The Human Body: An Orientation

I.An Overview of Anatomy and Physiology

II.Levels of Organization

III.Maintaining Life

IV.Homeostasis

V.The Language of Anatomy

Overview

A. Topics of Anatomy

  1. Two complementary branches of science
  2. Anatomy – studies the structure of body parts and their relationships to one another
  3. Physiology – function of the body’s structural machinery, harder to “see”
  4. Topics in Anatomy
  5. Gross (Macroscopic) Anatomy - study of large body structures visible to the naked eye
  6. Heart, lungs and kidneys
  7. Regional – structures in an area
  8. Muscles, bones, blood vessels, nerves in the leg
  9. Systemic - system by system
  10. Cardiovascular system  heart, blood vessels, etc
  11. Surface - how underlying structures relate to overlying skin surface
  12. How to draw blood
  13. Microscopic - small things in the body
  14. Cytology – cells in the body
  15. Histology – tissues
  16. Developmental - changes that occur over a lifespan
  17. Embryology- Development before birth
  18. Topics in Physiology
  19. Renal Physiology - study of the kidneys
  20. Neurophysiology - workings of the nervous system
  21. Cardiovascular Physiology - examines the operation of heart and blood vessels
  22. Principle of Complementarity of Structure and Function
  23. Function reflects structure

Levels of Structural Organization

A. Overview of Levels (fig )

  1. Chemical
  2. Cellular
  3. Tissue
  4. Organ
  5. Organ System (fig )
  6. Organismal level

Maintaining Life

A. Necessary Life Functions

  1. Important to note that all systems work together (fig )
  2. Maintaining Boundaries
  3. Most keep the external environment separate from the internal environment
  4. Integumentary system protects from the sun, heat, bacteria, dehydration, etc
  5. Movement
  6. All activities promoted by the muscular system with the help of the skeletal system
  7. Also the movement of food and waste through the body
  8. Responsiveness (Irritability)
  9. Ability to sense changes in the environment
  10. Nervous system is overseer, but all systems are involved
  11. Digestion - Breaking down food into small molecules to absorb
  12. Metabolism - means a state if change
  13. All chemical reactions in body cells
  14. Catabolism – breaking down substances into simpler building blocks
  15. Anabolism – synthesizing complex cellular structures from simpler substances
  16. Cellular Respiration – using nutrients and oxygen to produce ATP
  17. Excretion - removing wastes; indigestible food, nitrogenous waste (urea), carbon dioxide
  18. Reproduction
  19. Cellular reproduction via mitosis
  20. Organismal reproduction via meiosis
  21. Growth - increase in size of a body part or an organism

B. Survival Needs

  1. Nutrients - contain chemical substances used for energy & cell building
  2. Plant –derived – carbohydrates, vitamins, minerals
  3. Carbohydrates are the major source of energy fuel for the body cells
  4. Animal – derived – protein and fat
  5. Proteins and fats are used to build cell structures
  6. Fats insulate and energy reserves
  7. Oxygen - reactions that release energy are oxidative, therefore they need oxygen
  8. Water
  9. 60-80% of body in water
  10. Guarantees the appropriate environment for all reactions to occur
  11. Appropriate Temperature
  12. Controls metabolic rates (98)
  13. Too low, slows things down; too high, reactions occur to quickly
  14. Atmospheric Pressure
  15. Important for breathing
  16. High altitudes – pressure is low, air is thin, can have problems maintaining cellular support

Homeostasis

A. Ability to maintain relatively stable internal condition s even though the outside world changes continuously

  1. Not a static system, very dynamic
  2. But always within borders of acceptability
  3. Involves all systems working together

B. Homeostatic Controls Mechanisms

  1. Communication within the body
  2. Accomplished by nervous system and endocrine system
  3. Use electrical impulses and chemical signals
  4. Steps in the Process
  5. Variable - factor of event being regulated
  6. Receptor - sensor that monitors the environment and responds to the stimuli
  7. Control Center - receives info from the receptor and determines level at which the variable is to be maintained
  8. Effector - means for the control centers response to the stimulus
  9. Follows pathway set by the control center – efferent pathway
  10. Homeostasis is restored
  11. Negative Feedback Mechanism
  12. Most controls are negative feedback
  13. Home heating system is best example
  14. Body thermostat is located in the hypothalamus
  15. Endocrine system and reflex response also work with this system
  16. Example of endocrine system (fig )
  17. High sugar intake leads to product of insulin
  18. Low sugar leads to production of glucagons
  19. Tells liver to release sugar
  20. Positive Feedback Mechanisms
  21. Changes occur in the same direction as the initial disturbance, causing the variable to deviate further from the original value or range
  22. Can run out of control, so they aren’t used to monitor daily activities

C. Homeostatic Imbalances

  1. If there is a problem with keeping the balance
  2. Mainly caused by disease and aging

Language of Anatomy

  1. Anatomical Position and Directional Terms
  2. Anatomical Position
  3. Erect body, feet slightly apart, palms forward
  4. Right and left refer to the body, not the observer
  5. Directional Terms (Table )
  6. Superior (cranial) –toward head
  7. Inferior (caudal) – away from the head
  8. Anterior – toward the front
  9. Posterior – toward the back
  10. Medial – toward the midline
  11. Lateral – away from the midline
  12. Intermediate – between medial and lateral
  13. Proximal – closer to trunk
  14. Distal – farther from trunk
  15. Superficial – toward the surface
  16. Deep – away from the surface
  17. Regional Terms (fig )
  18. Axial – head, neck, trunk
  19. Appendicular - appendages
  20. Body Plans and Sections (fig )
  21. Sagittal – vertical plane dividing body into left and right
  22. Median (Midsagittal) – on midline
  23. Parasagittal – offset from midline
  24. Frontal –lie vertically, divide body into anterior and posterior
  25. Also called the coronal plane
  26. Transverse – horizontal plane, divides body into superior and inferior parts
  27. Also called cross sections
  28. Oblique sections are diagonally between horizontal and vertical planes
  29. Body Cavities and Membranes
  30. Cavities (fig )
  31. Dorsal – 2 parts
  32. Protects the nervous system
  33. Cranial cavity – skull to encase the brain
  34. Vertebral cavity (spinal) – to protect spinal cord
  35. Ventral – 2 parts
  36. Viscera (visceral organs) – all housed in the ventral cavity
  37. Thoracic – 2 parts
  38. Surrounded by the ribs & muscles of the chest
  39. Pleural cavity - lungs
  40. Mediastinum
  41. Superior mediastinum – trachea, esophagus
  42. Pericardia cavity – encloses the heart
  43. Abdominopelvic – 2 parts
  44. Separated by the diaphragm (muscle)
  45. Abdominal cavity
  46. Contains the stomach, intestines, spleen, liver, other organs
  47. Pelvic Cavity
  48. Within the bony pelvis
  49. Contains the bladder, the reproductive organs & the rectum
  50. Membranes of the Ventral Body Cavities
  51. Serosa – very thin double-layered membrane (fig 1.10)
  52. Parietal serosa - Part that lines the cavity walls
  53. Visceral serosa – lines the organs in the cavity
  54. Serous fluid keeps the area between the layers
  55. Layers are named for the organ/area they protect
  56. Parietal pericardium lines pericardial cavity
  1. Other Body Cavities
  2. Oral and digestive cavities – starts with mouth, teeth and tongue, includes all the digestive organs to anus
  3. Nasal Cavity – within and posterior to the nose
  4. Orbital Cavity – houses the eyes in the skull
  5. Middle ear cavities – medial to eardrum, contains bones to transmit vibrations
  6. Synovial cavities – joint cavities, around elbow and knee
  7. Have lubricant to reduce friction
  1. Abdominopelvic Regions and Quadrants (fig 1.11)
  2. Regions – used by regional anatomists
  3. Umblical region
  4. Epigastric region
  5. Hypogastric region
  6. Right and left iliac (inguinal) region
  7. Right and left lumbar region
  8. Right and left hypochondriac region
  9. Quadrants – used by medical personnel
  10. Right Upper
  11. Left Upper
  12. Right Lower
  13. Left Lower

______

Study Questions

Anatomy and Physiology

-What does each study cover? Be sure you can give examples

Levels of Organization

-What are they? How do they relate to each other

Maintaining Life

-What are the main functions? Survival needs?

-What is Metabolism? What’s the difference between anabolism & catabolism?

Homeostasis

-What is homeostasis? What are the mechanisms for control?

-What are the reasons for aging?

Language of Anatomy

-Use the terms in the appropriate manner

-Be able to identify the regions, and determine the organs you would find it them

-What does each cavity protect? Why does it make sense to have cavities?

-Try to use the organs to help the regions make sense

Body Planes and Orientation

-Learn the terms!

-Make up sentences using the word to describe the regions & parts

Lab 1 fig.s 1.1, 1.2, 1.3, 1.4, 1.6, 1.7 (4 quadrants only), 1.8

Lab 2  know the major systems, what organs they contain and where they are on a torso model

Models: torsos

Microscopes

-Know the parts (fig 3.1), be sure you remember the equations!

-Be able to calculate total magnification & explain how it affects field of view?

Chemistry

Basic Chemistry

  1. Matter and Energy
  2. Composition of Matter: Atoms and Elements
  3. Molecules and Mixtures
  4. Chemical Bonds
  5. Chemical Reactions

Biochemistry

  1. Inorganic Compounds
  2. Organic Compounds

Basic Chemistry

Matter and Energy

A. Matter

  1. Anything that occupies space and has mass
  2. Mass is the amount of matter in the object
  3. Weight varies with gravity
  4. Weigh less on a mountaintop, less gravity
  5. Three States of Matter
  6. Solid – has definite shape and volume (bones and teeth)
  7. Liquid – definite volume, variable shape (blood plasma)
  8. Gaseous states – Neither shape or volume (air)

B. Energy

  1. The capacity to do work, or to put matter into motion
  2. The more work do, the more energy required
  3. Two Types of Energy
  4. Kinetic – energy in action (battery in a toy being used)
  5. Potential – stored energy, inactive energy (battery in a toy not being used)
  6. Forms of Energy
  7. Chemical Energy - form stored in the bonds of chemical substances
  8. When the bonds rearrange, energy is released (Potential  Kinetic)
  9. Ex: Adenosine Triphosphate (ATP)
  10. How we store energy in our bodies
  11. The breaking of these bonds fuel all our systems
  12. Electrical Energy - movement of charged particles
  13. Ions are charged and move across cell membranes
  14. Nerve Impulses – electrical current used by the nervous system to transmit messages from one part of the body to another
  15. Mechanical Energy - directly involved in moving matter
  16. Radiant Energy (Electromagnetic energy)
  17. Electromagnetic spectrum (talk about more when we get to vision)
  18. All energy transformations release heat, even in the body

Atoms and Elements

A. Elements

  1. All matter is composed of fundamental substances
  2. Cannot be broken down into simpler substances by ordinary chemical methods
  3. Four Elements make up the majority of body weight (96.1%; Table )
  4. Oxygen, Carbon, Hydrogen, Nitrogen
  5. 112 are known, only 92 exist in nature, they rest are made in a particle accelerator
  6. Periodic Table lists all known elements (Appendix D)
  7. Atoms - building block of elements, tiny
  8. Physical properties - detectable (smell, size, texture) or measurable (boiling, freezing point)
  9. Chemical properties - Way atom reacts to other atoms (bonding behavior)
  10. Atomic Symbol - one or two letter symbol (shorthand)
  11. Usually the first letter of the name of the element (Latin sodium  natrium Na)

B. Atomic Structure

  1. Not indivisible as name implies (Greek)
  2. Consists of
  3. Nucleus: protons (+) & neutrons (no charge)
  4. Tightly bound together
  5. Overall its positively charged
  6. Both have same mass  1 atomic mass unit
  7. Electrons that orbit the nucleus
  8. Negative charge, very small mass
  9. Number of electrons have to equal number of protons for the atom to carry no charge
  10. Planetary Model (Fig )
  11. Planetary is a simplified model of atom
  12. Electrons don’t really travel in a ring, travel in orbitals or regions (fig )
  13. Electron Cloud – area that the electron is likely to be found
C. Identifying Elements
  1. All elements have a different number of protons, neutrons and electrons
  2. Hydrogen, Helium, Lithium (fig )
  3. Hydrogen - One Proton – One Electron
  4. Helium – 2 of each; Lithium – 3 of each
  5. We classify elements based on atomic number, atomic mass and atomic weight
  6. Atomic Number
  7. Number of protons in the nucleus
  8. Also tells you how many electrons it has to (Hydrogen – 1)
  9. Mass Number and Isotopes
  10. Mass Number – the sum of the protons and neutrons
  11. Hydrogen  1; Helium  2 protons, 2 neutrons  4 (4/2 He)
  12. Mass number – atomic number = number of neutrons
  13. Isotopes (fig ) - Same number of protons, different number of neutrons
  14. Atomic Weight
  15. Average of the relative weights of all isotopes found in nature
  16. Equal to mass number of the most abundant isotope
D. Radioisotopes
  1. Isotopes that decay to stable forms because they are heavy and unstable
  2. Radioactivity – process of decay
  3. Dense nuclear particles are composed of even smaller particles (quarks) that associate in one way to form protons and another way to form neutrons
  4. Bonds between quarks is less effective in heavy isotopes
  5. Half-life – the time needed to loss half of its activity
  6. Used in diagnosis of damaged and cancerous tissues
Molecules and Mixtures

A. Molecules and Compounds

  1. Combination of atoms held together by chemical bonds
  2. Compounds – two different atoms bound together to form a molecule

B. Mixtures

  1. Solutions – homogeneous mixtures of components that may be gases, liquids or solids
  2. Two parts
  3. Solvent – dissolving medium (usually a liquid (water is the universal solvent)
  4. Solute – what’s being dissolved
  5. Concentrations of Solutions
  6. Percent tells you how much solute there is in the solution
  7. Morality – moles per liter (M)
  8. Mole – equal to its atomic weight or molecular weight (sum of weights) in grams
  9. Add up the atomic weight or each atom X the number of atoms of each
  10. One molar solution = total grams in 1 liter of solution
  11. Avogadro’s number – 6.02 x 1023 molecules of substance
  12. Same number of molecules for each mole, regardless of atom
  13. Colloids - emulsions, heat erogenous mixtures
  14. Usually gel-like mixtures, particles are larger than those in watery (true) solutions
  15. Cytosol – inside the cell
  16. Suspensions
  17. Heterogeneous mixtures with large often visible solutes that tend to settle out
  18. Blood will separate into plasma, platelets, WBCs and RBCs

C. Distinguishing Mixtures from Compounds

  1. No bonding occurs in a mixture, just physically intermixed
  2. Components can separate by physical means (straining, filtering, evaporation, etc
  3. Mixtures can be homogeneous or heterogeneous

Homogeneous – any sample of the mixture will be exactly the same

Heterogeneous – substance varies in make up from place to place

Chemical Bonds

A. How are molecules held together?

  1. Electrons form a cloud around the nucleus of an atom = electron shell
  2. Number of electron shells occupied in a given atom depends on # of e atom has
  3. Each shell contains 1+ orbital
  4. Each shell represents a different level of energy
  5. Potential Energy = depends on the energy level the bond occupies
  6. Valence Shell = used specifically to indicate an atoms outermost energy level containing the electrons that are chemically reactive
  7. Shell 1 = 2 e
  8. Shells 2+ = 8 e

B. Types of Bonds

  1. Ionic (fig ) - Forms an ion
  2. Anion – gains an electron (-)
  3. Cation – loses an electron (+)
  4. Most are salts, crystals
  5. Sodium Chloride (NaCl)
  6. Covalent (fig ) - Share electrons & share an orbital
  7. Often forms gases
  8. Polar - Positive and Negative sides to the molecule due to shifts in size, electric charge, etc
  9. Nonpolar - Electrically balanced
  10. Hydrogen (fig )
  11. Too weak to bind atoms, just attraction between a positive end of a polar covalent bond and a negative end

Chemical Reactions

A. Reactions occur whenever chemical bonds are formed, rearranged or broken

  1. Written as Chemical Equations
  2. H + H = H2or4H + C = CH4
  3. Subscript = atoms that are bonded
  4. Prefix = atoms that are not bonded
  5. Reactants - # or kind or reacting substances
  6. Products = proportions of reactants after reaction

B. Patterns of Chemical Reactions

  1. Three patterns
  2. Synthesis (combination)  A + B = AB
  3. Basis for constructive (or anabolic) activities like building cells
  4. Decomposition  AB = A + B
  5. Molecule is broken into smaller parts or constituent atoms
  6. Underlie catabolic or degradative activities
  7. Exchange of reactions (displacement)  AB + C = A + BC
  8. Oxidation Reduction Reactions (Red-Ox)
  9. Reactant that is losing the electron (donor) is Oxidized
  10. Reactant that is gaining the electron (acceptor) is Reduced

C. Energy Flow in Chemical Reactions

  1. Exergonic – release energy
  2. Endergonic – energy absorbing

D. Reversibility of Reactions

  1. Some reactions can go either way – said to be in a state of Chemical Equilibrium
  2. Shown by double directional arrows

E. Four Factors that Influence Rate of Reaction

  1. Temperature
  2. Particle Size
  3. Concentration
  4. Catalysts

Biochemistry

A. What is biochemistry?
  1. The study of the chemical composition and reactions of living matter
  2. Organic Compounds - contain carbon, are covalently bonded molecules, usually large
  3. Inorganic Compounds - water, salts, acids and bases

Inorganic Compounds

A. Water

  1. Most abundant and important inorganic compound in living material
  2. Special qualities of water
  3. High heat capacity
  4. Absorbs & releases large amounts of heat before changing in temperature itself
  5. Prevents sudden changes in internal body temperature
  6. Redistributes temperature throughout the body
  7. High heat of vaporization
  8. Takes a lot of heat to change from liquid into a gas (water vapor)
  9. Breaking of hydrogen bonds
  10. Therefore large amounts of heat are released from the body
  11. Polar solvent properties
  12. Universal solvent - biological molecules do not react unless they are in a solution
  13. Dissociate properties (fig. )
  14. Orient positive ends toward negatively charged end of solutes
  15. Separates ionic-ly bonded molecules (salt) via dissociation
  16. Actually surrounds Na and Cl atoms
  17. Hydration layers
  18. Layers of water molecules around large charged molecules such as proteins, shielding them from the effects of other charged substances (colloids)
  19. Water serves as the body’s major transport medium
  20. Reactivity
  21. Hydrolysis - decomposition reactions using water
  22. Foods are broken down into building blocks via water
  23. Dehydration synthesis – when you remove water from protein and carbohydrates (causes those to bond together)
  24. Cushioning - forms a cushion for body’s organs

B. Salts