Chapter 14
 Endocrine System - Notes  (Changes and Suggestions in blue - 3/6/06)
Return to Chapter Index

Return to Main Index

 1. Name and describe the main functions of the endocrine system.

     1. monitoring - checking conditions
     2. communicating - sending messages
     3. stimulating - making adjustments happen
     4. coordinating - making parts work together and not interfere (incr. cooperation, decr. antagonism)

 2. Describe the role of the endocrine system in modulating body conditions and functions through negative feedback systems.

      - provides gradations of responses to prevent or reverse changes and maintain proper and fairly stable conditions

 3. Compare the nervous and endocrine systems with respect to speed of action, area of influence, and duration of effects.

     1. speed - nervous = fast; endocrine = slower
     2. area - nervous = local on muscles and glands; endocrine = local or diffuse on allstructures
     3. duration - nervous = short term; endocrine = longer term

 4. Explain that the effectiveness of a hormone depends upon many factors and therefore is difficult to measure.

     - factors include (1) rate of secretion, (2) rate of elimination, (3) number and activity of hormone receptors, (4) conditions in the target cells, (5) hormone-binding blood chemicals, (6) multiple forms of a hormone, (7) target modification of the hormone, (8) timing of pulsatile and rhythmic hormone secretion, (9) hormone interactions, (10) and hormone/nervous system interactions

 5. For each of the following hormones, describe its overall effects and the effects of aging on the hormone's ability to perform its roles: growth hormone (GH), melatonin, thymosin, aldosterone, testosterone (in males), estrogen and progesterone (in females).

     GH -> build and maintain size of structures,e.g., muscle, bone matrix (Note: diurnal rhythm with peak at night)
           - age -> variable but average decline -> decr. size of structures, decr. lean body mass:fat ratio (e.g., muscle, bone matrix, skin, liver, kidney, spleen, blood glucose) -> decr. function of structures (Note: decrease in nocturnal peak in GH -> flattening of diurnal rhythm curve ?->? altered biorhythms such as sleep)

     melatonin -> seems to regulate daily rhythms (e.g., sleep), serves as an antioxidant
           - age -> decr. diurnal hormone rhythm -> altered diurnal rhythms (?e.g., sleep?), possible decr. in *FR defense

     thymosin -> stimulates immune functions (e.g., maturation of T-lymphocytes)
           - age -> decr. thymosin -> decr. immune functions -> decr. warning from inflammation rash, incr. risk of infection and cancer

     aldosterone -> regulates water, salts, pH, and blood pressure
           - age -> decr. aldosterone  (from decr. kidney production of renin) -> decr. control of water, salts, pH, and blood pressure

     testosterone -> male reproductive system + other effects (e.g., skin, hair, muscle, bone)
           - age -> variable but average decrease in amount and diurnal rhythm -> OK reproductive functions, changes in skin, hair, muscle, decr. bone

     estrogen + progesterone -> female reproductive system + skin, hair, LDLs, bone
           - age -> very great decr. estrogen and very great decr. progesterone -> very great decr. reproduction, altered sexual response, skin, great incr. LDLs, very great decr. bone matrix

 6. Explain that the effectiveness of several hormones does not change substantially with aging.

      -e.g., ADH, thyroid, calcitonin, parathormone, CCK, glucocorticoids Note: harmful effects from high glucocorticoids in elderly from anti-inflammatory therapy or diseases {e.g., Alzheimer s, depression} -> risk for diabetes, osteoporosis, high BP, decreased immune function, ulcers and G.I. bleeding

 7. Name and describe two main temporary effects and three main permanent effects from hormone changes resulting from menopause.

      - temporary
           1. hot flashes
           2. altered psychological and mental functions (e.g., depression, anxiety, confusion, decr. memory)
      - permanent
           1. altered reproductive and breast structure and functions and hair distribution
           2. great decr. bone matrix
           3. great incr. LDLS and great decr. HDLs

 8. Describe beneficial and harmful effects from estrogen replacement therapy (ERT).

      - beneficial = decr. hot flashes, incr. psychology and mental activity, incr. vaginal secretion, incr. skin, decr. LDLs and incr. HDLs, slower bone loss
      - harmful = incr. risk from cancer, blood clots, gall bladder problems in some women

 9. Describe the role of insulin and the effects of aging on its effectiveness.

      - insulin -> decr. blood sugar and incr. energy supply for cells
           - age -> no effect on ability

10. For diabetes mellitus among the elderly, name three contributing factors and five harmful effects and describe real life practical consequences from the harmful effects.

      - contributing factors
          1. genetics
          2. obesity
          3. decr. exercise
      - harmful effects
           1. cataracts -> poor vision and blindness ->
           2. diabetic retinopathy -> poor vision and blindness ->
           3. decr. sensory neuron functions -> loss of sensations ->
           4. decr. muscle control -> loss of muscle control, muscle weakness ->
           5. decr. autonomic reflexes (e.g., digestion, incontinence, sexual response)
           6. great incr. atherosclerosis ->
           7. decr. WBC functioning -> decr. defense ->
           8. kidney failure ->
           9. incr. osmotic pressure -> cell shrinking ->
          10. dehydration -> cell shrinking, decr. blood pressure ->
          11. salt loss -> nerve and muscle cell malfunction ->
          12. incr. infection ->
          13. decr. tissue perfusion -> cell weakness ->
          14. decr. O2 in blood -> muscle weakness ->
          15. decr. diffusion in tissue spaces -> cell weakness and waste build-up ->
          16. glaucoma -> poor vision and blindness ->
          17. autoimmune activity ->
          18. joint stiffness ->

11. Name and describe the three common signs and symptoms of diabetes mellitus.

      1. polyuria = excess urine production
      2. polydipsia = excess drinking from excess thirst
      3. polyphagia = excess eating from excess hunger

12. Name and describe methods for reducing the incidence and severity of problems from diabetes mellitus among the elderly.

     - prevention
           1. avoid risk factors such as obesity, decr. exercise, incr. CHOs
           2. watch for signs and symptoms
     - treatment must be individualized
           1. diet control
           2. weight control
           3. exercise control
           4. medications and insulin
           5. prevent, recognize, and treat complications

Return to Top of Page

Return to Chapter Index

Return to Main Index
 
© Copyright 1999 - Augustine G. DiGiovanna - All rights reserved.
This material MAY be reproduced or distributed in any form or by any means, or stored in any data base or retrieval system ONLY under one of the following two conditions: (1) If no individual, group, organization, institution, company, corporation or other entity is charged for its use and only for use by instructors and students in courses where students are required to purchase the book HUMAN AGING: BIOLOGICAL PERSPECTIVES by Augustine G. DiGiovanna, The McGraw-Hill Companies, New York, 1994 or 2000; (2) If prior written permission is obtained from Augustine G. DiGiovanna.