1 Aden, Yemen is at 12 49'N, 45 1'E, 3 m (10 ft). 2  See map. 3  Aden has a subtropical desert / low-latitude arid hot climate (K ppen-Geiger classification: BWh). 4  The annual average temperature is 29.2 degrees Celsius (84.5 degrees Fahrenheit).
The core of a sphingolipid is an amino alcohol called sphingosine. Complex sphingolipids located in the plasma membrane of animal cells (especially nerve cells) have a structural function and are believed to protect the cell surface from harmful environmental factors.
Learning Objectives. 1  Describe how different types of epithelia (simple, stratified, squamous, columnar) facilitate the performance of different functions. 2  List the junctional complexes that hold epithelial cells together and their primary functions. 3  List the functions of the basement membrane and how epithelial cells attach to the basement 4  ... Diagiven the wide distribution, epithelial cells perform a variety of functions: protection (skin), absorption (intestine), secretion (glands), excretion (kidney), gas exchange (lung and blood vessels). To perform these functions, epithelia assemble into different structures.