BSC215 Lecture 9 Histology part 1 3

Histology

The study of the normal structure of tissues.

Extracellular matrix

A complex network composed of ground substance and fibrous proteins that supports cells.

Epithelial tissue

Tissue that covers and lines surfaces, or forms glands; characterized by tightly packed cells and little extracellular matrix.

Connective tissue

Tissue that supports, binds, protects and connects parts of the body; composed of scattered cells and a prominent extracellular matrix.

Nervous tissue

Tissue consisting of cells that process and transmit information through electrical signals.

Muscle tissue

Tissue composed of contractile cells that generate force; includes skeletal, cardiac, and smooth muscle.

Fibrous proteins

Proteins in the extracellular matrix that provide structural support; includes collagen, elastic, and reticular fibers.

Ground substance

The gel-like material in the extracellular matrix that contains water, ions, nutrients and macromolecules.

Goblet cells

Specialized epithelial cells that secrete mucus.

Exocrine glands

Glands that maintain contact with body surfaces via ducts and secrete substances such as sweat and saliva.

Endocrine glands

Glands that secrete hormones directly into the bloodstream without ducts.

Simple squamous epithelium

A single layer of thin, flat cells that facilitates diffusion and filtration; found in alveoli and glomeruli.

Stratified squamous epithelium

Multiple layers of cells, where the outermost layers are flat and scaly; provides protection against abrasion.

Transitional epithelium

Multilayered epithelium that can change shape; found in the bladder, allowing for stretching.

Merocrine secretion

A secretion mode where products are released from secretory vesicles through exocytosis.

Apocrine secretion

A secretion mode where part of the cytoplasm is pinched off along with the secretion.

Holocrine secretion

A secretion mode where entire cells accumulate product and rupture to release their contents.

Cell junctions

Physical connections between tissue cells that include tight junctions, desmosomes, and gap junctions.

Basal lamina

A non-cellular layer that separates epithelial tissue from connective tissue.

Tight junctions

Connections between adjacent cells that prevent leakage of materials between them.

Desmosomes

Connections between cells that provide structural stability by resisting mechanical stress.

Gap junctions

Interlinked protein pores that allow for communication and the passage of substances between cells.