cell walls
cell membrane
epimysium
Neuron
"Exo" means external or outer in the word exoskeletons. Exoskeletons are rigid external coverings found in certain animal species that provide support and protection.
The rigid outer covering a plant cell is known as the cell wall. The cell wall is composed mainly of cellulose.
One is the Myelin Sheath, the other I would assume is the Neurilemma.
The cell structure that is located in the external boundaries of the cell is the cell membrane. The cell membrane is a semipermeable membrane composed of lipids and proteins that surrounds the cell, providing a barrier between the cell's interior and its external environment.
The term for an animal shedding its external coverings is "molting." This process is common in various species, including insects, crustaceans, and reptiles, as they grow and develop. During molting, the old exoskeleton or skin is replaced with a new, larger one to accommodate growth or to renew the outer layer for better functionality or appearance.
The cell part that contains the external boundary of the cell is the cell membrane. It acts as a barrier that separates the cell from its surroundings and regulates the passage of substances in and out of the cell.
Cell Membrane
Glycocalyx is part of the external structure of cells which offers protection, adherence, and communication from cell to cell
The collection of carbohydrate groups on a human cell's external surface is called the glycocalyx. These carbohydrate groups play important roles in cell-cell recognition, adhesion, and signaling.