Human Anatomy and Physiology 1: Chemistry and Cell Structures

Vocabulary flashcards covering introductory human anatomy and physiology concepts including chemistry, cellular organelles, tissue types, and homeostatic feedback.

Matter

Anything that has mass and takes up space.

Protons

Positively charged particles found in the nucleus of an atom.

Neutrons

Particles in the nucleus of an atom that are neutral and have no charge.

Electrons

Negatively charged particles located outside the nucleus; their number is always equal to the number of protons in a stable element.

$2-8-8$ Rule

The general rule for the maximum number of electrons in the first three electron shells of an atom utilized in healthcare board exams.

pH Scale

A measure of hydrogen ions where a value of $7$ is neutral, values below $7$ are acidic, and values between $7$ and $14$ are basic or alkaline.

Normal Blood pH

The specific pH range required to maintain homeostasis, which is between $7.35$ and $7.45$.

Organic Compounds

Compounds that must contain both carbon and hydrogen.

Inorganic Compounds

Compounds that do not contain both carbon and hydrogen, such as water ($H_2O$) or hydrochloric acid ($HCl$).

Carbohydrates

The body's main source of energy and fuel, categorized into monosaccharides, disaccharides, and polysaccharides.

Monosaccharides

A single molecule of sugar that is the easiest for the body to break down and use for energy.

Disaccharides

Sugar molecules composed of two pieces that the body must break down to utilize.

Polysaccharides

Complex sugar structures made of multiple molecules that take a longer time for the body to break down for energy.

Lipids

A stored form of energy used in cell membranes, some hormones, and the coverings of the nervous system.

Phospholipid Bilayer

The outer covering of every cell in the human body, composed of hydrophilic phosphoric heads and hydrophobic lipid tails.

Proteins

Building blocks of the body that provide structural support, act as membrane receptors, and function as enzymes.

Amino Acids

The building blocks of proteins that join together to form polypeptide chains.

Tertiary Structure

A protein structure that forms when the polypeptide chain starts to bend on itself due to slight positive and negative attractions.

DNA (Deoxyribonucleic Acid)

The genetic blueprint of the cell composed of adenine ($A$), thymine ($T$), cytosine ($C$), and guanine ($G$).

RNA (Ribonucleic Acid)

The genetic material used to make a copy of DNA for protein synthesis, which contains uracil ($U$) instead of thymine ($T$).

ATP (Adenosine Triphosphate)

The primary energy currency for the body produced in the mitochondria.

Plasma Membrane

The outer portion of the cell that separates the exterior from the interior; also known as the phospholipid bilayer.

Cytoplasm

A gel-like substance that fills the interior of the cell between the organelles.

Nucleolus

The innermost part of the nucleus containing the greatest concentration of chromatin.

Nuclear Pores

Small openings in the nucleus that allow for the movement of RNA to the job sites in the cell.

Ribosomes

Organelles that assemble amino acids to create proteins; can be free or attached to the endoplasmic reticulum.

Rough Endoplasmic Reticulum

A portion of the endoplasmic reticulum with ribosomes attached that is involved in protein synthesis.

Smooth Endoplasmic Reticulum

Organelles close to the nucleus that produce phospholipids, lipids, and other non-protein molecules.

Golgi Apparatus

The 'post office' of the cell that packages, labels, and sends molecules to be excreted outside of the cell.

Mitochondria

The site of ATP production through aerobic respiration; these organelles uniquely possess their own DNA.

Lysosomes and Peroxisomes

Organelles that function as the 'stomach' or 'garbage can' of the cell, breaking down old pieces or harmful substances.

Cytoskeleton

The internal support system of the cell made of microfilaments and microtubules.

Centrioles

Structures involved in cell replication that migrate to the ends of the cell to help split DNA.

Cilia

Whip-like extensions on the surface of membranes that help move materials, such as dust, out of the lungs.

Microvilli

Small finger-like projections that increase the surface area of the cell to assist in digestion.

Flagella

Long extensions used for movement, found only in sperm cells in the human body.

Epithelial Tissue

Continuous sheets of cells that serve as inner and outer coverings for the body and its organs.

Squamous

A term describing flat or 'squashed' epithelial cells.

Cuboidal

Epithelial cells that are shaped like a cube.

Columnar

Epithelial cells that have a rectangular shape.

Stratified

A classification for tissue that contains multiple layers of cells.

Simple Tissue

A classification for tissue that contains only one layer of cells.

Pseudostratified

Cells that appear to be layered because the nuclei do not line up, but are actually a single layer.

Connective Tissue

Supporting tissue that brings everything together, including tendons, ligaments, bone, blood, and cartilage.

Collagen

A component of connective tissue that provides strength, found in large amounts in tendons.

Elastic Fibers

Fibers that allow tissues like the skin to stretch and return to their original size and shape.

Skeletal Muscle

Voluntary muscle tissue characterized by a 'train track' appearance and the presence of multiple nuclei per cell.

Cardiac Muscle

Involuntary muscle tissue found only in the heart, characterized by branching Y-shapes and intercalated discs.

Smooth Muscle

Involuntary muscle tissue found in the walls of arteries, veins, and the digestive system.

Neurons

The conducting cells of the nervous system that carry signals along an axon.

Neuroglia

Support cells for the nervous tissue.

Homeostasis

The process of maintaining life by constantly responding to internal and external changes to keep conditions consistent.

Negative Feedback Loop

A homeostatic mechanism that reacts to a change by bringing conditions back to a neutral set point, such as body temperature or blood sugar.

Positive Feedback Loop

A homeostatic mechanism where an initial stimulus triggers a further and stronger reaction, such as the contractions during childbirth.