Chap 2/5/6 Flashcards
What are the major elements in the body?
Oxygen (O), Carbon (C), Hydrogen (H), Nitrogen (N)
What is the Octet Rule?
A stable atom has 8 electrons in its outermost (valence) shell.
What is an endergonic reaction?
A reaction that absorbs energy (energy input required).
What is an exergonic reaction?
A reaction that releases energy (spontaneous energy output).
What are free radicals?
Atoms or molecules with an unpaired electron in the outer shell, making them highly reactive.
Free radicals can damage proteins, lipids, and DNA, contributing to aging and diseases like cancer.
What are the protection functions of skin?
Acts as a physical barrier against injury, pathogens, and UV radiation. Provides chemical defense (e.g., acidic pH inhibits bacteria) and prevents water loss.
How can the skin absorb medications?
The skin can absorb lipid-soluble drugs, often administered via transdermal patches (e.g., nicotine, pain relief).
Where are sebaceous glands located?
Found in the dermis, mostly associated with hair follicles, concentrated on the scalp, face, chest, and back.
What skin changes occur after the 40s?
Thinner, less elastic skin; decreased production of collagen, elastin, and sebum; slower wound healing.
What is yellow bone marrow?
Stores fats (lipids for energy).
How do bones regulate calcium and phosphate?
Bones act as a reservoir for calcium and phosphate, releasing them into the blood as needed.
What does parathyroid hormone (PTH) do?
Increases blood calcium levels by stimulating osteoclasts to break down bone and releasing calcium into the blood.
What is hemopoiesis?
Production of blood cells occurs in red bone marrow, found in spongy bone.
