Key Concepts for Anatomy Exam #1

Characteristics of Life

All living things are composed of cells, have a complex structural arrangement, can detect and respond to stimuli, maintain a relatively stable internal environment (homeostasis), grow (increase in size) and develop (undergo natural progression in physical maturation), produce offspring through reproduction, and exhibit metabolism

Respiration

The process where oxygen is obtained from the atmosphere for chemical processes and delivered to the cardiovascular system, while carbon dioxide is removed by the cardiovascular system. This involves gas exchange.

Digestion

A mechanical and chemical process to convert ingested food into simple absorbable substances. Nutrients are absorbed, and waste is processed.

Circulation

The internal movement and distribution of oxygen, wastes, and digestion products throughout the body.

Excretion

The elimination of undigested food and metabolic wastes from the body, including removal of waste products like urine, feces, and carbon dioxide.

Secretion

Epithelial tissues are capable of selective secretion. Glandular epithelial cells produce secretions. Exocrine glands secrete onto external surfaces or into ducts, while endocrine glands secrete hormones into interstitial fluid for bloodstream distribution.

Organism

The whole living animal entity.

Organ System

Consists of organs that interact to perform specific functions.

Organ

A part of the entity (e.g., skin).

Tissue

Cells working together form tissues. The study of tissues is called histology. There are four basic types: Epithelial, Connective, Muscle, and Neural.

Cell

The smallest stable units of life.

Chemical Level

The first level of organization, which studies the structure of matter. Atoms are the smallest stable units of matter.

Cardiovascular System

Responsible for circulation, oxygen delivery, and carbon dioxide removal. Includes the heart and blood vessels.

Digestive System

Involved in food digestion, nutrient absorption, and guarding entrances/exits. Organs like the stomach, intestine, and gallbladder are lined by simple columnar epithelium.

Respiratory System

Handles oxygen intake and carbon dioxide removal, and guards entrances/exits. Structures include nasal cavities, trachea, larger airways in lungs (lined by pseudostratified columnar epithelium), and lung alveoli (containing simple squamous epithelium).

Urinary System

Moves urine and handles excretion. Includes the urinary bladder, ureters, and urine-collecting chambers of the kidneys (which have transitional epithelium).

Reproductive System

Involved in reproductive secretions and guarding entrances/exits. Uterine tubes are lined by simple columnar epithelium, and portions of the male reproductive tract are lined by pseudostratified columnar epithelium.

Skeletal System

Functions in moving and stabilizing the skeleton. Bones (osseous tissue) are a type of supporting connective tissue.

Nervous System

Specialized for conducting electrical impulses and processing information. 98% found in the brain and spinal cord.

Anatomical Position

Standing erect, face forward (anteriorly), arms at the sides, palms facing anteriorly, and feet together and facing forward.

Supine

Lying down face up.

Prone

Lying down face down.

Sagittal Plane

Divides the body into right and left portions, parallel to the long axis.

Midsagittal Plane

Sagittal plane exactly at the midline.

Parasagittal Plane

Sagittal plane off the midline.

Frontal (Coronal) Plane

Divides the body into anterior (front) and posterior (back) portions, parallel to the long axis.

Transverse (Horizontal) Plane

Divides the body into superior (upper) and inferior (lower) portions, perpendicular to the long axis.

Directional Terms

Terms used to describe specific points of reference in anatomy.

Anterior/Ventral

Refers to the front of the body.

Posterior/Dorsal

Refers to the back of the body.

Superficial

Near the surface of the body.

Deep

Toward the interior of the body.

Protons (p+)

Have a positive electrical charge.

Neutrons (n or n0)

Are electrically neutral (uncharged).

Electrons

Have a negative electrical charge.

Electron Cloud

The area created by the whirl of electrons around the nucleus.

Nucleus

The center of an atom containing protons and possibly neutrons.

Valence Shells

The outermost energy level of an atom.

Reactive Atoms

Atoms with unfilled outer (valence) shells that tend to react with other atoms.

Nonreactive Atoms (Inert)

Atoms with full outer (valence) shells that are stable and do not readily react.

Cation

A positive ion that forms when an atom loses electrons.

Anion

A negative ion that forms when an atom gains electrons.

Ionic Bond

Created by the electrical attraction between cations and anions involving electron transfer.

Covalent Bonds

Involve the sharing of electrons between atoms to form molecules.

Nonpolar Molecule

Formed by a covalent bond where electrons are shared equally, resulting in no electrical charge.

Polar Molecule

Formed by polar covalent bonds with unequal sharing of electrons, creating slight charges.

Metabolism

All the chemical reactions occurring in the body at any given moment.

Reactants

The atoms or substances that participate in a chemical reaction.

Products

The results or substances formed from a chemical reaction.

Metabolites

Substances synthesized or decomposed in the body, typically processed by enzymatic reactions.

Monomer

A single molecule that can bond with other identical molecules to form a polymer.

Polymer

A large molecule formed by the bonding of repeating monomer subunits.

Anabolism

The collective term for synthesis reactions that involve forming new chemical bonds.

Catabolism

The collective term for decomposition reactions that involve breaking down larger molecules.

Energy for Anabolism

usually from the kinetic energy released by catabolic reactions.

Synthesis reactions

They assemble smaller molecules into larger molecules and always involve the formation of new chemical bonds.

Decomposition reactions

They break a molecule into smaller fragments and occur inside and outside cells, such as in the digestion of food.

Hydrolysis

A specific type of decomposition reaction where a molecule's bond is broken by adding components of a water molecule (H and OH).

Carbohydrates

Organic compounds that include monosaccharides, disaccharides, and polysaccharides, serving primarily as an energy source for cells.

Monosaccharides

Simple sugars like glucose and fructose that are the monomers of carbohydrates.

Disaccharides

Two monosaccharides joined together (e.g., sucrose).

Polysaccharides

Complex carbohydrates formed from multiple monosaccharides/disaccharides.

Starches

Complex carbohydrates formed by plants from glucose; a major dietary energy source (e.g., potatoes, grains).

Glycogen

'Animal starch' formed by animals from glucose, stored in muscle cells, and broken down when glucose is in high demand.

Lipids

Organic compounds that include fats, which are composed of fatty acids and serve various functions in the body.

Fatty Acids

Long carbon chains with a hydrophilic ('water loving') head and a hydrophobic ('water fearing') tail.

Micelles

Large droplets formed by phospholipids and glycolipids in water.

Nucleic Acids

Organic compounds that store genetic information, including DNA and RNA.

Nucleotides

The monomers of nucleic acids.

DNA

Consists of a pair of nucleotide chains that twist to form a double helix and stores instructions for protein synthesis.

RNA

A single chain of nucleotides that contains uracil (U) instead of thymine.

Messenger RNA (mRNA)

Carries commands from DNA in the nucleus to ribosomes in the cytoplasm.

Transfer RNA (tRNA)

Carries specific amino acids to the ribosome, binding to mRNA codons.

Ribosomal RNA (rRNA)

A component of ribosomes, responsible for stringing amino acids together during protein synthesis.

Amino Acid

The building block (monomer) of proteins.

Peptide Bond

A covalent bond formed by dehydration synthesis that links amino acids together.

Proteins

Complex molecules formed by chains of amino acids that perform various functions in the body.

Cells

The basic, smallest stable units of life.

Tissues

Formed when groups of cells work together to perform specific functions.

Cytoplasm

The site where ribosomes function to synthesize proteins.

Active Transport

An active process that requires energy (ATP).

Passive Transport

A transport mechanism that requires no ATP and moves substances from an area of high concentration to an area of low concentration (down the concentration gradient).

Cotransport

A process where carrier proteins move more than one substance in the same direction across the cell membrane.

Countertransport

A process where carrier proteins (called exchange pumps) move more than one substance in opposite directions across the cell membrane.

Ribosomes

Located in the cytoplasm, they are the site where mRNA binds to tRNA and amino acids are strung together by rRNA to synthesize proteins.

Mitochondria

Produce ATP, the energy molecule for the cell.

Centrioles

they move to poles during prophase. They are part of the centrosome and are found in cells.

Cytoskeleton

Provides structural support for the cell. Proteins can be part of the cytoskeleton. It includes components like microfilaments and provides strong attachments for structures like desmosomes.

Diffusion

The net movement of a substance from an area of higher concentration to an area of lower concentration. This movement occurs down a concentration gradient until an even distribution is reached, at which point molecular motion continues but there is no net movement.

Movement across the lipid portion of the membrane

Examples include lipids, lipid-soluble molecules, and soluble gases.

Movement through membrane channels

Examples include water, small water-soluble molecules, and ions.

Movement using carrier molecules

Examples include large molecules.

Carrier proteins

Transport hydrophilic or large molecules across the cell membrane. They can move specific molecules in one direction, or more than one substance in the same direction (cotransport) or opposite directions (countertransport).

Facilitated Diffusion

A type of passive transport that requires no ATP. A carrier protein binds to a molecule and changes shape to move it across the membrane, moving from high to low concentration.

Vesicular Transport

Materials move across the cell membrane in small membranous sacs called vesicles. This process requires ATP.

Endocytosis

The process of importing extracellular substances into vesicles called endosomes.

Exocytosis

The process of moving wastes or secretory products from an intracellular vesicle to outside the cell.

Epithelial Tissue Characteristics

Avascular layers: They lack blood vessels and rely on underlying connective tissue for nourishment. They cover exposed surfaces and line internal cavities and passageways. They often contain secretory or gland cells. They exhibit polarity, meaning structural differences between their exposed (apical) and attached (basal) surfaces. Their functions include providing physical protection from abrasion, dehydration, and chemical/biological agents; controlling permeability through selective absorption or secretion; providing sensation via specialized cells (neuroepithelium); and producing specialized secretions via glandular cells.

Adhesion Belts

Continuous bands of membrane proteins that strengthen the apical region of cells, reinforcing tight junctions. They attach to microfilaments and encircle cells to bind them to adjacent cells.

Hemidesmosomes

Attach the deepest epithelial cells to the underlying basement membrane.