1

1

Biology 1120 – Anatomy & Physiology

2

Chapter 1 Major Themes of Anatomy & Physiology

  Form (anatomy) fits function (physiology)   History of Biomedical Science   Scientific Method   Human Origins and Adaptations   Human Structure & function   Homeostasis   Language of Medicine   Imaging

3

Anatomy – the study of form

  Describes the structures of the body: □  what they are made of □  where they are located □  associated structures

□  Example: the heart

4

What is the difference between the heart of an athlete …

5 Couch potato – someone who sits around on the couch all day

and a couch potato?

6

Anatomy

We study by   Observation, palpation, auscultation,

percussion

  Cadaver dissection □ cutting and separation of organs

  Comparative anatomy □ study of more than one species to analyze

evolutionary trends

2

7

  Microscopic Anatomy □  Involves studying anatomical structures that

cannot be seen with the unaided eye •  Cytology - cells •  Histology – tissue

8 Vitruvian man - Leonardo da Vinci

Early Anatomical Drawings

9 10

Unrealistic anatomy: human barbie – had ribs removed to have the same dimensions as barbie doll

11

Physiology – the study of function

  Describes □  functions of anatomical structures

-  operation of the heart and blood vessels (eg blood pressure)

-  kidney function -  workings of the nervous system

12

Physiology

We study by:   Using methods of experimental science   Comparative physiology □ study of different species (can’t test drugs on

humans) □ Basis for the development of new drugs and medical

procedures

  Fields include: □ Pathophysiology □ Neurophysiology

3

13

THE HISTORY OF MEDICINE

  China □ Yin and yang □ Herbal remedies □ Channels in body through which energy (Qi) flows □ Acupuncture – based on opening channels

  Ancient Egypt and Mesopotamia □ Knowledge from preparation of dead □ Heart weighed against feather by 42 divine judges

to allow person into world of gods

14

  Ancient Greeks □ Hippocrates (460-375 bce)

-  believed there were natural causes of disease

-  established basis for a code of ethics □ Aristotle

- Believed in natural (physici) or supernatural causes (theologi)

- Complex structures build from simpler, smaller components

15

The Hippocratic Oath

I swear by Apollo the physician, and Asclepius, and Health, and All-heal, and all the gods and goddesses . . . to reckon him who taught me this Art equally dear to me as my parents, to share my substance with him, and relieve his necessities if required; to look upon his offspring in the same footing as my own brothers, and to teach them this art, if they shall wish to learn it, without fee or stipulation; and that by precept, lecture, and every other mode of instruction, I will impart a knowledge of the Art to my own sons, and those of my teachers, and to disciples bound by a stipulation and oath according to the law of medicine, but to none others. I will follow that system of regimen which, according to my ability and judgment, I consider for the benefit of my patients, and abstain from whatever is deleterious and mischievous. I will give no deadly medicine to any one if asked, nor suggest any such counsel; and in like manner I will not give to a woman a pessary to produce abortion. . . . Into whatever houses I enter, I will go into them for the benefit of the sick, and will abstain from every voluntary act of mischief and corruption; and, further from the seduction of females or males, of freemen and slaves. Whatever, in connection with my professional practice or not, in connection with it, I see or hear, in the life of men, which ought not to be spoken of abroad, I will not divulge, as reckoning that all such should be kept secret. 16

The Roman World (up to about 450 CE)

  Claudius Galen of Pergamum (130-210)   Physician to gladiators & Roman emperors □ Produced 500 books and other writings on medicine

and philosophy □ Galen’s understanding of the human body prevailed

for 1,500 years. □ Adopted the idea of four humors of the body

-  Black bile, yellow bile, phlegm, blood □ Began bloodletting to balance these humors

17

Dark Ages / Medieval (400 – 1450 CE)

  Medieval Europe adopted Galen’s writings without question

  Adopted bloodletting (barbers & leeches)

  Abandoned sanitation

  Dark Ages were dominated by the Church

  Hospitalia established to provide shelter for pilgrims & evolved into places of refuge for the sick and dying.

  Classical medical knowledge was preserved in the Muslim world.

18

Canon of Medicine

  Avicenna (980-1037) □ Studied ancient medicine – Greek, Persian, Indian □ Compiled the Canon of Medicine in 1025, including

his own experience -  Body consists of organs, four humors, four elements

(earth, air, fire water) and vital force (link between body, spirit and soul)

-  Developed treatments such as clearing airways with reeds or tubes of gold

-  Toothache: dissolve opium seeds in rose-oil & drop in ear nearest painful tooth

4

19

Renaissance / Enlightenment (post 1450)

  A revival of interest in scientific enquiry   Andreas Vesalius □ Displaced much of Galen’s work with cadaver

dissections   William Harvey (1578-1657) □  published his views on the circulation of blood in

1628.   René's Descartes (1590-1650) □  put forward the idea that the body was a machine

made up of parts (Cartesian view).   Hospitals and medical schools established in

18th century. 20

  James Lind (1716-1794) identified a cure for scurvy (citrus fruit) using a controlled experiment in 1747.

  Edward Jenner (1749-1823) noticed that milkmaids who caught coxpox rarely developed smallpox. □  Innoculated a boy with cowpox in 1796. He then

unsuccessfully attempted to infect him with smallpox. □ Jenner’s vaccination was much safer than smallpox

inoculation, became popular and did much to reduce smallpox mortality.

Vaccinia

21 22

The 19th Century (1)

  Girolamo Fracastoro (1478-1553) had suggested that diseases were caused by invisible ‘seminaria’ (germs).

  Prevailing view in early 19th century was that diseases were caused by ‘miasmas’.

  French investigation of yellow fever epidemic in Barcelona in 1822 ‘proved’ contagion was not possible (people not in contact with other contracted it – but they didn’t know about mosquito carriers)

  We know now that germ theory is correct.

23

The 19th Century (2)

  Ignaz Philipp Semmelweiss (1818-1865) reduced deaths from fever in Vienna & Budapest by insisting that anyone delivering a baby should wash in chlorinated lime.

  Joseph Lister (1827-1912) reduced mortality from infections after surgery from 50% to 15% in 1861 using antiseptics.

24

Florence Nightingale

  1820 – 1910   Founded the modern

nursing profession   Nightingale School of

Nursing   Nightingale Research

Foundation (Canada)   Florence Nightingale

Effect

5

25

The 19th Century (3)

  Louis Pasteur (1822-1885) published his germ theory in 1861. Devised method for agents to use as vaccines.

  Robert Koch (1843-1910) identified causal agents of tuberculosis (1882) and cholera (1883).

  By 1900 miasmatic theory was totally discredited.

26

Scientific Method

  Bacon (1561-1626) and Descartes (1596-1650) Invented new habits of scientific thought □ scientific method as habits of disciplined creativity,

careful observations, logical thinking & analysis □ way of seeking trends & drawing generalizations

  Scientific way of thinking based on assumptions & methods that are reliable, objective & testable

27

Two scientific methods: Inductive and Deductive

Inductive:   Making observations until generalizations

can be drawn and prediction made □ Anatomy is a product of inductive method □ Specific observations lead to generalizations

Deductive:   Observations lead to questions □ Q. what causes uterine contractions in childbirth?

  Form an hypothesis □ Oxytocin causes uterine contractions

  Test the hypothesis with an experiment □  Isolate muscle tissue and apply oxytocin

28

29

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

30

Peer Review

  Critical evaluation by other experts in the field

  Ensures honesty, objectivity & quality in science

6

31

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 □  first law of thermodynamics

  Theory is a summary of conclusions drawn from observable facts □  it provides explanations and predictions □  sliding filament theory of muscle contraction

32

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

33

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.

34

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 relationships help us choose animals for biomedical research □  rats & mice used extensively

35

Adaptations

36

Wisdom teeth

Third eyelid Vomeronasal organ Extrinsic ear

muscles

Darwin’s point

Neck rib

Palmaris muscle

Erector pili

Body hair

Thirteenth rib

Pyramidalis muscle

Male uterus

Female vas deferens

Fifth toe Plantaris muscle

Appendix

Male nipples

Subclavius muscle

7

37

Primate Adaptations

38

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

39

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 40

Primate Phylogeny

41

Human Structure

 Hierarchy of complexity □ organ systems □ organs □ tissues □ cells □ organelles □ molecules □ atoms

42

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)

8

43

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 44

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

45

Homeostasis

  Internal environment described as dynamic equilibrium □  fluctuates within a range around a certain set point

  Loss of homeostatic control causes illness or death

46

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

47

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 48

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

9

49

Useful Tables in Textbook

50

Review of Major Themes

  Cell theory □  activity of cells determine structure and function

  Homeostasis □  maintaining stable internal conditions

  Evolution □  our body evolved by natural selection

  Hierarchy of structure □  levels of complexity

  Unity of form and function □  physiology is inseparable from anatomy

51

Medical Imaging

  Radiography (x rays) □  William Roentgen - 1885 □  penetrate soft tissues and

darken photographic film □  dense tissue remains white

  Radiopaque substances □  injected or swallowed □  hollow structures

–  blood vessels –  intestinal tract

52

Medical Imaging

  Computed Tomography (CT scan) □  low-intensity X rays and computer analysis

-  slice type image -  increased sharpness

  Magnetic Resonance Imaging (MRI) □  slice type image □  best for soft tissue □  Mechanics

-  magnetic field aligns atoms -  radio waves realign the atoms -  radio turned off -  atoms realign to the magnetic field -  energy given off depending on tissue type

53

Medical Imaging

  Positron Emission Tomography (PET scan) □ assesses metabolic state □ mechanics

-  inject labeled glucose –  positrons and electrons collide –  gamma rays given off

-  analyzed by computer –  image glucose usage

54

Medical Imaging

  Sonography □  mechanics

-  high-frequency sound waves echo back from internal organs

□  avoids harmful x rays □  obstetrics □  2nd most commonly used

technique

10

55

Summary (1)

  Anatomy & physiology intimately related (form fits function)

  Gross (naked eye) & micro (histology)   Two contexts in which to place A&P: □ Evolutionary adaptations of humans □ Health and wellness

  History of medicine □ Science emerged in Greece, disappeared during the

dark ages (in Europe), and remerged in the Renaissance

56

Summary (2)

  Technology and new discoveries intimately related □  Especially the microscope and imaging techniques

  Francis Bacon and Renee Descartes helped propagate scientific thought □  Inductive and deductive reasoning □ Experimental design & rigorous testing □ Peer review

  Facts, laws and theories

57

Summary (3)

  Human origins & adaptations □ Adaptive traits are selected by environmental

pressures – called natural selection – resulting in disproportionate survival

□ Hereditary traits passed on to next generation □ Results in descent with modification (evolution), and

speciation

  Primate adaptations and phylogeny □ Our ancestors went from quadripedalsim to

bipedalism, from forest & trees to grasslands 58

Summary (4)

  Gives context to current human anatomy & physiology (vestigial organs, fight or flight response)

  Human structure □ Hierarchy of complexity, simple level entrains into

next level. -  Cells together form tissue, which can perform functions

cells cannot on their own (eg muscles)

  Human function – all functions to support life □ Energy, growth, response, reproduction

59

Summary (5)

  Homeostasis (property of life) □ Negative & positive feedback loops

  Medical terminology   Medical imaging   Orientation □ Anatomical position, planes, directional terms □ Body regions □ Body cavities and membranes

  Organ systems