BIOS-1113 Lecture Notes - Lecture 19: Histology, Thyroid, Air Sacs
7 Aug 2018
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Document Summary
Tissue group of cells which act together to perform a specific function group of similar cells and extracellular products that carry out a common function. 4 basic types of tissues: epithelium, connective tissue, muscle - contracts, nervous tissue - conducts. Epithelium consists of cells held closely together by cellular adhesions resting on a basement for. Highly cellular, very little intercellular material (has lots of cells, but little material b/t the cell) Poorly vascularized (avascular) - low blood supply, little room for blood. Avascular = not penetrated by blood vessels; receives nutrients by diffusion from underlying tissue. Lines body cavities - e. g. , digestive tract, blood vessels. Function of glandular epithelium production of various hormones and substances. Pseudostratified considered a single layer of cells since each cell contacts the basement gives appearance of multiple layers since cells are not all the same size and shape. Good for exchange and diffusion, easy to move across the cell, ease of transport.
