Anatomy of the Human Body: Introductory Concepts, Chemistry, and Cytology

Comprehensive vocabulary flashcards covering human anatomy definitions, chemical organization, biomolecules, and cellular structures based on lecture material.

Gross Anatomy

A subdivision of anatomy focusing on internal and external body structures visible to the unaided eye, such as bones, the heart, and the stomach.

Microanatomy

A subdivision of anatomy that requires a microscope to observe structures; includes cytology and histology.

Cytology

The branch of microanatomy that studies the internal structures of individual cells.

Histology

The branch of microanatomy that studies tissues, which are groups of structurally similar cells working together.

Epithelial Tissue

One of the four major tissue types that functions to line body surfaces and cavities.

Connective Tissue

One of the four major tissue types that connects and holds other tissue types together, including fat, blood, and areolar tissue.

Muscle Tissue

One of the four major tissue types specialized to contract and generate movement.

Nervous Tissue

One of the four major tissue types specialized for signaling and transmitting electrical signals.

Protons ($p^+$)

Subatomic particles located in the atomic nucleus that possess a positive electrical charge.

Neutrons ($n^0$)

Subatomic particles located in the atomic nucleus that possess a neutral charge.

Electrons ($e^-$)

Subatomic particles orbiting the atomic nucleus that possess a negative electrical charge.

Isotopes

Different structural forms of an element's atom that contain the same number of protons but a different number of neutrons.

Ion

An atom or molecule that is no longer electrically neutral because it has lost or gained one or more electrons.

Anion

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

Cation

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

Ionic Bond

A chemical bond formed by the transfer of electrons from one atom to another, resulting in oppositely charged ions that attract each other.

Covalent Bond

A chemical bond formed when two or more atoms share electrons.

Organic Substances

Chemical compounds containing covalently bonded carbon ($C$) atoms, such as carbohydrates, lipids, proteins, and nucleic acids.

Inorganic Substances

Chemical compounds that usually lack carbon ($C$) atoms, with specific exceptions including carbonic acid ($H_2CO_3$), bicarbonate ($HCO_3^-$), carbon dioxide ($CO_2$), and carbon monoxide ($CO$).

Polar Molecules

Molecules with an unequal sharing of electrons that results in a slight positive charge on one end and a slight negative charge on the other, such as water ($H_2O$).

Acid

A substance that dissociates in water to release hydrogen ions ($H^+$), increasing the free $[H^+]$ concentration and lowering the pH.

Base

A substance that binds to or buffers free hydrogen ions ($H^+$) in water, decreasing free $[H^+]$ concentration and raising the pH.

pH Scale

A numerical measure of the concentration of free hydrogen ions ($[H^+]$) in a solution, ranging from $0$ (highly acidic) to $14$ (highly basic), with $7$ being neutral.

Monosaccharides

Simple single-sugar carbohydrates that serve as the basic building blocks for complex carbohydrates; examples include glucose, fructose, ribose, and deoxyribose.

Disaccharides

Carbohydrates formed when two monosaccharides are covalently bonded together; examples include sucrose, lactose, and maltose.

Polysaccharides

Complex carbohydrates composed of many monosaccharide building blocks bonded together; examples include glycogen in animals and starch in plants.

Triglyceride

A neutral fat glyceride composed of a glycerol backbone bonded to three fatty acid chains.

Phospholipid

A diglyceride lipid consisting of a polar, hydrophilic phosphate head group, a glycerol backbone, and two non-polar, hydrophobic fatty acid tails.

Amino Acids

The basic building-block molecules of all proteins, consisting of an amino group ($-NH_2$), an acidic carboxyl group ($-COOH$), and a variable $R$ group.

Dipeptide

A molecule formed when two amino acids are linked together by a peptide bond.

Polypeptide

A long chain consisting of many amino acids linked together by peptide bonds.

Nucleotide

The basic structural subunit of nucleic acids, consisting of a phosphate group ($PO_4^-$), a pentose sugar (ribose or deoxyribose), and a nitrogenous base.

DNA (Deoxyribonucleic Acid)

A double-stranded helical nucleic acid containing deoxyribose sugar and bases Adenine ($A$), Thymine ($T$), Cytosine ($C$), and Guanine ($G$); functions in cellular reproduction and acts as a template for RNA.

RNA (Ribonucleic Acid)

A single-stranded nucleic acid containing ribose sugar and bases Adenine ($A$), Uracil ($U$), Cytosine ($C$), and Guanine ($G$); functions in protein synthesis.

Adenosine Triphosphate (ATP)

A high-energy molecule consisting of three phosphate groups, ribose, and adenine that stores and provides immediately usable energy for cellular work.

Plasma Membrane

The outer boundary of a cell composed of a phospholipid bilayer, cholesterol, membrane proteins, and membrane carbohydrates.

Intracellular Fluid (ICF)

The fluid contained entirely within the interior of cells.

Extracellular Fluid (ECF)

The fluid found outside of cells, including interstitial fluid (ISF) and blood plasma.

Integral Proteins

Membrane proteins integrated within the cell membrane that possess at least one hydrophobic region.

Transmembrane Proteins

Integral membrane proteins that extend completely across the entire lipid bilayer.

Peripheral Proteins

Membrane proteins attached to either the inner or outer surface of integral proteins on the periphery of the membrane.

Microvilli

Small, finger-like projections of the plasma membrane that function to increase cell surface area.

Fluid Mosaic Model

A model describing the plasma membrane structure as fluid, because phospholipids and proteins move around, and mosaic, because proteins dot the surface like tiles.

Cytoplasm

The cellular area situated between the inside of the plasma membrane and the outside of the nuclear envelope.

Cytosol

The gel-like intracellular fluid of the cytoplasm containing water, ions, suspended macromolecules, and inclusions.

Ribosomes

Non-membranous organelles composed of ribosomal RNA ($\text{rRNA}$) and proteins that serve as the sites of protein synthesis.

Centrosomes

Non-membranous organelles consisting of a pair of centrioles and pericentriolar matrix that serve as organizing centers for microtubules.

Cytoskeleton

An internal network of protein filaments that provides structural support for cell shape, assists in cell movement, and anchors organelles.

Microfilaments

Cytoskeletal elements composed of the protein actin that function in muscle contraction, cell locomotion, and cytokinesis.

Intermediate Filaments

Tissue-specific cytoskeletal filaments (such as keratin) that provide mechanical and structural support to cells.

Microtubules

Hollow cytoskeletal tubes made of tubulin protein that form centrioles, spindle apparatus, cilia, and flagella, and transport organelles.

Mitochondria

Double-membrane-bound organelles that serve as the primary site of ATP synthesis and contain their own DNA, RNA, and proteins.

Rough Endoplasmic Reticulum (RER)

A membranous network studded with attached ribosomes that synthesizes secretory, lysosomal, and membrane proteins.

Smooth Endoplasmic Reticulum (SER)

A membranous network lacking attached ribosomes that synthesizes lipids and steroid hormones.

Golgi Apparatus

Stacks of membrane discs that modify, sort, package, and deliver proteins to the plasma membrane, lysosomes, or for extracellular secretion.

Lysosomes

Membranous organelles filled with digestive enzymes that breakdown bacteria, viruses, and worn-out organelles.

Nuclear Envelope

A double membrane pierced with nuclear pores that encloses the nucleus and is continuous with the endoplasmic reticulum.

Nucleolus

A dense, non-membranous region within the nucleus composed of DNA, RNA, and proteins where ribosome subunits are assembled.

Chromatin

The uncoiled, dispersed form of DNA and histone proteins present in the nucleus when a cell is not actively dividing.