Anatomy and Physiology - Test 1 (Stephens)

Eicosanoids

20-carbon compounds derived from a fatty acid called arachidonic acid. They function as hormonelike chemical signals between cells.

Metabolic pathway

A chain of reactions with each step usually catalyzed by a different enzyme. Reactant --> Product

Fatty acid

A chain of usually 4 to 24 carbon atoms with a carboxyl group at one end and a methyl group at the other. Fatty acids and their fats are classified as saturated or unsaturated. Saturated fatty acid = Has as much hydrogen as it can carry. No more could be added without exceeding four covalent bonds per carbon; thus it is "saturated" with hydrogen. Unsaturated fatty acid = Some carbon atoms are joined by double covalent bonds. Each of these could share one pair of electrons with another hydrogen atom instead of the adjacent carbon, so hydrogen could be added to this molecule. Polyunsaturated fatty acid = Those with multiple c=c bonds. Essential fatty acids = must be obtained from the diet because we cannot synthesize them.

Reduction

A chemical reaction in which a molecule gains electrons and energy. When a molecule accepts electrons, it is said to be reduced; a molecule that donates electrons to another is called a reducing agent (electron donor). The oxidation of one molecule is always accompanied by the reduction of another, so these electron transfers are known as oxidation-reduction (redox) reactions. Not all redox reactions transfer electrons. Often, electrons are transferred in the form of hydrogen atoms.

Holism

A complementary theory that there are "emergent" properties of the whole organism that cannot be predicted from the properties of its separate parts - human beings are more than the sum of their parts. In order to be effective, a health care provider treats not just a disease, but a whole person. A patients perceptions, emotions, ad confidence profoundly effect the outcome of the treatment. Often times, these psychological factors play a greater role in a patients recovery than the physical treatments.

A Law of Nature

A generalization about the predictable ways in which matter and energy behave. Result of inductive reasoning. Some laws are expressed as concise verbal statements while others are expressed as mathematical formulas. Laws are descriptions. They do not "govern", but "describe".

Organ System

A group of organs with a unique collective function. Ex. Circulation, respiration, digestion The human body has 11 organ systems: 1. Integumentary 2. Skeletal 3. Muscular 4. Nervous 5. Endocrine 6. Circulatory 7. Lymphatic 8. Respiratory 9. Urinary 10. Digestive 11. Reproductive The organs in each system are usually usually physically interconnected.

Carbohydrate (CH2O)n

A hydrophilic organic molecule. n = the number of carbon atoms. Carbohydrates have a 2:1 ratio of hydrogen to oxygen. Ex. n = 6 C6H12O6 The names of individual carbohydrates are often built on the word root sacchar- or the suffix -ose, both of which mean "sugar" or "sweet". The most familiar carbohydrates are sugars and starches. Carbohydrates are categorized into: monosaccharides, disaccharides, polysaccharides, and conjugated carbohydrates. Carbohydrates monomers are Monosaccharides.

Decomposition Reactions

A large molecule breaks down into two or more smaller ones. AB ----> A + B Ex. When you eat a potato, digestive enzymes decompose its starch into thousands of glucose molecules, and most cells convert that glucose to water and carbon dioxide.

Steroid

A lipid with 17 of its carbon atoms arranged in four rings.

Tissue

A mass of similar cells and cell products that form a discrete region of an organ and perfoms a specific function. The body contains four primary classes of tissue: Epithelial Connective Nervous Muscular Histology is the study of tissues with the use of a microscope.

pH

A measure derived from the molarity of H+. Represented by square brackets. [H+]. The pH scale was invented in 1909 by Soren Sorensen. The pH scale extends from 0.0 to 14.0. A solution with a pH of 7.0 is neutral; pH's below 7 are acidic and pH's above 7 are basic (alkaline). The lower the pH value (the more acidic), the more hydrogen ions a solution has. The pH scale is logarithmic, this one whole number on the scale represents a 10-fold change in H+ concentration. Ex. A solution with pH 4 is 10 times as acidic as one with pH 5, and 100x more acidic as one with pH 6. Slight disturbances of pH can seriously disrupt physiological functions. Chemical solutions that resist changes in pH are called buffers.

Tyiglyceride

A molecule consisting of a three-carbon alcohol called glycerol linked to three fatty acids. Each bond between a fatty acid and glycerol is formed by dehydration synthesis. Once joined to glycerol, a fatty acid can no longer donate a proton to solution and is therefore no longer an acid. For this reason, triglycerides are also called neutral fats. Triglycerides are broken down by hydrolysis reactions, which split each of these bonds apart by the addition of water. Triglycerides that are liquid at room temperature are called oils.

Molecules

A particle composed of at least two atoms. The largest molecules (macromolecules) are proteins, fats, and DNA.

Chemical Reaction

A process in which a covalent or ionic bond is formed or broken. The course of a chemical reaction is symbolized by a chemical equation that shows the reactants on the left, products on the right, and an arrow pointing from the reactants to the products. Chemical reactions can be classified as decomposition, synthesis, or exchange reactions.

Negative Feedback

A process in which the body senses a change and activates mechanisms that negate or reverse it. Ex. Shivering to produce heat when cold This is a fundamental mechanism that keeps a variable close to its set point. Negative feedback is the key mechanism for maintaining health.

Base

A proton acceptor. Many bases are substances that release hydroxide ions (sodium hydroxide).

Experimenter Bias

A situation in which an experimenters bias, explicit or otherwise, influence the way the experimenter analyzes and interprets the data, therefore resulting in a biased conclusion. This is remedied using a Double-Blind Method - Neither the subject nor the person administering the drug or placebo know which is being received.

Cellulose

A structural polysaccharide that gives strength to the cell walls of plants. It is the principal component of wood, cotton, and paper. It is composed of a chain of a few thousand glucose monomers. Cellulose is the most abundant organic compound on earth and it is a common component of the diet of humans and other animals. However, we have no enzymes to digest it and thus derive no energy or nutrition from it. It still works as a dietary fiber because it swells with water in the digestive tract and helps move other materials through the intestine.

Organ

A structure composed of two or more tissue types that work together to carry out a particular function. Organs have definite anatomical boundaries, are distinguishable from other structures, and fall within the gross anatomy domain (because you can see them with the naked eye) However, there are smaller organs within large organs that can only be seen under a microscope, such as in the integumentary system (the skin is the body's largest organ). Some of the skins organs are hair, nails, glands, nerves, and blood vessels. A single organ may belong to two organ systems. ex. Pancrease is part of the endocrine and digestive systems.

Emulsion

A suspension of one liquid in another. Ex. Oil and vinegar salad dressing.

Arboreal

A treetop habitat that provides safety from predators, less competition, and a rich food supply. Animals able to move about most easily in this environment was much more likely to survive. In fact, this type of habitat set the groundwork for human genetics. Primates in the Arboreal habitat eventually developed opposable thumbs and mobile shoulders, allowing them to reach in any direction and grasp/manipulate small objects precisely. Primates also gained forward facing eyes = stereoscopic vision (depth perception). Primates also advanced in bipedalism = standing and walking on two legs.

Statistical Testing

A type of test that is applied to data that decides the probability of that data being accurate, reliable, and profound.

Hydrolysis

A water molecule ionizes into OH- and H+. An enzyme breaks the covalent bond linking one monomer to another, and adds OH- to one monomer and H+ to the other one. All chemical digestion consists of hydrolysis reactions.

Palpation

A way of examining the structures of the human body that is done by feeling a structure with the hands. Ex. Palpating a swollen lymph node or taking a pulse.

Auscultation

A way of examining the structures of the human body that is done by listening to the natural sounds made by the body. Ex. Listening to heart and lung sounds via a stethoscope.

Inspection

A way of examining the structures of the human body that is done by simply looking at the body's appearance. Ex. Physical examination

Percussion

A way of examining the structures of the human body that is done by tapping on the body. Ex. Feeling for abnormal tissue and listening for emitted sounds that may signal abnormalities such as pockets of fluid or scar tissue.

Reproduction

All living organisms can produce copies of themselves, thus passing their genes on to new, younger containers - offspring.

Evolution (characteristic of life)

All living species exhibit genetic change from generation to generation and therefore evolve. Evolution occurs because of mutations (changes in DNA structure). Mutations are inevitable and cause evolution because environmental selection pressure favor the transmission of some genes more than others. Evolution is a characteristic seen only in the population as a whole. No single individual evolves over the course of its life.

Metabolism

All the chemical reactions in the body. Metabolism is divided into: Catabolism and Anabolism.

Hypothesis

An educated speculation or possible answer to the question. The purpose of a hypothesis is to suggest a method for answering a question. From the hypothesis, a researcher makes a deduction (if-then). An experiment then yields an observation that either supports the hypothesis or requires the scientist to modify or abandon it for a better hypothesis. Hypothesis testing operates as a cycle of conjecture and disproof until one is found that is supported by the evidence.

Psychosomatic Effects

An effect on a persons physiology that is caused by a state of mind. Ex. In an experiment, if a person is aware that they are only receiving a sugar pill in an experiment on the effects of a new cancer treatment drug, this could cause severe distress because they know that they are not receiving the treatment. That is why they are given a sugar pill instead, and not informed of what they are receiving, that way their state of mind won't be affected by that knowledge.

Glycogen

An energy-storage polysaccharide made by cells of the liver, muscles, brain, uterus, and vagina. It is a long, branched glucose polymer. The liver produces glycogen after a meal, when the blood glucose level is high, and then breaks it down between meals to maintain blood glucose levels when there is no food intake. Muscle store glycogen for its own energy needs, and the uterus uses it in early pregnancy to nourish the embryo.

Dehydration Synthesis (Condensation)

An enzyme removes a hydroxyl group (-OH) from one monomer and a hydrogen (-H) from another, producing water as a by-product. The two monomers become joined by a covalent bond, forming a dimer. This is repeated for each monomer added to the chain, potentially leading to a chain long enough to be considered a polymer.

Theory

An explanatory statement or set of statements derived from facts, laws, and confirmed hypotheses. Some theories have names, but many remain unnamed. The purpose of a theory is not only to summarize what we know, but to suggest directions for further study and to help predict what the findings should be if the theory is correct. Ex. Cell theory, fluid-mosaic theory, etc.

Homeostasis

An organism maintains relatively stable internal conditions despite the constantly changing environment around the organism. Ex. Stable temperature, blood pressure, body weight. Homeostasis usually occurs as negative feedback. Negative meaning the opposite. Ex. A person who is cold will want the opposite (heat), so they will shiver. This should help return their temperature to a state of equilibrium. Claude Bernard is credited with observing that the internal conditions of the body remain quite constant even when external conditions vary greatly. Ex. Whether it's freezing or hot outside, the internal temp of our body stays within 97-99 degrees Fahrenheit. Walter Cannon coined the term "homeostasis" for this tendency to maintain internal stability. Physiology is largely seen as a group of mechanisms for maintaining homeostasis, and the loss of homeostatic control as the cause of illness and death. Pathophysiology is the study of unstable conditions that result when our homeostatic controls go awry.

Evolutionary Medicine

Analyzes how human disease and dysfunctions can be traced to differences between the artificial environment in which we now live, and the prehistoric environment to which homo sapiens were biologically adapted. Ex. Relating sleep to mood disorders, artificial lighting to night-shift work, obesity, skin cancer, etc.

Development

Any change in form or function over the lifetime of the organism. The development process usually involves differentiation and growth. Differentiation = The transformation of cells with no specialized function into cells that are committed to a particular task. Growth = An increase in size. Growth can occur in different ways, not just the way our bodies do. Ex. Letting a saturated sugar solution evaporate results in crystals to grow from it, but not through a change in the composition of the sugar. More sugar molecules are added from the solution to the crystal surface. However, growth in the body occurs through chemical change (metabolism). Our bodies are composed not of the molecules we eat, but of molecules made by chemically altering the food we eat.

Oxidation

Any chemical reaction in which a molecule gives up electrons and releases energy. A molecule is "oxidized" by this process, and whatever molecule takes the electrons from it is an oxidizing agent (electron acceptor) Ex. The rusting of iron is a slow oxidation process in which oxygen is added to iron to form iron oxide. Many oxidation reactions don't involve oxygen at all. Ex. When yeast ferments glucose to ethanol, no oxygen is required.

Peptide

Any molecule composed of two or more amino acids joined by a peptide bond. A peptide bond, formed by dehydration synthesis, joins the amino group of one amino acid to the carboxyl group of the next. Peptides are named for the number of amino acids they have. Ex. Dipeptides have two and tripeptides have three. Chains of fewer than 10 or 15 amino acids are oligopeptides, and chains larger than that are polypeptides. Ex. Oligopeptide = oxytocin, composed of 9 amino acids.

Acid

Any proton donor (a molecule that releases a proton (H+) in water. Acidity is expressed in terms of pH, a measure derived from the molarity of H+. Molarity is represented by square brackets [H+]. Pure water has a neutral pH because it contains equal amounts of H+ and OH-.

Isotopes

Atoms of an element that differ in the number of neutrons. (atomic mass is affected) Ex. Hydrogen typically only has one proton. Hydrogen's isotopes are Deuterium(2H): with one proton and one neutron (therefore has 1 more neutron than H because H has no neutrons) Tritium (3H): one proton and two neutrons (2 more neutrons than H). Ex. Over 99% of carbon atoms have an atomic mass of 12 (6 protons and 6 neutrons), therefore being called carbon-12. However, carbon has a couple of isotopes: (13C) with 6 protons and 7 neutrons and (14C) with 6 protons and 8 neutrons. Notice how the isotopes differ from the original by the number of neutrons. All isotopes of any given element behave the same chemically (they only differ physically). Ex. Deuterium reacts with oxygen the same way H does to produce water. The atomic mass of an element accounts for the fact that an element is a mixture of isotopes (thus is the reason most atomic mass numbers aren't whole numbers).

Genetic Revolution

By the end of the 20th century, we had discovered the chemical base sequence of every human gene. Because of this discovery, we have made efforts of gene therapy. This period will be known as the genetic revolution.

Reversible Reactions

Can go in either direction under different circumstances. Ex. Carbon dioxide combines with water to produce carbonic acid, which in turn decomposes into bicarbonate ions and hydrogen ions. The direction in which a reversible reaction goes is determined by the relative abundance of substances on each side of the equation. These reactions follow the law of mass action: they proceed from the reactants in greater quantity to the substances with the lesser quantity. In the absence of upsetting influences, reversible reactions exist in a state of equilibrium, in which the ratio of products to reactants is stable. Ex. Carbonic acid normally maintains a 20:1 ratio of bicarbonate ions to carbonic acid molecules. This equilibrium can be upset by a surplus of hydrogen ions, which drives the reaction to the left, or adding carbon dioxide and driving it to the right.

Monosaccharides

Carbohydrates simplest monomers: Glucose = "blood sugar" that provides energy to most of our cells. Glucose is oxidized in the body to make ATP(energy) Galactose Fructose C6H12O6 (all three have the same formula and are isomers. We obtain these sugars mainly by the digestion of more complex carbohydrates. Ribose(RNA) and Deoxyribose(DNA) are important as well.

Conjugated Carbohydrates

Carbohydrates that are covalently bound to proteins and lipids. The external surface of the cell membrane is made from glycolipids and glycoproteins as a result. Lipids and protein molecules at the surface have up to 12 sugars attached to them, forming those glycolipids and glycoproteins. Glycoproteins are a major component of mucus.

Carbon Backbones

Carbon atoms that have readily bonded with one another to form long chains, branched molecules, and rings. Carbon also commonly forms covalent bonds with hydrogen, oxygen, nitrogen, and sulfur. Carbon backbones carry a variety of function groups - small clusters of atoms that determine many properties of an organic molecule. Ex. Organic acids bear a carboxyl group and ATP is named for its three phosphate groups.

Evolution

Change in the genetic composition of a population of organisms. Chimpanzees are humans closest living relatives. Their genetics differ from ours only by 1.6%. Ex. bacterial resistance to antibiotics, new strains of AIDS, new species of organisms.

Ions

Charged particles with unequal numbers of protons and electrons. Ions are created through ionization, which is the process of electrons transferring from one atom to another. Elements with 1-3 valence electrons tend to give theirs away and those with 4-7 tend to gain more. The particle that gains electrons acquires a negative charge and is called an anion. The particle that loses electrons acquires a positive charge (it has a positive charge because when it gives up it's electrons, it has a surplus of protons, which are positively charged) and is called a cation. The charge of an ion is called its valence. Ions with opposite charges are attracted to each other and tend to follow one another.

Molecules (Chapter 2)

Chemical particles composed of two or more atoms united by a chemical bond. These atoms may be identical or different. Molecules composed of two or more elements are called compounds. Ex. CO2 is a compound because it is made up of carbon and oxygen. Molecules with an identical molecular formula but different arrangement of their atoms are called Isomers of each other. Ex. Ethanol and Ethyl both have the same molecular formula, but their structure, chemical properties, and physiological effects are different. Molecules are held together and attracted to one another by chemical bonds. (ionic, covalent, hydrogen, van der waals forces).

Buffers

Chemical solutions that resist changes in pH.

Catabolism

Consists of energy-releasing decomposition reactions. These reactions break covalent bonds, produce smaller molecules from larger ones, and release energy that can be used for other physiological work. These reactions are called exergonic reactions. Ex. If you hold a beaker of water in your hand and pour sulfuric acid into it, the beaker will get so hot you may have to put it down. This heat signifies that exergonic reactions are occurring.

Anabolism

Consists of energy-storing synthesis reactions, such as the production of protein or fat. These reactions require an energy input, and are called endergonic reactions. Anabolism is driven by the energy that catabolism releases, so endergonic and exergonic processes are linked.

Marie Curie (Madame Curie)

Discovered that polonium and radium darkened photographic plates through several thick layers of paper. She coined this term radioactivity for the emission of energy by these elements. She was the first woman in the world to receive a Nobel Prize and the first woman in France to receive a Ph.D. Curie had a daughter, and the two of them crusaded to train women for careers in science. In World War 1, they trained physicians in the use of X-ray machines. Marie pioneered radiation therapy for breast and uterine cancer. At first, people thought of radium as a wonder drug, consuming and bathing in it. Many people, including Marie and her daughter died from radiation induced illnesses.

Dissection

Earning a deeper understanding of the body by carefully cutting and separating tissues to reveal their relationships. Anatomy and dissection mean "cutting apart" Before the 19th century, dissection was called "anatomizing".

Potential Energy

Energy contained in an object because of its position or internal state but that is not doing work at the time. Ex. The water behind a dam has potential energy because of its position. Let the water through, however, and it is kinetic energy. Ex. Ions concentrated on one side of a cell membrane have potential energy that can be released by opening gates in the membrane. As the ions flow through the gates, their kinetic energy can be tapped to create a nerve signal or make the heart beat

Kinetic Energy

Energy of motion, energy that is doing work. Ex. Kinetic energy is observed in functions such as musculoskeletal movements, the flow of ions into a cell, and vibration of the eardrum.

Starch

Energy-storage polysaccharide of plants. They store it when sunlight and nutrients are available and draw from it when photosynthesis is not possible. Starch is the only significant digestible polysaccharide in the human diet.

Adaptations

Features of anatomy, physiology, and behavior that evolve in response to selection pressures and enable an organism to cope with the challenges of its environment.

Feedback Loops

Feedback mechanisms alter the original changes that triggered them. Ex. A houses heating system turning on and off consistently in response to varying temperature readings.

Life

From a biological standpoint, life is not a single property. It is a collection of properties that help to distinguish living from nonliving things.

Enzymes

Global proteins that function as biological catalysts. They enable biochemical reactions to occur rapidly at normal body temperatures. The substance an enzyme acts upon is called its substrate. Substrates approach pockets on the enzymes surface called "active sites". Many enzymes have two active sites, enabling them to bind two different substrates and bring them together in a way that makes them react more readily with eachother. When the substrate binds to an enzyme, it forms an enzyme-substrate complex.

William Harvey (English Physiologist)

Harvey is famous for his studies of blood circulation, his published work called De Motu Cordis (On the Motion of the Heart). He realized that blood must circulate continuously around the body from the heart to the other organs and back to the heart again. Harvey's colleagues ridiculed him because his beliefs went against Galen. However, Harvey was correct. Harvey's contributions represent the birth of experimental physiology.

Electrical Energy

Has both potential and kinetic forms. It is potential energy when charged particles have accumulated at a point such as a battery terminal or on one side of a cell membrane. It becomes kinetic energy when these particles begin to move and create an electrical current. Ex. When electrons move through your household wiring or sodium ions move through a cell membrane.

Antony Van Leeuwenhoek (Inventor)

He invented the Simple Microscope. This microscope was simpler in style than Hooke's, but it achieved much greater magnification (up to 200x). He used his simple microscope to examine lake water where he discovered microorganisms. He also examined blood cells, sperm, muscular tissue, and bacteria. In Hooke and Leeuwenhoek's time, people were very excited about the microscope at first, but eventually came to see it as a toy for the upper class. However, their discoveries laid an entirely new foundation for modern medicine centuries later.

Michael Servetus

He realized how blood circulation works at the same time as William Harvey.

Avicenna (Ibn Sina - Galen of Islam)

He was a highly regarded medical scholar who studied Galen and Aristotle and was not afraid to question the material where evidence demanded. Because of inclination toward science and research, the Mideast soon became superior to European medicine. Avicenna's textbook (The Canon of Medicine) was then taught in European schools for over 500 years.

Ionizing Radiation

High-energy radiation such as that emitted by radioisotopes that ejects electrons from atoms, converting those atoms to ions. Ionizing radiation destroys molecules and produces free radicals and ions in human tissues that may be fatal in high doses, or mutagenic (causing mutations in DNA) and carcinogenic (triggering cancer as a result of mutation) in lower doses. Examples of ionizing radiation are: Ultraviolet rays, x-rays, and radiation produced by nuclear decay: alpha (a) particles, beta (B) particles, and gamma (y) particles. Alpha particles are too large to penetrate skin, and beta particles penetrate only a few milimeters. Thus, these types of radioisotopes outside the body aren't very harmful, but if inside the body can be very dangerous. Gamma rays, on the other hand have high penetrating power and are dangerous when emitted from both outside and inside of the body. Physical Half-Life: the time required for 50% of its atoms to decay to a more stable isotope. Biological Half-Life: the time required for half of it to disappear from the body. In general, biological-half life is way shorter than physical half-life.

Robert Hooke (Inventor)

Hooke designed scientific instruments of various kinds, most notably the compound microscope. He was the first to see and name cells. He observed cork shavings, describing them as "a great many little boxes", which he referred to as cellulae (little cells) after the cubicles of a monastery. He also observed that living cells are "filled with juices", or as we would call it "cytoplasm" or "cytosol". He published the first comprehensive book of microscopy (Micrographia) in 1665.

Variability

Humans vary anatomically and physiology. The anatomy we study as "normal" accounts for only about 70% of variation. Physiology is even more variable than anatomy.

Lipids

Hydrophobic organic molecule, usually composed only of carbon, hydrogen and oxygen, with a high ratio of hydrogen to oxygen. Lipids are variable in structure. Five primary types of lipids in humans are: fatty acids, triglycerides, phospholipids, eicosanoids, and steroids.

Atoms (Chapter 2)

Imaginary particles so small we can't cut them. Democritus reasoned that such things exist. Atoms were just philosophical until John Dalton began to develop the atomic theory. Niels Bohr proposed a model of atomic structure similar to planets orbiting the sun. (planetary model) At the center of an atom is the nucleus (composed of protons and neutrons). Protons (P+) have a single positive charge. Neutrons (N0) have no charge. Each proton or neutron weighs approximately 1 atomic mass unit (amu). Thus, the atomic mass of an element is approximately its total number of protons and neutrons. Electrons (E-) surround the nucleus in one or more clouds (electron shells - energy levels) of tiny particles with a single negative charge and virtually no mass. Electrons determine the chemical properties of an atom, governing what molecules can exist and what chemical reactions can occur. The electrons that determine this are the outermost layer, called valence electrons. The number of electrons = the number of protons, so their charges cancel each other and an atom is electrically neutral. Electrons can have up to 8 shells, but in humans it never exceeds 4.

Dynamic Equilibrium (balanced change)

In internal state of the body in which there is a certain set point (average value) for a given variable and conditions fluctuate slightly around this point. Ex. When it comes to body temperature, the set point is 37 degrees Celsius and temp is constantly fluctuating around that number.

Scientific Fact

Information that can be independently verified by any trained person. Ex. Iron deficiency leads to anemia

Minerals

Inorganic elements extracted from the soil by plants and passed up the food chain to humans and other organisms. Minerals constitute about 4% of the human body weight. About 75% of this weight is due to Calcium and Phosphorus. The rest is Cl, Mg, K, Na and S. (Chlorine, Magnesium, Potassium, Sodium, Sulfur) Minerals enable enzymes and other organic molecules to function. They also allow nerve and muscle to function.

Suspension

Large particles of a mixture that exceed 100nm in size, are cloudy or opaque, too large to penetrate selectively permeable membranes, and are too heavy to remain permanently suspended. Suspensions separate on standing. Ex. Blood cells form a suspension in the blood plasma and settle to the bottom of a tube when blood is allowed to stand without mixing.

Cellular Composition

Living matter is always compartmentalized into one or more cells.

Organization

Living things exhibit a higher level of organization than the nonliving world around them. They expend a great deal of energy to maintain order. A breakdown in that order is accompanied by disease and often death.

Metabolism

Living things take in molecules from the environment and chemically change them into molecules that form their own structures, control their physiology, or provide them with energy. Metabolism is the sum of that internal chemical change. It produces chemical wastes, which must be dispelled from the body. This means that there is a constant turnover of molecules in the body. Nearly every molecule of your body has been replaced within the past year.

Polysaccharides

Long chains of monosaccharides, up to thousands of monosaccharides long. There is no criteria for when a chain is long enough to be called a polysaccharide, but a chain of 10 or 20 monosaccharides would generally be called an oligosaccharide, where a chain of 50 or more would generally be called a polysaccharide. Three polysaccharides are: Glycogen, starch, and cellulose. These are all composed of glucose. Humans make glycogen, but starch and cellulose are plant products.

Proteoglycans

Macromolecules in which the carbohydrate component is dominant and a peptide or protein forms a smaller component. They form gels that hold cells and tissues together, form a gelatinous filler in the umbilical cord and eye, etc.

Moses ben Maimon (Maimonides)

Maimonides was a Jewish physician who fled to Egypt to escape anti-Semitic persecution. He spent the rest of his life in Egypt serving as a physician to the court of the sultan, Saladin. He was a highly admired rabbi who wrote 10 influential medical books and many treatises on specific diseases.

Medical Imaging Techniques

Methods of viewing the inside of the body without surgery. This branch of medicine is called Radiology.

Organelles

Microscopic structures in a cell that carry out its individual functions Ex. Some organelles are mitochondria, centrioles, and lysosomes. Organelles are composed of molecules.

Colloids

Mixtures of protein and water. Can change from liquid to gel states. Can range from 1 to 100nm in size. Colloids are large in size, so they scatter light and are usually cloudy They are too large to pass through most selectively permeable membranes. However, they are still small enough to remain permanently mixed with the solvent when the mixture stands.

Polymers

Molecules made of a repetitive series of identical or similar subunits called monomers. (monomers form polymers) Ex. Starch is a polymer of about 3,000 glucose monomers. In starch, the monomers are identical. Other polymers have a basic structural similarity but differ in detail. Ex. DNA is made of 4 different kinds of monomers (nucleotides) Proteins are made of 20 different kinds (amino acids) The joining of monomers to form a polymer is called polymerization. Living cells achieve this through a reaction called dehydration synthesis (condensation).

Nucleotides

Monomers of nucleic acids. Made up of a single or double carbon-nitrogen ring called a nitrogenous base, a monosaccharide, and one or more phosphate groups. One of the best-known nucleotides is ATP (energy). Adenine, ribose, and three phosphate groups.

Hypothetico-Deductive Method

Most of our physiological knowledge has been obtained by this method. An investigator begins by asking a question and forming a hypothesis (an educated speculation or possible answer to the question). A good hypothesis must be: 1. Consistent with what is already known 2. Capable of being tested and possibly falsified by evidence. Falsifiability means that if we claim something is scientifically true, we must be able to specify what evidence it would take to prove it wrong. If nothing could possibly prove it wrong, then it's not scientific.

Selection Pressures

Natural forces that promote the reproductive success of some individuals more than others. Ex. Climate, predators, disease, competition, no food.

Physiology Subdisciplines

Neurophysiology = Physiology of the nervous system Endocrinology = Physiology of hormones Pathophysiology = Mechanisms of disease

Amino Group (-NH2)

Occurs in amino acids and proteins.

Carboxyl Group (-COOH)

Occurs in amino acids, sugars and proteins

Methyl (-CH3)

Occurs in fats, oils, steroids and amino acids.

Hydroxyl (-OH)

Occurs in sugars and alcohols.

Aristotle (Philosopher)

One of the first philosophers to write about anatomy and physiology. He believed that diseases could have supernatural causes (theologi) or natural ones (physici or physiologi) In his book, On the Parts of Animals, he tried to identify unifying themes in nature. He said that complex structures are built from a smaller variety of simple components.

Andreas Vesalius

One of the founding physicians of modern western medicine. Vesalius taught anatomy in Italy during the time where the Catholic Church allowed cadaver dissection in cases of suspicious death. Vesalius is famous for having come down off of the cathedra during lessons to perform dissections of cadavers for his students, rather than having a barber-surgeon do it. He was the first to publish accurate illustrations for teaching anatomy after pointing out that much of Galen's books were wrong. He published the first atlas of anatomy (De Humani Corporis Fabrica - On the Structure of the Human Body)

Exploratory Surgery

Opening the body and taking a look inside to see what was wrong and what could be done about it. This process was risky and was replaced by medical imaging techniques instead.

Macromolecules

Organic molecules made from carbon. Their molecular weights range from the thousands (as in starch and proteins) to the millions (as in DNA). Most macromolecules are polymers.

Solution

Particles of matter called a solute mixed with a more abundant substance called the solvent (usually water). The solute may be a gas, solid, or liquid. A solute and solvent cannot be visually distinguished from each other, even with a microscope, because of their size. They don't scatter light noticeably, so solutions are usually transparent. Solute particles can pass through most selectively permeable membranes, such as dialysis tubing and cell membranes. The solute doesn't separate from the solvent when the solution is allowed to stand.

Protein

Polymer of amino acids (made up of amino acids) A protein is a polypeptide of 50 amino acids or more. Proteins have complex coiled and folded structures; slight changes in their "conformation" (3d Shape) can destroy the proteins function. A proteins functions are structure, communication, membrane transport, catalysis, recognition and protection, movement, and cell adhesion. Ex. Keratin is a protein, and so are enzymes.

Nucleic Acids

Polymers of nucleotides. The largest is DNA (deoxyribonucleic acid). RNA (ribonucleic acid) forms DNA.

Chemical Energy

Potential energy stored in the bonds of molecules. Chemical reactions release this energy and make it available for physiological work.

The Inductive Method

Prescribed by Bacon. It is the process of making numerous observations until one feels confident in drawing generalizations and predictions from them. Ex. Our knowledge of anatomy is inductive because we have described the normal structure of the body through observations of many bodies. We must be careful not to assume that our observations are proof. We can never prove a claim beyond all possible refutation, only beyond a reasonable doubt if arrived at by reliable methods of observation, tested and confirmed repeatedly and not falsified by any credible observation.

Temperature

Reaction rate increases as the temperature rises. This is because heat causes molecules to move more rapidly and collide with greater force and frequency.

Concentration

Reaction rate increases when the reactants are more concentrated. This is because the molecules are more crowded and collide more frequently.

Scientific Method

Refers to an approach to science with disciplined creativity, careful observation, logical thinking, and honest analysis of one's observations and conclusions. Within the scientific method, we must constantly judge which claims are trustworthy and which are not.

Ionic Bond

Relatively weak attraction between an anion and a cation. Easily disrupted in water, as when salt dissolves.

Responsiveness and Movement

Responsiveness = The ability to sense and react to stimuli (changes in the environment). Also may be called excitability. Responsiveness occurs at all levels from the single cell tot he entire body. It characterizes all living things. Responsiveness is obvious in animals because of nerve and muscle cells that exhibit high sensitivity to environmental stimuli, rapid transmission of information, and quick reactions. Most living organisms can self-propel from place to place. All organisms and cells can at least move substances internally (move food along the digestive tract or molecules and organelles from place to place within the cell)

Covalent Bond

Sharing of one or more pairs of electrons between nuclei. Single Covalent Bond = sharing of one electron pair. Double Covalent Bond = Sharing of two electron pairs. Often occurs between carbon atoms, between carbon and oxygen, and between carbon and nitrogen. Nonpolar Covalent Bond = Covalent bond in which electrons are equally attracted to both nuclei. May be single or double. Strongest type of chemical bond. Polar Covalent Bond = Covalent bond in which electrons are more attracted to one nucleus than to the other, resulting in slightly positive and negative regions in one molecule. May be single or double.

Oligosaccharides

Short chains of three or more monosaccharides.

Organism

Single, complete individual

Functional Groups

Small clusters of atoms that determine many of the properties of an organic molecule. Ex. Organic acids bear a carboxyl group = (COOH) (amino acids, sugars, proteins) ATP is named for it's three phosphate groups. Other common functional groups include hydroxyl, methyl, and amino groups.

Hierarchy of Complexity

Smallest to Largest: atoms, molecules, organelles, cells, tissues, organs, organ systems, organism

Natural Selection

Some individuals within a species have hereditary advantages over their competitors. Ex. Better camoflage, disease resistance, etc.

Gross Anatomy

Structures that can be seen with the naked eye, either through surface observation, radiology, or dissection. For example, histology (microscopy) would NOT be gross anatomy because the structures viewed within the microscope can only be seen because of the microscope (not the naked eye).

Histology (microscopic anatomy)

Studying individual cells and tissues with the use of a microscope. Histopathology is the examination of tissues for signs of disease.

Mixture

Substances that are physically blended but not chemically combined. Each substance retains it's own chemical properties. Most of the mixtures in our bodies consist of chemicals dissolved or suspended in water.

Electrolytes

Substances that ionize in water (acids, bases, or salts) and form solutions capable of conducting electricity. Electrolytes conduct electrical currents and are important for their chemical reactivity, osmotic effects, and electrical effects. This is why electrolyte balance is one of the most important things to have. An electrolyte imbalance can cause things such as muscle cramps, brittle bones, coma, and cardiac arrest.

Disaccharides

Sugars composed of two monosaccharides: Sucrose = Glucose + Fructose Lactose = Glucose + Galactose Maltose = Glucose + Glucose Sucrose is table sugar, lactose is milk sugar, and maltose is a product of starch digestion and is in malt beverages.

Hippocrates (Greek Physician)

The "father of medicine". He established a code of ethics for physicians. (Hippocratic Oath) He urged physicians to stop attributing disease to the activities of gods and demons and to seek their natural causes.

Cholesterol

The "parent" steroid from which the other steroids are synthesized. We obtain dietary cholesterol only from foods of animal origin. Plants make only trace amounts of no dietary importance. It is an important component of cell membranes and is required for proper nervous system function. Only 15% of our cholesterol comes from the diet; the other 85% is internally synthesized by the liver.

Thermal Stability

The ability of water to help stabilize the internal temperature of the body. This results from the high heat capacity of water (the amount of heat required to raise the temperature of 1g of a substance by 1 degree Celsius). The base unit of heat is the calorie (cal) - 1 cal is the amount of heat that raises the temperature of 1g of water to 1 degree Celcius. The same amount of heat in a nonpolar substance would raise the temp 4x as much. The difference is the presence or absence of hydrogen bonds. The hydrogen bonds of water molecules inhibit the movement of said molecules, thus reducing the ability to increase temperature.

Solvency

The ability to dissolve other chemicals. Water is considered a universal solvent because it dissolves a broader range of substances than any other liquid. Substances that dissolve in water (such as sugars) are hydrophilic. Substances that do not dissolve in water (such as fats) are hydrophobic. Virtually all metabolic reactions depend on the solvency of water. The solvency of water makes it the body's primary means of transporting substances from place to place. In order for a molecule to be soluble in water, it must usually be polarized or charged so that it can interact with water.

Adenosine Triphosphate (ATP)

The body's most important energy transfer molecule. It gains energy from exergonic reactions such as glucose oxidation and releases it within seconds for physiological work such as polymerization reactions, muscle contraction, and pumping ions through cell membranes. The second and third phosphate groups of ATP are attached to the rest of the molecule by high-energy covalent bonds. Since phosphate groups are negatively charged, they repel each other. It requires a high-energy bond to overcome that repellent force and hold them together. Most energy transfers to and from ATP involve removing that third phosphate. Enzymes called adenosine triphosphatases (ATPases) are specialized to hydrolyze the third phosphate bond, producing adenosine diphosphate (ADP). ADP is short lived - usually consumed within 60 seconds of its formation. The reason cyanide is so lethal is because it halts ATP synthesis. Much of the energy for ATP synthesis comes from glucose oxidation. Glucose oxidation begins with glycolysis = "sugar splitting".

Energy

The capacity to do work. To "do work" means to move something, such as a muscle or a molecule. Ex. Breaking chemical bonds, building molecules, pumping blood, and contracting skeletal muscles. Energy is classified as potential or kinetic energy.

Activation energy

The energy needed to get a reaction to start.

Heat

The kinetic energy of molecular motion. The temperature of a substance is a measure of rate of this motion, and adding heat to a substance increases molecular motion.

Electromagnetic Energy

The kinetic energy of moving "packets" of radiation called photons. The most familiar form of electromagnetic energy is light.

Charles Darwin

The most influential biologist of all time. Wrote the book "On the Origin of Species by Means of Natural Selection". Charles Darwin presented the first well-supported theory of evolution. He is also known for his principle of Natural Selection.

Free Energy

The potential energy available in a system to do useful work. Ex. The energy stored in the chemical bonds of organic molecules.

Element

The simplest form of matter to have unique chemical properties. Ex. Water is made of two elements; hydrogen and oxygen. Each element is identified by an atomic number = the number of protons in its nucleus. The periodic table of the elements lists elements in order by their atomic number. There are 91 naturally occurring elements on earth, 24 of which play normal physiological roles in humans. 6 of the 24 elements in humans make up 98.5% of the body's weight: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. 0.8% is made up of: sulfur, potassium, sodium, chlorine, magnesium, and iron. The last 0.7% of our body weight is made up of 12 elements known as "trace elements": Chromium, fluorine, molybdenum, tin, cobalt, iodine, selenium, vanadium, copper, manganese, silicon, and zinc.

Atoms

The smallest particles with unique chemical identities.

Cells

The smallest unit of an organism that carry out all the basic functions of life. Cells are the simplest living thing. Cells are enclosed in a plasma membrane composed of lipids and proteins. Cells have one nucleus (an organelle containing its DNA) Cytology is the study of cells and organelles.

Phospholipids

The structural foundation of cell membranes. A phosphate group linked to other functional groups. Phospholipids have a dual nature; The two fatty acid "tails" of the molecule are hydrophobic, but the phosphate "heat" is hydrophilic. This is called "amphipathic". It is shaped like a clothespin.

Organic Chemistry

The study of compounds of carbon. These large organic molecules are categorized into four primary groups: Carbohydrates, lipids, proteins, and nucleic acids.

Physiology

The study of function

Comparative Physiology

The study of how different species have solved problems of life such as water balance, respiration, and reproduction. Used for the development of new drugs and medical procedures. Ex. A cardiac surgeon may learn animal surgery before practicing on humans. Ex. A new vaccine must be tested on animals such as rats to see whether it's has significant benefits and acceptable risk.

Comparative Anatomy

The study of multiple species in order to examine similarities and differences and analyze evolutionary trends. Ex. Rats are often used for anatomical study because their anatomy is very similar to ours.

Anatomy

The study of structure

Cytology

The study of structure and function of individual cells. Ultrastructure refers to fine detail, down to the molecular level (revealed by an electron microscope)

Cohesion

The tendency of molecules of the same substance to cling to each other. The cohesion of water is evident at its surface, because of surface film held together by a force called surface tension.

Adhesion

The tendency of one substance to cling to another.

Reductionism

Theory that a large, complex system such as the human body can be understood by studying its simpler components. The reductionist approach was coined by Aristotle and has proved to be highly productive. It is essential to scientific thinking.

Catalysts

These are substances that temporarily bind to reactants, hold them in a favorable position to react with each other, and may change the shapes of reactants in ways that make them more likely to react. By reducing the element of chance in molecular collisions, a catalyst speeds up a reaction. It then releases the products and is available again to attach to more reactants. The catalyst itself is not consumed or changed by the reaction. Enzymes are the most important biological catalysts.

Francis Bacon and Rene Descartes (philosophers)

These men envisioned science as a systematic method with enormous possibilities in human health and made strides to establish a Scientific Method that could be used to interact with science in an unbiased, objective way. They are known for paving a way for scientific thought.

Matthias Schleiden and Theodor Schwann

These men said that all organisms were composed of cells. This ideal became the groundwork for the cell theory. The cell theory was probably the most important breakthrough in biomedical history because it taught people that all functions of the body are the effects of cellular activity.

Exchange Reactions

Two molecules exchange atoms or groups of atoms AB + CD ---> AC + BD Ex. When stomach acid (HCI) enters the small intestine, the pancreas secretes sodium bicarbonate (NaHCO3) to neutralize it. The sodium atom exchanges its bicarbonate group for a chlorine atom.

Synthesis Reactions

Two or more small molecules combine to form a larger one A + B ----> AB Ex. When the body synthesizes proteins, it combines 50 or more amino acids into one protein molecule.

Radioisotopes

Unstable isotopes that decay to more stable isotopes by giving off radiation. This process of decay is known as radioactivity. Every element has at least one radioisotope. Ex. Oxygen has three stable isotopes and five radioisotopes.

Free Radicals

Unstable, highly reactive chemical particles with an odd number of electrons. Ex. Oxygen has two electrons. If an additional electron is added, it becomes a free radical because it then has an odd number of electrons. This type of free radical is called a superoxide anion. Free radicals are produced by some normal metabolic reactions of the body, radiation, and chemicals. They are short lifed and combine with molecules such as fats, proteins, and DNA, converting those to free radicals and triggering chain reactions that destroy more molecules. Free radical damage can cause some forms of cancer and myocardial infarction. It is assumed that aging is due in part by cellular damage by free radicals throughout the life cycle. Antioxidants are chemicals that neutralize free radicals.

Water

Water constitutes 50-75% of our body weight. Two aspects of water's structure that are very important are: 1. Its atoms are joined by polar covalent bonds 2. The molecule is V-shaped, with a 105 degree bond angle. This means that water molecules are polar because there is a slight negative charge on the oxygen at the apex of the v and a slight positive charge on each hydrogen. Water molecules are attracted to one another by hydrogen bonds. Water is solvent, cohesive, adhesive, chemically reactive, and thermally stable.

Hydrogen Bond

Weak attraction between polarized molecules or between polarized regions of the same molecule. Important in the three-dimensional folding and coiling of large molecules. Easily disrupted by temperature and pH changes.

Van der Waals Force Bonds

Weak, brief attraction due to random disturbances in the electron clouds of adjacent atoms. Weakest of all bonds individually, but can have strong effects collectively.

Measures of Concentration

Weight per Volume = the weight of solute in a given volume of solution. Ex. typical cholesterol concentration is 200 mg/dL Percentage = The weight of solute as a percentage of solution volume or volume of a liquid as a percentage of total solution volume. Ex. Common intravenous fluid is D5W, which means 5% w/v dextrose in distilled water. Molarity = One mole of a chemical is the number of grams equal to its molecular weight, and molarity (M) is a measure of the number of moles of solute per liter of solution. The number of molecules determines the physiological effect of a solution. Body fluids are usually quantified in millimolar (mM) concentrations, since they are much less than 1 molar. Milliequivalents per liter = Measure used to express electrolyte concentrations; takes into account not only the millimolar concentration of a solute but the electrical charge on its particles.

Claudius Galen (Roman Gladiator Physician)

Wrote the most influential medical textbook of the ancient era, of which was worshipped by professors for centuries. In his time, dissection was banned in humans, but he had a few glimpses when he treated gladiators wounds. Aside from that, he dissected pigs, monkeys, etc. Galen's guesses on human anatomy were often wrong because he studied mainly animals, but he urged people not to view his books as fact. Unfortunately, professors did not take his advice and taught his textbooks as fact for about 1500 years.

Chemical Reactivity

the ability to participate in chemical reactions. A couple of these reactions may be hydrolysis and dehydration synthesis.