Question

which type(s) of junction would be most needed in the following tissues? • neurons transmitting electrical impulses • skin cells

Explanation:

For Neurons transmitting electrical impulses:

Neurons use synapses (a type of junction, specifically chemical synapses mainly, though electrical synapses also exist) to transmit electrical impulses between each other. Synapses allow the transfer of signals (via neurotransmitters in chemical synapses or direct ion flow in electrical synapses) from one neuron to another or to target cells. Also, gap junctions can be involved in some electrical signal propagation between neurons in certain cases, but synapses are the primary junctions for neuronal signal transmission.

Skin cells (epithelial cells of the skin) primarily use tight junctions, adherens junctions, and desmosomes. Tight junctions prevent the passage of substances between cells, helping to form a barrier (like in the epidermis to prevent water loss and pathogen entry). Desmosomes provide strong adhesion between skin cells to resist mechanical stress (since skin is subject to abrasion). Adherens junctions also help in cell - cell adhesion.

Answer:

Synapses (and potentially gap junctions in some cases)

For Skin cells: