Physiology of growth & aging process. Factors affecting/ regulating growth & aging

1. Growth Physiology & Physiology of Aging
Prof. Dr. Rashid Mahmood
10/10/2018 Physiology of Growth & Aging| Prof. Dr. Rashid Mahmood 1

2. •How the height of a patient will be affected
in sexual precocity (appearance of
secondary sexual characteristics before the
normal age)?
•How the height of a patient will be affected
in men who are castrated (remove the
testicles) before puberty?
•What is ageing?
•How a person becomes older?
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3. Q?
• Is Growth hormone essential for fetal
development?
•No
• Most important hormone for post-natal growth
•Growth hormone
• Which intermediate substance must be
synthesized 1st for growth hormone to cause
growth?
•Somatomedin10/10/2018 Physiology of Growth & Aging| Prof. Dr. Rashid Mahmood 3

4. Objectives
•At the end of the lesson student will be able to:
•List the hormones & factors necessary for normal growth
•List Requirements for Growth Hormone to cause growth
•Describe the role of different hormones & factors
necessary for normal growth
•Define aging
•Name the possible causes/ theories & biological
mechanism of aging
•Describe briefly the effects of aging on different body
system/ organs
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5. Lesson contents
• Role of different hormones required for growth
• Non-hormonal factors required for growth/
affecting growth
• Growth of different tissues at various ages
• Definition of aging
• Causes/ Biological basis of aging
• Changes in Physiology with Aging
• Systems/ organs affected by Aging
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6. Other hormones required for growth
•Thyroid hormone
•Androgens
•Estrogens
•Glucocorticoids
•Insulin
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7. Relative importance of different hormones at
various ages
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8. Roll of sex hormones in determining a
person’s height
•Androgens & estrogens
•Initially stimulate growth
•Estrogens
•Terminate growth by causing the epiphysis to
fuse with ling bones (Epiphyseal closure)
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9. Permissive role of thyroid hormones in
causing growth
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10. Assessment Q.1
1. How the height of a patient will be
affected in sexual precocity (appearance of
secondary sexual characteristics before the
normal age)?
2. How the height of a patient will be
affected in men who are castrated
(remove the testicles) before puberty?
10/10/2018 Physiology of Growth & Aging| Prof. Dr. Rashid Mahmood 10
1.Dwarf
2.Tall

11. Non-hormonal factors required for growth/
affecting growth
•Genetic factors
•Nutrition
•Proteins
•Vitamins
•Minerals
•Calories
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12. Non-hormonal factors that can growth
•Injury
•Disease
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13. Growth
Periods
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14. Growth of different tissues at various ages
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15. Catch-up growth
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16. Assessment Q.2
•List hormonal causes of short stature
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Deficiency of
1.GHRH
2.GH
3.IGF-I
4.Thyroid hormone
5.Sex hormones
6.Insulin

17. Physiology of Aging
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18. Definition OF AGING
“Age is an issue of mind
over matter.
If you don't mind, it
doesn't matter."
Mark Twain
(1835-1910)
SO
“You're Only As Old As
You Feel”
• The process of
becoming
older, a
process that is
genetically
determined and
environmentally
modulated
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Rashid Mahmood 18

19. Causes of ageing
• Damage concept
• DNA oxidation
• DNA methylation
• free radicals
• programmed ageing concept
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Rashid Mahmood 19

20. Biological basis
• loss of proteostasis (protein folding and
proteolysis)
• RNA interference
• deregulated nutrient sensing
• mitochondrial dysfunction
• Cellular senescence (accumulation of no
longer dividing cells in certain tissues)10/10/2018
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21. START OF AGING PROCESS
• Normal Part of Life.
• Begins around ……..
age 30.
“If I'd known I was gonna live this
long, I'd have taken better care of
myself.”
Eubie Blake (1883-1983)
American Jazz Musician
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Rashid Mahmood
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22. Changes in Physiology with Aging
• May be no changes in baseline function
• Decreased ability to adapt to stress.
• Various body systems lose reserve
capacity
• Impaired homeostasis
• Sensory Deprivation
• Increased risk for falls
• Decreased quality of life
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Rashid Mahmood 22

23. Systems/ organs affected by Aging
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Rashid Mahmood 23

24. Factors affecting aging of facial features
Smoking
Exposure to sun
Use of alcohol
BMI
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Rashid Mahmood
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Facial features

25. Changes in Vision
– Loss of fat – sunken appearance; eye
bags
– – Slower adaptation to darkness
– Diminished tolerance to glare
– Increasing impairment to colour
discrimination
– Increased lens density
– Macular degeneration
– Degeneration of tear gland
 Cannot get glasses clean
 Difficulty night driving
 Difficulties reading
 Double vision (in one eye)
 Night-time glare
 Cataract
 Glaucoma
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Rashid Mahmood
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Presbyopia

26. Night-time glare
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Rashid Mahmood 26

27. Normal Lens
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Rashid Mahmood
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Cataract

28. Vision like with cataract
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Rashid Mahmood
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29. Glaucoma
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Rashid Mahmood 29

30. Age-Related Macular Degeneration
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Rashid Mahmood 30

31. Diabetic Neuropathy
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Rashid Mahmood 31

32. Changes in Hearing Ears
• Hearing Loss
• Loss of high
frequency
hearing.
• Sounds from
speech is
distorted
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Rashid Mahmood 32
Presbycusis

33. Changes in
Heart
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34. 10/10/2018 Physiology of Growth & Aging| Prof. Dr.
Rashid Mahmood
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Changes in
Heart
Decrease in
capacity to
cope with the
demands of
physical
activity.

35. Changes in Pulmonary Physiology
• Decreased vital capacity
• Increased residual volume
• Decreased number of small
airways open during normal
breathing
• Increased
- Chest wall stiffness
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Rashid Mahmood
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Poor effort
tolerance

36. Renal System
• Loss of nephrons
• Reduced plasma blood flow
and GFR
• Relative excess of antidiuretic
hormone (ADH)
• Alterations in renal potassium
handling
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Rashid Mahmood
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37. Musculoskeletal Changes
• Decrease in muscle weight
relative to total body weight
• Changes in water content of
cartilage
• Bone loss in both sexes but
more pronounced in women
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Rashid Mahmood
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38. Neuromuscular Changes
• Reduced propioceptive information
• Delayed nerve conduction
• Reduced numbers of motor neurons
• Reduced fast twitch fibers
• Reduced muscle mass
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Rashid Mahmood 38

39. The Digestive System
Motility
Secretion
Absorption
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Rashid Mahmood 39

40. “The secret of staying young
live honestly,
eat slowly, and…….
lie about your age.”
Lucille Ball
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Rashid Mahmood
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41. Standard eating environment
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Rashid Mahmood
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42. Improved eating environment
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Rashid Mahmood
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43. • General decrease in taste due to
decreased central sensation.
• Decreased salivary volume.
• Formation of fissures and furrows on the
tongue.
Age Related Changes of Taste
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Rashid Mahmood
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44. 10/10/2018 Physiology of Growth & Aging| Prof. Dr.
Rashid Mahmood 44
Age Related Changes of Teeth

45. Take Home points (1/2)
Hormones required for
growth
•Growth hormone
•Thyroid hormone
•Androgens
•Estrogens
•Glucocorticoids
•Insulin
Non-hormonal factors required
for growth/ affecting growth
•Genetic factors
•Nutrition
•Proteins
•Vitamins
•Minerals
•Calories

46. Take Home points (2/2)
•AGING is the process of becoming older, a process
that is genetically determined and environmentally
modulated
•There are theories of aging
•RNA interference
•DNA interference
•programmed ageing concept
•Almost all Systems/ organs are affected by aging

47. References/ Resources
• Guyton and Hall Textbook of Physiology , 13th Edition
• Ganong’s review of Medical Physiology,25th edition
• Human Physiology, from cells to system, Lauralee
Sherwood, 9th edition
• Internet

48. Next Topic
•Parathyroid hormone
•Wed, 17/10/2018, 11.00-12.00
•Prior knowledge required for next topic:
•Anatomy & Histology of Parathyroid Gland
•Biochemistry of Calcium

49. Assessment Q. No. 4
•What is the topic of my next
LGF?

50. Thank You
10/10/2018 Physiology of Growth & Aging| Prof. Dr. Rashid Mahmood 50
Questions ?
Comments
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rashid.mahmood@rmi.edu.pk
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