Transcript Unit 1 Intro ppt #1

Unit 1 Intro
ppt #1
1-1
Anatomy - The Study of Form
• Examining structure of the Human Body
–
–
–
–
Inspection-----eyes
Palpation------fingers
Auscultation---hearing
Percussion----tapping, hearing
• Cadaver dissection
– cutting and separation of tissues to reveal their
relationships
• Comparative anatomy
– study of more than one species in order to examine
structural similarities and differences, and analyze
1-2
evolutionary trends
Anatomy - The Study of Form
• Exploratory Surgery
– open body and take a look inside
• Medical imaging
– viewing the inside of the body without surgery
– Radiology – branch of medicine concerned with imaging
• Gross Anatomy
– study of structures that can be seen with the naked eye
• Cytology
– study of structure and function of cells
• Histology (microscopic anatomy)
– examination of cells with microscope
• Ultrastructure
– the molecular detail seen in electron microscope
• Histopathology
– microscopic examination of tissues for signs of disease
1-3
Physiology - The Study of
Function
• Subdisciplines
– neurophysiology (physiology of nervous system)
– endocrinology (physiology of hormones)
– pathophysiology (mechanisms of disease)
• Comparative Physiology
– limitations on human experimentation
– study of different species to learn about bodily function
• animal surgery
• animal drug tests
– basis for the development of new drugs and medical
1-4
procedures
Beginnings of Medicine
• Aristotle
– one of the first philosophers to write about
anatomy and physiology
– believed that diseases had either supernatural
causes or physical causes
• called supernatural causes of disease theologi
• called natural causes for disease physiologi
• this gave rise to the terms: physician and physiology
– believed that complex structures are built from
simpler parts
1-5
Early Medical Illustrations
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Art Resource
Figure 1.2
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
© SPL/Photo Researchers, Inc.
Figure 1.3
1-6
Birth of Modern Medicine
• Robert Hooke (1635-1703)
– made many improvements to the compound
microscope -2 lenses-ocular lens
– published first comprehensive book of
microscopy (Micrographia) in 1665
• Antony van Leeuwenhoek(1632-1723)
– invented a simple (single-lens) microscope with
great magnification to look at fabrics (200X)
– published his observations of blood, lake water,
sperm, bacteria from tooth scrapings and many
other things
1-7
• Theodor Schwann(1810-1882)
– concluded that “all organisms were composed of cells”
– ** Cell Theory
• ****considered as the most important breakthrough in biomedical history
• **** all functions of the body are interpreted as effects of cellular activity
• Gray’s Anatomy (1856) (not the TV show!)
• Continual improvements from then on!
• Anatomy preceeded Physiology!
1-8
Living in a Revolution
• Modern biomedical science
– technological enhancements
• advances in Medical Imaging have enhanced our
diagnostic ability and life-support strategies
• Genetic Revolution
• human genome is finished
• gene therapy is being used to treat disease
• Early pioneers were important
– established scientific way of thinking
– replaced superstition with natural laws
1-9
Scientific Thinking :
Inductive Method
• Described by Francis Bacon
– making numerous observations until one becomes
confident in drawing generalizations and predictions from
them
– knowledge of anatomy obtained by this method
• Proof in science
– reliable observations
– tested and confirmed repeatedly
– not falsified by any credible observation
• In science, all truth is tentative
– “proof beyond a reasonable doubt”
1-10
Hypothetico-Deductive Method
• physiological knowledge gained by this method
• investigator asks a question
• formulates a hypothesis- an educated speculation or
possible answer to the question
– characteristics of a good hypothesis
• consistent with what is already known
• testable and possibly falsifiable with evidence
• Hypothesis - to suggest a method for
answering questions - are written as ‘If-Then’
statements
1-11
Experimental Design
considerations
• Sample size
– number of subjects used in a study
– controls for chance events and individual variation
• Controls
– control group and treatment group
– comparison of treated and untreated individuals
• Psychosomatic Effects
– effects of the subject’s state of mind on his or her
physiology
1-12
– use of placebo in control group
Proper Experimental Design
• Experimenter bias
– prevented with double-blind study
• Statistical testing
– provides statements of probability
– difference between control and test subjects
was not random variation
– results due to the variable being tested
1-13
Peer Review
• Critical evaluation by other experts in
the field
– done prior to funding or publication
– done by using verification and repeatability of
results
• Ensures honesty, objectivity and quality
in science
1-14
When we study Anatomy and Physiology
we must consider:
Human Origins & Adaptations
• Charles Darwin
– On the Origin of Species by Means of Natural
Selection (1859) – ‘book that shook the world’
– The Descent of Man (1871) – human evolution
• Theory of natural selection
– how species originate and change through time
– changed view of “our origin, our nature and our place
in the universe”
– increases understanding of human form and function
1-15
Evolution, Selection, and
Adaptation
• Evolution
– change in genetic composition of population of organisms
• development of bacterial resistance to antibiotics
• appearance of new strains of AIDS virus
• Natural Selection
– some individuals within a species have hereditary
advantage over their competitors
• better camouflage
• disease resistance
• ability to attract mates
– produce more offspring and advantage passed on
– Selection Pressures – natural forces that promote
the reproductive success of some individuals more
than others
1-16
Evolution, Selection, and
Adaptation
• Adaptations – features of an organism’s
anatomy, physiology, or behavior that have evolved
in response to these selection pressures and
enable the organism to cope with the challenges of
its environment.
– Model – animal species selected for research on a
particular problem
1-17
Animal Relations
• Closest relative - chimpanzee
– difference of only 1.6% in DNA structure
– chimpanzees and gorillas differ by 2.3%
• Study of evolutionary relationships
– help us chose animals for biomedical
research (the animal model)
– rats and mice used extensively due to issues
involved with using chimpanzees
1-18
Vestiges of Human Evolution
• Vestigial Organs – remnants of organs that
apparently were better developed and more
functional in the ancestors of a species, and now
serve little or no purpose
– piloerector muscle
– auricularis muscles
1-19