physiology. vertebrate physiology dr. kristin hager –334 jordan life sciences –[email protected]...
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PHYSIOLOGY
Vertebrate Physiology• Dr. Kristin Hager
– 334 Jordan Life Sciences– [email protected]
• Office Hours– Tuesdays 11:00 AM-1:00 PM– Sign-up sheet outside of Jordan 232
How to do well...• Reading in the textbook ‘Human Physiology’ (D.U.
Silverthorn) is required. Do it BEFORE the lecture.
• Use CourseWare (webfile) for Syllabus, Lectures, Movies:
– CourseWare: CourseWare (sp.11): /afs/nd.edu/courses/bios/bios30344.01
– Lecture PowerPoints for the week will be uploaded every Monday
• Hesburgh reserve readings available for extra help.
Suggested Supplementary Reading Material
•Textbook of medical physiology / Arthur C. Guyton, John E. Hall. 2011.
•Essentials of human anatomy & physiology / Elaine N. Marieb. 2009.
•Human physiology and mechanisms of disease / Arthur C. Guyton and John E. Hall. 1997.
•Human physiology: from cells to systems / Lauralee Sherwood. 2010.
•Review of medical physiology/ William F. Ganong. 2010.
EXAMS• Four exams
– Feb 10– March 10– April 14– Finals week (May 9-13)
• Each exam will contribute 25% of grade.• Material will come from text and lecture.
Copyright © 2009 Pearson Education, Inc.
Levels of organization and the related fields of study
System Organ Tissue Cell
Cardiovascular Heart Myocardium Muscle Cell
Integration between systems of the body
Homeostasis
HomeostasisClaude Bernard (1880’s) ‘constancy of the internal environment’
Walter B. Cannon (1929)Regulation of a ‘relatively constant internal environment’
Physiology is an Integrative Science
HomeostasisSummary
Physiological control systems keep regulated variables within a desired range during homeostasis
Factors underhomeostatic control
• nutrients
• gases
• waste products
• pH
• salt and other electrolytes
• temperature
• volume and pressure
Normal Ranges for Some Blood Values
Arterial pH 7.35-7.45
Bicarbonate 24-28 mEq/L
Sodium 135-145 mEq/L
Calcium 4.5-5.5 mEq/L
Oxygen content 17.2-22 ml/100ml
Urea 12-35 mg/100 ml
Amino acids 3.3-5.1 mg/100ml
Protein 6.5-8 g/100ml
Total lipids 400-800 mg/100ml
Glucose 75-110 mg/100ml
Homeostatic Mechanisms
• Intracellular level• e.g. allosteric modification of enzymes
• Local or Intrinsic level• autoregulation within a tissue
• usually nervous or endocrine systems not required• e.g. dilation of blood vessels in response to CO2
• Reflex control or Extrinsic level• control system is outside the organ or tissue being
influenced
• nervous or endocrine systems involved
Compensating regulatory responses that correct deviations from a stable condition.
Antagonistic homeostatic control of heart rate
Tonic control of blood vessel diameter
Local vs. Reflex Control
Variable toControl
SensorReceptor
IntegratingCenter
Effector
Functions of the Integrator
• Possess a “set point”• Look for error signals• Respond by
controlling the effector
Positive Feedback Systems
• Reproductive hormone cycles in females
• Action potentials in nerve cells
• Uterine contractions during childbirth
NOT always homeostatic
Set-points can be modified
e.g. thermostat in brain hypothalamus (integrator)Increase in set-point for core body temperature during fever
e.g. acclimatization to environmental temperature, altitude (increase red blood cells)
e.g. circadian rhythms
Loop efficiency can be altered
• Frequency
• Speed
• Sensitivity• Anticipation (Feed-Forward Control)
• continual observation
• prediction from other information
• e.g. salivation in response to smell of food
Variable
Receptor
Integrator
Effector
Arterial bloodpressure decrease
Baroreceptordecreases firing
Brainstem
Heart andblood vessels
AfferentPathway
EfferentPathway
Homeostatic control of blood sugar (glucose)
Eating
Increased Blood Glucose
Pancreas Islets of LangerhansBeta cells
Increased Insulin
Cellular Uptake of Glucose
Decreased Blood Glucose
Blood glucose negative feedback loop
Variable
Receptor
Integrator
Effector
Glucose
Pancreasislet beta cells
Pancreasislet beta cells
Body cellsliver, muscle, fat
noneInsulin
Decreased blood glucose
Pancreas alpha cells
Increased glucagon
Increased glucose synthesisIncreased glycogen breakdown
Increased blood glucose
Antagonistic homeostatic control of blood sugar
Decreased blood glucose
Pancreas alpha cells
Increased glucagon
Increased glucose synthesisIncreased glycogen breakdown
Increased blood glucose
Antagonistic homeostatic control of blood sugar
Insulin vs. glucagon