1. 3. Receptors Rods – sense low levels of light Cones – sense higher level blue, green & red light Fig. 10.36

2. 3. Receptors Rods – sense low levels of light Fig. 10.40 Cones – sense higher level blue, green & red light

3. 3. Receptors Rods – sense low levels of light Fig. 10.36 Cones – sense higher level blue, green & red light C. Receptor transduction 1. Rhodopsin

4. 3. Receptors Rods – sense low levels of light Cones – sense higher level blue, green & red light C. Receptor transduction 1. Rhodopsin Retinene (photopigment) + opsin (protein) Fig. 10.37 2. Light Retinene – cis  trans configuration

5. C. Receptor transduction 1. Rhodopsin Retinene (photopigment) + opsin (protein) Fig. 10.37 2. Light Retinene – cis  trans configuration

6. C. Receptor transduction 1. Rhodopsin Retinene (photopigment) + opsin (protein) Fig. 10.37 2. Light Retinene – cis  trans configuration 3. trans Retinene Activates g-protein (transducin) cascade Closes Na + channels Hyperpolarizes cell

7. 3. trans Retinene Activates g-protein (transducin) cascade Closes Na + channels Hyperpolarizes cell Fig. 10.37

8. 3. trans Retinene Activates g-protein (transducin) cascade Closes Na + channels Hyperpolarizes cell D. Dark vs. light Photoreceptors depolarized and inhibitory 1. Dark Inhibit adjacent cells in retina

9. D. Dark vs. light Photoreceptors depolarized and inhibitory 1. Dark Inhibit adjacent cells in retina Fig. 10.39 2. Light

10. Photoreceptors inhibitory and depolarized 1. Dark Inhibit adjacent cells in retina 2. Light Receptors hyperpolarized (inhibited) Fig. 10.39

11. Photoreceptors inhibitory and depolarized 1. Dark Inhibit adjacent cells in retina 2. Light Receptors hyperpolarized (inhibited) Light is sensed E. Dark adaptation 1. Light Receptors “bleached”  rhodopsin in receptors 2. Dark 1 st 5 minutes –  rhodopsin in cones ~ 20 minutes – max sensitivity

12. E. Dark adaptation 1. Light Receptors “bleached”  rhodopsin in receptors 2. Dark 1 st 5 minutes –  rhodopsin in cones ~ 20 minutes – max. sensitivity Due to  rhodopsin in rods Light sensitivity  by 100,000x Chapter 11 – Endocrine Endocrine glands – secrete into blood

13. Chapter 11 – Endocrine I. General info. A. Classifications Endocrine glands – secrete into blood Fig. 11.1

14. Chapter 11 – Endocrine I. General info. A. Classifications Endocrine glands – secrete into blood 1. Amines – derived from single amino acids Thyroid hormone Fig. 11.3 Fig. 9.9 Epinephrine

15. I. General info. A. Classifications 1. Amines – derived from single amino acids Thyroid hormone Epinephrine 2. Polypeptides – chains of amino acids Antidiuretic hormone disulfide bridges Insulin

16. I. General info. A. Classifications 1. Amines – derived from single amino acids Thyroid hormone Epinephrine 2. Polypeptides – chains of amino acids Antidiuretic hormone Insulin 3. Glycoproteins – carbohydrate + amino acids chains Follicle stimulating hormone (FSH) Luteinizing hormone (LH) 4. Steroids – based on cholesterol (lipid)

17. 3. Glycoproteins – carbohydrate + amino acids chains Follicle stimulating hormone (FSH) Luteinizing hormone (LH) 4. Steroids – based on cholesterol (lipid) Progesterone Testosterone Cortisol Fig. 11.2

18. 3. Glycoproteins – carbohydrate + amino acids chains Follicle stimulating hormone (FSH) Luteinizing hormone (LH) 4. Steroids – based on cholesterol (lipid) Progesterone Testosterone Cortisol B. Pre- vs. Prohormones 1. Prohormones Peptide contained in longer peptide (e.g. opioids)

19. B. Pre- vs. Prohormones 1. Prohormones Peptide contained in longer peptide (e.g. opioids) Unessential peptide portions cleaved True of all peptide hormones

20. B. Pre- vs. Prohormones 1. Prohormones Peptide contained in longer peptide (e.g. opioids) Unessential peptide portions cleaved True of all peptide hormones 2. Prehormones Single molecule (e.g. thyroid hormone) Inactive until changed by target cell Fig. 11.3

21. B. Pre- vs. Prohormones 1. Prohormones Peptide contained in longer peptide ( e.g. opioids ) Unessential peptide portions cleaved True of all peptide hormones 2. Prehormones Single molecule (e.g. thyroid hormone) Inactive until changed by target cell C. Hormone common aspects Blood born Receptors on/in target cells Specific effect on target cell

22. C. Hormone common aspects Blood born Receptors on/in target cells Specific effect on target cell Can be turned off D. Interactions 1. Synergistic e.g. – epinephrine & norepi. on heart 2. Permissive Additive or complementary

23. D. Interactions 1. Synergistic e.g. – epinephrine & norepi. on heart 2. Permissive Additive or complementary Hormone increases responsiveness of different hormone e.g. – cortisol allows epi. & norepi. to have catabolic effects 3. Priming effect Hormone presence increases sensitivity/effect of same hormone

24. 2. Permissive Hormone increases responsiveness of different hormone e.g. – cortisol allows epi. & norepi. to have catabolic effects 3. Priming effect Hormone presence increases sensitivity/effect of same hormone e.g. – GnRH causes AP to be more sensitive to GnRH 4. Antagonistic Opposite effects

25. 3. Priming effect Hormone presence increases sensitivity/effect of same hormone e.g. – GnRH causes AP to be more sensitive to GnRH 4. Antagonistic Opposite effects e.g. – Insulin (  glucose stores) & glucagon (  glucose stores) E. Hormone levels 1. Half-life Time for metabolic clearance of half of hormone

26. E. Hormone levels 1. Half-life Time for metabolic clearance of half of hormone 2. Physiological levels Normal levels 3. Pharmacological levels Abnormally high levels Different physiological effects 4. Downregulation/desensitization Prolonged exposure  sensitivity of target tissue

27. 4. Downregulation/desensitization Prolonged exposure  sensitivity of target tissue II. Hormone mechanisms A. Steroid hormones 1. Transport On carrier protein in blood

28. II. Hormone mechanisms A. Steroid hormones 1. Transport On carrier protein in blood Passive diffusion through membrane Fig. 11.4

29. A. Steroid hormones 1. Transport On carrier protein in blood Passive diffusion through membrane Fig. 11.5 Binds receptor in cytoplasm 2. Receptor Ligand binding domain – binds steroid DNA binding domain – binds DNA 3. Receptor-ligand complex

30. Fig. 11.5 2. Receptor Ligand binding domain – binds steroid DNA binding domain – binds DNA 3. Receptor-ligand complex Translocates to nucleus Fig. 11.4 Two complexes bind two receptor half sites on DNA (dimerization)

31. 3. Receptor-ligand complex Translocates to nucleus Two complexes bind two receptor half sites on DNA (dimerization) Fig. 11.4 Fig. 11.5 Form homodimer Activate transcription

32. 3. Receptor-ligand complex Translocates to nucleus Two complexes bind two receptor half sites on DNA (dimerization) Fig. 11.5 Form homodimer Activate transcription 4. On DNA Hormone response element recognized by complex

33. Fig. 11.5 Form homodimer Activate transcription 4. On DNA Hormone response element recognized by complex 2 must bind (dimerization) for activity B. Thyroid hormone T 3 and T 4 Based on # of iodines

34. B. Thyroid hormone T 3 and T 4 Based on # of iodines Fig. 11.3 T 4 converted to T 3 (active form) in cell 1. Transport Most carried on proteins in blood

35. B. Thyroid hormone T 3 and T 4 Based on # of iodines T 4 converted to T 3 (active form) in cell 1. Transport Most carried on proteins in blood Passive diffusion into cell

36. T 4 converted to T 3 (active form) in cell 1. Transport Most carried on proteins in blood Passive diffusion into cell Fig. 11.6 2. Receptor-ligand complex Formed in nucleus Complex forms heterodimer

37. Fig. 11.6 2. Receptor-ligand complex Formed in nucleus Complex forms heterodimer Other site bound by receptor-RXR (vit. A) complex Fig. 11.7 Transcription produces specific enzymes

38. 2. Receptor-ligand complex Formed in nucleus Complex forms heterodimer Other site bound by receptor-RXR (vit. A) complex Transcription produces specific enzymes C. 2 nd messenger – adenylate cyclase

39. Other site bound by receptor-RXR (vit. A) complex Transcription produces specific enzymes C. 2 nd messenger – adenylate cyclase Membrane receptor binding Fig. 11.8 Intracellular g-protein  subunit dissociation

40. C. 2 nd messenger – adenylate cyclase Membrane receptor binding Fig. 11.8 Intracellular g-protein  subunit dissociation Subunit activates adenylate cyclase Forms cAMP from ATP

41. Fig. 11.8 Intracellular g-protein  subunit dissociation Subunit activates adenylate cyclase Forms cAMP from ATP cAMP activates protein kinase

42. Fig. 11.8 Subunit activates adenylate cyclase Forms cAMP from ATP cAMP activates protein kinase Protein kinase phosphorylates (adds a phosphate) specific enzymes

43. Fig. 11.8 Forms cAMP from ATP cAMP activates protein kinase Protein kinase phosphorylates (adds a phosphate) specific enzymes Enzymes activated or inhibited

44. Forms cAMP from ATP cAMP activates protein kinase Protein kinase phosphorylates (adds a phosphate) specific enzymes Enzymes activated or inhibited D. Phospholipase C-Ca ++ second messenger Membrane receptor binding G-protein dissociates intracellularly

45. D. Phospholipase C-Ca ++ second messenger Membrane receptor binding G-protein dissociates intracellularly Fig. 11.9 Activates phospholipase C (PLC) Releases inositol trisphosphate (IP 3 ) from lipid IP 3 releases Ca ++ from endoplasmic reticulum

46. Membrane receptor binding G-protein dissociates intracellularly Fig. 11.9 Activates phospholipase C (PLC) Releases inositol trisphosphate (IP 3 ) from lipid IP 3 releases Ca ++ from endoplasmic reticulum Ca ++ activates calmodulin Calmodulin has a variety of effects