1. Human Anatomy & Physiology I BIO 201
Major Themes of Anatomy & Physiology
Chapter 1 By
Abdul Fellah, Ph.D.

2. Major Themes of Anatomy & Physiology
Form and Function
Origins of Biomedical Science
Scientific Method
Human Origins and Adaptations
Human Structure
Human Function
Language of Medicine

3. Anatomy - The Study of Form
Observation of surface structure
Cadaver dissection is cutting & separation of organs to study their relationships
Comparative anatomy is the study of more than one species to analyze evolutionary trends
Physical examination
palpation, auscultation, percussion
Gross anatomy is what is visible with naked eye
Histology is examination of cells with microscope

4. Physiology - The Study of Function
Study of bodily functions by use of methods of experimental science
Comparative physiology involves the study of different species
Basis for the development of new drugs and medical procedures

5. Beginnings of Medicine
Physicians in Mesopotamia & Egypt 3000 years ago used herbal drugs, salts & physical therapy
Greek physician Hippocrates established a code of ethics & urged physicians to seek causes of disease
Aristotle called causes for disease physiologi & said that complex structures are built from simpler parts

6. Beginnings of Medicine
Galen, physician to the Roman gladiators, saw science as a method of discovery
did animal dissections since use of cadavers banned
wrote book advising followers to trust their own observation

7. Birth of Modern Medicine
Little advancement during the Middle ages since medicine was taught as dogma with no new ideas
Avicenna from Muslim world supported free inquiry over authority
wrote The Canon of Medicine, used in medical schools until 16th century
Vesalius published accurate gross anatomy atlas (1543)
Harvey realized blood flow out from heart & back in 1628
Leeuwenhoek invented microscope to look at fabrics ( )

8. Birth of Modern Medicine
Hooke (1665) and Zeiss (1860) developed & improved compound microscope (described plant cell walls in 1665)
Schleiden & Schwann thought that all organisms were composed of cells -- cell theory of 1839
Clinical practice was in dismal state
bleeding patients to remove toxins, operate with dirty hands, no anesthesia for amputations

9. Early Microscopes

10. Living in a Revolution Pioneers in 19th & 20th centuries
established scientific way of thinking
replaced superstition with natural laws
momentous discoveries
germ theory of disease
heredity & structure of DNA
Now at threshold of modern biomedical science
technology enhanced diagnostic ability & life-support strategies
genetic revolution --library of the molecular structure of every human gene is finished
Gene therapy being used to treat disease

11. Scientific Method Bacon (1561-1626) and Descartes (1596-1650)
were not scientists but did invent new habits of scientific thought
scientific method as habits of disciplined creativity, careful observations, logical thinking & analysis of observations
way of seeking trends & drawing generalizations
Convinced governments of England & France to form academies of science that still exist today
Scientific way of thinking based on assumptions & methods that are reliable, objective & testable

12. Inductive Method First described by philosopher Francis Bacon
Making observations until capable of drawing generalizations and making predictions
anatomy is a product of inductive method
Proof in science can not go past “proved beyond reasonable doubt”
reliable methods of observation
tested and confirmed repeatedly
not falsified by any credible observation
In science, all truth is tentative

13. Hypothetico-Deductive Method
Physiological knowledge gained by this method
Ask a question and formulate a hypothesis -- an educated possible answer
Good hypothesis
consistent with what is already known
capable of being tested and falsified with certain evidence
If nothing could prove it wrong, it is not a scientific belief
Hypotheses are written as If-Then predictions
modified and rewritten after testing

14. Experimental Design Sufficient sample size to prevent chance event
Control group and treatment group receive the same treatment except for the variable being tested
Prevention of psychosomatic effects
use of placebo in control group
Experimenter bias
prevented with double-blind study
Statistical testing to be sure the difference between groups was not random, but was due to variable being tested

15. Peer Review Critical evaluation by other experts in the field
prior to funding
verification and repeatability of results
Ensures honesty, objectivity & quality in science

16. Facts, Laws and Theories
Scientific fact is information that can be independently verified by any trained person
iron deficiency leads to anemia
Law of nature is a description of the way matter and energy behave
resulting from inductive reasoning & repeated observations
written as verbal statements or mathematical formulae
Theory is a summary of conclusions drawn from observable facts
it provides explanations and predictions
sliding filament theory of muscle contraction

17. Human Origins and Adaptations
Charles Darwin’s theory of natural selection explains how species originate and change through time
On the Origin of Species by Means of Natural Selection (1859)
The Descent of Man (1871) discussed human evolution & our relationships to other animals
Changed our view of our origin, our nature & our place in the universe
Good understanding of our evolutionary history deepens our understanding of form & function

18. Evolution, Selection, and Adaptation
Evolution is change in genetic composition of a population of organisms
development of bacterial resistance to antibiotics, new strains of AIDS virus and emergence of new species
Theory of natural selection
some individuals have hereditary advantages (adaptations) enabling them to produce more offspring
if they pass these characteristics on it brings about a genetic change in the population (evolution)
forces that favor some individuals over others are called selection pressures -- climate, disease, etc.

19. Adaptations
Adaptations are useful features that evolved in response to selection pressures
DNA hybridization suggests a difference of only 1.6% in DNA structure between humans & chimpanzees
Evolutionary developments help explain some aspects of our anatomy (vestigial organs)
piloerector muscle in the skin have no use
auricularis muscles do not move in most people
Evolutionary relationships help us chose animals for biomedical research
rats & mice used extensively

20. Primate Adaptations
Some human features can be traced to the earliest primates
Squirrel-sized, insect-eating mammals became arboreal probably due to safety, food supply & lack of competition
shoulder became more mobile (reach any direction)
thumbs became opposable to encircle branches with thumb & fingers (prehensile)
forward-facing eyes provide depth perception
judge distances accurately for leaping & catching prey
color vision to distinguish ripe fruit
larger brains & good memory to remember food sources

21. Walking Upright African forest became grassland 5 million years ago
Bipedalism (standing & walking on 2 legs) evolved
spot predators, carry food or infants
Adaptations for bipedalism
pelvis, femur, knee, great toe, arch, skull, vertebrae, etc.
Australopithecus (2.5mya) gave rise Homo habilis
taller, larger brain volume, speech, tool-making
Homo erectus (1.1mya) and Homo sapiens (.3mya)
Homo sapiens include Neanderthal & Cro-Magnon
Evolutionary medicine traces our diseases to evolutionary past

22. Primate Phylogeny

23. Human Structure Hierarchy of complexity Reductionism versus holism
organism is composed of organ systems
organ systems composed of organs
organs composed of tissues
tissues composed of cells
organelles composed of molecules
molecules composed of atoms
Atoms compose molecules
Reductionism versus holism

24. Anatomical Variation No 2 humans are exactly alike Missing organs
palmaris longus or plantaris muscles
More or less organs than normal
2 spleens, single kidney, 6 or 4 lumbar vertebrae
Variation in organ locations (situs inversus, dextrocardia, situs perversus)

25. Human Function Characteristics of life
organization
cellular composition
excretion
metabolism
responsiveness and movement
homeostasis
development (growth or differentiation)
reproduction
evolution
Clinical death is no brain waves for 24 hours

26. Physiological Variation
Differs with sex, age, diet, weight, degree of physical activity
Typical human values
reference man
22 years old, 154 lbs, light physical activity
2800 kcal/day
reference woman
same as man except 128 lbs and 2000 kcal/day

27. Homeostasis
Hippocrates noted that body normally returns to a state of equilibrium by itself
needs to detect the change & oppose it
Walter Cannon ( ) coined the term homeostasis indicating stable internal environment
Internal environment described as dynamic equilibrium
fluctuates within a range around a certain set point
Loss of homeostatic control causes illness or death

28. Negative Feedback Loops
Mechanism to keep a variable close to its set point
Body senses a change & activates mechanisms to reverse it

29. Negative Feedback, Set Point
Room temperature does not stay at set point of 68 degrees -- it only averages 68 degrees

30. Human Thermoregulation
Blood temperature sensing nerve cells in base of brain control shivering, sweating & vasomotor activity
vasodilation with heat & vasoconstriction with cold
Evaporation of water & heat radiation occur

31. Control of Blood Pressure
Rise in blood pressure detected
stretch receptors in wall of heart and major arteries
Nerve signals travel to cardiac center in brainstem
Nerve signals slow heart and lower blood pressure

32. Structures Needed for Feedback Loop
Receptor = structure that senses change
stretch receptors in heart & large blood vessels send information of an elevated BP to integrator
Integrator = control center
cardiac center in brainstem that signals heart to slow
Effector = structures that carry out commands of the control center
heart slows and BP decreases
sweating begins and evaporation cools the body

33. Positive Feedback Loops
Physiological change that leads to an even greater change in the same direction (self-amplifying)
Normal way of producing rapid changes
birth, blood clotting, protein digestion, generation of nerve signals

34. Life-Threatening Fever
If temperature rises above 108 degrees due to bacterial infection
metabolic rate increases causing body to produce heat faster still
Temperature increases & cycle repeats
Fatal at 113 degrees

35. History of Anatomical Terminology
Most medical terms are formed from Greek and Latin roots
Fast-paced anatomical discoveries during the Renaissance resulted in naming confusion
different countries naming same structures with different names
structures being named after people (eponyms)
Anatomy meetings in 1895 began search for uniform international terminology
Nomina Anatomica (NA) rejected all eponyms
gave each structure a unique Latin name to be used worldwide
Terminologia Anatomica was codified in 1998

36. Analyzing Medical Terms
Medical terminology based on word elements
lexicon of 400 common word elements in back of book
Scientific terms are composed of the following elements
at least one root (stem) that bears the core meaning
combining vowels that join roots together
prefix that modifies the core meaning of the word
suffix that modifies the core meaning of the word
acronyms – words composed of the first few letters of a series of words

37. Useful Tables in Textbook

38. Review of Major Themes
Unifying principles behind all aspects of human anatomy and physiology
cell theory: all structure & function result from the activity of cells
homeostasis: maintaining stable conditions within the body
evolution: the body is a product of evolution, molded by years of natural selection
hierarchy of structure: levels of complexity
unity of form and function: physiology can not be separated from anatomy

39. Medical Imaging Radiography Sonography
x-rays discovered (William Roentgen) in 1885
penetrate soft tissues & darken photographic film on other side of the body
dense tissue (bone, teeth and tumors) are not penetrated so photographic film remains white
radiopaque substances can be either injected (angiography) or swallowed for examination of the gastrointestinal tract
Sonography
high-frequency ultrasound waves echoes
back from internal organs
obstetrics uses to locate placenta, evaluate fetal age, position and development

40. Medical Imaging Computed Tomography (CT scan)
low-intensity X rays applied to the body
computer analysis produces an image of a slice of the body about as thin as a coin
tumors, aneurysms, hemorrhages, kidney stones, etc
Magnetic Resonance Imaging (MRI)
magnetic field aligns hydrogen atoms; radio waves realign the atoms; when radio is turned off the atoms give off energy depending on tissue type
computer analysis produces a “slice” type image
better for soft tissue analysis than CT

41. Medical Imaging Positron Emission Tomography (PET scan)
assesses the metabolic state of a tissue
injection of radioactively labeled glucose emits positrons
colliding positrons & electrons give off gamma rays that are analyzed by computer
color image of glucose usage at that moment
extent of damaged heart tissue
activity of brain of neurology patients

42. Basic Anatomical Terminology
Anatomical position
Regions of the body
Anatomical planes, sections and directional terms

43. Anatomical Position
Standardized position from which to describe directional terms
standing upright
facing the observer, head level
eyes facing forward
feet flat on the floor
arms at the sides
palms turned forward
Prone position = lying face down
Supine position = lying face up
anatomical position?

44. Clinical terminology based on a Greek or Latin root word.
Common Regional Names
Clinical terminology based on a Greek or Latin root word.

45. Planes and Sections
A plane is an imaginary flat surface that passes through the body.
A section is one of the 2 surfaces (pieces) that results when the body is cut by a plane passing through it.

46. Sagittal Plane Sagittal plane Midsagittal plane Parasagittal plane
divides the body or an organ into left and right sides
Midsagittal plane
produces equal halves
Parasagittal plane
produces unequal halves

47. Other Planes and Sections
Frontal or coronal plane
divides the body or an organ into front (anterior) and back (posterior) portions
Transverse(cross-sectional) or horizontal plane
divides the body or an organ into upper (superior) or lower (inferior) portions
Oblique plane
some combination of 2 other planes

48. Planes and Sections of the Brain (3-D anatomical relationships revealed)
Horizontal Plane
Frontal Plane
Midsagittal Plane

49. Major Directional Terms
See Definitions page 14

50. Superior or Inferior Superior Inferior towards the head
The eyes are superior to the mouth.
Inferior
away from the head
The stomach is inferior to the heart.

51. Dorsal or Ventral Dorsal or Posterior Ventral or Anterior
at the back of the body
The brain is posterior to the forehead.
Ventral or Anterior
at the front of the body
The sternum is anterior to the heart.

52. Medial or Lateral Medial nearer to the midline of the body
The heart lies medial to the lungs.
Lateral
farther from the midline of the body
The thumb is on the lateral side of the hand.

53. Proximal or Distal Proximal
nearer to the attachment of the limb to the trunk
The knee is proximal to the ankle.
Distal
farther from the attachment of the limb to the trunk
The wrist is distal to the elbow.

54. Dorsal Body Cavity Near dorsal surface of body 2 subdivisions
cranial cavity
holds the brain
formed by skull
vertebral or spinal canal
contains the spinal cord
formed by vertebral column
Meninges line dorsal body cavity

55. Ventral Body Cavity Near ventral surface of body 2 subdivisions
thoracic cavity above diaphragm
abdominopelvic cavity below diaphragm
Diaphragm = large, dome-shaped muscle
Organs called viscera
Organs covered with serous membrane

56. Abdominopelvic Cavity
Inferior portion of ventral body cavity below diaphragm
Encircled by abdominal wall, bones & muscles of pelvis

57. Thoracic Cavity
Encircled by ribs, sternum, vertebral column and muscle
Divided into 2 pleural cavities by mediastinum
Mediastinum contains all thoracic organs except lungs

58. Mediastinum
Midline wall of tissue that contains heart and great vessels, esophagus, trachea and thymus.

59. Serous Membranes
Thin slippery membrane lines body cavities not open to the outside
parietal layer lines walls of cavities
visceral layer covers viscera within the cavities
Serous fluid reduces friction

60. Pleural & Pericardial Cavities
Visceral pleura clings to surface of lungs --- Parietal pleura lines chest wall
Visceral pericardium covers heart --- Parietal pericardium lines pericardial sac

61. Peritoneum
Visceral peritoneum --- serous membrane that covers the abdominal viscera
Parietal peritoneum --- serous membrane that lines the abdominal wall

62. Abdominopelvic Regions & Quadrants
Describe locations of organs or source of pain
Tic-tac-toe grid or intersecting lines through navel