This document provides an overview of integrated human physiology. It discusses the study of body function and homeostasis through feedback loops. The four primary tissues - muscle, nervous, epithelial and connective tissue - are examined, as well as the scientific method and development of new drugs. Physiological processes and their alterations in disease are explored.
Measures of Dispersion and Variability: Range, QD, AD and SD
INTEGRATED HUMAN PHYSIOLOGY OVERVIEW
1. INTEGRATED HUMAN PHYSIOLOGY OVERVIEW
The Study of Body Function
Prepared by Marc Imhotep Cray, M.D.
Professor Basic Medical Sciences
IVMS Intro to Anat.
& Physio. Basics/
Video-Animations
Anatomy and Physiology Tutorial
http://www.le.ac.uk/pathology/teach/va/anatomy/frmst.htm
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2. Human Physiology
• Study of how the human body functions.
• How organisms accomplish tasks essential for
life.
• Pathophysiology:
– How physiological processes are altered in
disease or injury.
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3. Scientific Method
• Confidence in rational ability, honesty and humility.
• Specific steps in scientific method:
– Formulate hypothesis:
• Observations.
– Testing the hypothesis:
• Quantitative measurements.
– Analyze results:
• Select valid statistical tests.
– Draw conclusion.
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4. Development of New Drugs
• Cellular research:
– Cells in tissue culture used to develop new drugs.
• Animal models:
– Laboratory animals, genetically susceptible to a
particular disease, are given doses of new drug.
• Phase I clinical trials:
– Drug tested on healthy human volunteers.
• Determine pharmacokinetics.
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5. Development of New Drugs (continued)
• Phase II clinical trials:
– Drug tested on target population.
• Phase III clinical trials:
– Occur in research centers across country to increase
number of participants.
• If passes trials, goes to FDA for approval.
• Phase IV:
– Test for other uses of the drug.
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6. Homeostasis
• Maintaining constancy of internal environment.
– Dynamic constancy.
• Within a certain normal range.
• Maintained by negative feedback loops.
• Regulatory mechanisms:
– Intrinsic:
• Within organ being regulated.
– Extrinsic:
• Outside of organ, such as nervous or hormonal systems.
• Negative feedback inhibition.
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7. Feedback Loops
• Sensor:
– Detects deviation from
set point.
• Integrating center:
– Determines the
response.
• Effector:
– Produces the response.
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8. Negative Feedback
• Defends the set point.
• Reverses the deviation.
• Produces change in opposite direction.
• Examples:
– Insulin decreases plasma [glucose].
– Thermostat.
– Body temperature.
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10. Positive Feedback
• Action of effectors amplifies the changes.
• Is in same direction as change.
• Examples:
– Oxytocin (parturition).
– Voltage gated Na+ channels
(depolarization).
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11. Primary Tissues
• The body composed of 4 different primary tissues:
– Muscle, nervous, epithelial, connective.
• Organs:
– Composed of at least two primary tissues.
– Serve different functions of the organ.
• Systems:
– Organs that are located in different regions of the body
and perform related functions.
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12. Muscle Tissues
• Specialized for contraction.
• 3 types of muscle tissue:
– Skeletal.
– Cardiac.
– Smooth.
• Skeletal and cardiac muscle have similar
mechanisms of contraction.
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13. Skeletal Muscles
• Voluntary, striated.
• Attached to bones by
tendons:
– Produce skeletal
movement.
• Muscle fibers arranged in
bundles, fibers arranged in
parallel.
• Produce graded
contractions.
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14. Cardiac Muscles
• Striated, found only in the
heart.
• Myocardial cells are
interconnected to form
continuous fabric.
• Intercalated discs couple
cells together mechanically
and electrically.
– Syncytium.
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15. Smooth Muscles
• Not striated.
• Do not contain sarcomeres.
• Ca2+ combines with
calmodulin, activating
contraction process.
• Contain gap junctions.
• Found in GI tract, blood
vessels, bronchioles, ducts
of urinary and reproductive
systems.
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17. Epithelial Tissue
• Cells that form membranes:
– Provide barrier between external and internal environments.
– Classified according to number of layers and shape of the
cells in upper layer.
• Simple:
– One cell layer thick.
– Specialized for transport.
• Stratified membranes:
– Composed of a number of layers.
– Specialized for protection.
– Squamous, columnar, cuboidal.
– Glands:
• Exocrine, endocrine glands.
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18. Epithelial Membranes
• Squamous cells:
– Flattened in shape.
– Function:
• Diffusion and
filtration.
–Line all blood
vessels,
pulmonary
alveoli.
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22. Exocrine Glands
• Derived from cells of epithelial membranes.
• Secretions are released through ducts.
– Simple tubes or modified as acini.
• Examples:
– Tear glands.
– Sweat glands.
– Prostate glands.
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23. Endocrine Glands
• Lack ducts.
• Secrete hormones into
capillaries/lymphatic system within
the body.
• May be discrete organs:
– Primary functions are the production and
secretion of hormones.
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24. Connective Tissue
• Large amounts of extracellular material in the
spaces between connective tissue cells.
• 4 types of connective tissue:
– Connective tissue proper.
– Cartilage.
– Bone.
– Blood.
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25. Connective Tissue Proper
• Loose connective tissue:
– Scattered collagen and tissue fluid.
• Dermis of skin.
• Dense fibrous connective tissue:
– Regularly arranged.
• Collagen oriented in same direction.
– Tendons.
– Irregularly arranged.
• Resists forces applied in many directions.
– Capsules and sheaths.
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26. Connective Tissue (continued)
• Cartilage:
– Chondrocytes.
• Supportive and protective tissue.
• Elastic properties to tissues.
• Precursor to many bones.
• Articular surfaces on joints.
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27. Connective Tissue (continued)
• Bone:
– Hydroxyapatite crystals.
• Osteoblasts:
– Bone-forming cells.
– Osteocytes:
• Trapped osteoblasts: less
active.
– Osteoclasts:
• Bone resorbing cells.
Rubin, Essentials of Pathophysiology,2001
• Blood:
– Classified as connective tissue.
• Half its volume is plasma.
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28. Body-Fluid Compartments
• 65-75% of total body weight is H20.
• Intracellular compartment:
– Fluid inside the cell.
• 2/3 of H20.
• Extracellular compartment:
– 2 Subdivisions:
• Blood plasma.
• Interstitial fluid.
• 1/3 H20.
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