1. Cell signals and control pathways List and describe the components in specific 2nd messenger signal transduction pathways Define each of the following and predict their effect on signal transduction: –agonist and antagonist for one receptor –receptor isoforms (one ligand, >1 receptor) –one ligand on one receptor (tonic control) –two antagonistic ligands on one tissue

2. http://www.blackwellpublishing. com/matthews/neurotrans.html

5. Class problem set: 1. Norepinephrine (NE) is a large protein. Where will receptors for NE be? inside the target cell or on the target cell membrane 2. When NE binds an  1 receptor on a cell’s membrane, there is an increase in IP 3 and DAG in the cell. What membrane bound amplifier enzyme is activated to cause the IP 3 and DAG increase? 3. What ion will be increased in the ICF due to IP 3 ? 4. What ICF enzyme will be activated by DAG?

6. Norepinephrine or Epinephrine Example of two ligands and two receptor isoforms

7.   Tonic control through one signal molecule

8. Predict the effect of the following on blood vessel smooth muscle controlled by catecholamines on adrenergic receptors: muscle cell receptor type  1  2 1.increased NE release 2.decreased NE release 3.addition of  1 agonist 4.addition of  2 agonist 5.addition of  1 antagonist 6.addition of  2 antagonist 7.addition of  1 antagonist 1. ConstrictDilate 2. 3. 4. 5. 6. 7.

9. Control pathways - List the components of a control pathway and identify those components in specific neural and endocrine reflex pathways.

11. Ex/ control of lactation

12. Negative feedback - maintains homeostasis

13. Positive feedback - increases response

15. Example control pathways You stand up. (A decision in the brain is transmitted by a motor neuron that releases neurotransmitter to cause coordinated leg muscle contraction.) Decreasing plasma Ca 2+ is detected by the parathyroid gland cells. The glands release PTH in response. PTH will remove some Ca 2+ from bone and increase plasma Ca 2+. You breath in carbon monoxide. You have no receptors for this gas.