What is membrane potential and how is it maintained?
Membrane potential is the difference in charge across the membrane, maintained mainly by ion gradients such as the sodium-potassium pump moving 3 Na+ out and 2 K+ in.
Name the major organelles and their primary functions.
What are the layers of the skin and their characteristics?
Epidermis (outer, keratinized stratified squamous epithelium), Dermis (dense irregular connective tissue with vessels and nerves), Hypodermis (adipose tissue).
What is keratin and its role in the skin?
Keratin is a tough, fibrous protein in the epidermis that provides waterproofing and protection.
Describe the degrees of burns and their effects.
First-degree: epidermis only, redness and pain; Second-degree: epidermis and part of dermis, blisters and pain; Third-degree: through dermis, may destroy nerves, requires medical care.
What are serous membranes and their function?
Serous membranes line body cavities not open to the exterior and secrete serous fluid to reduce friction around organs.
What is the anatomical position?
Standing upright, facing forward, arms at sides, palms facing forward; standard reference for body directions.