Presentation is loading. Please wait.

Presentation is loading. Please wait.

Announcements Personal Information due Friday at beginning of class. Lab Days –If you’d like to swap lab days: Name Lab you’re registered for now Lab you’d.

Similar presentations


Presentation on theme: "Announcements Personal Information due Friday at beginning of class. Lab Days –If you’d like to swap lab days: Name Lab you’re registered for now Lab you’d."— Presentation transcript:

1 Announcements Personal Information due Friday at beginning of class. Lab Days –If you’d like to swap lab days: Name Lab you’re registered for now Lab you’d like to move to Justification for the move

2 1QQ # 1 Name on top edge, back side of paper Answer on blank side of paper. Answer one of the following: 1.The 200+ cell types in the human body can be classified into one of 4 cell types or tissue types. List 3 of the 4 types. 2.List 3 of the 4 modes of heat exchange. 3.What is the difference between an organ and a tissue?

3 Cognitive Domain (Revised Bloom) Description Action verbs Original Bloom’s term 1.Remember (LOCS)** Retrieve relevant knowledge Recognize, identify, recall, list, label Knowledge 2. Understand (LOCS) Describe meaning Interpret, exemplify, classify, summarize/ explain/describe in own words Comprehension 3. Apply (LOCS/HOCS) Use/apply procedures or info in novel context Execute, predict Application 4. Analyze (HOCS) Infer relationships between components or parts and bigger picture Differentiate, organize, link, attribute, infer, interpret, diagnose, compare/contra st, conclude, speculate Analysis 5. Evaluate (HOCS) Make judgments based on evidence, criteria, and standards Verify, critique, assess merit Evaluation 6. Create (HOCS) Piece together info to form novel whole; create original product Generate, plan, build, produce, design, model Synthesis A Taxonomy of Cognitive Skills for Developing Student Assignments and Assessments* *SC SDE (Pat Mohr). Adapted from Lorin W. Anderson, David R. Krathwohl et al (Eds.) A Taxonomy for Learning, Teaching, and Assessing: A Revision of Bloom’s Taxonomy of Educational Objectives  2001; modified by Ellen Goldey, Wofford College, to incorporate “Biology in Bloom,” Crowe et al., 2008, CBE – Life Sci Edu., 7: **HOCS = higher order cognitive skills, LOCS = lower order cognitive skills.

4 The body: A society of interdependent cells, each type with its own needs and contributions.

5 O2O2 pH CO 2 Temp, [glucose], [Na+], [K+], [Ca++], amino acids Nucleic acids

6 Cell Membrane: selectively permeable Capillaries: highly permeable except to proteins

7 Homeostasis: The relative constancy of the internal environment Steady state vs. equilibrium Beggar Thessaloniki, Greece

8 Homeostasis: The relative constancy of the internal environment Steady state vs. equilibrium Street vendor Thessaloniki, Greece

9 Homeostasis: The relative constancy of the internal environment Steady state vs. equilibrium San woman Kalahari Desert, Botswana

10 Homeostasis: Camp’s Bay Beach, Cape Town, South Africa

11 ~37 o C O 2, CO 2, Glucose, Na+, etc….

12 Homeostasis Regulated via reflex arcs and naturally maintained by the process of negative feedback Measurement –Which physiological variables? –Averages and ranges

13 Fig Awake Sleep Diurnal cycles, Zietgebers & entrainment Major point: Set points are not absolute!

14 Thermoregulation An example of homeostasis by negative feedback.

15 The Challenge: # 1: Melt these 7 ice cubes as fast as possible. How to do it? # 2: Make these 7 ice cubes last as long as possible? How to do it? These are non-living objects: heat exchanges with the environment but they don’t generate heat from metabolism as living things do!

16 Conduction Convection Evaporation Radiation Metabolism generates heat. Metabolism is variable! ~37 o C In steady state: Heat gain = Heat loss

17 Modes of Heat Exchange: Conduction Convection Radiation Evaporation ~37 o C

18 Modes of Heat Exchange: Conduction Convection Radiation Evaporation ~37 o C

19 Modes of Heat Exchange: Conduction Convection Radiation Evaporation ~37 o C

20

21 Mechanisms of thermoregulation For constant body temp heat in = heat out Reflex arc Negative feedback Examples Acclimatization

22

23 Negative feedback Negative Feedback Loop; response is in opposite direction of the disturbance.

24 Add covers or clothing or enter sleeping bag Skin tempAnd Core body temp Detected by thermoreceptors in skin Activity in sensory nerves Hypothalamus Sympathetic nerves Relax smooth muscle in cutaneous arterioles Blood flow to skin Heat loss by conduction & radiation Somatic nerves Muscle tone Heat production Sweat Glands Sweat production Evaporative heat loss Core temp. Voluntary behaviors Remove covers Turn on fan, etc via Heat loss Cerebral cortex Conductive heat loss Radiative heat loss Convective heat loss Central thermoreceptors Skeletal Muscles Somatic nerves

25 Negative feedback loops: What to look for The stimulus (temperature, [glucose], pressure, etc.) Sensors (thermo-, chemo-, photo-, mechano- receptors Afferent pathways to integrator (may not exist) Integrators (typically neurons or endocrine cells) Efferent pathways from integrator –nerves –hormones Effector cells or organs –virtually any cell –especially glands and muscles The response (opposes stimulus)

26 Thermoregulation in a comatose patient? In steady state: Heat gain = Heat loss What if room temperature was increased or decreased? What if additional covers were added to the patient?

27 Add covers or clothing or enter sleeping bag Skin tempAnd Core body temp Detected by thermoreceptors in skin Activity in sensory nerves Hypothalamus Sympathetic nerves Relax smooth muscle in cutaneous arterioles Blood flow to skin Heat loss by conduction & radiation Somatic nerves Muscle tone Heat production Sweat Glands Sweat production Evaporative heat loss Core temp. Voluntary behaviors Remove covers Turn on fan, etc via Heat loss Cerebral cortex Conductive heat loss Radiative heat loss Convective heat loss Central thermoreceptors Skeletal Muscles Somatic nerves

28 Explain “chills” at onset of a fever Explain “sweat” when a fever “breaks” How does Tylenol reduce a fever? To reach new, Higher set point If setpoint is suddenly reset to a higher temperature, then actual temperature is LESS THAN the new set point, so one feels “cold” and adds clothing, curls up, and shivers. These are “Chills.” If setpoint is reset to a lower temperature or back to normal, then actual temperature is GREATER THAN the new lower set point, so one feels “hot” and removes clothing, fans, and sweats. These are “the sweats” when a fever breaks. Central & Peripheral Thermoreceptors Tylenol and other non- steroidal anti- inflammatory drugs (NSAIDS) suppress the production of eicosanoids (IL-1, IL-6, etc) so effect of these on the set point in hypothalamus is minimized. p. 579 Fig 16-18

29 Are negative feedback loops subject to modification?

30 Which roofers are most appropriately dressed for the job? Red shirts No shirts 1 st day on the job –Increase body temp….. Delayed sweating via negative feedback 10 th day on the job –Sweating precedes changes in core body temperature –and sweating is increased –And salt loss in sweat is minimized Responses begin even before core temperature increases! Not just negative feedback, this is Feedforward (requires experience). FF is evidence of Acclimitization. Advantage of feedforward: anticipates disruption and minimizes fluctuation from the set point.

31 Acclimatization & Feedforward Deviations from set point are minimized Learned (by experience) Anticipates changes of a physiological parameter Response begins before there is a change in the physiological variable Minimizes fluctuations

32 ~37 o C Be able to explain the physiology in each of these situations with a detailed diagram of negative feedback responses and the modes of heat exchange involved.

33 Failure of 1. Brain function & 2. Heat loss mechanisms Increase Body Temp. Increase cell metabolism Sympathetic outflow Blood Pressure Blood Flow to brain Disrupted function of neurons Cutaneous vasodilation Heat Stroke Sweating Blood volume Excessive Sweating Massive Cutaneous Vasodilation

34 Positive feedback Inherently unstable Examples of Positive Feedback in Physiology –Heat stroke –formation of blood clot –menstrual cycling of female sex hormone concentrations –generation of action potentials in nerve fibers –uterine contractions during childbirth Each of these examples terminate naturally (self limiting) Homeostasis is achieved by negative feedback loops: the integrator detects deviations from set point and orchestrates responses produced by effectors that return the parameter toward the set point.


Download ppt "Announcements Personal Information due Friday at beginning of class. Lab Days –If you’d like to swap lab days: Name Lab you’re registered for now Lab you’d."

Similar presentations


Ads by Google