated Discs

Dark junctions connecting cardiac muscle cells end-to-end that contain pores allowing electrical or chemical signals to pass between cells.

Smooth Muscle Tissue

Involuntary, non-striated tissue consisting of short, tapered uninucleate cells lining blood vessels and hollow visceral organs.

Proper Epithelium

The subcategory of epithelial tissue that covers external body surfaces and lines internal body cavities and organ walls.

Glandular Epithelium

The subcategory of epithelial tissue that forms glands and secretes substances such as hormones and enzymes.

Avascular

Lacking a direct blood supply; a characteristic of epithelial tissue, which relies on nutrients diffusing from underlying connective tissue.

Squamous Cells

Flat, scale-like epithelial cells with flat nuclei that facilitate rapid transport and absorption across membranes.

Cuboidal Cells

Cube-shaped epithelial cells with round nuclei that function in absorbing nutrients and producing secretions.

Columnar Cells

Tall, column-like epithelial cells with elongated nuclei that cushion underlying tissues and produce mucus.

Simple Epithelium

An epithelial tissue arrangement consisting of a single layer of cells.

Stratified Epithelium

An epithelial tissue arrangement composed of multiple layers of cells stacked on top of one another.

Pseudostratified Epithelium

Epithelial tissue that appears multilayered due to varying cell shapes and nucleus heights, but actually consists of a single layer.

Apical Side

The upper surface of an epithelial cell that is exposed to the outside of the body or an internal cavity.

Basal Side

The inner surface of an epithelial cell attached to the basement membrane.

Basement Membrane

A thin layer primarily made of collagen fibers that anchors epithelial tissue to the underlying connective tissue.

Endocrine Glands

Ductless glands that secrete hormones directly into the blood stream or surrounding tissue fluid.

Exocrine Glands

Glands that release secretions through specialized ducts onto the exterior body surface or into internal body cavities.

Marfan Syndrome

A genetic disorder affecting connective tissue that progressively weakens structural fibers throughout the body.

Ground Substance

The nonliving, unstructured extracellular material made of starches and proteins that fills spaces between connective tissue cells.

Osteoblasts

Immature stem cells in bone tissue that secrete the calcium carbonate matrix to construct bone.

Chondroblasts

Immature stem cells in cartilage tissue that build the spongy matrix forming structural components like the nose and ears.

Areolar Tissue

The most common type of loose connective tissue, featuring open spaces and randomly arranged fibers that hold fluid for surrounding tissues.

Dense Regular Tissue

Connective tissue consisting of parallel bundles of collagen fibers that provide strong resistance to tension in one direction, found in tendons and ligaments.

Dense Irregular Tissue

Connective tissue with collagen fibers arranged in sporadic patterns to withstand tension from multiple directions, found in the dermis.

Hyaline Cartilage

The most common form of cartilage, featuring a glassy appearance and a rich starch-protein matrix that provides flexible support.