Anatomy and Physiology Anatomy • Studies the structure of body parts and their relationships to one another • Anatomy (from Greek, meaning "to cut apart") • Gross or macroscopic anatomy - study of large body structures visible to the naked eye • Regional anatomy - one region examined at time • Ex. such as the abdomen or leg • Systemic anatomy - body structure is studied system by system • Ex. cardiovascular system • Surface anatomy - study of internal structures as they relate to the overlying skin surface • • Microscopic anatomy - deals with structures too small to be seen with the naked eye -Cytology (Cells) -Histology (Tissues) Developmental anatomy - Traces structural changes that occur throughout the life span • Embryology -concerns developmental changes that occur before birth. Physiology - Study with regards to function/s of the body - how the body parts work and carry out their life sustaining activities. - Physiology often focuses on events at the cellular or molecular level - Subdivisions - operation of specific organ systems Ex. Renal physiology and cardiovascular physiology Anatomy - provides us with a static image of the body's architecture. Physiology - reveals the body's dynamic and animated workings. F f F – FORM follows FUNCTION Correlation of Anatomy and Physiology • Anatomy and physiology is inseparable because function always reflects structure. • Form follows function -principle of complementarity of structure and function. Example: The sharp edges of the incisors (structure) make them ideal for cutting like scissors (function). The flat surfaces of molars (structure) make them ideal for grinding, like a mortar and pestle (function) Levels of structural organization • • • • • Atoms - tiny building blocks of matter (electrons, protons and neutrons) Molecules - combination of atoms - associate in specific ways to form organelles that are the basic components of cells Cells - are the smallest units of living things Tissues - are groups of similar cells that have a common function An Organ is a discrete structure composed of at least two tissue types that performs a specific function for the body (ie. liver, brain) Organs that work together to accomplish a common purpose make up an organ system (ie. Cardiovascular system) Organ Systems 1. Integumentary System - Forms the external body covering, and protects deeper tissues from injury. Synthesizes vitamin D, and houses cutaneous (pain, pressure, etc.) receptors, sweat and oil glands. 2. Skeletal Sytem - Protects and supports body organs and provides a framework the muscle use to cause movement. Blood cells are formed within bones. Bones store minerals. 3. Muscular System - Allows manipulation of the environment, locomotion, and facial expression. Maintains posture, and produces heat. 4. Nervous System - As the fast-acting control system of the body, it responds to internal and external changes by activating appropriate muscles and glands. 5. Endocrine System - Glands secret hormones that regulate processess such as growth, reproduction, and nutrient use(metabolism) by body cells. 6. Cardiovascular System - Blood vessels transport blood, which carries oxygen , carbon dioxide, nutrients, waste, etc. The heart pumps blood. 7. Lymphatic System/Immunity - Picks up fluid leaked from blood vessels and returns it to blood. Disposes of debris in the lymphatic stream. Houses white blood cells (lymphocytes) involved in immunity. The immune response mounts the attack against foreign substances within the body. 8. Respiratory System - Keeps blood constantly supplied with oxygen and removes carbon dioxide. Theese exchangees occur through the walls of the air sacs of the lungs. 9. Digestive System - Breaks down food into absorbable units that enter the blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces. 10. Urinary System Eliminates nitrogenous wastes from the bodyd. Regulates water, electrolyte, and acid-base balance of the blood. 11. Male Reproductive and Female Reproductive System - Overall function is prroduction of the offspring. Testes produce sperm and male sex hormones, and malee ducts and glands aid in delivery of sperm to the female reprroductive tract. Ovaries produce eggs and female sex hormones. The remaining female structures serves as sites for fertilization and development of the fetus. Mammary glands of femalee breasts produce milk to nourish the newborn. Functions to maintain life . Maintain boundaries .Movement .Responsiveness or Irritability .Digestion .Metabolism .Excretion .Reproduction .Growth Survival needs Nutrients .Carbohydrates, Proteeins, Fats .Minerals and vitamins Water – composes of 60-80% of the body’s weight. Oxygen – required for many chemical reactions Temperature .Metabolic reactions slower if the body temperature drops below 37 degrees celcius. .At either extreme death occurs. Appropriate atmospheric pressure – pressure exerted by homeostasis. Homeostasis - The ability to maintain relatively stable internal conditions even though the outside world changes continuously - A balance, in which internal conditions vary, but always within relatively narrow limits - The body is in homeostasis when its needs are adequately met, and it is functioning smoothly. Homeostatic control • Receptor - Sensor - Delivers the message to the control center (afferent pathway) • Control center - Determines the set point - Receives input from the receptor and provides input to the effector • Effector - Carries out the control center’s response (efferent pathway) Variable - factor or event being regulated • Negative Feedback Mechanisms • Most homeostatic control mechanisms • These mechanisms cause the variable to change in a direction opposite to that of the initial change, returning it to its "ideal“ value • Positive Feedback Mechanisms • initial response enhances the original stimulus so that further responses are even greater • Amplification of the original stimulus • Ie. Clotting mechanism, uterine contractions during labor Positive Feedback Anatomical Position - The anatomical reference point is a standard body position called the anatomical position • • Regional terms • Axial – make up the main axis of the body - head, neck, and trunk • Appendicular - appendicular part consists of the appendages or limbs, which are attached to the body's axis Directional terms - Is used to explain where one body structure is in relation to another - Position with regards to a reference point example. Lateral, medial Regional Terms Anatomical Planes – Sagittal - A vertical plane that divides the body into right and left parts. - A sagittal plane that lies exactly in the midline is the median plane, or midsagittal plane. - All other sagittal planes, offset from the midline, are parasagittal planes Anatomical Planes – Frontal - Frontal planes, like sagittal planes, lie vertically. - Frontal planes, however, divide the body into anterior and posterior parts. - A frontal plane is also called a coronal plane Anatomical Planes – Transveres - A transverse, or horizontal, plane runs horizontally from right to left, dividing the body into superior and inferior parts. - A transverse section is also called a cross section Anatomical Cavities Membranes in the Ventral Body Cavity • The walls of the ventral body cavity and the outer surfaces of the organs it contains are covered by a thin, double-layered membrane – Serosa • Parietal serosa - membrane lining the cavity walls is called the • Visceral serosa – membrane covering the organs in the cavity • Membranes are separated by a thin layer of lubricating fluid, called serous fluid • Pleura , Peritoneum, Pericardium – “itis“ inflammation “Pericarditis“ - inflammation of the pericardial serosa Abdominopelvic Quadrants • Designated area is associated with specific organs involved • Parietal peritoneum- contains sensory nerve endings which emits sharp and localizing pain • Visceral peritoneum - contains sensory nerve ending which emits dull, vague pain BASIC CHEMISTRY OF LIFE Chemical composition of living matter • Organic compounds – carbon containing compounds of living things • Inorganic compounds - all other chemicals in the body • Ex. water, salts, and many acids and bases • Inorganic compounds are generally defined as compounds that lack carbon • a few exceptions to this generalization: Carbon dioxide and carbon monoxide • Organic and inorganic compounds are equally essential for life Inorganic Compounds Water - Is the most abundant and important inorganic compound in living material. - Makes up 60-80% of the volume of most living cells Properties of water High heat capacity - it absorbs and releases large amounts of heat before changing appreciably in temperature itself - prevents sudden changes in temperature caused by external factors - As part of blood, water redistributes heat among body tissues High heat of vaporization - Evaporation requires that large amounts of heat be absorbed to break the hydrogen - Sweating - As sweat (mostly water) evaporates from our skin, large amounts of heat are removed from the body, providing efficient cooling - Problem: burn patients Salts - Salt is an ionic compound containing cations other than H+ and anions other than the hydroxyl ion (OH- ) When salts are dissolved in water, they dissociate into their component ions Salts commonly found in the body include NaCl, CaC0 3 (calcium carbonate), and KCI (potassium chloride) Most plentiful salts are the calcium phosphates that make bones and teeth hard • • All ions are electrolytes that conduct an electrical current in a solution. Electrolytes properties of sodium and potassium ions are essential for nerve impulse transmission and muscle contraction Acids and Base Acids • • • • • An acid is a substance that releases hydrogen ions (H +) in detectable amount - proton donor When acids dissolve in water, they release hydrogen ions (protons) and anions. It is the concentration of protons that determines the acidity of a solution Acids have a sour taste, can react with (dissolve) many substances Ex. Gastric juices Bases • • • • Proton acceptors-that is, they take up hydrogen ions (H+) in detectable amounts Common inorganic bases include the hydroxides - such as magnesium hydroxide hydroxides dissociate when dissolved and form hydroxyl ions (OH-) Bases have a bitter taste and feel slippery Examples: • Bicarbonate ion (HC03), an important base in the body is particularly abundant in blood • Ammonia (NH3) - a common waste product of protein pH: Acid-Base Concentration • • • • The relative concentration of hydrogen ions in various body fluids is measured in concentration units called pH units The more hydrogen ions in a solution, the more acidic the solution Conversely, the greater the concentration of hydroxyl ions (the lower the concentration of H+), the more basic At a pH of 7 the solution is neutral-neither acidic nor basic Neutralization • • Mixing basic and acid results in neutralization They react with each other in displacement reactions to form water and a salt Acid-base homeostasis • • • Living cells are extraordinarily sensitive to even slight changes in the pH of the environment Acid-base balance is carefully regulated by the kidneys and lungs and by chemical systems (proteins and other types of molecules) called buffers Buffers resist abrupt and large swings in the pH of body fluids by releasing hydrogen ions (acting as acids) when the pH begins to rise and by binding hydrogen ions (acting as bases) when the pH drops TOO much base or acid • Bases with a pH greater than 10 can cause chemical burns • Ex. Strong bases include, calcium hydroxide, sodium hydroxide and potassium hydroxide • Chemical burns from bases do not cause as much pain as acid burns, but the damage can be more extensive. • Bases can also react strongly with water, and the reactions of several bases with water are exothermic, meaning they give off heat • Bases feel slippery and can be more difficult to remove from the skin than acids • Acids with a pH of less than 4 can cause chemical burns • Ex. Strong acids include hydrochloric, nitric, sulfuric and phosphoric acids. • Acids can react violently with water and are harmful in the presence of moisture in the mouth or eyes or in proximity with other aqueous solutions. • Vapors from some acids are soluble in water and can cause damage to the eyes, nasal passages, throat and lungs • Burns from acids tend to be felt right away Organic compounds • Molecules unique to living systems that contain carbon • Carbohydrates -A group of molecules that includes sugars and starches, represent 1-2 % of cell mass -Contain carbon, hydrogen, and oxygen (CHO) -Classified according to size and solubility -Provide a ready, easily used source of cellular fuel -Most cells can use only a few types of simple sugars, and glucose is at the top of the cellular "menu”. Ex. Brain -Fuels can also be formed from fats and protein -Glucose is broken down and oxidized within cells -During these reactions, electrons are transferred, releasing the bond energy stored in glucose -This energy is used to synthesize Adenosine Triphosphate (ATP) – energy carrier When ATP supplies are sufficient, dietary carbohydrates are converted to glycogen or fat and stored • monosaccharide ("one sugar"), disaccharide ("two sugars"), or polysaccharide ("many sugars") In general, the larger the carbohydrate molecule, the less soluble it is in water -Building blocks of the other carbohydrates. -Monosaccharides or simple sugars are single-chain or single-ring structures containing from three to seven carbon atom • Disaccharide -A disaccharide or double sugar, is formed when two monosaccharides are joined • • • sucrose (glucose + fructose), which is cane or table sugar lactose (glucose + galactose), found in milk maltose (glucose + glucose), also called malt sugar • Disaccharides are too large to be transported through cell membranes, so they must be hydrolyzed to monosaccharides before the digestive tract can absorb them. Polysaccharides - Polymers of simple sugars linked together Polysaccharides must be digested for its glucose units to be absorbed Major importance to the body: glycogen (energy storage used in the body – liver, muscles) During fasting state majority of the glucose comes from glycogen through glycogenolysis Cellulose, another polysaccharide found in all plant products that is not digestible but provides bulk (one form of fiber) • • Lipids (fats) -Lipids are insoluble in water but dissolve readily in other lipids and in organic solvents such as alcohol and ether. -Like carbohydrates, all lipids contain carbon, hydrogen, and oxygen, but the proportion of oxygen in lipids is much lower. -In addition, phosphorus is found in some of the more complex lipids. -Lipids: triglycerides, phospholipids, steroids and a number of other lipoid substances. Triglycerides are commonly known as fats when solid or oils when liquid. Large molecules, often consisting of hundreds of atoms They provide the body's most efficient and compact form of stored energy, and when they are oxidized, they yield large amounts of energy. • 1g of fat = 9 calories • 1g of carbohydrates = 4 calories • 1g of protein= 4 calories Triglycerides common in many margarines and baked products, are oils that have been solidified by addition of H atoms at sites of carbon double bonds. • increase the risk of heart disease Conversely, the omega-3 fatty acids (MUFA) , found naturally in cold-water fish, appear to decrease the risk of heart disease and some inflammatory diseases fatty acids and glycerol, in a 3: I ratio of fatty acids to glycerol Protein • 10- 30% of cell mass • basic structural material of the body • building blocks of proteins are molecules called amino acids Amino Acids • • • Amine group (-NH2), and an organic acid group (-COOH) All amino acids are identical except for a single group of atoms called their R group Amino acids are linked together through peptide bonds dipeptide, tripeptide and so on Enzymes and Enzyme Activity • • • • • • Act as biological catalysts • substances that regulate and accelerate the rate of biochemical reactions but are not used up or changed in those reactions Each enzyme is chemically specific (lock and key mechanism) The substance on which an enzyme acts is called a substrate Catalytic activity occurs at the active site. Coenzyme – cofactors that may be needed to activate an enzyme You can recognize most enzyme names by the suffix -ase Energy efficiency DNA and RNA Nucleic Acid Nucleic acids - composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus - largest molecules in the body - major classes • deoxyribonucleic acid (DNA) • ribonucleic acid (RNA) Roles of DNA and RNA • • DNA - found in the nucleus (control center) of the cell, where it constitutes the genetic ,material also called the genes - Two main functions • replicates (reproduces) itself before a cell divides, ensuring that the genetic information in the descendant cells is identical • provides the basic instructions for building every protein in the body - DNA fingerprinting can help solve forensic – each person is unique RNA - located chiefly outside the nucleus and can be considered a "molecular slave" of DNA. - Carries out the orders for protein synthesis issued by DNA - 3 types - messenger RNA, ribosomal RNA, and transfer RNA DNA – 2 nucleotides linked by hydrogen bonds forming A double helix. Double helix – “spiral staircase”
