APHY 101 Lecture & Lab Vocabulary Review

Anatomy

The study of body structure and form, focusing on what a body part is and where it is located.

Physiology

The study of body function, focusing on how a body part works.

Levels of Organization

The structural hierarchy of living organisms, ordered from simplest to most complex: Chemical level -> Cellular level -> Tissue level -> Organ level -> Organ system level -> Organismal level.

Homeostasis

The maintenance of a relatively stable internal environment within a normal physiological range.

Homeostatic Control System

A physiological feedback mechanism consisting of a receptor (sensor) that detects change, a control center (integrator) that processes information, and an effector that executes the response.

Negative Feedback

A primary homeostatic mechanism in which the body's response opposes or reverses the direction of the initial stimulus change.

Positive Feedback

A homeostatic mechanism in which the response amplifies or reinforces the initial stimulus change until a climactic event ends the loop.

Anatomical Position

A standardized body stance where the body is upright, head and eyes facing forward, arms at the sides with palms facing forward, and feet flat and parallel.

Superior (Cranial)

Anatomical directional term meaning toward the head or upper part of a structure.

Inferior (Caudal)

Anatomical directional term meaning toward the feet or lower part of a structure.

Anterior (Ventral)

Anatomical directional term meaning toward the front of the body.

Posterior (Dorsal)

Anatomical directional term meaning toward the back of the body.

Proximal

Anatomical directional term meaning closer to the point of attachment of a limb to the trunk.

Distal

Anatomical directional term meaning farther from the point of attachment of a limb to the trunk.

Atom

The fundamental unit of matter, composed of positively charged protons and uncharged neutrons in a central nucleus surrounded by negatively charged electrons.

Octet Rule

The chemical principle stating that atoms gain, lose, or share electrons to obtain a stable valence shell of 8 electrons.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Electrolyte

A substance that dissolves in water to form ions capable of conducting an electrical current.

Nonpolar Covalent Bond

A chemical bond formed when electrons are shared equally between two atoms of similar electronegativity.

Polar Covalent Bond

A chemical bond formed when electrons are shared unequally due to differing electronegativities, creating partial positive ($\delta+$) and partial negative ($\delta-$) charges.

pH Scale

A measurement scale from 0 to 14 quantifying hydrogen ion concentration, where values below 7 indicate acidity, 7 indicates neutrality, and values above 7 indicate alkalinity.

Phospholipid

An amphipathic lipid consisting of a hydrophilic polar head and two hydrophobic nonpolar tails, serving as the main component of cell membrane bilayers.

Rough Endoplasmic Reticulum

A membrane network studded with bound ribosomes that functions in protein synthesis and modification.

Smooth Endoplasmic Reticulum

A ribosome-free membrane network involved in lipid and steroid synthesis, calcium storage, and drug detoxification.

Golgi Apparatus

A series of stacked, flattened membranous sacs that modify, package, and sort proteins received from the rough ER.

Lysosome

A membrane-bound organelle containing digestive enzymes involved in cellular breakdown, autophagy, autolysis, and pathogen destruction.

Peroxisome

A detoxifying membrane-bound organelle responsible for fatty acid breakdown and chemical detoxification.

Mitochondrion

A double-membrane powerhouse organelle responsible for aerobic cellular respiration, ATP production, and apoptosis.

Sodium-Potassium Pump

A primary active transport membrane protein that uses 1 ATP molecule to pump 3 $\text{Na}^+$ ions out of the cell and 2 $\text{K}^+$ ions into the cell.

Hypertonic Solution

A solution with a higher concentration of solutes than the intracellular fluid, causing water to flow out of the cell and leading to cell shrinkage.

Hypotonic Solution

A solution with a lower concentration of solutes than the intracellular fluid, causing water to enter the cell and leading to cell swelling or lysis.

Cell Cycle

The sequence of events in a cell's life consisting of Interphase ($\text{G}_1$, S, $\text{G}_2$) and M phase (Mitosis and Cytokinesis).

Simple Cuboidal Epithelium

A single layer of cube-shaped cells arranged in circular rings, specialized for secretion and absorption in kidney tubules.

Simple Columnar Epithelium

A single layer of tall, narrow cells arranged in rows, specialized for absorption and secretion in the stomach and intestines.

Stratified Squamous Epithelium

A tissue comprising multiple cell layers with flat apical cells, specialized to protect underlying tissues against physical wear and abrasion.

Adipose Tissue

A loose connective tissue dominated by lipid-storing adipocytes with peripheral nuclei, functioning in energy storage, insulation, and cushioning.

Areolar Connective Tissue

A loose connective tissue containing unorganized fibers and abundant ground substance, serving to loosely bind epithelial tissues and organs.

Dense Regular Connective Tissue

A dense connective tissue featuring tightly packed, parallel collagen fibers designed to resist tensile stress in a single direction within tendons and ligaments.