Human Body Anatomy, Physiology, Chemistry, and Cell Biology

Vocabulary-style study flashcards created from lecture notes on basic anatomy, body organization, homeostasis, bio-chemistry, membrane transport, cell organelles, cell division, and protein synthesis.

Gross Anatomy

The study of large, visible body structures such as the heart.

Principle of Complementarity

The concept that anatomy and physiology are inseparable because function always reflects structure, and what a structure can do depends on its specific form.

Homeostasis

The maintenance of relatively stable internal conditions despite continuous changes in the external or internal environment.

Receptor (Sensor)

A homeostatic control component that monitors the environment and responds to stimuli.

Control Center

A homeostatic control component, usually the brain, that determines the set point at which a variable is maintained, receives input from receptors, and determines the appropriate response.

Effector

A homeostatic control component that receives output from the control center and provides the means to respond, either reducing or enhancing the stimulus.

Negative Feedback Mechanism

The most-used feedback mechanism in the body, where the output response reduces or shuts off the original stimulus, causing the variable to change in the opposite direction of the initial change.

Positive Feedback Mechanism

A homeostatic feedback mechanism where the response enhances or exaggerates the original stimulus, typically controlling infrequent events that do not require continuous adjustment.

Anatomical Position

The standard reference position where the body is erect, feet are slightly apart, and palms face forward with thumbs pointing away from the body.

Sagittal Plane

A vertical body plane that divides the body into right and left parts.

Frontal Plane (Coronal Plane)

A body plane that divides the body into anterior (front) and posterior (back) portions.

Transverse Plane (Horizontal Plane)

A body plane that divides the body into superior (upper) and inferior (lower) portions, producing a cross section.

Radioisotopes

Isotopes that exhibit radioactivity and share the same chemistry as their stable counterparts, allowing them to be used for biological imaging, diagnosis, and medical treatment.

Ionic Bond

A chemical bond formed by the complete transfer of electrons from one atom to another, resulting in oppositely charged ions (cations and anions).

Covalent Bond

A chemical bond formed when two atoms share electrons, which can be polar (unequal sharing) or non-polar (equal sharing).

Enzyme

A biological catalyst that increases the rate of a chemical reaction without being chemically changed or consumed by decreasing the activation energy.

pH Scale

A measurement scale ranging from $0$ to $14$ that measures hydrogen ion concentration, where $7$ is neutral, values below $7$ are acidic, and values above $7$ are alkaline.

pH Buffer

A chemical system, such as bicarbonate ($HCO_3^-$), that resists abrupt and large swings in pH by binding hydrogen ions when conditions become acidic or releasing them when conditions become alkaline.

Triglycerides

Lipids composed of three fatty acids bonded to a glycerol molecule that function in long-term energy storage, insulation, and organ protection.

Saturated Fatty Acids

Fatty acid chains containing only single covalent bonds, fully saturated with hydrogen atoms, which form linear molecules that pack closely to form solids at room temperature.

Unsaturated Fatty Acids

Fatty acid chains containing one or more double bonds that introduce kinks, preventing dense packing and remaining liquid at room temperature.

Phospholipids

Modified triglycerides consisting of a glycerol molecule, two fatty acids, and a phosphorus-containing group, forming a polar hydrophilic head and nonpolar hydrophobic tails.

Protein Denaturation

The process in which globular proteins unfold and lose their functional 3D shape and active sites, caused by increased temperature or decreased pH.

Passive Transport

The movement of substances across a plasma membrane down their concentration gradient without requiring cellular energy ($ATP$).

Active Transport

The movement of solutes across a plasma membrane against their concentration gradient (from low to high concentration), requiring transport proteins and cellular energy ($ATP$).

Osmosis

The passive diffusion of water across a semipermeable membrane toward an area of higher solute concentration.

Hypertonic Solution

A solution with a higher solute concentration (osmolarity) than inside a cell, causing water to flow out of the cell and leading to cell shrinkage.

Hypotonic Solution

A solution with a lower solute concentration (osmolarity) than inside a cell, causing water to flow into the cell and leading to cell swelling and potential lysing.

Rough Endoplasmic Reticulum

A membranous organelle continuous with the nuclear envelope, studded with ribosomes, where proteins destined for membrane integration or cellular export are synthesized.

Golgi Apparatus

A stack of flattened membranous sacs that functions as a cellular traffic director, modifying and packaging proteins and lipids received from the rough ER.

Peroxisomes

Membranous sacs containing oxidase and catalase enzymes that neutralize toxic free radicals and convert hydrogen peroxide ($H_2O_2$) into harmless water.

Lysosomes

Spherical membranous bags containing digestive enzymes that break down ingested bacteria, viruses, toxins, and non-functional organelles.

Prophase

The initial stage of mitosis where chromatin condenses into visible chromosomes, the mitotic spindle forms, and the nuclear envelope breaks down.

Metaphase

The stage of mitosis where duplicated chromosomes align along the equator or metaphase plate of the cell.

Anaphase

The stage of mitosis in which centromeres split simultaneously and sister chromatids are pulled toward opposite poles of the cell.

Telophase

The final stage of mitosis where chromosome movement stops, nuclear membranes reform around separated chromatin, and the mitotic spindle disappears.

Transcription

The process in the cell nucleus where a segment of double-stranded DNA is converted into a single-stranded mRNA template by RNA polymerase.

Translation

The process occurring at the ribosome where an mRNA transcript is decoded into a polypeptide chain using tRNA molecules carrying specific amino acids.

Hyperplasia

An accelerated rate of cell division that increases total cell numbers in response to physiological demand.

Atrophy

A decrease in the size of a tissue or organ resulting from a loss of stimulation or disuse.

Hypertrophy

An increase in cell or tissue size caused by overuse or increased functional demands.