3. Learning objectives
• By the end of the presentation trainees should be
able to:
▫ Define aging.
▫ Describe the changes in the various systems of the
body with age.
▫ Enumerate the physical theories of aging.
▫ Enlist ways to achieve healthy aging.
▫ Define cloning.
▫ Enlist the two types of cloning.
▫ Explain how the two types of cloning are done.
▫ Enumerate the advantages and disadvantages of
cloning.
5. Definition
• It is the gradual structural and functional
changes in the cells, and ultimately the body,
that occur over passage of time.
6. Changes in the body during aging
Physiologic
Characteristic
Aging Exercise
Fat mass
Bone mineral density
VO2 max
Muscle strength
Glucose tolerance
Insulin sensitivity
Cholesterol
7. Integumentary system
• Loss of subcutaneous fat.
• Thinning of skin (leading to wrinkles)
• Decreased collagen.
• Nails brittle and flake.
• Mucous membranes drier.
• Less sweat glands.
• Hair pigment decreases.
• Hair thins.
8. Musculoskeletal system
• Lean body mass decreases.
• Bone mineral content
diminished which leads to
osteoporosis.
• Degeneration of joints which
leads to osteoarthritis.
• Decrease in height due to
narrow vertebral spaces.
• May have exaggerated
curvature of spine.
• Synovial fluid more viscous.
9. Nervous system
• Decrease in nerve cell number in CNS and PNS
as neurons degenerate.
• Decreased vibratory sensation in PNS.
• Nerve transmission slows resulting in increased
reaction time.
• Hypothalamus less effective in regulating body
temperature.
10. Respiratory system
• Lungs become more rigid.
• Pulmonary function decreases.
• Number and size of alveoli decreases.
• Vital capacity declines.
• Reduction in respiratory fluid.
• Bony changes in chest cavity.
11. Cardiovascular system
• By age 70 cardiac output reduced to
70%.
• Heart smaller and less elastic with
age.
• Heart valves become sclerotic.
• Heart muscle more irritable
resulting in more chances of
arryhthmias.
• Increased vascular stiffness which
may cause arteries to become more
rigid.
• Veins dilate.
12. Immune system
• Decline in immune function.
• Decreases antibody response.
• Fatty marrow replaced red marrow.
• Vitamin B12 absorption might decrease -
decreased hemoglobin and hematocrit.
13. Digestive system
• Reduced GI secretions.
• Reduced GI motility.
• Reduced GI absorptive cells.
• Reduced active transport across intestines.
• Reduced GI blood flow.
• Reduced sphincter activity.
• Decreased weight of liver.
• Reduced regenerative capacity of liver.
• Liver metabolizes less efficiently.
14. Excretory system
• After 40 renal function decreases.
• By 90 lose of 50% of function.
▫ GFR decreases.
▫ Tubular function decreases.
▫ Renal plasma flow decreases.
▫ Filtration and reabsorption reduced.
▫ Size and number of nephrons decrease.
• Bladder muscles weaken.
• Less able to clear drugs from system.
• Smaller kidneys and bladder.
15. Eyes and vision
• Eyelids baggy and wrinkled.
• Eyes deeper in sockets.
• Night and depth vision decreases.
• Impaired color vision, also - especially greens and
blues because cone degenerate.
• Lens becomes less transparent or even clouded
resulting in cataracts.
• Accommodation decreases
• Predisposed to glaucoma due to decreased
absorption of intraocular fluid.
• Macular degeneration becoming more frequent
which can lead to blindness.
17. Psycological issues
• Decreased social contact – friends and family
die- person may withdraw.
• Depression relatively common.
18. Physical theories of aging
• Program theory:
▫ Cells replicate a specific number of
times and then die.
• Error theory:
▫ The structure of DNA is altered as
people age.
▫ Due to alterations, DNA is not read
correctly.
▫ Results in transcription and
translation malfunction.
▫ Results in aging, illness or cancer
directly or indirectly.
19. • Cellular theory:
▫ Normal wear and tear causes cells to function
improperly.
• Free radical theory:
▫ Lipids in cell membranes are exposed to radiation or
free radicals.
▫ Cell membrane ruptures and cell dies.
Continued…
O2 Activated oxygen species
Superoxide (O2-)
Hydrogen peroxide (H2O2)
Hydroxyl radical (OH+)
20. Continued…
• Collagen theory:
▫ As we age, collagen also ages in our body.
▫ This causes hypertension and other organ
malfunctions.
• Neuro aging theory:
▫ All cells undergo nervous system
degeneration.
▫ Results in changes in hormonal release.
▫ Leads to decline in cell function.
21. Continued…
• None of these theories is totally
accepted.
• Scientists hypothesize it might be
a combination of several or all
theories.
• All theories are influenced by:
▫ Genetics.
▫ Gender.
▫ Lifestyle.
▫ Environment
24. Defination
• Clone is a group of genetically identical cells.
• Clone is also an organism which is genetically an
exact replica of another organism.
• Cloning is to duplicate a cell or an organism,
usually asexually, which is genetically an exact
replica of the other cell or organism.
25. Why do cloning?
• Cloning produces cells that are
genetically similar to each other
(have the same DNA).
• This prevents an organ (or cells)
made through cloning from
being rejected.
• Thus can be used:
▫ For treating human diseases.
▫ Producing organs for
transplantation.
▫ For research.
26. Types of cloning
• There are two types of
cloning:
1. Reproductive cloning is
the using of stem cells to
create whole organisms
e.g. humans.
2. Therapeutic cloning is the
use of stem cells for
medicinal or research
purposes.
28. Steps in reproductive cloning
• Step 1: Take any cell from the body
e.g. the skin.
• Step 2: Take an egg cell (ovum)
from a female of the same species.
1
2
29. Continued…
• Step 3: Take the nucleus out of the
egg cell.
• Step 4: Place the nucleus of the body
cell in the egg cell. It will start to
multiply forming a microscopic ball
of identical cells called the pre-
embryo.
3
4
30. Continued…
• Step 5: In about 6 days place it in
the uterus of a female of the same
species (surrogate mother).
• Step 6: In 9 months a baby will born
that will be identical to animal from
which the body cell was taken.
5
6
31. Problems with reproductive cloning
• Deemed morally wrong
because it is creating a
human life just to be a
walking organ donor for the
person after whom they
were created.
• Not accepted by many
religious groups as it is
considered interfering in
God’s creation.
32. Continued…
• Results in decreased genetic diversity.
• Physical problems, like birth defects and
quick aging, can result.
• Possible future problems for the clone e.g.
financial, emotional etc.
• May be used to make human armies for
warfare.
33. Therapeutic cloning
• Initial stages are identical to reproductive cloning.
• However, stem cells are removed from the pre-
embryo to produce tissue for a whole organ for
transplant back into the person who supplied the
DNA.
34.
35. Problems with therapeutic cloning
Therapeutic cloning creates embryos and then
destroys them for stem cells, which is morally
wrong to some.
36. Summary: Aging
• Aging is the gradual structural and functional changes in
the cells that occur over passage of time.
• All systems in the body undergo changes during aging.
• The six main physical theories for aging are the program,
error, cellular, free radical, collagen and neuro aging
theories.
• Aging results as a combination of several or all these
theories.
• Healthy aging can be achieved by:
▫ Exercise.
▫ Good balanced diet.
▫ Positive pursuits.
▫ Indulging in social activity.
37. Summary: Cloning
• Cloning is to duplicate a cell or an organism,
usually asexually, which is genetically an exact
replica of the other cell or organism.
• It is of two main types:
1. Reproductive cloning which is done to clone
entire organisms.
2. Therapeutic cloning which is done by cloning
stem cells for research, drug tests and to produce
cells for theapy.
• Cloning has many ethical issues.
38. MCQ 1
• A 72 year old man present to the opd with pain in
joints, blurred vision and decreased hearing. He
states he lives in an old age home. Which of the
following could also be associated with this
patient:
A. Muscle strength increased.
B. Fat mass decreased.
C. Insulin sensitivity decreased.
D. Bone mineral density increased.
39. MCQ 2
• A mouse was cloned in a laboratory using a cell
from another mouse’s tail. What was done to the
tail cell?
A. The nucleus of the tail cell was removed and
replaced with an egg nucleus.
B. The nucleus of the tail cell was removed and
inserted into an empty egg cell.
C. The tail cell was inserted into a surrogate uterus
after it multiplied.
D. The tail cell was first fertilized by a sperm and
then inserted into a surrogate uterus.
40. References
• Guyton And Hall Textbook Of
Medical Physiology.
• Lauralee Sherwood Human
Physiology From Cells To
Systems.
• Wikipedia.com.
• Google Images.
