The Biology of Ageing

Question 1

what is the average life expectancy worldwide?

Answer 1

67.2

women live more

Question 2

why do women live longer than men on average

Answer 2

• women have high levels of oestrogen so less likely to get cardiovascular disease
• women have lower iron levels than men due to menstruation.iron forms damaging free radicals
• young men engage in risky
  behaviour. testosterone.

-one x chromosome for men so dangerous mutations expressed.

Question 3

what happens toyou halth as you get older?

Answer 3

get more sick

Question 4

why do e not live longer than 100 yrs?

Answer 4

• cell division mitosis decreases
• DNA is damaged by environment
• breakdown in the accuracy of protein synthesis
• decline in immune function.

Question 5

As we age what are the cellular/morphological changes?

Answer 5

• cell loss in amitotic tissue such as corneal endothelium
• skeletal and smooth muscle loss (wasting of iris dilator)
• changes in cellular organelles (mitochondria and endoplasmic reticulum)
• accumulation of lipofusein.
• accumulation of advanced glycation end products (AGEs)
• irreversible DNA damage

Question 6

What does AGEs cause in crystalline lens?

Answer 6

cross-linking between crystallines is associated with cataract.

Question 7

what is a telomere?

Answer 7

repetitive nucleotide sequence at each end of chromosome.

non coding.

Question 8

what happens to the telomeres as the cell divides?

Answer 8

ends of the chromosome are lost

Question 9

what are the coding parts of the DNA protected by?

Answer 9

telomeres

Question 10

how does the elastic tissue change?

Answer 10

wrinkles and loss of arterial elasticity which leads to increase in blood pressure with age.

Question 11

what happens to enzymes as connective tissue changes?

Answer 11

enzymes that destroy collagen upregulated (ptosis)

Question 12

what happens to cartilage as connective tissue changes?

Answer 12

osteoarthrosis

Question 13

what happen to bones as connective tissue changes?

Answer 13

osteoporosis

Question 14

what happens to hair as connective tissue changes?

Answer 14

hairloss and pigment goes

Question 15

what happens to the reproductive system of females due to ageing?

Answer 15

menopause

Question 16

what is multisensory deterioration?

Answer 16

taste,smell

hearing (presbycusis)

Question 17

what happens as the immune system declines?

Answer 17

elderly more prone to cancer.

Question 18

what is the proximate cause?

Answer 18

immediate trigger.

Question 19

what is the ultimate cause?

Answer 19

evolutionary explanation

adaptive

Question 20

What is antagonistic pleiotrophy?

Answer 20

genes beneficial early in life but dangerous effects i old age

Question 21

what is neoplasia?

Answer 21

excessive cellular proliferation producing a tumour.

uncoordinated growth

Question 22

what are oncogenes?

Answer 22

promote cell growth

Question 23

what are tumour supressor genes?

Answer 23

inhibit cell division

Question 24

what triggers neoplasia?

Answer 24

• viruses
• hereditary factors
• failure of immune system
• chemical carcinogens
• uv or x-ray radiation

Question 25

what are benign tumours?

Answer 25

• don’t move from the site they arose
• slow rate growth
• capsulated
• cells resemble normal tissue

Question 26

what are malignant tumours?

Answer 26

• invade other tissues
• rapid rate of growth
• encapsulated
• does not resemble normal tissue

Question 27

what is the cell of origin of tumour?

Answer 27

e.g neuroma (neural)

Question 28

what is the most common ocular tumour?

Answer 28

melanoma

Question 29

where is melanoma found?

Answer 29

choroid
cilliary body
iris

Question 30

what are intercranial tumours?

Answer 30

affect any point in the visual pathway ,as well as other areas of he brain associated with visual reflexes.

Question 31

where do intercranial in adults come from?

Answer 31

in adults dont come from neuromas
come from :
10%meningiomas
65% gliomas

Question 32

what is an Acoustic neuroma?

Answer 32

• survive
• 10%
• 4th and 5th decade of life
• arises from schwann cell on the vestibular part of 8th cranial nerve
• originates in internal acoustic meatus.

Question 33

what does a large tumour do?

Answer 33

squashes cerebellum

Question 34

what are the symptoms of acoustic neuroma?

Answer 34

• loss of hearing (8th)
• disturbances of balances (8th)
• facial palsy (7th)
• disturbances of taste (7th)
• odd facial sensation(5th)
• difficulty swallowing (10th)
• Ataxia (cerebellum) uncoordinated movements.
• intracranial pressure goes up (pressure on the optic nerve)

Question 35

how does intracranial pressure build up?

Answer 35

cerebrous spinal fluid builds up and isn’t drained off.

Question 36

what are the ocular symptoms of acoustic neuroma?

Answer 36

-inability to close eyelids due to the disruption of 7th nerve innervation of orbicularis oculi.
-reduced tear secretion (7th)
-loss of corneal sensation (5th)
loss of stability of surface of cornea(5th)
-affect on lateral rectus (6th)

Question 37

how to alleviate symptoms of lack of eyelid closure?

Answer 37

• ointment,taping at night.
• surgical tarsorrhaphy
• botulinum toxin tarsorrhaphy
• insertion of weight into upper eyelid.

Question 38

what is ectropian?

Answer 38

symptom of acoustic neuroma

lower eyelid droops down

Question 39

what is epiphora?

Answer 39

watering of the eye

Question 40

what should you do about a non functional 7th nerve?

Answer 40

• facial nerves usually regenerate
• Nerve graft to connect functional 7th nerve on non-functional side
• Facelifts (including gold weight in eyelid,Teflon plate in lower lid.)

Question 41

where is the pituitary located/

Answer 41

below the Optic Chiasm

Question 42

how does the pituitary tumour grow?

Answer 42

grows upwards impacting the chiasm.

Question 43

pituitary tumours will compress which fibres first?

Answer 43

fibres originating from the nasal inferior retina of both retinae.causes bitemporal field defect.

Question 44

what does compressing fibres on the ventral surface of the chiasm cause?

Answer 44

bilateral superior scotomas.